Previous research has highlighted the significant role of progestins and glucocorticoids in fish oocyte maturation and ovulation.To clarify the molecular mechanisms underlying these processes,comprehensive investigati...Previous research has highlighted the significant role of progestins and glucocorticoids in fish oocyte maturation and ovulation.To clarify the molecular mechanisms underlying these processes,comprehensive investigations were conducted using a cyp17a2 mutant Nile tilapia(Oreochromis niloticus) model.Analysis revealed pronounced Cyp17a2 expression in ovarian somatic cells of the tilapia.Female cyp17a2-deficient mutants exhibited markedly reduced levels of 17,20β-dihydroxy-4-pregnen-3-one(DHP) and cortisol/cortisone,leading to delayed meiotic initiation and impaired oocyte maturation and spawning.Notably,supplementation with human chorionic gonadotrophin(hCG),DHP,and cortisol effectively induced germinal vesicle breakdown(GVBD) and facilitated oocyte release with follicular cell layers in cyp17a2^(-/-)females.Additionally,cyp17a2-/-and rescued cyp17a2-/-females showed elevated transcription of steroidogenic enzymes involved in 17β-estradiol(E2)production compared to spawning wild-type females.Moreover,the reduction in Akt phosphorylation observed in cyp17a2-deficient females and upon inhibitor treatment impaired hCG-induced oocyte maturation.Conversely,activation of the phosphoinositide 3-kinase/protein kinase B(PI3K-Akt) signaling pathway partially rescued the oocyte maturation impairment caused by cyp17a2mutation.Overall,these findings provide functional evidence supporting the critical role of Cyp17a2 in DHP and cortisol biosynthesis,which,in turn,facilitates oocyte maturation and ovulation through activation of the PI3K-Akt signaling pathway in fish.展开更多
AIM: To correlate gastric contractility, gastrointestinal transit, and hormone levels in non-pregnant(estrous cycle) and pregnant rats using noninvasive techniques. METHODS: Female rats(n = 23) were randomly divided i...AIM: To correlate gastric contractility, gastrointestinal transit, and hormone levels in non-pregnant(estrous cycle) and pregnant rats using noninvasive techniques. METHODS: Female rats(n = 23) were randomly divided into(1) non-pregnant,(contractility, n =6; transit, n = 6); and(2) pregnant(contractility, n = 5; transit, n = 6). In each estrous cycle phase or at 0, 7, 14, and 20 d after the confirmation of pregnancy, gastrointestinal transit was recorded by AC biosusceptometry(ACB), and gastric contractility was recorded by ACB and electromyography. After each recording, blood samples were obtained for progesterone and estradiol determination. RESULTS: In the estrous cycle, despite fluctuations of sex hormone levels, no significant changes in gastrointestinal motility were observed. Days 7 and 14 of pregnancy were characterized by significant changes in the frequency of contractions(3.90 ± 0.42 cpm and 3.60 ± 0.36 cpm vs 4.33 ± 0.25 cpm) and gastric emptying(168 ± 17 min and 165 ± 15 min vs 113 ± 15 min) compared with day 0. On these same days, progesterone levels significantly increased compared with control(54.23 ± 15.14 ng/m L and 129.96 ± 30.52 ng/mL vs 13.25 ± 6.31 ng/mL). On day 14, we observed the highest level of progesterone and the lowest level of estradiol compared with day 0(44.3 ± 15.18 pg/mL vs 24.96 ± 5.96 pg/mL). CONCLUSION: Gastrointestinal motility was unaffected by the estrous cycle. In our data, high progesterone and low estradiol levels can be associated with decreased contraction frequency and slow gastric emptying.展开更多
Background The provision of habitat for fishery species in estuaries is highly valued and represents one of the most challenging ecosystem service values to quantify.However,quantifying this value is challenging due t...Background The provision of habitat for fishery species in estuaries is highly valued and represents one of the most challenging ecosystem service values to quantify.However,quantifying this value is challenging due to complex relationships between habitat change,ecological processes,and environmental variations.This study aims to estimate estuarine habitat degradation and its impact on the reproduction process of the crab Eriocheir sinensis by characterizing the changes in breeding habitat and investigating relationships between the species and its habitat in the Yang-tze River Estuary.Methods A species distribution model recently developed was applied to estimate the extent and quality of breeding habitat changes from 2014-2021.The intrinsic(physiological)and external(structural)reproductive attributes of the breeding process were measured to assess the effects of habitat change.The relationships among habitat change,reproductive attributes and environmental factors were analyzed to understand the underlying driving forces of habitat degradation for breeding process by multivariate statistical analysis.Results About 34.24%of essential habitat was lost,mainly in highly suitable areas due to reclamation and waterway construction.Habitat degradation significantly affects female distribution and their reproductive processes,particularly gonad development during the pre-reproductive period and fecundity during the reproductive period,without altering population structure.These results indicated that the main ecological function served by the highly suitable breeding ground was the provision for development of gonad and improvement of fecundity.Increases of salinity and turbidity,caused by hydrodynamic changes from large-scale waterway construction,were identified as the environmental determinants contributing to cumulative habitat degradation.These influences ultimately led to a decrease in the fecundity of E.sinensis.Conclusions Our research sheds light on the quantification of habitat degradation in the Yangtze River Estuary and its implications for the reproduction process of E.sinensis,which can serve as a foundation for assessing and quantifying the ecosystem service values provided by these breeding grounds.This information is valuable for policymakers and resource managers in making informed decisions regarding habitat conservation and the sustainable utilization of fishery resources.展开更多
Apomixis is an asexual reproductive process that generates clonal seeds genetically identical to the maternal plant,presenting revolutionary potential in plant breeding and crop improvement[1–3].Through combining gen...Apomixis is an asexual reproductive process that generates clonal seeds genetically identical to the maternal plant,presenting revolutionary potential in plant breeding and crop improvement[1–3].Through combining genome editing of the mitosis instead of meiosis(MiMe)genes with ectopic expression of parthenogenesis-related genes such as OsBBM1,OsBBM4,ToPAR,or OsWUS in egg cells,synthetic apomixis with high fertility or clonal seed rate has been engineered in rice[4–8].Additionally,by fully editing the MiMe genes and the OsMTL gene,we have successfully obtained clonal seeds in hybrid rice[9–11].展开更多
基金supported by the National Key Research and Development Program of China (2022YFD2401800)National Natural Science Foundation of China (32403005, 32293253, 32072957)+1 种基金Chongqing Science and Technology Commission (cstc2021jcyjmsxm X0088)Fundamental Research Funds for the Central Universities (SWU-KQ22026)。
文摘Previous research has highlighted the significant role of progestins and glucocorticoids in fish oocyte maturation and ovulation.To clarify the molecular mechanisms underlying these processes,comprehensive investigations were conducted using a cyp17a2 mutant Nile tilapia(Oreochromis niloticus) model.Analysis revealed pronounced Cyp17a2 expression in ovarian somatic cells of the tilapia.Female cyp17a2-deficient mutants exhibited markedly reduced levels of 17,20β-dihydroxy-4-pregnen-3-one(DHP) and cortisol/cortisone,leading to delayed meiotic initiation and impaired oocyte maturation and spawning.Notably,supplementation with human chorionic gonadotrophin(hCG),DHP,and cortisol effectively induced germinal vesicle breakdown(GVBD) and facilitated oocyte release with follicular cell layers in cyp17a2^(-/-)females.Additionally,cyp17a2-/-and rescued cyp17a2-/-females showed elevated transcription of steroidogenic enzymes involved in 17β-estradiol(E2)production compared to spawning wild-type females.Moreover,the reduction in Akt phosphorylation observed in cyp17a2-deficient females and upon inhibitor treatment impaired hCG-induced oocyte maturation.Conversely,activation of the phosphoinositide 3-kinase/protein kinase B(PI3K-Akt) signaling pathway partially rescued the oocyte maturation impairment caused by cyp17a2mutation.Overall,these findings provide functional evidence supporting the critical role of Cyp17a2 in DHP and cortisol biosynthesis,which,in turn,facilitates oocyte maturation and ovulation through activation of the PI3K-Akt signaling pathway in fish.
基金Supported by Fundacao de Amparo à Pesquisa do Estado de Sao Paulo(Fapesp),No.2010/14845-4 and No.2015/14923-9Conselho Nacional de Desenvolvimento Científico e Tecnológico(CNPq),No.150456/2009-3
文摘AIM: To correlate gastric contractility, gastrointestinal transit, and hormone levels in non-pregnant(estrous cycle) and pregnant rats using noninvasive techniques. METHODS: Female rats(n = 23) were randomly divided into(1) non-pregnant,(contractility, n =6; transit, n = 6); and(2) pregnant(contractility, n = 5; transit, n = 6). In each estrous cycle phase or at 0, 7, 14, and 20 d after the confirmation of pregnancy, gastrointestinal transit was recorded by AC biosusceptometry(ACB), and gastric contractility was recorded by ACB and electromyography. After each recording, blood samples were obtained for progesterone and estradiol determination. RESULTS: In the estrous cycle, despite fluctuations of sex hormone levels, no significant changes in gastrointestinal motility were observed. Days 7 and 14 of pregnancy were characterized by significant changes in the frequency of contractions(3.90 ± 0.42 cpm and 3.60 ± 0.36 cpm vs 4.33 ± 0.25 cpm) and gastric emptying(168 ± 17 min and 165 ± 15 min vs 113 ± 15 min) compared with day 0. On these same days, progesterone levels significantly increased compared with control(54.23 ± 15.14 ng/m L and 129.96 ± 30.52 ng/mL vs 13.25 ± 6.31 ng/mL). On day 14, we observed the highest level of progesterone and the lowest level of estradiol compared with day 0(44.3 ± 15.18 pg/mL vs 24.96 ± 5.96 pg/mL). CONCLUSION: Gastrointestinal motility was unaffected by the estrous cycle. In our data, high progesterone and low estradiol levels can be associated with decreased contraction frequency and slow gastric emptying.
基金supported by grants from the National Key R&D Program of China(2019YFD0901202)the National Natural Science Foundation of China(grant Nos.32071584,32072982&32271658)the Program of Shanghai Academic Research Leader(21XD1405000).
文摘Background The provision of habitat for fishery species in estuaries is highly valued and represents one of the most challenging ecosystem service values to quantify.However,quantifying this value is challenging due to complex relationships between habitat change,ecological processes,and environmental variations.This study aims to estimate estuarine habitat degradation and its impact on the reproduction process of the crab Eriocheir sinensis by characterizing the changes in breeding habitat and investigating relationships between the species and its habitat in the Yang-tze River Estuary.Methods A species distribution model recently developed was applied to estimate the extent and quality of breeding habitat changes from 2014-2021.The intrinsic(physiological)and external(structural)reproductive attributes of the breeding process were measured to assess the effects of habitat change.The relationships among habitat change,reproductive attributes and environmental factors were analyzed to understand the underlying driving forces of habitat degradation for breeding process by multivariate statistical analysis.Results About 34.24%of essential habitat was lost,mainly in highly suitable areas due to reclamation and waterway construction.Habitat degradation significantly affects female distribution and their reproductive processes,particularly gonad development during the pre-reproductive period and fecundity during the reproductive period,without altering population structure.These results indicated that the main ecological function served by the highly suitable breeding ground was the provision for development of gonad and improvement of fecundity.Increases of salinity and turbidity,caused by hydrodynamic changes from large-scale waterway construction,were identified as the environmental determinants contributing to cumulative habitat degradation.These influences ultimately led to a decrease in the fecundity of E.sinensis.Conclusions Our research sheds light on the quantification of habitat degradation in the Yangtze River Estuary and its implications for the reproduction process of E.sinensis,which can serve as a foundation for assessing and quantifying the ecosystem service values provided by these breeding grounds.This information is valuable for policymakers and resource managers in making informed decisions regarding habitat conservation and the sustainable utilization of fishery resources.
基金supported by the National Natural Science Foundation of China(32025028,32188102,and 32372177)the earmarked fund for CARS(CARS-01-10)+1 种基金the Zhejiang Provincial Natural Science Foundation(LZYQ25C130002)the Agricultural Science and Technology Innovation Program(CAAS-ASTIP2021-CNRRI).
文摘Apomixis is an asexual reproductive process that generates clonal seeds genetically identical to the maternal plant,presenting revolutionary potential in plant breeding and crop improvement[1–3].Through combining genome editing of the mitosis instead of meiosis(MiMe)genes with ectopic expression of parthenogenesis-related genes such as OsBBM1,OsBBM4,ToPAR,or OsWUS in egg cells,synthetic apomixis with high fertility or clonal seed rate has been engineered in rice[4–8].Additionally,by fully editing the MiMe genes and the OsMTL gene,we have successfully obtained clonal seeds in hybrid rice[9–11].
