Primordial germ cells(PGCs)are the stem-cell population of adult animal gametes,which develop into sperm or eggs.It can be propagated in vitro and injected into the host chicken for genome editing to obtain germline c...Primordial germ cells(PGCs)are the stem-cell population of adult animal gametes,which develop into sperm or eggs.It can be propagated in vitro and injected into the host chicken for genome editing to obtain germline chimeric chicken.However,it has the limitation that the host embryo contains endogenous PGCs,which raises complications,resultantly donor PGCs fail to compete,and transmission efficiency reduced.Therefore,to increase the transmission efficiency,we generated a novel sterile chicken with the inducible elimination of endogenous PGCs in the host.This is the first study that applied the herpes simplex virus thymidine kinase(HSV-TK)cell ablation system in avian.CRISPR/Cas9-mediated homology-directed repair was performed to localize the HSV-TK suicide gene to the last exon of the deleted in azoospermialike(DAZL)gene,and ganciclovir(GCV)was added to induce the apoptosis in the germ cells of the host embryo.The sterilized host embryo introduced genome-edited PGCs to produce chimeric chicken carrying exogenous germ cells only.It was observed that the germline transmission efficiency was 100%achieved,and the obtained chicks were purely from donor breeds.The technologies established in the current study have important applications in germplasm conservation and gene editing in chicken.展开更多
[Objective] This research aimed to study the FTIR spectra of corn germs and endosperms so as to provide a scientific way for identifying corn of different types. [Method] The corn germs and endosperms of three types w...[Objective] This research aimed to study the FTIR spectra of corn germs and endosperms so as to provide a scientific way for identifying corn of different types. [Method] The corn germs and endosperms of three types were studied by using Fourier transform infrared spectroscopy（FTIR） technology, combined with cluster analysis. [Result] The overall characteristics of original FTIR spectra were basically similar within the range of 700-1 800 cm^-1. The FTIR spectra were mainly composed by the absorption peaks of polysaccharides, proteins and lipids. Within the wavelength range of 700-1 800 cm^-1, there were only tiny differences in original FTIR spectra among the corn germs and endosperms of three different types. The spectra were then processed by using first derivative and second derivative. The second derivative spectra were used for hierarchical cluster analysis（HCA）. The results showed that with the wavelength range of 700-1 800 cm^-1, the second derivative spectra of the 52 samples could be better clustered according to the tree types and corn germ and corn endosperm. The clustering correct rate reached 96.1%.[Conclusion] FTIR technology, combined with cluster analysis, can be used to identify different types of corn germs and endosperms, and it is characterized by convenience and rapidness.展开更多
In this article, we provide estimates for the degree of V bilipschitz determinacy of weighted homogeneous function germs defined on weighted homogeneous analytic variety V satisfying a convenient Lojasiewicz condition...In this article, we provide estimates for the degree of V bilipschitz determinacy of weighted homogeneous function germs defined on weighted homogeneous analytic variety V satisfying a convenient Lojasiewicz condition.The result gives an explicit order such that the geometrical structure of a weighted homogeneous polynomial function germs is preserved after higher order perturbations.展开更多
The pharyngeal dental formula of Mylopharyngodon piceus is 4-5 as a rule, and the dentition isasymmetrical. It is difficult to identify each tooth in the larval dentition. In this paper the appearancepattem of tooth g...The pharyngeal dental formula of Mylopharyngodon piceus is 4-5 as a rule, and the dentition isasymmetrical. It is difficult to identify each tooth in the larval dentition. In this paper the appearancepattem of tooth germ with developmental process in this fish is described in detail. The formationpattern of the left dentition is contrasted with that of the right one. In the developmental process,the left pharyngeal dentition lacks teeth at position An3. Thus the left dentition is D-type as designatedby Nakajima(1984), while the right one is A-type.展开更多
Mather gave the necessary and suffcient conditions for the ?nite determinacy smooth function germs with no more than codimension 4. The theorem is very effective on determining low codimension smooth function germs. I...Mather gave the necessary and suffcient conditions for the ?nite determinacy smooth function germs with no more than codimension 4. The theorem is very effective on determining low codimension smooth function germs. In this paper, the concept of right equivalent for smooth function germs ring generated by two ideals ?nitely is de?ned. The containment relationships of function germs still satisfy ?nite k-determinacy under suffciently small disturbance which are discussed in orbit tangent spaces. Furthermore, the methods in judging the right equivalency of Arnold function family with codimension 5 are presented.展开更多
Given a reflexive Banach space X .In the ring of C ∞ function germs ε(X) ,any real singular germ f in ε(X) whose second Frechet derivative at origin f″(0)=T is a Fredholm operator is isomorp...Given a reflexive Banach space X .In the ring of C ∞ function germs ε(X) ,any real singular germ f in ε(X) whose second Frechet derivative at origin f″(0)=T is a Fredholm operator is isomorphic to a germ of the form 12<Tz,z>+g(v) .If we replace g by a g 1 which is isomorphic to g ,we clearly obtain a germ in ε(X) which is isomorphic to the original one. However,is true converse of this proposition?In this paper,we will show that the converse is also true.展开更多
The cell fate of primordial germ cell(PGC)in zebrafish is pre-determined by maternally deposited germ plasm,which is packaged into ribonucleoprotein complex in oocytes and inherited into PGC-fated cells in embryos.How...The cell fate of primordial germ cell(PGC)in zebrafish is pre-determined by maternally deposited germ plasm,which is packaged into ribonucleoprotein complex in oocytes and inherited into PGC-fated cells in embryos.However,the maternal factors regulating the assembly of germ plasm and PGC development remain poorly understood.In this study,we report that the maternal transcription factor Znf706 regulates the assembly of germ plasm factors into a granule-like structure localized perinuclearly in PGC during migration.Maternal and zygotic mutants of znf706 exhibit deficient germ plasm scattering at the early embryonic stage,decreased PGC numbers with some mislocation during PGC migration,and a lower female ratio in adulthood.Notably,the implementation of Znf706 CUT&Tag and RNA-seq on immature oocytes uncovers that Znf706 in stage I oocytes may promote transcription of several mitochondrial genes in addition to other functions.Hence,we propose that Znf706 is implicated in germ plasm assembly and PGC development in zebrafish.展开更多
Germplasm resources are essential for the sustainable development of biodiversity and husbandry of local chickens, as well as for the breeding and industry of superior quality chickens. Unfortunately, many local and i...Germplasm resources are essential for the sustainable development of biodiversity and husbandry of local chickens, as well as for the breeding and industry of superior quality chickens. Unfortunately, many local and indigenous chicken breeds are at risk of declining numbers, emphasizing the need to conserve breed resources for endangered chickens. Primordial germ cells(PGCs) are crucial for preserving germplasm resources by inheriting genetic information from parents to offspring and ensuring stability of genetic material between germlines. In this study,PGCs were isolated from chicken embryos' gonads and cultured in FAcs medium without feeder cells. Over a period of approximately 40 d, the cells proliferated to a number of up to 10^(6), establishing various cell lines. Particularly, 18 PGC lines were created from Rugao Yellow chicken and Shouguang chicken, with an efficiency ranging from 39.1 to 45%. Furthermore, PGCs that had been cultured for 40 passages exhibited typical PGC characteristics, suchas glycogen staining reaction, and expression of pluripotency and reproductive markers. These results confirmthat PGCs maintain stem cell properties even after long-term in vitro culture. Additionally, PGCs cryopreserved for up to 120 d remained viable, maintained typical PGC morphologies, and possessed stable cell proliferation ability. Through intravascular injection into chicken embryos, green fluorescent protein(GFP)-PGCs were found in the recipient embryos' gonads and could develop into gametes to produce offspring, indicating that even after extended culture, PGCs retain their migratory and lineage-transmitting capabilities. This research offers valuable insights into the in vitro cultivation and preservation of PGCs of Chinese indigenous chickens. The findings of this study can be applied in transgenic chicken production and the preservation of genetic resources of indigenous chicken breeds.展开更多
Primordial germ cells(PGCs)are the precursors of germline that are specified at the embryonic stage.Recent studies reveal that humans employ different mechanisms for PGC specification compared with model organisms suc...Primordial germ cells(PGCs)are the precursors of germline that are specified at the embryonic stage.Recent studies reveal that humans employ different mechanisms for PGC specification compared with model organisms such as mice.Moreover,the specific regulatory machinery remains largely unexplored,mainly due to the inaccessible nature of this complex biological process in humans.Here,we curate and integrate multi-omics data,including 581 RNA-seq,54 ATAC-seq,45 ChIP-seq,and 69 single-cell RNA-seq samples from different stages of human PGC development to recapitulate the precisely controlled and stepwise process,presenting an atlas in the human PGC database(hPGCdb).With these uniformly processed data and integrated analyses,we characterize the potential key transcription factors and regulatory networks governing human germ cell fate.We validate the important roles of some of the key factors in germ cell development by CRISPRi knockdown.We also identify the soma-germline interaction network and discover the involvement of SDC2 and LAMA4 for PGC development,as well as soma-derived NOTCH2 signaling for germ cell differentiation.Taken together,we have built a database for human PGCs(http://43.131.248.15:6882)and demonstrate that hPGCdb enables the identification of the missing pieces of mechanisms governing germline development,including both intrinsic and extrinsic regulatory programs.展开更多
Objective:Testicular germ cell tumors(TGCTs)represent the most common malignancy among young men aged 20–40 years.Transglutaminase 7(TG7),encoded by TGM7,is a poorly characterized enzyme whose function in TGCT remain...Objective:Testicular germ cell tumors(TGCTs)represent the most common malignancy among young men aged 20–40 years.Transglutaminase 7(TG7),encoded by TGM7,is a poorly characterized enzyme whose function in TGCT remains unknown.This study aimed to assess TG7 expression in clinical specimens and investigate its functional role in a testicular germ cell tumor cell line(NT2/D1).Methods:TG7 protein expression was evaluated in clinical testicular tissue samples via immunohistochemistry(IHC)and immunofluorescence(IF).Functional analysis was conducted in the NT2/D1 human testicular cancer cell line usingDicer-substrate small interferingRNAs(DsiRNAs)targeting TG7.Gene knockdown efficiency was confirmed by reverse transcription quantitative PCR(qRT-PCR),and protein suppression was validated by immunofluorescence.Cell viability was assessed using the MTT assay.The expression of inflammation and apoptosis-related genes was quantified via qRT-PCR.Results:TG7 expression was significantly elevated in testicular germ cell tumor tissues,showing approximately a 4.5-fold increase compared to normal testis,with strong localization in tumor nests and stromal compartments.In NT2/D1 cells,TG7 silencing using 20 nM DsiRNA3 led to a dose-dependent reduction in cell viability,with up to 48%inhibition observed at 200 nM(MTT assay,****p<0.0001).qRT-PCR analysis revealed significant upregulation of IL6(3.2-fold),TNFα(2.8-fold),and CASP3(2.5-fold)mRNA levels following TG7 knockdown(p<0.0001),while p53 expression remained unchanged.These findings support TG7’s role in modulating tumor cell survival,inflammation,and apoptosis via p53-independent pathways.Conclusion:Collectively,TG7 is significantly overexpressed in TGCT tissues and supports tumor cell viability in vitro.This study establishes TG7 as a novel biomarker and therapeutic target in testicular cancer,laying the groundwork for future studies on TG7-targeted interventions.展开更多
Primordial germ cells(PGCs),the precursors of oocytes and spermatozoa,are highly pluripotent.In recent years,the in vitro induction of human primordial germ cell-like cells(h PGCLCs)has advanced significantly.However,...Primordial germ cells(PGCs),the precursors of oocytes and spermatozoa,are highly pluripotent.In recent years,the in vitro induction of human primordial germ cell-like cells(h PGCLCs)has advanced significantly.However,the stability and efficacy of obtaining h PGCLCs in vitro still require improvement.In the current study,we identified a novel induction system using Dulbecco's Modified Eagle Medium/Nutrient Mixture F-12(DMEM/F-12)as the basal medium,supplemented with B27 and N2(referred to as N2B27)in combination with four cytokines:bone morphogenetic protein 4,stem cell factor,epidermal growth factor,and leukemia inhibitory factor.The h PGCLCs induced under these conditions closely resembled PGCs from 4-to 5-week-old embryos at the transcriptomic level.Compared with traditional GK15(GMEM supplemented with 15%Knockout?Serum Replacement)-based induction conditions,the N2B27 system significantly increased the speed and efficacy of h PGCLC induction.RNA sequencing analysis revealed that this improvement was due to an increased cellular capacity to cope with hypoxic stress and avoid apoptosis.The N2B27 medium promoted enhanced mitochondrial activity,enabling cells to better manage hypoxic stress while reducing the production of reactive oxygen species.Moreover,through gradient concentration experiments,we demonstrated that the addition of the common antioxidant N-acetyl-L-cysteine at an optimized concentration further enhanced the efficiency of PGCLC induction under GK15 conditions.In summary,we have established an optimized induction system that enhances the efficiency of h PGCLC differentiation by improving cellular resilience to hypoxic stress and apoptosis.展开更多
[Objective] The paper was to establish embryonic stem cell system of goats. [Method] Numerous primordial germ cell colonies were derived from gonadal ridge and the surrounding tissues in 20 millimeter fetuses of down ...[Objective] The paper was to establish embryonic stem cell system of goats. [Method] Numerous primordial germ cell colonies were derived from gonadal ridge and the surrounding tissues in 20 millimeter fetuses of down producing goat. Primordial germ cells and goats embryonic fibroblasts obtained from conceptus of equivaient gestational age were co-cultured. [Result] The colonies showed some characteristics of embryonic stem cells, such as the morphology of nest-like, they continued to be AKP positive and the ability to be continuously passed [Conclusion] These cells were pluripotent and ES-like cells.展开更多
基金supported by the National Key R&D Program of China(2021YFD1300100)Guangxi Key R&D Program,China(AB21220005)+1 种基金Reproductive Medicine,Guangxi Medical and Health Key Discipline Construction Project of the Affiliated Hospitalthe National Natural Science Foundation of China(32360180)。
文摘Primordial germ cells(PGCs)are the stem-cell population of adult animal gametes,which develop into sperm or eggs.It can be propagated in vitro and injected into the host chicken for genome editing to obtain germline chimeric chicken.However,it has the limitation that the host embryo contains endogenous PGCs,which raises complications,resultantly donor PGCs fail to compete,and transmission efficiency reduced.Therefore,to increase the transmission efficiency,we generated a novel sterile chicken with the inducible elimination of endogenous PGCs in the host.This is the first study that applied the herpes simplex virus thymidine kinase(HSV-TK)cell ablation system in avian.CRISPR/Cas9-mediated homology-directed repair was performed to localize the HSV-TK suicide gene to the last exon of the deleted in azoospermialike(DAZL)gene,and ganciclovir(GCV)was added to induce the apoptosis in the germ cells of the host embryo.The sterilized host embryo introduced genome-edited PGCs to produce chimeric chicken carrying exogenous germ cells only.It was observed that the germline transmission efficiency was 100%achieved,and the obtained chicks were purely from donor breeds.The technologies established in the current study have important applications in germplasm conservation and gene editing in chicken.
基金Supported by National Natural Science Foundation of China(30960179)Natural Science Foundation of Yunnan Province(2007A048M)~~
文摘[Objective] This research aimed to study the FTIR spectra of corn germs and endosperms so as to provide a scientific way for identifying corn of different types. [Method] The corn germs and endosperms of three types were studied by using Fourier transform infrared spectroscopy（FTIR） technology, combined with cluster analysis. [Result] The overall characteristics of original FTIR spectra were basically similar within the range of 700-1 800 cm^-1. The FTIR spectra were mainly composed by the absorption peaks of polysaccharides, proteins and lipids. Within the wavelength range of 700-1 800 cm^-1, there were only tiny differences in original FTIR spectra among the corn germs and endosperms of three different types. The spectra were then processed by using first derivative and second derivative. The second derivative spectra were used for hierarchical cluster analysis（HCA）. The results showed that with the wavelength range of 700-1 800 cm^-1, the second derivative spectra of the 52 samples could be better clustered according to the tree types and corn germ and corn endosperm. The clustering correct rate reached 96.1%.[Conclusion] FTIR technology, combined with cluster analysis, can be used to identify different types of corn germs and endosperms, and it is characterized by convenience and rapidness.
基金Supported by the National Nature Science Foundation of China(10671009,60534080,10871149)
文摘In this article, we provide estimates for the degree of V bilipschitz determinacy of weighted homogeneous function germs defined on weighted homogeneous analytic variety V satisfying a convenient Lojasiewicz condition.The result gives an explicit order such that the geometrical structure of a weighted homogeneous polynomial function germs is preserved after higher order perturbations.
基金This project was funded by the International Cooperation of japan-Chinathe National Natural Science Foundation of China
文摘The pharyngeal dental formula of Mylopharyngodon piceus is 4-5 as a rule, and the dentition isasymmetrical. It is difficult to identify each tooth in the larval dentition. In this paper the appearancepattem of tooth germ with developmental process in this fish is described in detail. The formationpattern of the left dentition is contrasted with that of the right one. In the developmental process,the left pharyngeal dentition lacks teeth at position An3. Thus the left dentition is D-type as designatedby Nakajima(1984), while the right one is A-type.
基金Supported by the National Natural Science Foundation of China(11671070,11501051)NSF of Heilongjiang Province of China(QC2016008)the Project of Science and Technology of Jilin Provincial Education Department(JJKH2090547KJ)
文摘Mather gave the necessary and suffcient conditions for the ?nite determinacy smooth function germs with no more than codimension 4. The theorem is very effective on determining low codimension smooth function germs. In this paper, the concept of right equivalent for smooth function germs ring generated by two ideals ?nitely is de?ned. The containment relationships of function germs still satisfy ?nite k-determinacy under suffciently small disturbance which are discussed in orbit tangent spaces. Furthermore, the methods in judging the right equivalency of Arnold function family with codimension 5 are presented.
文摘Given a reflexive Banach space X .In the ring of C ∞ function germs ε(X) ,any real singular germ f in ε(X) whose second Frechet derivative at origin f″(0)=T is a Fredholm operator is isomorphic to a germ of the form 12<Tz,z>+g(v) .If we replace g by a g 1 which is isomorphic to g ,we clearly obtain a germ in ε(X) which is isomorphic to the original one. However,is true converse of this proposition?In this paper,we will show that the converse is also true.
基金supported by the National Natural Science Foundation of China(31988101 to A.M.)the National Key Research and Development Program of China(2023YFA1800300 to X.W.and 2018YFC1003304 to A.M.)the Yunnan Provincial Science and Technology Project at Southwest United Graduate School(202302A0370011 to A.M.).
文摘The cell fate of primordial germ cell(PGC)in zebrafish is pre-determined by maternally deposited germ plasm,which is packaged into ribonucleoprotein complex in oocytes and inherited into PGC-fated cells in embryos.However,the maternal factors regulating the assembly of germ plasm and PGC development remain poorly understood.In this study,we report that the maternal transcription factor Znf706 regulates the assembly of germ plasm factors into a granule-like structure localized perinuclearly in PGC during migration.Maternal and zygotic mutants of znf706 exhibit deficient germ plasm scattering at the early embryonic stage,decreased PGC numbers with some mislocation during PGC migration,and a lower female ratio in adulthood.Notably,the implementation of Znf706 CUT&Tag and RNA-seq on immature oocytes uncovers that Znf706 in stage I oocytes may promote transcription of several mitochondrial genes in addition to other functions.Hence,we propose that Znf706 is implicated in germ plasm assembly and PGC development in zebrafish.
基金supported by the National Key Research and Development Program of China (2021YFD1200301 and 2021YFD1200302)the Natural Science Foundation of Jiangsu Province, China (BK20210813)+1 种基金the National Natural Science Foundation of China (32102534)the Yangzhou International Science and Technology Cooperation Projects, China (YZ2021175)。
文摘Germplasm resources are essential for the sustainable development of biodiversity and husbandry of local chickens, as well as for the breeding and industry of superior quality chickens. Unfortunately, many local and indigenous chicken breeds are at risk of declining numbers, emphasizing the need to conserve breed resources for endangered chickens. Primordial germ cells(PGCs) are crucial for preserving germplasm resources by inheriting genetic information from parents to offspring and ensuring stability of genetic material between germlines. In this study,PGCs were isolated from chicken embryos' gonads and cultured in FAcs medium without feeder cells. Over a period of approximately 40 d, the cells proliferated to a number of up to 10^(6), establishing various cell lines. Particularly, 18 PGC lines were created from Rugao Yellow chicken and Shouguang chicken, with an efficiency ranging from 39.1 to 45%. Furthermore, PGCs that had been cultured for 40 passages exhibited typical PGC characteristics, suchas glycogen staining reaction, and expression of pluripotency and reproductive markers. These results confirmthat PGCs maintain stem cell properties even after long-term in vitro culture. Additionally, PGCs cryopreserved for up to 120 d remained viable, maintained typical PGC morphologies, and possessed stable cell proliferation ability. Through intravascular injection into chicken embryos, green fluorescent protein(GFP)-PGCs were found in the recipient embryos' gonads and could develop into gametes to produce offspring, indicating that even after extended culture, PGCs retain their migratory and lineage-transmitting capabilities. This research offers valuable insights into the in vitro cultivation and preservation of PGCs of Chinese indigenous chickens. The findings of this study can be applied in transgenic chicken production and the preservation of genetic resources of indigenous chicken breeds.
基金supported by the National Natural Science Foundation of China awarded to D.C.(32270835)Zhejiang Natural Science Foundation awarded to D.C.(Z22C129553)Dr.Li Dak Sum&Yip Yio Chin Development Fund for Regenerative Medicine,Zhejiang University,awarded to D.C.
文摘Primordial germ cells(PGCs)are the precursors of germline that are specified at the embryonic stage.Recent studies reveal that humans employ different mechanisms for PGC specification compared with model organisms such as mice.Moreover,the specific regulatory machinery remains largely unexplored,mainly due to the inaccessible nature of this complex biological process in humans.Here,we curate and integrate multi-omics data,including 581 RNA-seq,54 ATAC-seq,45 ChIP-seq,and 69 single-cell RNA-seq samples from different stages of human PGC development to recapitulate the precisely controlled and stepwise process,presenting an atlas in the human PGC database(hPGCdb).With these uniformly processed data and integrated analyses,we characterize the potential key transcription factors and regulatory networks governing human germ cell fate.We validate the important roles of some of the key factors in germ cell development by CRISPRi knockdown.We also identify the soma-germline interaction network and discover the involvement of SDC2 and LAMA4 for PGC development,as well as soma-derived NOTCH2 signaling for germ cell differentiation.Taken together,we have built a database for human PGCs(http://43.131.248.15:6882)and demonstrate that hPGCdb enables the identification of the missing pieces of mechanisms governing germline development,including both intrinsic and extrinsic regulatory programs.
文摘Objective:Testicular germ cell tumors(TGCTs)represent the most common malignancy among young men aged 20–40 years.Transglutaminase 7(TG7),encoded by TGM7,is a poorly characterized enzyme whose function in TGCT remains unknown.This study aimed to assess TG7 expression in clinical specimens and investigate its functional role in a testicular germ cell tumor cell line(NT2/D1).Methods:TG7 protein expression was evaluated in clinical testicular tissue samples via immunohistochemistry(IHC)and immunofluorescence(IF).Functional analysis was conducted in the NT2/D1 human testicular cancer cell line usingDicer-substrate small interferingRNAs(DsiRNAs)targeting TG7.Gene knockdown efficiency was confirmed by reverse transcription quantitative PCR(qRT-PCR),and protein suppression was validated by immunofluorescence.Cell viability was assessed using the MTT assay.The expression of inflammation and apoptosis-related genes was quantified via qRT-PCR.Results:TG7 expression was significantly elevated in testicular germ cell tumor tissues,showing approximately a 4.5-fold increase compared to normal testis,with strong localization in tumor nests and stromal compartments.In NT2/D1 cells,TG7 silencing using 20 nM DsiRNA3 led to a dose-dependent reduction in cell viability,with up to 48%inhibition observed at 200 nM(MTT assay,****p<0.0001).qRT-PCR analysis revealed significant upregulation of IL6(3.2-fold),TNFα(2.8-fold),and CASP3(2.5-fold)mRNA levels following TG7 knockdown(p<0.0001),while p53 expression remained unchanged.These findings support TG7’s role in modulating tumor cell survival,inflammation,and apoptosis via p53-independent pathways.Conclusion:Collectively,TG7 is significantly overexpressed in TGCT tissues and supports tumor cell viability in vitro.This study establishes TG7 as a novel biomarker and therapeutic target in testicular cancer,laying the groundwork for future studies on TG7-targeted interventions.
基金funded by the National Key R&D Program(Grant Nos.2022YFC2702800 and 2021YFC2700302 to Y.Y.)the National Natural Science Foundation of China(Grant Nos.82122025 to Y.Y.,82221005 to J.S.,and 82201763 to L.L.)。
文摘Primordial germ cells(PGCs),the precursors of oocytes and spermatozoa,are highly pluripotent.In recent years,the in vitro induction of human primordial germ cell-like cells(h PGCLCs)has advanced significantly.However,the stability and efficacy of obtaining h PGCLCs in vitro still require improvement.In the current study,we identified a novel induction system using Dulbecco's Modified Eagle Medium/Nutrient Mixture F-12(DMEM/F-12)as the basal medium,supplemented with B27 and N2(referred to as N2B27)in combination with four cytokines:bone morphogenetic protein 4,stem cell factor,epidermal growth factor,and leukemia inhibitory factor.The h PGCLCs induced under these conditions closely resembled PGCs from 4-to 5-week-old embryos at the transcriptomic level.Compared with traditional GK15(GMEM supplemented with 15%Knockout?Serum Replacement)-based induction conditions,the N2B27 system significantly increased the speed and efficacy of h PGCLC induction.RNA sequencing analysis revealed that this improvement was due to an increased cellular capacity to cope with hypoxic stress and avoid apoptosis.The N2B27 medium promoted enhanced mitochondrial activity,enabling cells to better manage hypoxic stress while reducing the production of reactive oxygen species.Moreover,through gradient concentration experiments,we demonstrated that the addition of the common antioxidant N-acetyl-L-cysteine at an optimized concentration further enhanced the efficiency of PGCLC induction under GK15 conditions.In summary,we have established an optimized induction system that enhances the efficiency of h PGCLC differentiation by improving cellular resilience to hypoxic stress and apoptosis.
基金Supported by Project of Baotou University(BSY2010-23)~~
文摘[Objective] The paper was to establish embryonic stem cell system of goats. [Method] Numerous primordial germ cell colonies were derived from gonadal ridge and the surrounding tissues in 20 millimeter fetuses of down producing goat. Primordial germ cells and goats embryonic fibroblasts obtained from conceptus of equivaient gestational age were co-cultured. [Result] The colonies showed some characteristics of embryonic stem cells, such as the morphology of nest-like, they continued to be AKP positive and the ability to be continuously passed [Conclusion] These cells were pluripotent and ES-like cells.
