PeerJ Preprints: Developmental Biologyhttps://peerj.com/preprints/index.atom?journal=peerj&subject=1000Developmental Biology articles published in PeerJ PreprintsInitial embedding of TRANSPARENT TESTA GLABRA 1 in the Arabidopsis thaliana flowering time regulatory pathwayhttps://peerj.com/preprints/279742019-09-202019-09-20Barbara A M PaffendorfRawan QassrawiAndrea M MeysLaura TrimbornAndrea Schrader
Pleiotropic regulatory factors mediate concerted responses of the plant’s trait network to endogenous and exogenous cues. TRANSPARENT TESTA GLABRA 1 (TTG1) is a pleiotropic regulator that has been predominantly described in its role as a regulator of early accessible developmental traits. Although its closest homologs LIGHT-REGULATED WD1 (LWD1) and LWD2 are regulators of photoperiodic flowering, a role of TTG1 in flowering time regulation has not been reported.
Here we reveal that TTG1 is a regulator of flowering time in Arabidopsis thaliana and changes transcription levels of different targets within the flowering time regulatory pathway. TTG1 mutants flower early and TTG1 overexpression lines flower late at long-day conditions. Consistently, TTG1 can suppress the transcript levels of the floral integrators FLOWERING LOCUS T and SUPPRESSOR OF OVEREXPRESSION OF CO1 and can act as an activator of circadian clock components. Moreover, TTG1 might form feedback loops at the protein level. The TTG1 protein interacts with PSEUDO RESPONSE REGULATOR (PRR)s and basic HELIX-LOOP-HELIX 92 (bHLH92) in yeast. In planta, the respective pairs exhibit interesting patterns of localization including a recruitment of TTG1 by PRR5 to subnuclear foci. This mechanism proposes additional layers of regulation by TTG1 and might aid to specify the function of bHLH92.
Within another branch of the pathway, TTG1 can elevate FLOWERING LOCUS C (FLC) transcript levels. FLC mediates signals from the vernalization, ambient temperature and autonomous pathway and the circadian clock is pivotal for the plant to synchronize with diurnal cycles of environmental stimuli like light and temperature. Our results suggest an unexpected positioning of TTG1 upstream of FLC and upstream of the circadian clock. In this light, this points to an adaptive value of the role of TTG1 in respect to flowering time regulation.
Pleiotropic regulatory factors mediate concerted responses of the plant’s trait network to endogenous and exogenous cues. TRANSPARENT TESTA GLABRA 1 (TTG1) is a pleiotropic regulator that has been predominantly described in its role as a regulator of early accessible developmental traits. Although its closest homologs LIGHT-REGULATED WD1 (LWD1) and LWD2 are regulators of photoperiodic flowering, a role of TTG1 in flowering time regulation has not been reported.Here we reveal that TTG1 is a regulator of flowering time in Arabidopsis thaliana and changes transcription levels of different targets within the flowering time regulatory pathway. TTG1 mutants flower early and TTG1 overexpression lines flower late at long-day conditions. Consistently, TTG1 can suppress the transcript levels of the floral integrators FLOWERING LOCUS T and SUPPRESSOR OF OVEREXPRESSION OF CO1 and can act as an activator of circadian clock components. Moreover, TTG1 might form feedback loops at the protein level. The TTG1 protein interacts with PSEUDO RESPONSE REGULATOR (PRR)s and basic HELIX-LOOP-HELIX 92 (bHLH92) in yeast. In planta, the respective pairs exhibit interesting patterns of localization including a recruitment of TTG1 by PRR5 to subnuclear foci. This mechanism proposes additional layers of regulation by TTG1 and might aid to specify the function of bHLH92.Within another branch of the pathway, TTG1 can elevate FLOWERING LOCUS C (FLC) transcript levels. FLC mediates signals from the vernalization, ambient temperature and autonomous pathway and the circadian clock is pivotal for the plant to synchronize with diurnal cycles of environmental stimuli like light and temperature. Our results suggest an unexpected positioning of TTG1 upstream of FLC and upstream of the circadian clock. In this light, this points to an adaptive value of the role of TTG1 in respect to flowering time regulation.An analysis of the mechanism of aging: endogenous viral stimulus and the deleterious effect of chronic inflammationhttps://peerj.com/preprints/274412019-09-132019-09-13Chingis Ochirov
This article describes a putative mechanism of aging based on the interaction of endogenous viral particles with the receptors of the innate immune system leading to producing pro-inflammatory cytokines. The innate immune response induces a complex of signaling pathways leading to senescence or tumorigenesis. The fate of a cell is depended on the activity of the p53 tumor-suppressive signaling pathway. Chronic inflammation is characterized by upregulation of the NF-kB signaling. The NF-kB protein stimulates the expression of matrix metalloproteinases (MMPs) leading to remodeling of extracellular matrix. The extracellular matrix alterations induce the loss of stem cell environment and their depletion. The innate immune system also mediates the PI3K-Akt-mTOR signaling pathway that inhibits autophagy and transforms energy metabolism providing cell senescence, high level of blood glucose, high lipid synthesis and mitochondrial alterations. The STAT3-HIF1 signaling pathway suppresses oxidative phosphorylation increasing ROS production and promoting the MAPK pathway leading to excessive cell proliferation. The increased ROS production causes the global DNA and histone demethylation contributing to retrotransposon reactivation whose activity leads to genome instability. However, the activity of retrotransposons may be partly explained by their role in adaptation. Among retrotransposons, endogenous retroviruses may be considered as an intrinsic stimulus for the innate immune system and are also able to avoid the adaptive immune system. Therefore, I consider endogenous retroviruses as promising targets in anti-aging therapies
This article describes a putative mechanism of aging based on the interaction of endogenous viral particles with the receptors of the innate immune system leading to producing pro-inflammatory cytokines. The innate immune response induces a complex of signaling pathways leading to senescence or tumorigenesis. The fate of a cell is depended on the activity of the p53 tumor-suppressive signaling pathway. Chronic inflammation is characterized by upregulation of the NF-kB signaling. The NF-kB protein stimulates the expression of matrix metalloproteinases (MMPs) leading to remodeling of extracellular matrix. The extracellular matrix alterations induce the loss of stem cell environment and their depletion. The innate immune system also mediates the PI3K-Akt-mTOR signaling pathway that inhibits autophagy and transforms energy metabolism providing cell senescence, high level of blood glucose, high lipid synthesis and mitochondrial alterations. The STAT3-HIF1 signaling pathway suppresses oxidative phosphorylation increasing ROS production and promoting the MAPK pathway leading to excessive cell proliferation. The increased ROS production causes the global DNA and histone demethylation contributing to retrotransposon reactivation whose activity leads to genome instability. However, the activity of retrotransposons may be partly explained by their role in adaptation. Among retrotransposons, endogenous retroviruses may be considered as an intrinsic stimulus for the innate immune system and are also able to avoid the adaptive immune system. Therefore, I consider endogenous retroviruses as promising targets in anti-aging therapiesTissue-specific expression of NANOG gene in human eyehttps://peerj.com/preprints/278742019-07-262019-07-26Yuliya MarkitantovaYulia SmirnovaRina Zinovieva
The genes associated with multipotency in the eye cells at different stages of differentiation continue to be in the focus of biomedical research. In this study we revealed the changes in the NANOG mRNA expression in the human eye tissues at the early developmental stages. Using in situ hybridization we have obtained the new evidence for NANOG transcriptional activity in the human eye tissues at 8−10.5 weeks of prenatal development. NANOG transcriptional activity was detected in ectodermal derivatives tissues (cornea epithelium and lens) as well as in neuroectodermal tissue (neural retina). The highest NANOG mRNA concentration has been registered in cornea epithelium. The differences in the NANOG mRNA expression pattern could relate to the eye cells properties and their microenvironment. It is known that even in definitive tissue the epithelium retains the self-renew ability, while the retinal cells self-maintenance potential in vivo is extremely limited. Our findings confirm the presence of NANOG mRNA in tissues derived from different germ layers and clarifies the cellular markers characteristic of various eye cell types. The data obtained could help facilitate the understanding the cell biology and cell differentiation mechanisms.
The genes associated with multipotency in the eye cells at different stages of differentiation continue to be in the focus of biomedical research. In this study we revealed the changes in the NANOG mRNA expression in the human eye tissues at the early developmental stages. Using in situ hybridization we have obtained the new evidence for NANOG transcriptional activity in the human eye tissues at 8−10.5 weeks of prenatal development. NANOG transcriptional activity was detected in ectodermal derivatives tissues (cornea epithelium and lens) as well as in neuroectodermal tissue (neural retina). The highest NANOG mRNA concentration has been registered in cornea epithelium. The differences in the NANOG mRNA expression pattern could relate to the eye cells properties and their microenvironment. It is known that even in definitive tissue the epithelium retains the self-renew ability, while the retinal cells self-maintenance potential in vivo is extremely limited. Our findings confirm the presence of NANOG mRNA in tissues derived from different germ layers and clarifies the cellular markers characteristic of various eye cell types. The data obtained could help facilitate the understanding the cell biology and cell differentiation mechanisms.A derived mechanism of nervous system functions shows features capable to have evolved and provides a testable explanation for age-related neurodegenerationhttps://peerj.com/preprints/274582019-07-242019-07-24Kunjumon I Vadakkan
By viewing memories as first-person internal sensations, it was possible to derive a potential mechanism of nervous system functions. Accordingly, a spectrum inter-postsynaptic (inter-dendritic spine) functional LINKs (IPLs) are the key structural changes responsible for encoding learning-changes in physiological time-scales of milliseconds that can be retained for different lengths of time and can be used for inducing first-person inner sensation of memory. The objective of this study was to examine a) where preconditions existed for an accident to trigger sparking of internal sensations, b) what conditions might have promoted the formation and selection of IPLs, and c) how the synaptically-connected neuronal circuitry accommodated the formation of IPLs through the simple steps of variations and selection. Sequence of events during the development of the nervous system was examined for the feasible sequence of steps that led to the formation of IPLs and optimization of the system. A stage of significant spine loss and neuronal death during the early stages of development indicate about a corresponding stage of inter-spine fusion that led to neuronal loss during evolution. When the generation of internal sensations by the IPLs started to become advantageous to the system, it started preserving the circuitry by developing an adaptation to prevent inter-spine fusion. This can be achieved only if a stage of transient inter-neuronal inter-spine fusion "turn on" certain mechanism to prevent the intermediate stage of inter-spine hemifusion from progressing to fusion. In summary, the derived IPL mechanism is capable to have evolved. An adaptation to prevent IPL hemifusion from progressing to fusion is a likely evolutionary adaptation. Since the IPL mechanism is utilized during every event of learning, any age-related factors that weaken the maintenance of this adaptation to prevent IPL fusion can lead to neurodegeneration.
By viewing memories as first-person internal sensations, it was possible to derive a potential mechanism of nervous system functions. Accordingly, a spectrum inter-postsynaptic (inter-dendritic spine) functional LINKs (IPLs) are the key structural changes responsible for encoding learning-changes in physiological time-scales of milliseconds that can be retained for different lengths of time and can be used for inducing first-person inner sensation of memory. The objective of this study was to examine a) where preconditions existed for an accident to trigger sparking of internal sensations, b) what conditions might have promoted the formation and selection of IPLs, and c) how the synaptically-connected neuronal circuitry accommodated the formation of IPLs through the simple steps of variations and selection. Sequence of events during the development of the nervous system was examined for the feasible sequence of steps that led to the formation of IPLs and optimization of the system. A stage of significant spine loss and neuronal death during the early stages of development indicate about a corresponding stage of inter-spine fusion that led to neuronal loss during evolution. When the generation of internal sensations by the IPLs started to become advantageous to the system, it started preserving the circuitry by developing an adaptation to prevent inter-spine fusion. This can be achieved only if a stage of transient inter-neuronal inter-spine fusion "turn on" certain mechanism to prevent the intermediate stage of inter-spine hemifusion from progressing to fusion. In summary, the derived IPL mechanism is capable to have evolved. An adaptation to prevent IPL hemifusion from progressing to fusion is a likely evolutionary adaptation. Since the IPL mechanism is utilized during every event of learning, any age-related factors that weaken the maintenance of this adaptation to prevent IPL fusion can lead to neurodegeneration.Appetite regulating genes may contribute to herbivory versus carnivory trophic divergence in haplochromine cichlidshttps://peerj.com/preprints/278652019-07-162019-07-16Ehsan P AhiAnna DuenserPooja SinghWolfgang GesslChristian Sturmbauer
Feeding is a complex behaviour comprised of satiety control, foraging, ingestion and subsequent digestion. Cichlids from the East African Great Lakes are renowned for their diverse trophic specializations, largely predicated on highly variable jaw morphologies. Thus, most research has focused on dissecting the genetic, morphological and regulatory basis of jaw and teeth development in these species. Here for the first time we explore another aspect of feeding, the regulation of appetite related genes that are expressed in the brain and control satiety in cichlid fishes. Using qPCR analysis, we first validate stably expressed reference genes in the brain of six haplochromine cichlid species at the end of larval development prior to foraging. We next evaluate the expression of 16 appetite related genes in herbivorous and carnivorous species from the parallel radiations of Lake Tanganyika, Malawi and Victoria. Interestingly, we find increased expression of two anorexigenic genes, cart and npy2r, in the brain of carnivorous species in all the lakes. This supports the notion that herbivory compared to carnivory requires stronger appetite stimulation in order to feed larger quantity of food and to compensate for the relatively poorer nutritional quality of a plant- and algae-based diet. Our study contributes to the limited body of knowledge on the neurological circuitry that controls feeding transitions and adaptations and in cichlids and other teleosts.
Feeding is a complex behaviour comprised of satiety control, foraging, ingestion and subsequent digestion. Cichlids from the East African Great Lakes are renowned for their diverse trophic specializations, largely predicated on highly variable jaw morphologies. Thus, most research has focused on dissecting the genetic, morphological and regulatory basis of jaw and teeth development in these species. Here for the first time we explore another aspect of feeding, the regulation of appetite related genes that are expressed in the brain and control satiety in cichlid fishes. Using qPCR analysis, we first validate stably expressed reference genes in the brain of six haplochromine cichlid species at the end of larval development prior to foraging. We next evaluate the expression of 16 appetite related genes in herbivorous and carnivorous species from the parallel radiations of Lake Tanganyika, Malawi and Victoria. Interestingly, we find increased expression of two anorexigenic genes, cart and npy2r, in the brain of carnivorous species in all the lakes. This supports the notion that herbivory compared to carnivory requires stronger appetite stimulation in order to feed larger quantity of food and to compensate for the relatively poorer nutritional quality of a plant- and algae-based diet. Our study contributes to the limited body of knowledge on the neurological circuitry that controls feeding transitions and adaptations and in cichlids and other teleosts.OLA1 is responsible for normal spindle assembly and SAC activation in mouse oocyteshttps://peerj.com/preprints/278372019-07-032019-07-03Di XieJuan ZhangJinLi DingJing YangYan Zhang
Background. OLA1 is a member of the GTPase protein family, unlike other members, it can bind and hydrolyze ATP more efficiently than GTP. OLA1 participates in cell proliferation, oxidative response and tumorigenesis. However, whether OLA1 is also required for oocyte meiosis is still unknown.
Methods. In this study, the localization, expression, and functions of OLA1 in the mouse oocyte meiosis were examined. Immunofluorescent and confocal microscopy were used to explore the location pattern of OLA1 in the mouse oocyte. Moreover, nocodazole treatment was used to confirm the spindle-like location of OLA1 during mouse meiosis. Western blot was used to explore the expression pattern of OLA1 in the mouse oocyte. Microinjection of siRNA was used to explore the OLA1 functions in the mouse oocyte meiosis. In addition, chromosome spreading was used to investigate the spindle assembly checkpoint (SAC) activity.
Results. Immunofluorescent staining showed that OLA1 evenly distributed in the cytoplasm at germinal vesicle (GV) stage. After meiosis resumption (GVBD), OLA1 co-localized with spindles, which was further identified by nocodazole treatment experiments. Knockdown of OLA1 impaired the germinal vesicle breakdown progression and finally resulted in a lower polar body extrusion rate. Immunofluorescence analysis indicated that knockdown of OLA1 led to abnormal spindle assembly, which was evidenced by multipolar spindles in OLA1-RNAi-oocytes. After 6 h post-GVBD in culture, an increased proportion of oocyte which has precociously entered into anaphase/telephase I (A/TI) was observed in OLA1-knockdown oocytes, suggesting that loss of OLA1 resulted in the premature segregation of homologous chromosomes. In addition, the chromosome spread analysis suggested that OLA1 knockdown induced premature anaphase onset was due to the precocious inactivation of SAC. Taken together, we concluded that OLA1 plays important role in GVBD, spindle assembly and SAC activation maintenance in oocyte meiosis.
Background. OLA1 is a member of the GTPase protein family, unlike other members, it can bind and hydrolyze ATP more efficiently than GTP. OLA1 participates in cell proliferation, oxidative response and tumorigenesis. However, whether OLA1 is also required for oocyte meiosis is still unknown.Methods. In this study, the localization, expression, and functions of OLA1 in the mouse oocyte meiosis were examined. Immunofluorescent and confocal microscopy were used to explore the location pattern of OLA1 in the mouse oocyte. Moreover, nocodazole treatment was used to confirm the spindle-like location of OLA1 during mouse meiosis. Western blot was used to explore the expression pattern of OLA1 in the mouse oocyte. Microinjection of siRNA was used to explore the OLA1 functions in the mouse oocyte meiosis. In addition, chromosome spreading was used to investigate the spindle assembly checkpoint (SAC) activity.Results. Immunofluorescent staining showed that OLA1 evenly distributed in the cytoplasm at germinal vesicle (GV) stage. After meiosis resumption (GVBD), OLA1 co-localized with spindles, which was further identified by nocodazole treatment experiments. Knockdown of OLA1 impaired the germinal vesicle breakdown progression and finally resulted in a lower polar body extrusion rate. Immunofluorescence analysis indicated that knockdown of OLA1 led to abnormal spindle assembly, which was evidenced by multipolar spindles in OLA1-RNAi-oocytes. After 6 h post-GVBD in culture, an increased proportion of oocyte which has precociously entered into anaphase/telephase I (A/TI) was observed in OLA1-knockdown oocytes, suggesting that loss of OLA1 resulted in the premature segregation of homologous chromosomes. In addition, the chromosome spread analysis suggested that OLA1 knockdown induced premature anaphase onset was due to the precocious inactivation of SAC. Taken together, we concluded that OLA1 plays important role in GVBD, spindle assembly and SAC activation maintenance in oocyte meiosis.Interspecific hybridization of Quasipaa and genetic characteristics of hybrid tadpolehttps://peerj.com/preprints/278142019-06-222019-06-22Dandan ZhangXiaoming FeiShenshen KongQipeng ZhangZeyuan JiangQiuqing LiRongquan Zheng
This study aims to reveal the formation mechanism of distant hybridization of Quasipaa. We collected five species of Quasipaa for hybridization experiment and raised tadpoles at three temperature groups (14 ℃, 22 ℃, and 28 ℃) and three density groups (5, 15, and 30 ind/L). We monitored the growth rate and swimming speed of the tadpoles. We also used nine microsatellite markers to evaluate genetic diversity and structure between the crossbred offspring and parents. Results suggested that the hybrid combinations of Quasipaa spinosa (♀) × Q. shini (♂) and Q. boulengeri (♀) × Q. spinosa (♂) obtained healthy crossbred offspring. Temperature and breeding density significantly affected the growth and development of purebred and crossbred tadpoles. Compared with purebred tadpoles, the hybrids showed heterosis under similar experimental conditions. The genetic diversity of the crossbred tadpoles was higher than that of the parents. Higher heterozygosity and genetic differentiation were also observed in the progeny population. A close genetic relationship was found between the offspring population and the female parent.
This study aims to reveal the formation mechanism of distant hybridization of Quasipaa. We collected five species of Quasipaa for hybridization experiment and raised tadpoles at three temperature groups (14 ℃, 22 ℃, and 28 ℃) and three density groups (5, 15, and 30 ind/L). We monitored the growth rate and swimming speed of the tadpoles. We also used nine microsatellite markers to evaluate genetic diversity and structure between the crossbred offspring and parents. Results suggested that the hybrid combinations of Quasipaa spinosa (♀) × Q. shini (♂) and Q. boulengeri (♀) × Q. spinosa (♂) obtained healthy crossbred offspring. Temperature and breeding density significantly affected the growth and development of purebred and crossbred tadpoles. Compared with purebred tadpoles, the hybrids showed heterosis under similar experimental conditions. The genetic diversity of the crossbred tadpoles was higher than that of the parents. Higher heterozygosity and genetic differentiation were also observed in the progeny population. A close genetic relationship was found between the offspring population and the female parent.Cell proliferation controls body size growth, tentacle morphogenesis, and regeneration in hydrozoan jellyfish Cladonema pacificumhttps://peerj.com/preprints/276272019-04-022019-04-02Sosuke FujitaErina KuranagaYuichiro Nakajima
Jellyfish have existed on the earth for around six hundred million years and have evolved in response to environmental changes. Hydrozoan jellyfish, members of phylum Cnidaria, exist in multiple life stages, including planula larvae, vegetatively-propagating polyps, and sexually-reproducing medusae. Although free-swimming medusae display complex morphology and exhibit increase in body size and regenerative ability, their underlying cellar mechanisms are poorly understood. Here, we investigate the roles of cell proliferation in body-size growth, appendage morphogenesis, and regeneration using Cladonema pacificum as a hydrozoan jellyfish model. By examining the distribution of S phase cells and mitotic cells, we revealed spatially distinct proliferating cell populations in medusae, uniform cell proliferation in the umbrella, and local cell proliferation in tentacle bulbs. Blocking cell proliferation by hydroxyurea caused inhibition of body size growth and defects in tentacle branching, nematocyte differentiation, and regeneration. Local cell proliferation in tentacle bulbs is observed in medusae of two other hydrozoan species, Cytaeis uchidae and Rathkea octopunctata, indicating that it may be a conserved feature among hydrozoan jellyfish. Altogether, our results suggest that hydrozoan medusae possess actively proliferating cells and provide experimental evidence regarding the role of cell proliferation in body-size control, tentacle morphogenesis, and regeneration.
Jellyfish have existed on the earth for around six hundred million years and have evolved in response to environmental changes. Hydrozoan jellyfish, members of phylum Cnidaria, exist in multiple life stages, including planula larvae, vegetatively-propagating polyps, and sexually-reproducing medusae. Although free-swimming medusae display complex morphology and exhibit increase in body size and regenerative ability, their underlying cellar mechanisms are poorly understood. Here, we investigate the roles of cell proliferation in body-size growth, appendage morphogenesis, and regeneration using Cladonema pacificum as a hydrozoan jellyfish model. By examining the distribution of S phase cells and mitotic cells, we revealed spatially distinct proliferating cell populations in medusae, uniform cell proliferation in the umbrella, and local cell proliferation in tentacle bulbs. Blocking cell proliferation by hydroxyurea caused inhibition of body size growth and defects in tentacle branching, nematocyte differentiation, and regeneration. Local cell proliferation in tentacle bulbs is observed in medusae of two other hydrozoan species, Cytaeis uchidae and Rathkea octopunctata, indicating that it may be a conserved feature among hydrozoan jellyfish. Altogether, our results suggest that hydrozoan medusae possess actively proliferating cells and provide experimental evidence regarding the role of cell proliferation in body-size control, tentacle morphogenesis, and regeneration.Melatonin improves the efficiency of super-ovulation and timed artificial insemination in sheephttps://peerj.com/preprints/275982019-03-182019-03-18Yukun SongHao WuXuguang WangAerman HairyXiaosheng ZhangJinlong ZhangYingjie WuZhengxing LianJuncai FuGuoshi LiuAbulizi Wusiman
It has been well proved that melatonin participates in the regulation of the seasonal reproduction of ewes. However, the effects of short term treatment of melatonin on ewe’s ovulation are still to be clarified. In this study, the effects of melatonin on the number of embryo s harvested from superovulation, and the pregnant rate in recipients after embryo transferred have been investigated. Hu sheep with synchronous estrus treatment were given melatonin subcutaneously injection (0, 5, and 10 mg/ewe, respectively). It was found that t he estrogen level in the group of 5 mg melatonin was significantly higher than that of other two groups a t the time of sperm insemination ( p < 0.05). The pregnant rate and number of lambs in the group of 5 mg melatonin treatment was also significantly higher than that of the rests of the groups ( P < 0.05). In another study, 31 Suffolk ewes as donors and 103 small-tailed han sheep ewes as recipients were used to produce pronuclear embryo and embryo transfer. Melatonin (5 mg) was given to the donors during estrus. The results showed that, the number of pronuclear embryos and the pregnancy rate were also significantly higher in melatonin group than that in the control group . In addition, 28 donors and 44 recipient ewes were used to produce morula/blastocyst and embryo transferring. Melatonin (5 mg) was given during estrus. The total number of embryos harvested ( 7.40±1.25/ewe vs. 3.96±0.73/ewe, P<0.05 ) and the pregnant rate (72.3±4.6% vs.54.7±4.0%, P<0.05) and number of lambs were also increased in melatonin group compared to the control group. Collectively, the results have suggested that melatonin treatment 36 hours after CIDR withdrawal could promote the number and quality of embryos in the in vivo condition and increased the pregnant rate and number of lambs.
It has been well proved that melatonin participates in the regulation of the seasonal reproduction of ewes. However, the effects of short term treatment of melatonin on ewe’s ovulation are still to be clarified. In this study, the effects of melatonin on the number of embryo s harvested from superovulation, and the pregnant rate in recipients after embryo transferred have been investigated. Hu sheep with synchronous estrus treatment were given melatonin subcutaneously injection (0, 5, and 10 mg/ewe, respectively). It was found that t he estrogen level in the group of 5 mg melatonin was significantly higher than that of other two groups a t the time of sperm insemination ( p < 0.05). The pregnant rate and number of lambs in the group of 5 mg melatonin treatment was also significantly higher than that of the rests of the groups ( P < 0.05). In another study, 31 Suffolk ewes as donors and 103 small-tailed han sheep ewes as recipients were used to produce pronuclear embryo and embryo transfer. Melatonin (5 mg) was given to the donors during estrus. The results showed that, the number of pronuclear embryos and the pregnancy rate were also significantly higher in melatonin group than that in the control group . In addition, 28 donors and 44 recipient ewes were used to produce morula/blastocyst and embryo transferring. Melatonin (5 mg) was given during estrus. The total number of embryos harvested ( 7.40±1.25/ewe vs. 3.96±0.73/ewe, P<0.05 ) and the pregnant rate (72.3±4.6% vs.54.7±4.0%, P<0.05) and number of lambs were also increased in melatonin group compared to the control group. Collectively, the results have suggested that melatonin treatment 36 hours after CIDR withdrawal could promote the number and quality of embryos in the in vivo condition and increased the pregnant rate and number of lambs.Opposite asymmetries of face and trunk and of kissing and hugging, as predicted by the axial twist hypothesishttps://peerj.com/preprints/275932019-03-162019-03-16Marc HE de Lussanet
The contralateral organization of the forebrain and the crossing of the optic nerves in the optic chiasm represent a long-standing conundrum. According to the Axial Twist Hypothesis (ATH) the rostral head and the rest of the body are twisted with respect to each other to form a left-handed half turn. This twist is the result, mainly, of asymmetric, twisted growth in the early embryo. Evolutionary selection tends to restore bilateral symmetry. Since selective pressure will decrease as the organism approaches symmetry, we expected a small control error in the form of a small, residual right-handed twist. We found that the mouth-eyes-nose (rostral head) region shows a left-offset with respect to the ears (posterior head) by up to 0.8° (P<0.01, Bonferroni-corrected). Moreover, this systematic aurofacial asymmetry was larger in young children (on average up to 3°) and reduced with age. Finally, we predicted and found a right-sided bias for hugging (78%) and a left-sided bias for kissing (69%). Thus, all predictions were confirmed by the data. These results are all in support of the ATH, whereas the pattern of results is not explained by existing alternative theories. As of the present results, the ATH is the first theory for the contralateral forebrain and the optic chiasm whose predictions have been tested empirically. We conclude that humans (and all other vertebrates) are fundamentally asymmetric, both in their anatomy and their behavior. This supports the thesis that the approximate bilateral symmetry of vertebrates is a secondary feature, despite their being bilaterians.
The contralateral organization of the forebrain and the crossing of the optic nerves in the optic chiasm represent a long-standing conundrum. According to the Axial Twist Hypothesis (ATH) the rostral head and the rest of the body are twisted with respect to each other to form a left-handed half turn. This twist is the result, mainly, of asymmetric, twisted growth in the early embryo. Evolutionary selection tends to restore bilateral symmetry. Since selective pressure will decrease as the organism approaches symmetry, we expected a small control error in the form of a small, residual right-handed twist. We found that the mouth-eyes-nose (rostral head) region shows a left-offset with respect to the ears (posterior head) by up to 0.8° (P<0.01, Bonferroni-corrected). Moreover, this systematic aurofacial asymmetry was larger in young children (on average up to 3°) and reduced with age. Finally, we predicted and found a right-sided bias for hugging (78%) and a left-sided bias for kissing (69%). Thus, all predictions were confirmed by the data. These results are all in support of the ATH, whereas the pattern of results is not explained by existing alternative theories. As of the present results, the ATH is the first theory for the contralateral forebrain and the optic chiasm whose predictions have been tested empirically. We conclude that humans (and all other vertebrates) are fundamentally asymmetric, both in their anatomy and their behavior. This supports the thesis that the approximate bilateral symmetry of vertebrates is a secondary feature, despite their being bilaterians.