title: PeerJ description: Articles published in PeerJ link: https://peerj.com/articles/index.rss3?journal=peerj&page=1368 creator: info@peerj.com PeerJ errorsTo: info@peerj.com PeerJ language: en title: A fixed agreement—consequences of brood size manipulation on alternation in blue tits link: https://peerj.com/articles/6826 last-modified: 2019-04-24 description: Recent studies have proposed that conditional cooperation may resolve sexual conflict over the amount of care provided by each parent. Such conditional cooperation may allow parents to equalize their investment by alternating their provisioning visits. This alternated pattern of male and female visits, that is, alternation, is thought to stimulate each other’s investment leading to higher levels of provisioning and potential benefits for offspring development. However, experimental studies testing the role of alternation as an adaptive parental strategy to negotiate the level of investment are still absent. Therefore, we manipulated blue tit (Cyanistes caeruleus) parents by temporarily changing their brood sizes to induce changes in demand and thus visit rates. Parents were expected to visit more—assuming that prey sizes were constant—and alternate at higher levels when confronted with an enlarged brood given the greater potential for sexual conflict. In contrast, in reduced broods visit rates and alternation may become lower due to the smaller investment that is needed for reduced broods. We show that the level of alternation did not differ in response to the manipulated brood sizes, despite a directional change in visit rates for enlarged and reduced broods as expected. Nestlings did not benefit from high levels of alternation as no effects on nestling mass gain were present in either of the different manipulations. These findings indicate that alternation does not serve as a mechanism to motivate each other to feed at higher rates. Parents hence appeared to be inflexible in their level of alternation. We therefore suggest that the level of alternation might reflect a fixed agreement about the relative investment by each of the caring parents. creator: Maaike Griffioen creator: Wendt Müller creator: Arne Iserbyt uri: https://doi.org/10.7717/peerj.6826 license: http://creativecommons.org/licenses/by/4.0/ rights: © 2019 Griffioen et al. title: Normal spermatogenesis in Fank1 (fibronectin type 3 and ankyrin repeat domains 1) mutant mice link: https://peerj.com/articles/6827 last-modified: 2019-04-24 description: BackgroundThe fibronectin type 3 and ankyrin repeat domains 1 gene, Fank1, is an ancient, evolutionarily conserved gene present in vertebrates. Short-hairpin RNA (shRNA)-based knockdown transgenic mice have oligospermia caused by an increase in apoptotic germ cells. In this study, we investigated the in vivo function of Fank1.MethodsIn this study, we generated Fank1-knockout mice using the CRISPR/Cas9 system. We then investigated the phenotype and in vivo function of Fank1. Testes and epididymis tissues were analyzed by histological and immunofluorescence staining. Apoptotic cells were analyzed in terminal deoxynucleotidyl transferase dUTP nick end-labeling assays. Fertility and sperm counts were also evaluated. The GTEx database were used to assess gene expression quantitative trait loci and mRNA expression of candidate genes and genes neighboring single nucleotide polymorphisms was analyzed by quantitative RT-PCR.ResultsIn contrast to the Fank1-knockdown model, no significant changes in epididymal sperm content and the number of apoptotic cells were observed in Fank1−/− homozygotes. In addition, a different pattern of Dusp1, Klk1b21 and Klk1b27 mRNA expression was detected in Fank1-knockout testis. These results reveal differences in the molecular changes between Fank1-knockdown mice and Fank1-knockout mice and provide a basic resource for population genetics studies. creator: Jintao Zhang creator: Xin Zhang creator: Yue Zhang creator: Wentao Zeng creator: Shuqin Zhao creator: Mingxi Liu uri: https://doi.org/10.7717/peerj.6827 license: http://creativecommons.org/licenses/by/4.0/ rights: © 2019 Zhang et al. title: Periodontal condition in growing subjects with Marfan Syndrome: a case-control study link: https://peerj.com/articles/6606 last-modified: 2019-04-23 description: BackgroundMarfan’s syndrome (MFS) is a systemic disorder of connective tissue caused by mutations in the extracellular matrix protein fibrillin-1. Orofacial characteristics may be useful in identification of the syndrome. Severe periodontitis is sometimes observed in MFS patients, but no in-depth information has been reported in Italian groups of growing subjects with MFS. The aim of this study was to analyze the periodontal condition on a group of growing subjects affected by MFS, in comparison with a typically developed control group.MethodsA group of 16 subjects with diagnosed MFS were recruited from the Centre for Rare Diseases for Marfan Syndrome and Related Disorders of Tor Vergata University Hospital. The Marfan Group (MG) was compared with a Control Group (CG) composed by 20 nonsyndromic subjects. The periodontal clinical parameters like Marginal Gingival Thickness (GT), Plaque Index (PI), Bleeding On Probing (BOP) and Modified Periodontal Screening and Recording (PSR) were assessed.ResultsThe mean value of PI in MG was 59%, instead in CG it reached 21%. Analysis showed a significant difference between MG and CG also for the BOP. In MG the mean value of BOP attained 36% and in CG it reached 16%. A statistical significant difference of distribution of PSR index between the two groups was found for all sextant examined.DiscussionPatients with Marfan syndrome reveal a higher presence of plaque and consequently a generalized inflammation in the oral cavity when compared with a control group. creator: Nicolò Venza creator: Carlotta Danesi creator: Diego Contò creator: Francesco Fabi creator: Gianluca Mampieri creator: Federica Sangiuolo creator: Giuseppina Laganà uri: https://doi.org/10.7717/peerj.6606 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2019 Venza et al. title: Preference classes in society for coastal marine protected areas link: https://peerj.com/articles/6672 last-modified: 2019-04-23 description: Marine protected areas (MPAs) are increasingly being used as conservation tools in the marine environment. Success of MPAs depends upon sound scientific design and societal support. Studies that have assessed societal preferences for temperate MPAs have generally done it without considering the existence of discrete groups of opinion within society and have largely considered offshore and deep-sea areas. This study quantifies societal preferences and economic support for coastal MPAs in Wales (UK) and assesses the presence of distinct groups of preference for MPA management, through a latent class choice experiment approach. Results show a general support for the protection of the marine environment in the form of MPAs and that society is willing to bear the costs derived from conservation. Despite a general opposition toward MPAs where human activities are completely excluded, there is some indication that three classes of preferences within society can be established regarding the management of potentially sea-floor damaging activities. This type of approach allows for the distinction between those respondents with positive preferences for particular types of management from those who experience disutility. We conclude that insights from these types of analyses can be used by policy-makers to identify those MPA designs and management combinations most likely to be supported by particular sectors of society. creator: Ana Ruiz-Frau creator: James M. Gibbons creator: Hilmar Hinz creator: Gareth Edwards-Jones creator: Michel J. Kaiser uri: https://doi.org/10.7717/peerj.6672 license: http://creativecommons.org/licenses/by/4.0/ rights: © 2019 Ruiz-Frau et al. title: Introgressive hybridization in a Spiny-Tailed Iguana, Ctenosaura pectinata, and its implications for taxonomy and conservation link: https://peerj.com/articles/6744 last-modified: 2019-04-23 description: Introgression, the transmission of genetic material of one taxon into another through hybridization, can have various evolutionary outcomes. Previous studies have detected signs of introgression between western populations of the Mexican endemic and threatened spiny-tailed iguana, Ctenosaura pectinata. However, the extent of this phenomenon along the geographic distribution of the species is unknown. Here, we use multilocus data together with detailed geographic sampling to (1) define genotypic clusters within C. pectinata; (2) evaluate geographic concordance between maternally and biparentally inherited markers; (3) examine levels of introgression between genotypic clusters, and (4) suggest taxonomic modifications in light of this information. Applying clustering methods to genotypes of 341 individuals from 49 localities of C. pectinata and the closely related C. acanthura, we inferred the existence of five genotypic clusters. Contact zones between genotypic clusters with signatures of interbreeding were detected, showing different levels of geographic discordance with mtDNA lineages. In northern localities, mtDNA and microsatellites exhibit concordant distributions, supporting the resurrection of C. brachylopha. Similar concordance is observed along the distribution of C. acanthura, confirming its unique taxonomic identity. Genetic and geographic concordance is also observed for populations within southwestern Mexico, where the recognition of a new species awaits in depth taxonomic revision. In contrast, in western localities a striking pattern of discordance was detected where up to six mtDNA lineages co-occur with only two genotypic clusters. Given that the type specimen originated from this area, we suggest that individuals from western Mexico keep the name C. pectinata. Our results have profound implications for conservation, management, and forensics of Mexican iguanas. creator: Eugenia Zarza creator: Víctor H. Reynoso creator: Christiana M. A. Faria creator: Brent C. Emerson uri: https://doi.org/10.7717/peerj.6744 license: http://creativecommons.org/licenses/by/4.0/ rights: © 2019 Zarza et al. title: Noblella thiuni sp. n., a new (singleton) species of minute terrestrial-breeding frog (Amphibia, Anura, Strabomantidae) from the montane forest of the Amazonian Andes of Puno, Peru link: https://peerj.com/articles/6780 last-modified: 2019-04-23 description: We describe a new species of minute, terrestrial-breeding frog in the genus Noblella. We collected a single specimen in the leaf litter of primary montane forest (2,225 m a.s.l.) near Thiuni, in the Provice of Carabaya, Department of Puno, in the upper watershed of a tributary of the Inambari River of southern Peru, the same locality where we found the types of Psychrophrynella glauca Catenazzi & Ttito 2018. We placed the new species within Noblella on the basis of molecular data, minute size, and overall morphological resemblance with the type species N. peruviana and other species of Noblella, including having three phalanges on finger IV (as in N. coloma, N. heyeri, N. lynchi, N. madreselva, N. peruviana, and N. pygmaea), and terminal phalanges T-shaped and pointed. Noblella thiuni sp. n. is distinguished from all other species of Noblella by having ventral surfaces of legs bright red, and chest and belly copper reddish with a profusion of silvery spots. The new species further differs from known Peruvian species of Noblella by the combination of the following characters: tympanic membrane absent, eyelids lacking tubercles, dorsal skin finely shagreen, tarsal tubercles or folds absent, three phalanges on Finger IV, tips of digits not expanded, no circumferential grooves on digits, inguinal spots present. The new species has a snout–vent length of 11.0 mm in one adult or subadult male. Our new finding confirms the high levels of endemism and beta diversity of small, terrestrial-breeding frogs inhabiting the moss layers and leaf litter in the montane forests of the Amazonian slopes of the Andes and adjacent moist puna grasslands, and suggests much work remains to be done to properly document this diversity. creator: Alessandro Catenazzi creator: Alex Ttito uri: https://doi.org/10.7717/peerj.6780 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2019 Catenazzi and Ttito title: A network approach to identify bioregions in the distribution of Mediterranean amphipods associated with Posidonia oceanica meadows link: https://peerj.com/articles/6786 last-modified: 2019-04-23 description: Although amphipods are key components of the macro-fauna associated with Posidonia oceanica meadows, to date no studies focused on the structure and diversity of their assemblages across the whole Mediterranean Sea. Here, we applied a network approach based on modularity on a dataset mined from literature to identify biogeographic modules and to assess the biogeographic roles of associated localities. We also correlated the patterns evidenced with the biogeographic distribution of amphipod groups by means of a multivariate analysis. Modularity analysis highlighted four biogeographic modules bounded by the main Mediterranean biogeographic divides and evidenced a decrease in species diversity along a NW-SE gradient. Assemblages associated with Central-Western Mediterranean and, to a lesser extent, Tunisian modules showed the highest species richness and were identified as hubs, characterized by species with regional distributions that behave as source in a biogeographic context. The paleogeographic history of the host seagrass and the ecology of associated amphipods, both suggest the joint effect of species persistence and post-Last Glacial Maximum expansion in explaining the pattern of amphipod distribution in the Mediterranean Sea. creator: Bruno Bellisario creator: Federica Camisa creator: Chiara Abbattista creator: Roberta Cimmaruta uri: https://doi.org/10.7717/peerj.6786 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2019 Bellisario et al. title: Gastrocnemius fascicles are shorter and more pennate throughout the first month following acute Achilles tendon rupture link: https://peerj.com/articles/6788 last-modified: 2019-04-23 description: The purpose of this study was to characterize the short-term effects of Achilles tendon ruptures on medial gastrocnemius. We hypothesized that the fascicles of the medial gastrocnemius muscle of the injured Achilles tendon would be shorter and more pennate immediately following the injury and would persist throughout 4 weeks post-injury. B-mode longitudinal ultrasound images of the medial gastrocnemius were acquired in 10 adults who suffered acute Achilles tendon ruptures and were treated non-operatively. Ultrasound images were acquired during the initial clinical visit following injury as well as 2 and 4 weeks following this initial clinical visit. Resting muscle structure was characterized by measuring fascicle length, pennation angle, muscle thickness, and muscle echo intensity in both the injured and contralateral (control) limbs. Fascicle length was 15% shorter (P < 0.001) and pennation angle was 21% greater (P < 0.001) in the injured muscle compared to the uninjured (control) muscle at the presentation of injury (week 0). These differences in fascicle length persisted through 4 weeks after injury (P < 0.002) and pennation angle returned to pre-injury levels. Muscle thickness changes were not detected at any of the post-injury visits (difference < 4%, P > 0.026). Echo intensity of the injured limb was 8% lower at the presentation of the injury but was not different compared to the contralateral muscle at 2 and 4 weeks post-injury. Our results suggest that Achilles tendon ruptures elicit rapid changes in the configuration of the medial gastrocnemius, which may explain long-term functional deficits. creator: Todd J. Hullfish creator: Kathryn M. O’Connor creator: Josh R. Baxter uri: https://doi.org/10.7717/peerj.6788 license: http://creativecommons.org/licenses/by/4.0/ rights: © 2019 Hullfish et al. title: The effect of pharmacological inhibition of Serine Proteases on neuronal networks in vitro link: https://peerj.com/articles/6796 last-modified: 2019-04-23 description: Neurons are embedded in an extracellular matrix (ECM), which functions both as a scaffold and as a regulator of neuronal function. The ECM is in turn dynamically altered through the action of serine proteases, which break down its constituents. This pathway has been implicated in the regulation of synaptic plasticity and of neuronal intrinsic excitability. In this study, we determined the short-term effects of interfering with proteolytic processes in the ECM, with a newly developed serine protease inhibitor. We monitored the spontaneous electrophysiological activity of in vitro primary rat cortical cultures, using microelectrode arrays. While pharmacological inhibition at a low dosage had no significant effect, at elevated concentrations it altered significantly network synchronization and functional connectivity but left unaltered single-cell electrical properties. These results suggest that serine protease inhibition affects synaptic properties, likely through its actions on the ECM. creator: Sebastiaan Van De Vijver creator: Stephan Missault creator: Jeroen Van Soom creator: Pieter Van Der Veken creator: Koen Augustyns creator: Jurgen Joossens creator: Stefanie Dedeurwaerdere creator: Michele Giugliano uri: https://doi.org/10.7717/peerj.6796 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2019 Van De Vijver et al. title: CYP2C11 played a significant role in down-regulating rat blood pressure under the challenge of a high-salt diet link: https://peerj.com/articles/6807 last-modified: 2019-04-23 description: BackgroundArachidonic acid (AA) is oxidized by cytochrome P450s (CYPs) to form epoxyeicosatrienoic acids (EETs), compounds that modulate ion transport, gene expression, and vasorelaxation. Both CYP2Cs and CYP2Js are involved in kidney EET epoxidation.MethodsIn this study, we used a CYP2C11-null rat model to explore the in vivo effects of CYP2C11 on vasorelaxation. For 2 months, CYP2C11-null and wild-type (WT) Sprague-Dawley rats were either fed normal lab (0.3% (w/w) sodium chloride) or high-salt (8% (w/w) sodium chloride) diets. Subsequently, an invasive method was used to determine blood pressure. Next, western blots, quantitative PCR, and immunohistochemistry were used to determine renal expression of CYPs involved in AA metabolism.ResultsAmong CYP2C11-null rats, a high-salt diet (females: 156.79 ± 15.89 mm Hg, males: 130.25 ± 16.76 mm Hg, n = 10) resulted in significantly higher blood pressure than a normal diet (females: 118.05 ± 8.43 mm Hg, P < 0.01; males: 115.15 ± 11.45 mm Hg, P < 0.05, n = 10). Compared with WT rats under the high-salt diet, western blots showed that CYP2C11-null rats had higher renal expression of CYP2J2 and CYP4A. This was consistent with the results of immunohistochemistry and the qPCR, respectively. The two rat strains did not differ in the renal expression of CYP2C23 or CYP2C24.ConclusionOur findings suggested that CYP2C11 plays an important role in lowering blood pressure under the challenge of a high-salt diet. creator: Wei Liu creator: Danjuan Sui creator: Huanying Ye creator: Zhen Ouyang creator: Yuan Wei uri: https://doi.org/10.7717/peerj.6807 license: http://creativecommons.org/licenses/by/4.0/ rights: © 2019 Liu et al.