Eight ewes of Hu sheep which bred multi-lamb were used as the high-fecundity group and the other eight ewes of Hu sheep which bred single lamb were used as the control group to investigate the relationship between the...Eight ewes of Hu sheep which bred multi-lamb were used as the high-fecundity group and the other eight ewes of Hu sheep which bred single lamb were used as the control group to investigate the relationship between the mRNA expression level of TGF-β receptor genes in tissues and ovulation rate in Hu sheep. Cloprostenol sodium was injected to make the synchronization of estrus treatment, then all ewes were slaughtered within 24-36 h after empathema and the ovaries were collected. Furthermore, the number of ovulation points was counted to determine ovulation rate for each sheep. Tissue expression analysis was conducted by RT-PCR for one ewe form the high-fecundity group and the relationship between the mRNA expression of genes encoding TGF-β receptors and ovulation rate was detected by real-time fluorescent quantitative PCR. The results showed that the relative expression level of TGF-flR I gene in the reproductive organ was significantly higher than in the lung and muscle （P 〈 0.01）, while relative expression level of TGF-βR H in reproductive organ was significantly higher than that of other tissues （P 〈 0.01）, indicating that these are highly expressed genes in the ovary. In addition, mRNA expression level of TGF-βR I and TGF-flRH in the ovaries of the high-fecundity group were significantly higher （P〈 0.01） and obviously higher （P= 0.011） than the control group, respectively. The mRNA expression level of TGF-βR I and TGF-βR H had a positive correlation with ovulation rate and the correlation coefficients were 0.562 （P〉 0.05） and 0.711 （P〈 0.05）, respectively. It is suggested that TGF-β receptors have close relationship with highfecundity in Hu sheep.展开更多
Hu Sheep is a local sheep breed in the plain of Taihu, China. Due to the natural conditions in Taihu and human domestication, Hu Sheep is gradually featured with high adaptability, fast growth rate, early maturity and...Hu Sheep is a local sheep breed in the plain of Taihu, China. Due to the natural conditions in Taihu and human domestication, Hu Sheep is gradually featured with high adaptability, fast growth rate, early maturity and high productivity, which make them to be a unique and rare breed of sheep. In the present study, an experiment was conducted by means of instantaneous scan sampling, focal animal sampling and all-occurrence sampling to learn about Hu Sheep's behavior and activity pattern under certain feeding management and ecological condition. The result showed that the activity time budgets for several behaviors were different between rams and ewes, with respect to feeding (rams 30.60% vs. ewes 33.23%), ruminating (33.43% vs.35.30%); sleeping (19.92% vs. 13.69%), standing (4.13% vs. 5.26%), moving (8.10% vs. 7.46%), and other behaviors (3.86% vs.5.06%). A circadian activity rhythm was shown in some behaviors; e.g., total feeding time was greater in the daytime than at night, whereas resting time showed the opposite tendency. Moving mostly occurred in the daytime, and ruminating mainly occurred at night. Additionally, feeding activity occurred 32.22 times per day in rams and 31.73 times per day in ewes, whereas ruminating activity after feeding occurred 19.83 times per day in rams and 24.34 times per day in ewes. For each food bolus,the average ruminating time was 51.22 s in rams and 49.52 s in ewes, with 68.22 bouts of rumination per day in rams and57.35 bouts of rumination in ewes. By conducting the experiment, we studied and grasped the local Hu Sheep's main behavior and regularity which are of great significance on improving the feeding management and reducing diseases.展开更多
The phenotypic diversity resulting from artificial or natural selection of sheep has made a significant contribution to human civilization.Hu sheep are a local sheep breed unique to China with high reproductive rates ...The phenotypic diversity resulting from artificial or natural selection of sheep has made a significant contribution to human civilization.Hu sheep are a local sheep breed unique to China with high reproductive rates and rapid growth.Genomic selection signatures have been widely used to investigate the genetic mechanisms underlying phenotypic variation in livestock.Here,we conduct whole-genome sequencing of 207 Hu sheep and compare them with the wild ancestors of domestic sheep(Asiatic mouflon)to investigate the genetic characteristics and selection signatures of Hu sheep.Based on six signatures of selection approaches,we detect genomic regions containing genes related to reproduction(BMPR1B,BMP2,PGFS,CYP19,CAMK4,GGT5,and GNAQ),vision(ALDH1A2,SAG,and PDE6B),nervous system(NAV1),and immune response(GPR35,SH2B2,PIK3R3,and HRAS).Association analysis with a population of 1299 Hu sheep reveals that those missense mutations in the GPR35(GPR35 g.952651 A>G;GPR35 g.952496 C>T)and NAV1(NAV1 g.84216190 C>T;NAV1 g.84227412 G>A)genes are significantly associated(P<0.05)with immune and growth traits in Hu sheep,respectively.This research offers unique insights into the selection characteristics of Hu sheep and facilitates further genetic improvement and molecular investigations.展开更多
Background In the modern sheep production systems,the reproductive performance of ewes determines the economic profitability of farming.Revealing the genetic mechanisms underlying differences in the litter size is imp...Background In the modern sheep production systems,the reproductive performance of ewes determines the economic profitability of farming.Revealing the genetic mechanisms underlying differences in the litter size is important for the selection and breeding of highly prolific ewes.Hu sheep,a high-quality Chinese sheep breed,is known for its high fecundity and is often used as a model to study prolificacy traits.In the current study,animals were divided into two groups according to their delivery rates in three consecutive lambing seasons(namely,the high and low reproductive groups with≥3 lambs and one lamb per season,n=3,respectively).The ewes were slaughtered within 12 h of estrus,and unilateral ovarian tissues were collected and analyzed by 10×Genomics single-cell RNA sequencing.Results A total of 5 types of somatic cells were identified and corresponding expression profiles were mapped in the ovaries of each group.Noticeably,the differences in the ovary somatic cell expression profiles between the high and low reproductive groups were mainly clustered in the granulosa cells.Furthermore,four granulosa cell subtypes were identified.GeneSwitches analysis revealed that the abundance of JPH1 expression and the reduction of LOC101112291 expression could lead to different evolutionary directions of the granulosa cells.Additionally,the expression levels of FTH1 and FTL in mural granulosa cells of the highly reproductive group were significantly higher.These genes inhibit necroptosis and ferroptosis of mural granulosa cells,which helps prevent follicular atresia.Conclusions This study provides insights into the molecular mechanisms underlying the high fecundity of Hu sheep.The differences in gene expression profiles,particularly in the granulosa cells,suggest that these cells play a critical role in female prolificacy.The findings also highlight the importance of genes such as JPH1,LOC101112291,FTH1,and FTL in regulating granulosa cell function and follicular development.展开更多
基金supported by a grant from the National Natural Science Foundation of China (30671503)the Natural Science Foundation of Jiangsu Province, Chnia(BK2007156)National Basic Research Program of China (973 Program, 2007CB947403)
文摘Eight ewes of Hu sheep which bred multi-lamb were used as the high-fecundity group and the other eight ewes of Hu sheep which bred single lamb were used as the control group to investigate the relationship between the mRNA expression level of TGF-β receptor genes in tissues and ovulation rate in Hu sheep. Cloprostenol sodium was injected to make the synchronization of estrus treatment, then all ewes were slaughtered within 24-36 h after empathema and the ovaries were collected. Furthermore, the number of ovulation points was counted to determine ovulation rate for each sheep. Tissue expression analysis was conducted by RT-PCR for one ewe form the high-fecundity group and the relationship between the mRNA expression of genes encoding TGF-β receptors and ovulation rate was detected by real-time fluorescent quantitative PCR. The results showed that the relative expression level of TGF-flR I gene in the reproductive organ was significantly higher than in the lung and muscle （P 〈 0.01）, while relative expression level of TGF-βR H in reproductive organ was significantly higher than that of other tissues （P 〈 0.01）, indicating that these are highly expressed genes in the ovary. In addition, mRNA expression level of TGF-βR I and TGF-flRH in the ovaries of the high-fecundity group were significantly higher （P〈 0.01） and obviously higher （P= 0.011） than the control group, respectively. The mRNA expression level of TGF-βR I and TGF-βR H had a positive correlation with ovulation rate and the correlation coefficients were 0.562 （P〉 0.05） and 0.711 （P〈 0.05）, respectively. It is suggested that TGF-β receptors have close relationship with highfecundity in Hu sheep.
基金Supported by Earmarked Fund for Modern Agro-industry Technology Research System of China(CARS-39)the Spark Program of China(2015GA750002)National Natural Science Foundation of China(31472059)
文摘Hu Sheep is a local sheep breed in the plain of Taihu, China. Due to the natural conditions in Taihu and human domestication, Hu Sheep is gradually featured with high adaptability, fast growth rate, early maturity and high productivity, which make them to be a unique and rare breed of sheep. In the present study, an experiment was conducted by means of instantaneous scan sampling, focal animal sampling and all-occurrence sampling to learn about Hu Sheep's behavior and activity pattern under certain feeding management and ecological condition. The result showed that the activity time budgets for several behaviors were different between rams and ewes, with respect to feeding (rams 30.60% vs. ewes 33.23%), ruminating (33.43% vs.35.30%); sleeping (19.92% vs. 13.69%), standing (4.13% vs. 5.26%), moving (8.10% vs. 7.46%), and other behaviors (3.86% vs.5.06%). A circadian activity rhythm was shown in some behaviors; e.g., total feeding time was greater in the daytime than at night, whereas resting time showed the opposite tendency. Moving mostly occurred in the daytime, and ruminating mainly occurred at night. Additionally, feeding activity occurred 32.22 times per day in rams and 31.73 times per day in ewes, whereas ruminating activity after feeding occurred 19.83 times per day in rams and 24.34 times per day in ewes. For each food bolus,the average ruminating time was 51.22 s in rams and 49.52 s in ewes, with 68.22 bouts of rumination per day in rams and57.35 bouts of rumination in ewes. By conducting the experiment, we studied and grasped the local Hu Sheep's main behavior and regularity which are of great significance on improving the feeding management and reducing diseases.
基金supported by the National Key Research and Development Program of China(2021YFD1300901,2022YFD1302000)National Natural Science Foundation of China(32260818,31960653)。
文摘The phenotypic diversity resulting from artificial or natural selection of sheep has made a significant contribution to human civilization.Hu sheep are a local sheep breed unique to China with high reproductive rates and rapid growth.Genomic selection signatures have been widely used to investigate the genetic mechanisms underlying phenotypic variation in livestock.Here,we conduct whole-genome sequencing of 207 Hu sheep and compare them with the wild ancestors of domestic sheep(Asiatic mouflon)to investigate the genetic characteristics and selection signatures of Hu sheep.Based on six signatures of selection approaches,we detect genomic regions containing genes related to reproduction(BMPR1B,BMP2,PGFS,CYP19,CAMK4,GGT5,and GNAQ),vision(ALDH1A2,SAG,and PDE6B),nervous system(NAV1),and immune response(GPR35,SH2B2,PIK3R3,and HRAS).Association analysis with a population of 1299 Hu sheep reveals that those missense mutations in the GPR35(GPR35 g.952651 A>G;GPR35 g.952496 C>T)and NAV1(NAV1 g.84216190 C>T;NAV1 g.84227412 G>A)genes are significantly associated(P<0.05)with immune and growth traits in Hu sheep,respectively.This research offers unique insights into the selection characteristics of Hu sheep and facilitates further genetic improvement and molecular investigations.
基金supported by the mutton sheep industry technology system construction project of Shaanxi Province(NYKJ-2021-YL(XN)43).
文摘Background In the modern sheep production systems,the reproductive performance of ewes determines the economic profitability of farming.Revealing the genetic mechanisms underlying differences in the litter size is important for the selection and breeding of highly prolific ewes.Hu sheep,a high-quality Chinese sheep breed,is known for its high fecundity and is often used as a model to study prolificacy traits.In the current study,animals were divided into two groups according to their delivery rates in three consecutive lambing seasons(namely,the high and low reproductive groups with≥3 lambs and one lamb per season,n=3,respectively).The ewes were slaughtered within 12 h of estrus,and unilateral ovarian tissues were collected and analyzed by 10×Genomics single-cell RNA sequencing.Results A total of 5 types of somatic cells were identified and corresponding expression profiles were mapped in the ovaries of each group.Noticeably,the differences in the ovary somatic cell expression profiles between the high and low reproductive groups were mainly clustered in the granulosa cells.Furthermore,four granulosa cell subtypes were identified.GeneSwitches analysis revealed that the abundance of JPH1 expression and the reduction of LOC101112291 expression could lead to different evolutionary directions of the granulosa cells.Additionally,the expression levels of FTH1 and FTL in mural granulosa cells of the highly reproductive group were significantly higher.These genes inhibit necroptosis and ferroptosis of mural granulosa cells,which helps prevent follicular atresia.Conclusions This study provides insights into the molecular mechanisms underlying the high fecundity of Hu sheep.The differences in gene expression profiles,particularly in the granulosa cells,suggest that these cells play a critical role in female prolificacy.The findings also highlight the importance of genes such as JPH1,LOC101112291,FTH1,and FTL in regulating granulosa cell function and follicular development.
