The steroid hormone brassinosteroid （BR） plays a broad role in plant growth and development. As the retarded growth in BR-insensitive and BR-deficient mutants causes a strong delay in days to flowering, BR signaling...The steroid hormone brassinosteroid （BR） plays a broad role in plant growth and development. As the retarded growth in BR-insensitive and BR-deficient mutants causes a strong delay in days to flowering, BR signaling has been thought to promote the floral transition inArabidopsis. In this study, using a developmental measure of flowering time, we show that BR signaling inhibits the floral transition and promotes vegetative growth in the Arabidopsis accessions Columbia and Enkheim-2. We found that BR signaling promotes the expression of the potent floral repressor FLOWERING LOCUS C （FLC） and three FLC homologs to inhibit flow- ering. In the presence of BR, the transcription factor BRASSINAZOLE-RESISTANT1 （BZR1）, together with BES1 -INTERACTING MYC-like proteins （BIMs）, specifically binds a BR- responsive element in the first intron of FLC and further recruits a histone 3 lysine 27 （H3K27） demethylase to downregulate levels of the repressive H3K27 trimethylation mark and thus antagonize Polycomb silencing at FLC, leading to its activation. Taken together, our findings demonstrate that BR signaling inhibits the floral transition inArabidopsis by a novel molecular mechanism in which BR signals are transduced into FLC activation and consequent floral repression.展开更多
Jasmonate(JA)regulates various aspects of plant growth and development and stress responses,with prominent roles in male reproductive development and defenses against herbivores and necrotrophic pathogens.JASMONATE-ZI...Jasmonate(JA)regulates various aspects of plant growth and development and stress responses,with prominent roles in male reproductive development and defenses against herbivores and necrotrophic pathogens.JASMONATE-ZIM DOMAIN(JAZ)proteins are key regulators in the JA signaling pathway and function to repress the expression of JA-responsive genes.Here,we show that JAZ proteins directly interact with several chromatin-associated Polycomb proteins to mediate repressive chromatin modifications at JA-responsive genes and,thus,their transcriptional repression in Arabidopsis.Genetic analyses revealed that the developmental defects,including anther and pollen abnormalities,resulting from loss or block of JA signaling were partially rescued by loss of Polycomb protein-mediated chromatin silencing(Polycomb repression).We further found that JAZ-mediated transcriptional repression during anther and pollen development requires Polycomb proteins at four key Regulatory loci.Analysis of genome-wide occupancy of a Polycomb factor and transcriptome reprogramming in response to JA revealed that Polycomb repression is involved in the repression of various JA-responsive genes.Taken together,our study reveals an important chromatin-based mechanism for JAZ-mediated transcriptional repression and JA signaling in plants.展开更多
Somatic cell nuclear transfer(SCNT)-derived piglets have signi?cantly higher stillbirth rate and postnatal mortality rate than arti?cial insemination(AI)-generated piglets. The question whether the low survival rate o...Somatic cell nuclear transfer(SCNT)-derived piglets have signi?cantly higher stillbirth rate and postnatal mortality rate than arti?cial insemination(AI)-generated piglets. The question whether the low survival rate of SCNT piglets was related to birth weight, umbilical cord or placenta development was investigated. In this study,stillbirth rate, neonatal death rate, birth weight, umbilical cord status, placental parameters and placental gene expression patterns were compared between SCNT and AI piglets. Results showed that mortality rates at birth and during the neonatal stage of SCNT piglets were signi?-cantly higher than those of AI piglets. The incidence of abnormal umbilical cord in SCNT and SCNT-liveborn(SCNT-LB) piglets was signi?cantly higher than in AI and AI-liveborn(AI-LB) piglets. Birth weight, placental weight, placental surface area and placental ef?ciency in SCNT and SCNT-LB piglets were signi?cantly lower than those of AI and AI-LB piglets. Placental expression pro?les of imprinting, angiopoiesis and nutrient transportrelated genes were defective in SCNT-LB piglets compared with those in AI-LB piglets. Thus, the low survival rate of SCNT piglets may be associated with abnormal umbilical cord and placenta development. These characteristics may have resulted from aberrant expression of angiogenesis, nutrient transport, and imprinting-related genes in the placentas.展开更多
Enucleation is a crucial procedure for mammalian somatic cell nuclear transfer(SCNT), especially for domestic animal cloning. Oocytes of domestic animals such as pigs and cattle contain dark lipid droplets that hinder...Enucleation is a crucial procedure for mammalian somatic cell nuclear transfer(SCNT), especially for domestic animal cloning. Oocytes of domestic animals such as pigs and cattle contain dark lipid droplets that hinder localization and removal of the nucleus. Using an oocyte enucleation technique that can obtain a high enucleation rate but has minimal negative effects on the reprogramming potential of oocyte for cloning is bene?cial for enhancing the outcome of SCNT. In this study, we compared the pig cloning ef?ciency resulting from blind aspiration-based(BA-B) enucleation and spindle imaging system-assisted(SIS-A) enucleation, and compared the pig SCNT success rate associated with BA-B enucleation and blind aspiration plus post-enucleation staining-based(BAPPS-B) enucleation. SIS-A enucleation achieved a signi?cantly higher oocyte enucleation success rate and tended to obtain a higher in vivo full term development rate of SCNT embryos than BA-B enucleation. BAPPS-B enucleation also obtained signi?cantly higher in vitro as well as in vivo full term development ef?ciency of cloned porcine embryos than BA-B enucleation. These data indicate that SIS-A and BAPPS-B enucleation are better approaches for pig SCNT than BA-B enucleation.展开更多
Dynamic crosstalk between the embryo and mother is crucial during implantation.Here,we comprehensively profile the single-cell transcriptome of pig peri-implantation embryos and corresponding maternal endometrium,iden...Dynamic crosstalk between the embryo and mother is crucial during implantation.Here,we comprehensively profile the single-cell transcriptome of pig peri-implantation embryos and corresponding maternal endometrium,identifying 4 different lineages in embryos and 13 cell types in the endometrium.Cell-specific gene expression characterizes 4 distinct trophectoderm subpopulations,showing development from undifferentiated trophectoderm to polar and mural trophectoderm.Dynamic expression of genes in different types of endometrial cells illustrates their molecular response to embryos during implantation.Then,we developed a novel tool,ExtraCellTalk,generating an overall dynamic map of maternal-foetal crosstalk using uterine luminal proteins as bridges.Through cross-species comparisons,we identified a conserved RBP4/STRA6 pathway in which embryonic-derived RBP4 could target the STRA6 receptor on stromal cells to regulate the interaction with other endometrial cells.These results provide insight into the maternal-foetal crosstalk during embryo implantation and represent a valuable resource for further studies to improve embryo implantation.展开更多
基金This work was supported in part by funding from the National Natural Science Foundation of China （grant number 31721001）, the National Key Research and Development Program of China （2017YFA0503803）, and the Chinese Academy of Sciences （XDPB0404）.
文摘The steroid hormone brassinosteroid （BR） plays a broad role in plant growth and development. As the retarded growth in BR-insensitive and BR-deficient mutants causes a strong delay in days to flowering, BR signaling has been thought to promote the floral transition inArabidopsis. In this study, using a developmental measure of flowering time, we show that BR signaling inhibits the floral transition and promotes vegetative growth in the Arabidopsis accessions Columbia and Enkheim-2. We found that BR signaling promotes the expression of the potent floral repressor FLOWERING LOCUS C （FLC） and three FLC homologs to inhibit flow- ering. In the presence of BR, the transcription factor BRASSINAZOLE-RESISTANT1 （BZR1）, together with BES1 -INTERACTING MYC-like proteins （BIMs）, specifically binds a BR- responsive element in the first intron of FLC and further recruits a histone 3 lysine 27 （H3K27） demethylase to downregulate levels of the repressive H3K27 trimethylation mark and thus antagonize Polycomb silencing at FLC, leading to its activation. Taken together, our findings demonstrate that BR signaling inhibits the floral transition inArabidopsis by a novel molecular mechanism in which BR signals are transduced into FLC activation and consequent floral repression.
基金supported in part by funding from Chinese Academy of Sciences,National Natural Foundation of China(grant no.31970533)Peking University Institute of Advanced Agricultural Sciences.
文摘Jasmonate(JA)regulates various aspects of plant growth and development and stress responses,with prominent roles in male reproductive development and defenses against herbivores and necrotrophic pathogens.JASMONATE-ZIM DOMAIN(JAZ)proteins are key regulators in the JA signaling pathway and function to repress the expression of JA-responsive genes.Here,we show that JAZ proteins directly interact with several chromatin-associated Polycomb proteins to mediate repressive chromatin modifications at JA-responsive genes and,thus,their transcriptional repression in Arabidopsis.Genetic analyses revealed that the developmental defects,including anther and pollen abnormalities,resulting from loss or block of JA signaling were partially rescued by loss of Polycomb protein-mediated chromatin silencing(Polycomb repression).We further found that JAZ-mediated transcriptional repression during anther and pollen development requires Polycomb proteins at four key Regulatory loci.Analysis of genome-wide occupancy of a Polycomb factor and transcriptome reprogramming in response to JA revealed that Polycomb repression is involved in the repression of various JA-responsive genes.Taken together,our study reveals an important chromatin-based mechanism for JAZ-mediated transcriptional repression and JA signaling in plants.
基金supported by two grants received from the Department of Science and Technology of Guangdong Province, China (2016B020233006 and 2016A020210074)
文摘Somatic cell nuclear transfer(SCNT)-derived piglets have signi?cantly higher stillbirth rate and postnatal mortality rate than arti?cial insemination(AI)-generated piglets. The question whether the low survival rate of SCNT piglets was related to birth weight, umbilical cord or placenta development was investigated. In this study,stillbirth rate, neonatal death rate, birth weight, umbilical cord status, placental parameters and placental gene expression patterns were compared between SCNT and AI piglets. Results showed that mortality rates at birth and during the neonatal stage of SCNT piglets were signi?-cantly higher than those of AI piglets. The incidence of abnormal umbilical cord in SCNT and SCNT-liveborn(SCNT-LB) piglets was signi?cantly higher than in AI and AI-liveborn(AI-LB) piglets. Birth weight, placental weight, placental surface area and placental ef?ciency in SCNT and SCNT-LB piglets were signi?cantly lower than those of AI and AI-LB piglets. Placental expression pro?les of imprinting, angiopoiesis and nutrient transportrelated genes were defective in SCNT-LB piglets compared with those in AI-LB piglets. Thus, the low survival rate of SCNT piglets may be associated with abnormal umbilical cord and placenta development. These characteristics may have resulted from aberrant expression of angiogenesis, nutrient transport, and imprinting-related genes in the placentas.
基金supported by the National Natural Science Foundation of China (31772554)the Department of Science and Technology of Guangdong Province, China (2016B020233006, 2015TX01N081 and 2016A020210074)the team project of Guangdong Agricultural Department (2017LM2148)
文摘Enucleation is a crucial procedure for mammalian somatic cell nuclear transfer(SCNT), especially for domestic animal cloning. Oocytes of domestic animals such as pigs and cattle contain dark lipid droplets that hinder localization and removal of the nucleus. Using an oocyte enucleation technique that can obtain a high enucleation rate but has minimal negative effects on the reprogramming potential of oocyte for cloning is bene?cial for enhancing the outcome of SCNT. In this study, we compared the pig cloning ef?ciency resulting from blind aspiration-based(BA-B) enucleation and spindle imaging system-assisted(SIS-A) enucleation, and compared the pig SCNT success rate associated with BA-B enucleation and blind aspiration plus post-enucleation staining-based(BAPPS-B) enucleation. SIS-A enucleation achieved a signi?cantly higher oocyte enucleation success rate and tended to obtain a higher in vivo full term development rate of SCNT embryos than BA-B enucleation. BAPPS-B enucleation also obtained signi?cantly higher in vitro as well as in vivo full term development ef?ciency of cloned porcine embryos than BA-B enucleation. These data indicate that SIS-A and BAPPS-B enucleation are better approaches for pig SCNT than BA-B enucleation.
基金supported by the National Key Research and Development Program of China(2021YFD1301103)the National Natural Science Foundation of China(31802033)+2 种基金the Guangdong Provincial Key Area Research and Development Program(2022B0202090002)the Guangdong Basic and Applied Basic Research Foundation(2022A1515011131,2023A1515030193)the Guangdong Provincial Promotion Project on Preservation and Utilization of Local Breed of Livestock and Poultry(2018143).
文摘Dynamic crosstalk between the embryo and mother is crucial during implantation.Here,we comprehensively profile the single-cell transcriptome of pig peri-implantation embryos and corresponding maternal endometrium,identifying 4 different lineages in embryos and 13 cell types in the endometrium.Cell-specific gene expression characterizes 4 distinct trophectoderm subpopulations,showing development from undifferentiated trophectoderm to polar and mural trophectoderm.Dynamic expression of genes in different types of endometrial cells illustrates their molecular response to embryos during implantation.Then,we developed a novel tool,ExtraCellTalk,generating an overall dynamic map of maternal-foetal crosstalk using uterine luminal proteins as bridges.Through cross-species comparisons,we identified a conserved RBP4/STRA6 pathway in which embryonic-derived RBP4 could target the STRA6 receptor on stromal cells to regulate the interaction with other endometrial cells.These results provide insight into the maternal-foetal crosstalk during embryo implantation and represent a valuable resource for further studies to improve embryo implantation.
