PeerJ
type: channel
link: https://peerj.com/articles/
description: Articles published in PeerJ
publisher: PeerJ Inc.
publication name: PeerJ
issn: 2167-8359
items: The case for extended lifespan in cooperatively breeding mammals: a re-appraisal
items: Plasma antioxidants and oxidative stress status in obese women: correlation with cardiopulmonary response
items: Expression and protease characterization of a conserved protein YgjD in Vibrio harveyi
items: The influence of surrounding land cover on wetland habitat conditions: a case study of inland wetlands in South Korea
items: Mitochondrial DNA variation in the Italian Heavy Draught Horse
items: A new genus of sinogaleaspids (Galeaspida, stem-Gnathostomata) from the Silurian Period in Jiangxi, China
items: The chemistry and histology of sexually dimorphic mental glands in the freshwater turtle, Mauremys leprosa
items: Spirometric traits show quantile-dependent heritability, which may contribute to their gene-environment interactions with smoking and pollution
items: Depigmenting potential of lichen extracts evaluated by in vitro and in vivo tests
items: Comparing race, gender, age, and career categories in recognizing and grouping tasks

The case for extended lifespan in cooperatively breeding mammals: a re-appraisal
type: item
type: AcademicArticle
description: Recent comparative studies have suggested that cooperative breeding is associated with increases in maximum lifespan among mammals, replicating a pattern also seen in birds and insects. In this study, we re-examine the case for increased lifespan in mammalian cooperative breeders by analysing a large dataset of maximum longevity records. We did not find any consistent, strong evidence that cooperative breeders have longer lifespans than other mammals after having controlled for variation in body mass, mode of life and data quality. The only possible exception to this general trend is found in the African mole-rats (the Bathyergid family), where all members are relatively long-lived, but where the social, cooperatively breeding species appear to be much longer-lived than the solitary species. However, solitary mole-rat species have rarely been kept in captivity or followed longitudinally in the wild and so it seems likely that their maximum lifespan has been underestimated when compared to the highly researched social species. Although few subterranean mammals have received much attention in a captive or wild setting, current data instead supports a causal role of subterranean living on lifespan extension in mammals.
format: application/pdf
format: text/html
creator: Jack Thorley
subject: Ecology
subject: Evolutionary Studies
description: doi:10.7717/peerj.9214
publisher: PeerJ Inc.
rights: © 2020 Thorley
abstract: Recent comparative studies have suggested that cooperative breeding is associated with increases in maximum lifespan among mammals, replicating a pattern also seen in birds and insects. In this study, we re-examine the case for increased lifespan in mammalian cooperative breeders by analysing a large dataset of maximum longevity records. We did not find any consistent, strong evidence that cooperative breeders have longer lifespans than other mammals after having controlled for variation in body mass, mode of life and data quality. The only possible exception to this general trend is found in the African mole-rats (the Bathyergid family), where all members are relatively long-lived, but where the social, cooperatively breeding species appear to be much longer-lived than the solitary species. However, solitary mole-rat species have rarely been kept in captivity or followed longitudinally in the wild and so it seems likely that their maximum lifespan has been underestimated when compared to the highly researched social species. Although few subterranean mammals have received much attention in a captive or wild setting, current data instead supports a causal role of subterranean living on lifespan extension in mammals.
bibliographic citation: Thorley (2020) The case for extended lifespan in cooperatively breeding mammals: a re-appraisal. PeerJ 8:e9214 https://doi.org/10.7717/peerj.9214
date submitted: 2019-09-20
date accepted: 2020-04-27
issued: 2020-05-19
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Thorley
  given name: Jack
doi: 10.7717/peerj.9214
volume: 8
issn: 2167-8359
publication name: PeerJ
publication date: 2020-05-19
copyright: © 2020 Thorley
attribution name: Thorley

Plasma antioxidants and oxidative stress status in obese women: correlation with cardiopulmonary response
type: item
type: AcademicArticle
description: Introduction A high body fat coupled with low cardiopulmonary fitness and an increase in oxidative stress has been connoted as contributing factors in developing cardiovascular comorbidities. This study aimed to investigate the correlation between antioxidants and oxidative stress status with cardiopulmonary responses in women of different body mass index (BMI). Subjects and Methods Eighty female adults were recruited and divided into three groups; normal weight (n = 23), overweight (n = 28) and obese (n = 29), according to their BMI. Blood samples were obtained prior to cardiopulmonary exercise testing. Plasma samples were separated by centrifugation and analysed for enzymatic antioxidant activity including catalase, glutathione peroxidase and superoxide dismutase. Non-enzymatic antioxidant activities were assessed using 2, 2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging and ferric reducing ability of plasma (FRAP) assays. To evaluate the oxidative stress status of subjects, levels of reactive oxygen species and malondialdehyde, the by-product of lipid peroxidation, were measured. Cardiopulmonary responses were analysed using cardiopulmonary exercise testing (CPET) which involved 15 various parameters such as peak oxygen consumption, metabolic equivalents and respiratory exchange ratio. Results The obese group had significantly lower ABTS radical scavenging and FRAP activities than the normal weight group. A higher catalase activity was observed in the obese group than the normal weight group. Spearman’s correlation showed an inverse relationship between catalase and peak oxygen consumption, while partial correlation analysis showed inverse correlations between superoxide dismutase and respiratory frequency, ABTS activity and oxygen pulse, and between ABTS activity and cardiac output. Conclusion Our results demonstrate a lower cardiovascular fitness and antioxidant capacity in obese women; the higher catalase activity may be a compe…
format: application/pdf
format: text/html
creator: Dyg Mastura Adenan
creator: Zulkarnain Jaafar
creator: Jaime Jacqueline Jayapalan
creator: Azlina Abdul Aziz
subject: Molecular Biology
subject: Public Health
subject: Women’s Health
description: doi:10.7717/peerj.9230
publisher: PeerJ Inc.
rights: © 2020 Adenan et al.
abstract: Introduction A high body fat coupled with low cardiopulmonary fitness and an increase in oxidative stress has been connoted as contributing factors in developing cardiovascular comorbidities. This study aimed to investigate the correlation between antioxidants and oxidative stress status with cardiopulmonary responses in women of different body mass index (BMI). Subjects and Methods Eighty female adults were recruited and divided into three groups; normal weight (n = 23), overweight (n = 28) and obese (n = 29), according to their BMI. Blood samples were obtained prior to cardiopulmonary exercise testing. Plasma samples were separated by centrifugation and analysed for enzymatic antioxidant activity including catalase, glutathione peroxidase and superoxide dismutase. Non-enzymatic antioxidant activities were assessed using 2, 2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging and ferric reducing ability of plasma (FRAP) assays. To evaluate the oxidative stress status of subjects, levels of reactive oxygen species and malondialdehyde, the by-product of lipid peroxidation, were measured. Cardiopulmonary responses were analysed using cardiopulmonary exercise testing (CPET) which involved 15 various parameters such as peak oxygen consumption, metabolic equivalents and respiratory exchange ratio. Results The obese group had significantly lower ABTS radical scavenging and FRAP activities than the normal weight group. A higher catalase activity was observed in the obese group than the normal weight group. Spearman’s correlation showed an inverse relationship between catalase and peak oxygen consumption, while partial correlation analysis showed inverse correlations between superoxide dismutase and respiratory frequency, ABTS activity and oxygen pulse, and between ABTS activity and cardiac output. Conclusion Our results demonstrate a lower cardiovascular fitness and antioxidant capacity in obese women; the higher catalase activity may be a compe…
bibliographic citation: Adenan et al. (2020) Plasma antioxidants and oxidative stress status in obese women: correlation with cardiopulmonary response. PeerJ 8:e9230 https://doi.org/10.7717/peerj.9230
date submitted: 2020-01-06
date accepted: 2020-04-30
issued: 2020-05-19
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Adenan
  given name: Dyg Mastura
author list: Agent
  family name: Jaafar
  given name: Zulkarnain
author list: Agent
  family name: Jayapalan
  given name: Jaime Jacqueline
author list: Agent
  family name: Abdul Aziz
  given name: Azlina
doi: 10.7717/peerj.9230
volume: 8
issn: 2167-8359
publication name: PeerJ
publication date: 2020-05-19
copyright: ©2020 Adenan et al.
attribution name: Adenan et al.

Expression and protease characterization of a conserved protein YgjD in Vibrio harveyi
type: item
type: AcademicArticle
description: The glycopeptidase GCP and its homologue proteins are conserved and essential for survival of bacteria. The ygjD gene (Glycopeptidase homologue) was cloned from Vibrio harveyi strain SF-1. The gene consisted of 1,017 bp, which encodes a 338 amino acid polypeptide. The nucleotide sequence similarity of the ygjD gene with that of V. harveyi FDAARGOS 107 was 95%. The ygjD gene also showed similarities of 68%, 67% and 50% with those of Salmonella enterica, Escherichia coli and Bacillus cereus. The ygjD gene was expressed in E. coli BL21 (DE3) and the recombinant YgjD was purified by Ni2+ affinity chromatography column. The purified YgjD showed a specific 37 kDa band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and exhibited protease activities of 59,000 units/mg, 53,700 units/mg and 8,100 units/mg, respectively, on N-Acetyl-L-tyrosine ethyl ester monohydrate (ATEE), N-Benzoyl-L-tyrosine ethyl ester (BTEE) and N-Benzoyl-DL-arginine-4-nitroanilide hydrochloride (BAPNA) substrates. When the conserved amino acids of His111, Glu113 and His115 in the YgjD were replaced with alanine, respectively, the protease activities of the mutants were partly decreased. The two conserved His111 and His115 of YgjD were mutated and the protein lost the protease activity, which implied that the two amino acid played very important roles in maintaining its protease activity. The addition of the purified YgjD to the culture medium of V. harveyi strain SF-1 can effectively promote the bacteria growth. These results indicated that the protease activities may be involved in the survival of bacteria.
format: application/pdf
format: text/html
creator: Yayuan Zhang
creator: Jixiang Chen
creator: Yonggang Wang
creator: Yanlin Li
creator: Wenhong Rui
creator: Jiyi Zhang
creator: Dan Luo
subject: Agricultural Science
subject: Biochemistry
subject: Bioengineering
subject: Biotechnology
subject: Molecular Biology
description: doi:10.7717/peerj.9061
publisher: PeerJ Inc.
rights: © 2020 Zhang et al.
abstract: The glycopeptidase GCP and its homologue proteins are conserved and essential for survival of bacteria. The ygjD gene (Glycopeptidase homologue) was cloned from Vibrio harveyi strain SF-1. The gene consisted of 1,017 bp, which encodes a 338 amino acid polypeptide. The nucleotide sequence similarity of the ygjD gene with that of V. harveyi FDAARGOS 107 was 95%. The ygjD gene also showed similarities of 68%, 67% and 50% with those of Salmonella enterica, Escherichia coli and Bacillus cereus. The ygjD gene was expressed in E. coli BL21 (DE3) and the recombinant YgjD was purified by Ni2+ affinity chromatography column. The purified YgjD showed a specific 37 kDa band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and exhibited protease activities of 59,000 units/mg, 53,700 units/mg and 8,100 units/mg, respectively, on N-Acetyl-L-tyrosine ethyl ester monohydrate (ATEE), N-Benzoyl-L-tyrosine ethyl ester (BTEE) and N-Benzoyl-DL-arginine-4-nitroanilide hydrochloride (BAPNA) substrates. When the conserved amino acids of His111, Glu113 and His115 in the YgjD were replaced with alanine, respectively, the protease activities of the mutants were partly decreased. The two conserved His111 and His115 of YgjD were mutated and the protein lost the protease activity, which implied that the two amino acid played very important roles in maintaining its protease activity. The addition of the purified YgjD to the culture medium of V. harveyi strain SF-1 can effectively promote the bacteria growth. These results indicated that the protease activities may be involved in the survival of bacteria.
bibliographic citation: Zhang et al. (2020) Expression and protease characterization of a conserved protein YgjD in Vibrio harveyi. PeerJ 8:e9061 https://doi.org/10.7717/peerj.9061
date submitted: 2019-12-26
date accepted: 2020-04-04
issued: 2020-05-18
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Zhang
  given name: Yayuan
author list: Agent
  family name: Chen
  given name: Jixiang
author list: Agent
  family name: Wang
  given name: Yonggang
author list: Agent
  family name: Li
  given name: Yanlin
author list: Agent
  family name: Rui
  given name: Wenhong
author list: Agent
  family name: Zhang
  given name: Jiyi
author list: Agent
  family name: Luo
  given name: Dan
doi: 10.7717/peerj.9061
volume: 8
issn: 2167-8359
publication name: PeerJ
publication date: 2020-05-18
copyright: ©2020 Zhang et al.
attribution name: Zhang et al.

The influence of surrounding land cover on wetland habitat conditions: a case study of inland wetlands in South Korea
type: item
type: AcademicArticle
description: Wetland ecosystems have been globally degraded and lost due to rapid urbanization and climate change. An assessment of national scale inventory, including wetland types and conditions, is urgently required to understand the big picture of endangered wetlands, such as where they are and how they look like. We analyzed the spatial patterns of each inland wetland type (brackish wetland was included) in South Korea and the relative importance of land cover categories on wetland conditions. The wetlands were grouped into four dominant types (riverine, lake, mountain, and human-made) according to their topography. Riverine wetlands constituted the largest area (71.3%). The relative ratio of wetlands in a well-conserved condition (i.e., “A” rank) was highest in riverine wetlands (23.8%), followed by mountain wetlands (22.1%). The higher proportion of grasslands was related to a better condition ranking, but the increasing bareland area had a negative impact on wetland conditions. We also found that wetlands located near wetland protected areas tend to be in a better condition compared to remote sites. Our results further support the importance of the condition of surrounding areas for wetland conservation.
format: application/pdf
format: text/html
creator: Ran-Young Im
creator: Taekyu Kim
creator: Chung-Yeol Baek
creator: Chang-Su Lee
creator: Song-Hyun Kim
creator: Jung-Hwan Lee
creator: Ji Yoon Kim
creator: Gea-Jae Joo
subject: Ecology
subject: Freshwater Biology
subject: Environmental Impacts
description: doi:10.7717/peerj.9101
publisher: PeerJ Inc.
rights: © 2020 Im et al.
abstract: Wetland ecosystems have been globally degraded and lost due to rapid urbanization and climate change. An assessment of national scale inventory, including wetland types and conditions, is urgently required to understand the big picture of endangered wetlands, such as where they are and how they look like. We analyzed the spatial patterns of each inland wetland type (brackish wetland was included) in South Korea and the relative importance of land cover categories on wetland conditions. The wetlands were grouped into four dominant types (riverine, lake, mountain, and human-made) according to their topography. Riverine wetlands constituted the largest area (71.3%). The relative ratio of wetlands in a well-conserved condition (i.e., “A” rank) was highest in riverine wetlands (23.8%), followed by mountain wetlands (22.1%). The higher proportion of grasslands was related to a better condition ranking, but the increasing bareland area had a negative impact on wetland conditions. We also found that wetlands located near wetland protected areas tend to be in a better condition compared to remote sites. Our results further support the importance of the condition of surrounding areas for wetland conservation.
bibliographic citation: Im et al. (2020) The influence of surrounding land cover on wetland habitat conditions: a case study of inland wetlands in South Korea. PeerJ 8:e9101 https://doi.org/10.7717/peerj.9101
date submitted: 2019-11-11
date accepted: 2020-04-09
issued: 2020-05-18
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Im
  given name: Ran-Young
author list: Agent
  family name: Kim
  given name: Taekyu
author list: Agent
  family name: Baek
  given name: Chung-Yeol
author list: Agent
  family name: Lee
  given name: Chang-Su
author list: Agent
  family name: Kim
  given name: Song-Hyun
author list: Agent
  family name: Lee
  given name: Jung-Hwan
author list: Agent
  family name: Kim
  given name: Ji Yoon
author list: Agent
  family name: Joo
  given name: Gea-Jae
doi: 10.7717/peerj.9101
volume: 8
issn: 2167-8359
publication name: PeerJ
publication date: 2020-05-18
copyright: ©2020 Im et al.
attribution name: Im et al.

Mitochondrial DNA variation in the Italian Heavy Draught Horse
type: item
type: AcademicArticle
description: Background In the last decades, Italy as well as other developed countries have registered a decrease in the population size of many local horse breeds. The continuous crossbreeding has determined the dilution of genetic heritage of several native breeds. The Italian Heavy Draught Horse (IHD) is the only autochthonous Italian coldblooded horse among these breeds; therefore, it represents a resource to be preserved. In 1927, the first generation of this breed was officially created by crossing different Heavy Draught horses with local mares and recorded in a Studbook. Methodology To provide the first comprehensive overview of the genetic diversity of Italian Heavy Draught horses from Central Italy, we produced and phylogenetically analysed 52 mitochondrial DNA (mtDNA) control-region sequences. Furthermore, we evaluated data available from GenBank (N = 568) to have a more complete scenario and to understand the relationships with other European Heavy Draught horse breeds. Results Among the IHD samples that were analysed, we identified ten of the 17 haplogroups described in modern horses. Most of these sequences fell into L, G, and M lineages, thus showing the overall mtDNA legacy of the ancestral mares that were probably used at the initial stages of breeding selections a long time ago. The high mitochondrial haplotype diversity (Hd = 0.969) found in our samples reflected the multiple maternal origins of the horses. Our results highlighted a considerable percentage of haplotypes shared especially with Bardigiano and Hungarian Heavy Draught breeds. Furthermore, both the presence of four unique haplotypes detected in our samples and their absence among all equine mitochondrial published data demonstrate a mitochondrial peculiarity that needs to be further investigated and preserved with careful breeding practices.
format: application/pdf
format: text/html
creator: Hovirag Lancioni
creator: Irene Cardinali
creator: Andrea Giontella
creator: Maria Teresa Antognoni
creator: Arianna Miglio
subject: Conservation Biology
subject: Genetics
subject: Zoology
description: doi:10.7717/peerj.8996
publisher: PeerJ Inc.
rights: © 2020 Lancioni et al.
abstract: Background In the last decades, Italy as well as other developed countries have registered a decrease in the population size of many local horse breeds. The continuous crossbreeding has determined the dilution of genetic heritage of several native breeds. The Italian Heavy Draught Horse (IHD) is the only autochthonous Italian coldblooded horse among these breeds; therefore, it represents a resource to be preserved. In 1927, the first generation of this breed was officially created by crossing different Heavy Draught horses with local mares and recorded in a Studbook. Methodology To provide the first comprehensive overview of the genetic diversity of Italian Heavy Draught horses from Central Italy, we produced and phylogenetically analysed 52 mitochondrial DNA (mtDNA) control-region sequences. Furthermore, we evaluated data available from GenBank (N = 568) to have a more complete scenario and to understand the relationships with other European Heavy Draught horse breeds. Results Among the IHD samples that were analysed, we identified ten of the 17 haplogroups described in modern horses. Most of these sequences fell into L, G, and M lineages, thus showing the overall mtDNA legacy of the ancestral mares that were probably used at the initial stages of breeding selections a long time ago. The high mitochondrial haplotype diversity (Hd = 0.969) found in our samples reflected the multiple maternal origins of the horses. Our results highlighted a considerable percentage of haplotypes shared especially with Bardigiano and Hungarian Heavy Draught breeds. Furthermore, both the presence of four unique haplotypes detected in our samples and their absence among all equine mitochondrial published data demonstrate a mitochondrial peculiarity that needs to be further investigated and preserved with careful breeding practices.
bibliographic citation: Lancioni et al. (2020) Mitochondrial DNA variation in the Italian Heavy Draught Horse. PeerJ 8:e8996 https://doi.org/10.7717/peerj.8996
date submitted: 2019-11-28
date accepted: 2020-03-26
issued: 2020-05-15
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Lancioni
  given name: Hovirag
author list: Agent
  family name: Cardinali
  given name: Irene
author list: Agent
  family name: Giontella
  given name: Andrea
author list: Agent
  family name: Antognoni
  given name: Maria Teresa
author list: Agent
  family name: Miglio
  given name: Arianna
doi: 10.7717/peerj.8996
volume: 8
issn: 2167-8359
publication name: PeerJ
publication date: 2020-05-15
copyright: ©2020 Lancioni et al.
attribution name: Lancioni et al.

A new genus of sinogaleaspids (Galeaspida, stem-Gnathostomata) from the Silurian Period in Jiangxi, China
type: item
type: AcademicArticle
description: Galeaspids are an endemic clade of jawless stem-gnathostomes known as ostracoderms. Their existence illuminates how specific characteristics developed in jawed vertebrates. Sinogaleaspids are of particular interest among the galeaspids but their monophyly is controversial because little is known about Sinogaleaspis xikengensis. Newly discovered sinogaleaspids from the Lower Silurian of Jiangxi, China provide a wealth of data and diagnostic features used to establish the new genus, Rumporostralis gen. nov., for Sinogaleaspis xikengensis. A morphological study showed that the sensory canal system of sinogaleaspids had mosaic features similar to those of three known galeaspids. There are 3–8 pairs of transverse canals in the Sinogaleaspidae, which suggests that the sensory canal system of galeaspid probably had a grid distribution with transverse canals arranged throughout the cephalic division. Phylogenetic analysis of Galeaspida supports the monophyly of the Sinogaleaspidae, consisting of Sinogaleaspis, Rumporostralis, and Anjiaspis. However, Shuyu and Meishanaspis form another monophyletic group, Shuyuidae fam. nov., which is outside all other eugaleaspidiforms. We propose a cladistically-based classification of Galeaspida based on our analysis.
format: application/pdf
format: text/html
creator: Xianren Shan
creator: Min Zhu
creator: Wenjin Zhao
creator: Zhaohui Pan
creator: Pingli Wang
creator: Zhikun Gai
subject: Paleontology
subject: Taxonomy
description: doi:10.7717/peerj.9008
publisher: PeerJ Inc.
rights: © 2020 Shan et al.
abstract: Galeaspids are an endemic clade of jawless stem-gnathostomes known as ostracoderms. Their existence illuminates how specific characteristics developed in jawed vertebrates. Sinogaleaspids are of particular interest among the galeaspids but their monophyly is controversial because little is known about Sinogaleaspis xikengensis. Newly discovered sinogaleaspids from the Lower Silurian of Jiangxi, China provide a wealth of data and diagnostic features used to establish the new genus, Rumporostralis gen. nov., for Sinogaleaspis xikengensis. A morphological study showed that the sensory canal system of sinogaleaspids had mosaic features similar to those of three known galeaspids. There are 3–8 pairs of transverse canals in the Sinogaleaspidae, which suggests that the sensory canal system of galeaspid probably had a grid distribution with transverse canals arranged throughout the cephalic division. Phylogenetic analysis of Galeaspida supports the monophyly of the Sinogaleaspidae, consisting of Sinogaleaspis, Rumporostralis, and Anjiaspis. However, Shuyu and Meishanaspis form another monophyletic group, Shuyuidae fam. nov., which is outside all other eugaleaspidiforms. We propose a cladistically-based classification of Galeaspida based on our analysis.
bibliographic citation: Shan et al. (2020) A new genus of sinogaleaspids (Galeaspida, stem-Gnathostomata) from the Silurian Period in Jiangxi, China. PeerJ 8:e9008 https://doi.org/10.7717/peerj.9008
date submitted: 2019-07-10
date accepted: 2020-03-27
issued: 2020-05-15
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Shan
  given name: Xianren
author list: Agent
  family name: Zhu
  given name: Min
author list: Agent
  family name: Zhao
  given name: Wenjin
author list: Agent
  family name: Pan
  given name: Zhaohui
author list: Agent
  family name: Wang
  given name: Pingli
author list: Agent
  family name: Gai
  given name: Zhikun
doi: 10.7717/peerj.9008
volume: 8
issn: 2167-8359
publication name: PeerJ
publication date: 2020-05-15
copyright: ©2020 Shan et al.
attribution name: Shan et al.

The chemistry and histology of sexually dimorphic mental glands in the freshwater turtle, Mauremys leprosa
type: item
type: AcademicArticle
description: Despite evidence from anatomy, behavior and genomics indicating that the sense of smell in turtles is important, our understanding of chemical communication in this group is still rudimentary. Our aim was to describe the microanatomy of mental glands (MGs) in a freshwater turtle, Mauremys leprosa (Geoemydidae), and to assess the chemical composition of their secretions with respect to variation among individuals and between sexes. MGs are paired sac-like organs on the gular region of the neck and are dimorphic in this species with males having fully functional holocrine glands while those of females appear non-secretory and vestigial. In adult males, the glandular epithelium of the inner portion of the gland provides exocytotic products as well as cellular debris into the lumen of the gland. The contents of the lumen can be secreted through the narrow duct portion of the gland ending in an orifice on the surface of the skin. Females have invaginated structures similar in general outline to male glands, but lack a glandular epithelium. Using gas chromatography coupled to mass spectrometry, we identified a total of 61 compounds in mental gland secretions, the most numerous being carboxylic acids, carbohydrates, alkanes, steroids and alcohols. The number of compounds per individual varied widely (mean (median) ± SD = 14.54 (13) ± 8.44; min = 3; max = 40), but only cholesterol was found in all samples. We found that the relative abundances of only six chemicals were different between the sexes, although males tended to have larger amounts of particular compounds. Although the lipid fraction of mental gland secretions is rich in chemical compounds, most occur in both sexes suggesting that they are metabolic byproducts with no role in chemical signaling. However, the relative amounts of some compounds tended to be higher in males, with significantly larger amounts of two carboxylic acids and one steroid, suggesting their putative involvement in chemical communication.
format: application/pdf
format: text/html
creator: Alejandro Ibáñez
creator: Albert Martínez-Silvestre
creator: Dagmara Podkowa
creator: Aneta Woźniakiewicz
creator: Michał Woźniakiewicz
creator: Maciej Pabijan
subject: Animal Behavior
subject: Zoology
subject: Histology
description: doi:10.7717/peerj.9047
publisher: PeerJ Inc.
rights: © 2020 Ibáñez et al.
abstract: Despite evidence from anatomy, behavior and genomics indicating that the sense of smell in turtles is important, our understanding of chemical communication in this group is still rudimentary. Our aim was to describe the microanatomy of mental glands (MGs) in a freshwater turtle, Mauremys leprosa (Geoemydidae), and to assess the chemical composition of their secretions with respect to variation among individuals and between sexes. MGs are paired sac-like organs on the gular region of the neck and are dimorphic in this species with males having fully functional holocrine glands while those of females appear non-secretory and vestigial. In adult males, the glandular epithelium of the inner portion of the gland provides exocytotic products as well as cellular debris into the lumen of the gland. The contents of the lumen can be secreted through the narrow duct portion of the gland ending in an orifice on the surface of the skin. Females have invaginated structures similar in general outline to male glands, but lack a glandular epithelium. Using gas chromatography coupled to mass spectrometry, we identified a total of 61 compounds in mental gland secretions, the most numerous being carboxylic acids, carbohydrates, alkanes, steroids and alcohols. The number of compounds per individual varied widely (mean (median) ± SD = 14.54 (13) ± 8.44; min = 3; max = 40), but only cholesterol was found in all samples. We found that the relative abundances of only six chemicals were different between the sexes, although males tended to have larger amounts of particular compounds. Although the lipid fraction of mental gland secretions is rich in chemical compounds, most occur in both sexes suggesting that they are metabolic byproducts with no role in chemical signaling. However, the relative amounts of some compounds tended to be higher in males, with significantly larger amounts of two carboxylic acids and one steroid, suggesting their putative involvement in chemical communication.
bibliographic citation: Ibáñez et al. (2020) The chemistry and histology of sexually dimorphic mental glands in the freshwater turtle, Mauremys leprosa. PeerJ 8:e9047 https://doi.org/10.7717/peerj.9047
date submitted: 2020-01-14
date accepted: 2020-04-02
issued: 2020-05-15
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Ibáñez
  given name: Alejandro
author list: Agent
  family name: Martínez-Silvestre
  given name: Albert
author list: Agent
  family name: Podkowa
  given name: Dagmara
author list: Agent
  family name: Woźniakiewicz
  given name: Aneta
author list: Agent
  family name: Woźniakiewicz
  given name: Michał
author list: Agent
  family name: Pabijan
  given name: Maciej
doi: 10.7717/peerj.9047
volume: 8
issn: 2167-8359
publication name: PeerJ
publication date: 2020-05-15
copyright: © 2020 Ibáñez et al.
attribution name: Ibáñez et al.

Spirometric traits show quantile-dependent heritability, which may contribute to their gene-environment interactions with smoking and pollution
type: item
type: AcademicArticle
description: Background “Quantile-dependent expressivity” refers to a genetic effect that is dependent upon whether the phenotype (e.g., spirometric data) is high or low relative to its population distribution. Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), and the FEV1/FVC ratio are moderately heritable spirometric traits. The aim of the analyses is to test whether their heritability (h2) is constant over all quantiles of their distribution. Methods Quantile regression was applied to the mean age, sex, height and smoking-adjusted spirometric data over multiple visits in 9,993 offspring-parent pairs and 1,930 sibships from the Framingham Heart Study to obtain robust estimates of offspring-parent (βOP), offspring-midparent (βOM), and full-sib regression slopes (βFS). Nonparametric significance levels were obtained from 1,000 bootstrap samples. βOPs were used as simple indicators of quantile-specific heritability (i.e., h2 = 2βOP/(1+rspouse), where rspouse was the correlation between spouses). Results βOP ± standard error (SE) decreased by 0.0009 ± 0.0003 (P = 0.003) with every one-percent increment in the population distribution of FEV1/FVC, i.e., βOP ± SE were: 0.182 ± 0.031, 0.152 ± 0.015; 0.136 ± 0.011; 0.121 ± 0.013; and 0.099 ± 0.013 at the 10th, 25th, 50th, 75th, and 90th percentiles of the FEV1/FVC distribution, respectively. These correspond to h2 ± SEs of 0.350 ± 0.060 at the 10th, 0.292 ± 0.029 at the 25th, 0.262 ± 0.020 at the 50th, 0.234 ± 0.025 at the 75th, and 0.191 ± 0.025 at the 90th percentiles of the FEV1/FVC ratio. Maximum mid-expiratory flow (MMEF) h2 ± SEs increased 0.0025 ± 0.0007 (P = 0.0004) with every one-percent increment in its distribution, i.e.: 0.467 ± 0.046, 0.467 ± 0.033, 0.554 ± 0.038, 0.615 ± 0.042, and 0.675 ± 0.060 at the 10th, 25th, 50th, 75th, and 90th percentiles of its distribution. This was due to forced expiratory flow at 75% of FVC (FEF75%), whose quantile-specific h2 increased an average of 0.0042 ± 0.0008 for…
format: application/pdf
format: text/html
creator: Paul T. Williams
subject: Genetics
subject: Public Health
subject: Respiratory Medicine
subject: Medical Genetics
description: doi:10.7717/peerj.9145
publisher: PeerJ Inc.
rights: © 2020 Williams
abstract: Background “Quantile-dependent expressivity” refers to a genetic effect that is dependent upon whether the phenotype (e.g., spirometric data) is high or low relative to its population distribution. Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), and the FEV1/FVC ratio are moderately heritable spirometric traits. The aim of the analyses is to test whether their heritability (h2) is constant over all quantiles of their distribution. Methods Quantile regression was applied to the mean age, sex, height and smoking-adjusted spirometric data over multiple visits in 9,993 offspring-parent pairs and 1,930 sibships from the Framingham Heart Study to obtain robust estimates of offspring-parent (βOP), offspring-midparent (βOM), and full-sib regression slopes (βFS). Nonparametric significance levels were obtained from 1,000 bootstrap samples. βOPs were used as simple indicators of quantile-specific heritability (i.e., h2 = 2βOP/(1+rspouse), where rspouse was the correlation between spouses). Results βOP ± standard error (SE) decreased by 0.0009 ± 0.0003 (P = 0.003) with every one-percent increment in the population distribution of FEV1/FVC, i.e., βOP ± SE were: 0.182 ± 0.031, 0.152 ± 0.015; 0.136 ± 0.011; 0.121 ± 0.013; and 0.099 ± 0.013 at the 10th, 25th, 50th, 75th, and 90th percentiles of the FEV1/FVC distribution, respectively. These correspond to h2 ± SEs of 0.350 ± 0.060 at the 10th, 0.292 ± 0.029 at the 25th, 0.262 ± 0.020 at the 50th, 0.234 ± 0.025 at the 75th, and 0.191 ± 0.025 at the 90th percentiles of the FEV1/FVC ratio. Maximum mid-expiratory flow (MMEF) h2 ± SEs increased 0.0025 ± 0.0007 (P = 0.0004) with every one-percent increment in its distribution, i.e.: 0.467 ± 0.046, 0.467 ± 0.033, 0.554 ± 0.038, 0.615 ± 0.042, and 0.675 ± 0.060 at the 10th, 25th, 50th, 75th, and 90th percentiles of its distribution. This was due to forced expiratory flow at 75% of FVC (FEF75%), whose quantile-specific h2 increased an average of 0.0042 ± 0.0008 for…
bibliographic citation: Williams (2020) Spirometric traits show quantile-dependent heritability, which may contribute to their gene-environment interactions with smoking and pollution. PeerJ 8:e9145 https://doi.org/10.7717/peerj.9145
date submitted: 2019-10-23
date accepted: 2020-04-17
issued: 2020-05-15
is part of: PeerJ
license: https://creativecommons.org/publicdomain/zero/1.0/
author list: Agent
  family name: Williams
  given name: Paul T.
doi: 10.7717/peerj.9145
volume: 8
issn: 2167-8359
publication name: PeerJ
publication date: 2020-05-15
attribution name: Williams

Depigmenting potential of lichen extracts evaluated by in vitro and in vivo tests
type: item
type: AcademicArticle
description: Melanin is the main pigment of human skin, playing the primary role of protection from ultraviolet radiation. Alteration of the melanin production may lead to hyperpigmentation diseases, with both aesthetic and health consequences. Thus, suppressors of melanogenesis are considered useful tools for medical and cosmetic treatments. A great interest is focused on natural sources, aimed at finding safe and quantitatively available depigmenting substances. Lichens are thought to be possible sources of this kind of compounds, as the occurrence of many phenolic molecules suggests possible effects on phenolase enzymes involved in melanin synthesis, like tyrosinase. In this work, we used four lichen species, Cetraria islandica Ach., Flavoparmelia caperata Hale, Letharia vulpina (L.) Hue, and Parmotrema perlatum (Hudson) M. Choisy, to obtain extracts in solvents of increasing polarity, viz. chloroform, chloroform-methanol, methanol, and water. Cell-free, tyrosinase inhibition experiments showed highest inhibition for L. vulpina methanol extract, followed by C. islandica chloroform-methanol one. Comparable results for depigmenting activities were observed by means of in vitro and in vivo systems, such as MeWo melanoma cells and zebrafish larvae. Our study provides first evidence of depigmenting effects of lichen extracts, from tyrosinase inhibition to cell and in vivo models, suggesting that L. vulpina and C. islandica extracts deserve to be further studied for developing skin-whitening products.
format: application/pdf
format: text/html
creator: Paola Malaspina
creator: Erica Catellani
creator: Bruno Burlando
creator: Daniele Brignole
creator: Laura Cornara
creator: Miriam Bazzicalupo
creator: Simona Candiani
creator: Valentina Obino
creator: Vincenzo De Feo
creator: Lucia Caputo
creator: Paolo Giordani
subject: Plant Science
subject: Dermatology
description: doi:10.7717/peerj.9150
publisher: PeerJ Inc.
rights: © 2020 Malaspina et al.
abstract: Melanin is the main pigment of human skin, playing the primary role of protection from ultraviolet radiation. Alteration of the melanin production may lead to hyperpigmentation diseases, with both aesthetic and health consequences. Thus, suppressors of melanogenesis are considered useful tools for medical and cosmetic treatments. A great interest is focused on natural sources, aimed at finding safe and quantitatively available depigmenting substances. Lichens are thought to be possible sources of this kind of compounds, as the occurrence of many phenolic molecules suggests possible effects on phenolase enzymes involved in melanin synthesis, like tyrosinase. In this work, we used four lichen species, Cetraria islandica Ach., Flavoparmelia caperata Hale, Letharia vulpina (L.) Hue, and Parmotrema perlatum (Hudson) M. Choisy, to obtain extracts in solvents of increasing polarity, viz. chloroform, chloroform-methanol, methanol, and water. Cell-free, tyrosinase inhibition experiments showed highest inhibition for L. vulpina methanol extract, followed by C. islandica chloroform-methanol one. Comparable results for depigmenting activities were observed by means of in vitro and in vivo systems, such as MeWo melanoma cells and zebrafish larvae. Our study provides first evidence of depigmenting effects of lichen extracts, from tyrosinase inhibition to cell and in vivo models, suggesting that L. vulpina and C. islandica extracts deserve to be further studied for developing skin-whitening products.
bibliographic citation: Malaspina et al. (2020) Depigmenting potential of lichen extracts evaluated by in vitro and in vivo tests. PeerJ 8:e9150 https://doi.org/10.7717/peerj.9150
date submitted: 2019-07-17
date accepted: 2020-04-17
issued: 2020-05-15
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Malaspina
  given name: Paola
author list: Agent
  family name: Catellani
  given name: Erica
author list: Agent
  family name: Burlando
  given name: Bruno
author list: Agent
  family name: Brignole
  given name: Daniele
author list: Agent
  family name: Cornara
  given name: Laura
author list: Agent
  family name: Bazzicalupo
  given name: Miriam
author list: Agent
  family name: Candiani
  given name: Simona
author list: Agent
  family name: Obino
  given name: Valentina
author list: Agent
  family name: De Feo
  given name: Vincenzo
author list: Agent
  family name: Caputo
  given name: Lucia
author list: Agent
  family name: Giordani
  given name: Paolo
doi: 10.7717/peerj.9150
volume: 8
issn: 2167-8359
publication name: PeerJ
publication date: 2020-05-15
copyright: ©2020 Malaspina et al.
attribution name: Malaspina et al.

Comparing race, gender, age, and career categories in recognizing and grouping tasks
type: item
type: AcademicArticle
description: The purpose of our research was to compare how participants weighed age, gender, race, and career categories in recognizing and grouping tasks. In Study 1, we used a category recognition task to compare participants’ speeds in recognizing information from different categories. The results showed that participants recognized the gender information most quickly, followed by career, race, and age information. In Study 2, a categorization task was used to compare participants’ category preferences. The results showed that the career category had the greatest weight, and the gender category had the lowest weight. Two targets who had different career identities were more possible considered as belonging to different groups than two targets with different gender, race or age identities. Our results have implications in understanding the weight of different categories, with gender and career category are the most important category that affects perception and evaluation.
format: application/pdf
format: text/html
creator: Jingjing Song
creator: Lin Li
subject: Psychiatry and Psychology
subject: Public Health
description: doi:10.7717/peerj.9156
publisher: PeerJ Inc.
rights: © 2020 Song and Li
abstract: The purpose of our research was to compare how participants weighed age, gender, race, and career categories in recognizing and grouping tasks. In Study 1, we used a category recognition task to compare participants’ speeds in recognizing information from different categories. The results showed that participants recognized the gender information most quickly, followed by career, race, and age information. In Study 2, a categorization task was used to compare participants’ category preferences. The results showed that the career category had the greatest weight, and the gender category had the lowest weight. Two targets who had different career identities were more possible considered as belonging to different groups than two targets with different gender, race or age identities. Our results have implications in understanding the weight of different categories, with gender and career category are the most important category that affects perception and evaluation.
bibliographic citation: Song et al. (2020) Comparing race, gender, age, and career categories in recognizing and grouping tasks. PeerJ 8:e9156 https://doi.org/10.7717/peerj.9156
date submitted: 2020-01-21
date accepted: 2020-04-18
issued: 2020-05-15
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Song
  given name: Jingjing
author list: Agent
  family name: Li
  given name: Lin
doi: 10.7717/peerj.9156
volume: 8
issn: 2167-8359
publication name: PeerJ
publication date: 2020-05-15
copyright: ©2020 Song and Li
attribution name: Song and Li

PeerJ
type: Periodical
uri: PeerJ
issn: 2167-8359