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
[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
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
Peripheral nerve injuries result in the rapid degeneration of distal nerve segments and immediate loss of motor and sensory functions;behavioral recovery is typically poor.We used a plasmalemmal fusogen,polyethylene g...Peripheral nerve injuries result in the rapid degeneration of distal nerve segments and immediate loss of motor and sensory functions;behavioral recovery is typically poor.We used a plasmalemmal fusogen,polyethylene glycol(PEG),to immediately fuse closely apposed open ends of severed proximal and distal axons in rat sciatic nerves.We have previously reported that sciatic nerve axons repaired by PEG-fusion do not undergo Wallerian degeneration,and PEG-fused animals exhibit rapid(within 2–6 weeks)and extensive locomotor recovery.Furthermore,our previous report showed that PEG-fusion of severed sciatic motor axons was non-specific,i.e.,spinal motoneurons in PEG-fused animals were found to project to appropriate as well as inappropriate target muscles.In this study,we examined the consequences of PEG-fusion for sensory axons of the sciatic nerve.Young adult male and female rats(Sprague–Dawley)received either a unilateral single cut or ablation injury to the sciatic nerve and subsequent repair with or without(Negative Control)the application of PEG.Compound action potentials recorded immediately after PEG-fusion repair confirmed conduction across the injury site.The success of PEG-fusion was confirmed through Sciatic Functional Index testing with PEG-fused animals showing improvement in locomotor function beginning at 35 days postoperatively.At 2–42 days postoperatively,we anterogradely labeled sensory afferents from the dorsal aspect of the hindpaw following bilateral intradermal injection of wheat germ agglutinin conjugated horseradish peroxidase.PEG-fusion repair reestablished axonal continuity.Compared to unoperated animals,labeled sensory afferents ipsilateral to the injury in PEG-fused animals were found in the appropriate area of the dorsal horn,as well as inappropriate mediolateral and rostrocaudal areas.Unexpectedly,despite having intact peripheral nerves,similar reorganizations of labeled sensory afferents were also observed contralateral to the injury and repair.This central reorganization may contribute to the improved behavioral recovery seen after PEG-fusion repair,supporting the use of this novel repair methodology over currently available treatments.展开更多
In [1], tile universal unfolding of Coo map germs under a subgroup of the group A,which is well known group defined by J.Mather [2], was discussed. In this papersSome conditions are given to characterize the infinites...In [1], tile universal unfolding of Coo map germs under a subgroup of the group A,which is well known group defined by J.Mather [2], was discussed. In this papersSome conditions are given to characterize the infinitesimally stability of unfoldings.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
Dear Editor,I would like to congratulate Mamsen et al.i on their extensive and scientifically valuable work.I analyzed their raw data presented in Table 1 of the original article from a different perspective and disco...Dear Editor,I would like to congratulate Mamsen et al.i on their extensive and scientifically valuable work.I analyzed their raw data presented in Table 1 of the original article from a different perspective and discovered an effect not mentioned in the article.My analysis showed that luteinizing hormone(LH)levels are significantly lower in patients at high infertility risk(HIR),whose testes lack A dark(Ad)spermatogonia and display an abnormal ratio of germ cells per crosssectional tubule(G/T).展开更多
Dear Editor,We are much obliged that Hadziselimovic1 has used our data2 to highlight the substantial proportion of boys with cryptorchidism where gonadotropin insufficiency is an important factor related to the pathog...Dear Editor,We are much obliged that Hadziselimovic1 has used our data2 to highlight the substantial proportion of boys with cryptorchidism where gonadotropin insufficiency is an important factor related to the pathogenesis.We have recently presented a study on a series of 453 consecutive boys with bilateral nonsyndromic cryptorchidism,in which we conducted hormonal evaluations and assessed germ cell numbers in testicular biopsies.3 In this series,45%of the boys were classified as having gonadotropin insufficiency.3 Identifying these patients at the time of surgery is important.A recent follow-up study of 208 boys with nonsyndromic bilateral cryptorchidism from our department showed that the boys with gonadotropin insufficiency had an impaired fertility potential after surgery compared to boys with an intact hypothalamus–pituitary–gonadal feedback mechanism.4 In a review from 2022,Hadziselimovic5 suggested that infertility in patients diagnosed with cryptorchid testes is a consequence of a hormonal deficiency rather than temperature-induced cellular damage.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
BACKGROUND Urinary tract infections(UTIs)in kidney transplant patients are a challenge.AIM To evaluate epidemiology,clinical status,therapeutic management,and clinical outcome of kidney transplant patients in a univer...BACKGROUND Urinary tract infections(UTIs)in kidney transplant patients are a challenge.AIM To evaluate epidemiology,clinical status,therapeutic management,and clinical outcome of kidney transplant patients in a university hospital for UTI.METHODS We conducted a retrospective observational study,enrolling all kidney transplant patients hospitalized for UTI,with the objective to evaluate the epidemiology,clinical status,therapeutic management,and clinical outcome of kidney transplant patients.RESULTS From our real-life experience,infection with multidrug-resistant germs was confirmed as a risk factor for the severe evolution of the infection.At the same time,the re-evaluation of immunosuppressive therapy could be an important therapeutic strategy in the course of infection.CONCLUSION Prompt initiation of empiric antibiotic therapy upon initiation of microbiological investigations may reduce the risk of severe infection progression.展开更多
Flight feathers represent a hallmark innovation of avian evolution.Recent comparative genomic analyses identified a 284 bp avian-specific highly conserved element(ASHCE)located within the eighth intron of the SIM bHLH...Flight feathers represent a hallmark innovation of avian evolution.Recent comparative genomic analyses identified a 284 bp avian-specific highly conserved element(ASHCE)located within the eighth intron of the SIM bHLH transcription factor 1(Sim1)gene,postulated to act as a cis-regulatory element governing flight feather morphogenesis.To investigate its functional significance,genome-edited(GE)primordial germ cell(PGC)lines carrying targeted ASHCE deletions were generated using CRISPR/Cas9-mediated editing,with germline chimeric males subsequently mated with wild-type(WT)hens to obtain GE progeny.The resulting GE chickens harbored 257-260 bp deletions,excising approximately half of the Sim1-ASHCE sequence.Reverse transcription-quantitative real-time polymerase chain reaction(RT-qPCR)analysis showed an average 0.32-fold reduction in Sim1 expression in the forelimbs of GE embryos at day 8(E8)compared to WT counterparts.Despite this,GE chickens developed structurally normal flight and tail feathers.In situ hybridization localized Sim1 expression to the posterior mesenchyme surrounding flight feather buds in E8 WT embryos,but not within the buds themselves.These results suggest that partial deletion of Sim1-ASHCE,despite diminishing Sim1 expression,does not disrupt flight feather formation.The excised region appears to possess enhancer activity toward Sim1 but is dispensable for flight feather development.Complete ablation of the ASHCE will be necessary to fully resolve the regulatory role of Sim1 in avian feather morphogenesis.展开更多
Tissue interactions play a crucial role in tooth development.Notably,extracellular vesicle-mediated interactions between the mandible and tooth germ are considered essential.Here,we revealed that mandible extracellula...Tissue interactions play a crucial role in tooth development.Notably,extracellular vesicle-mediated interactions between the mandible and tooth germ are considered essential.Here,we revealed that mandible extracellular vesicles could modulate the proliferation and differentiation of dental mesenchymal cells by regulating the histone demethylase KDM2B.Further investigation showed that mandible derived extracellular vesicles could deliver miR-206 to KDM2B,thereby regulating tooth development.An animal study demonstrated that the miR-206/KDM2B pathway affected tooth morphogenesis and mineralization after eight weeks of subcutaneous transplantation in nude mice.In conclusion,this study suggested that the mandible played a critical role in tooth morphogenesis and mineralization,which could be a potential therapeutic target for abnormal tooth development and an alternative model for tooth regeneration.展开更多
The spatiotemporal relationships in high-resolution during odontogenesis remain poorly understood.We report a cell lineage and atlas of developing mouse teeth.We performed a large-scale(92,688 cells)single cell RNA se...The spatiotemporal relationships in high-resolution during odontogenesis remain poorly understood.We report a cell lineage and atlas of developing mouse teeth.We performed a large-scale(92,688 cells)single cell RNA sequencing,tracing the cell trajectories during odontogenesis from embryonic days 10.5 to 16.5.Combined with an assay for transposase-accessible chromatin with high-throughput sequencing,our results suggest that mesenchymal cells show the specific transcriptome profiles to distinguish the tooth types.Subsequently,we identified key gene regulatory networks in teeth and bone formation and uncovered spatiotemporal patterns of odontogenic mesenchymal cells.CD24^(+)and Plac8^(+)cells from the mesenchyme at the bell stage were distributed in the upper half and preodontoblast layer of the dental papilla,respectively,which could individually induce nonodontogenic epithelia to form tooth-like structures.Specifically,the Plac8^(+)tissue we discovered is the smallest piece with the most homogenous cells that could induce tooth regeneration to date.Our work reveals previously unknown heterogeneity and spatiotemporal patterns of tooth germs that may lead to tooth regeneration for regenerative dentistry.展开更多
Gervais has already characterised finitely I--[q,k]-determinacy of C<sup>∞</sup> map-germs. It seems that Cao Yi’s expressions are in better form than Gervais’（cf. Ref. [2]）. This note will deal with ...Gervais has already characterised finitely I--[q,k]-determinacy of C<sup>∞</sup> map-germs. It seems that Cao Yi’s expressions are in better form than Gervais’（cf. Ref. [2]）. This note will deal with the I-<sub>q,k</sub>-determinacy of C<sup>∞</sup> map-germs which develop the basic results in Refs. [1]and [2]. We shall adopt the notations in Ref. [3],if not specialized, and every map-germ is C<sup>∞</sup>.展开更多
Hair follicle stem cells(HFSCs)in the bulge are a multipotent adult stem cell population.They can periodically give rise to new HFs and even regenerate the epidermis and sebaceous glands during wound healing.An increa...Hair follicle stem cells(HFSCs)in the bulge are a multipotent adult stem cell population.They can periodically give rise to new HFs and even regenerate the epidermis and sebaceous glands during wound healing.An increasing number of biomarkers have been used to isolate,label,and trace HFSCs in recent years.Considering more detailed data from single-cell transcriptomics technology,we mainly focus on the important HFSC molecular markers and their regulatory roles in this review.展开更多
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 Department of Defense AFIRMⅢW81XWH-20-2-0029 grant subcontractLone Star Paralysis gift,UT POC19-1774-13 grant+1 种基金Neuraptive Therapeutics Inc.26-7724-56 grantNational Institutes of Health R01-NS128086(all to GDB)。
文摘Peripheral nerve injuries result in the rapid degeneration of distal nerve segments and immediate loss of motor and sensory functions;behavioral recovery is typically poor.We used a plasmalemmal fusogen,polyethylene glycol(PEG),to immediately fuse closely apposed open ends of severed proximal and distal axons in rat sciatic nerves.We have previously reported that sciatic nerve axons repaired by PEG-fusion do not undergo Wallerian degeneration,and PEG-fused animals exhibit rapid(within 2–6 weeks)and extensive locomotor recovery.Furthermore,our previous report showed that PEG-fusion of severed sciatic motor axons was non-specific,i.e.,spinal motoneurons in PEG-fused animals were found to project to appropriate as well as inappropriate target muscles.In this study,we examined the consequences of PEG-fusion for sensory axons of the sciatic nerve.Young adult male and female rats(Sprague–Dawley)received either a unilateral single cut or ablation injury to the sciatic nerve and subsequent repair with or without(Negative Control)the application of PEG.Compound action potentials recorded immediately after PEG-fusion repair confirmed conduction across the injury site.The success of PEG-fusion was confirmed through Sciatic Functional Index testing with PEG-fused animals showing improvement in locomotor function beginning at 35 days postoperatively.At 2–42 days postoperatively,we anterogradely labeled sensory afferents from the dorsal aspect of the hindpaw following bilateral intradermal injection of wheat germ agglutinin conjugated horseradish peroxidase.PEG-fusion repair reestablished axonal continuity.Compared to unoperated animals,labeled sensory afferents ipsilateral to the injury in PEG-fused animals were found in the appropriate area of the dorsal horn,as well as inappropriate mediolateral and rostrocaudal areas.Unexpectedly,despite having intact peripheral nerves,similar reorganizations of labeled sensory afferents were also observed contralateral to the injury and repair.This central reorganization may contribute to the improved behavioral recovery seen after PEG-fusion repair,supporting the use of this novel repair methodology over currently available treatments.
文摘In [1], tile universal unfolding of Coo map germs under a subgroup of the group A,which is well known group defined by J.Mather [2], was discussed. In this papersSome conditions are given to characterize the infinitesimally stability of unfoldings.
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.
文摘Dear Editor,I would like to congratulate Mamsen et al.i on their extensive and scientifically valuable work.I analyzed their raw data presented in Table 1 of the original article from a different perspective and discovered an effect not mentioned in the article.My analysis showed that luteinizing hormone(LH)levels are significantly lower in patients at high infertility risk(HIR),whose testes lack A dark(Ad)spermatogonia and display an abnormal ratio of germ cells per crosssectional tubule(G/T).
文摘Dear Editor,We are much obliged that Hadziselimovic1 has used our data2 to highlight the substantial proportion of boys with cryptorchidism where gonadotropin insufficiency is an important factor related to the pathogenesis.We have recently presented a study on a series of 453 consecutive boys with bilateral nonsyndromic cryptorchidism,in which we conducted hormonal evaluations and assessed germ cell numbers in testicular biopsies.3 In this series,45%of the boys were classified as having gonadotropin insufficiency.3 Identifying these patients at the time of surgery is important.A recent follow-up study of 208 boys with nonsyndromic bilateral cryptorchidism from our department showed that the boys with gonadotropin insufficiency had an impaired fertility potential after surgery compared to boys with an intact hypothalamus–pituitary–gonadal feedback mechanism.4 In a review from 2022,Hadziselimovic5 suggested that infertility in patients diagnosed with cryptorchid testes is a consequence of a hormonal deficiency rather than temperature-induced cellular damage.
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BACKGROUND Urinary tract infections(UTIs)in kidney transplant patients are a challenge.AIM To evaluate epidemiology,clinical status,therapeutic management,and clinical outcome of kidney transplant patients in a university hospital for UTI.METHODS We conducted a retrospective observational study,enrolling all kidney transplant patients hospitalized for UTI,with the objective to evaluate the epidemiology,clinical status,therapeutic management,and clinical outcome of kidney transplant patients.RESULTS From our real-life experience,infection with multidrug-resistant germs was confirmed as a risk factor for the severe evolution of the infection.At the same time,the re-evaluation of immunosuppressive therapy could be an important therapeutic strategy in the course of infection.CONCLUSION Prompt initiation of empiric antibiotic therapy upon initiation of microbiological investigations may reduce the risk of severe infection progression.
基金supported by the Ministry of Agriculture and Rural Affairs of the People's Republic of China(125A0607)Department of Science and Technology of Yunnan Province(XDYC-KJLJ-2022-0004)。
文摘Flight feathers represent a hallmark innovation of avian evolution.Recent comparative genomic analyses identified a 284 bp avian-specific highly conserved element(ASHCE)located within the eighth intron of the SIM bHLH transcription factor 1(Sim1)gene,postulated to act as a cis-regulatory element governing flight feather morphogenesis.To investigate its functional significance,genome-edited(GE)primordial germ cell(PGC)lines carrying targeted ASHCE deletions were generated using CRISPR/Cas9-mediated editing,with germline chimeric males subsequently mated with wild-type(WT)hens to obtain GE progeny.The resulting GE chickens harbored 257-260 bp deletions,excising approximately half of the Sim1-ASHCE sequence.Reverse transcription-quantitative real-time polymerase chain reaction(RT-qPCR)analysis showed an average 0.32-fold reduction in Sim1 expression in the forelimbs of GE embryos at day 8(E8)compared to WT counterparts.Despite this,GE chickens developed structurally normal flight and tail feathers.In situ hybridization localized Sim1 expression to the posterior mesenchyme surrounding flight feather buds in E8 WT embryos,but not within the buds themselves.These results suggest that partial deletion of Sim1-ASHCE,despite diminishing Sim1 expression,does not disrupt flight feather formation.The excised region appears to possess enhancer activity toward Sim1 but is dispensable for flight feather development.Complete ablation of the ASHCE will be necessary to fully resolve the regulatory role of Sim1 in avian feather morphogenesis.
基金supported by the National Natural Science Foundation of China(No.82071078,82370939)the Shaanxi Provincial High-level Talent Program and Young Talent Support Plan of Xi’an Jiaotong University.
文摘Tissue interactions play a crucial role in tooth development.Notably,extracellular vesicle-mediated interactions between the mandible and tooth germ are considered essential.Here,we revealed that mandible extracellular vesicles could modulate the proliferation and differentiation of dental mesenchymal cells by regulating the histone demethylase KDM2B.Further investigation showed that mandible derived extracellular vesicles could deliver miR-206 to KDM2B,thereby regulating tooth development.An animal study demonstrated that the miR-206/KDM2B pathway affected tooth morphogenesis and mineralization after eight weeks of subcutaneous transplantation in nude mice.In conclusion,this study suggested that the mandible played a critical role in tooth morphogenesis and mineralization,which could be a potential therapeutic target for abnormal tooth development and an alternative model for tooth regeneration.
基金supported by the National Key Research and Development Program of China Stem Cell and Translational Research,China(2017YFA0104800)the Research Funds from Health@InnoHK Program launched by Innovation Technology Commission of the Hong Kong SAR,China+4 种基金National Natural Science Foundation of China(81570944 and 92068201)Science and Technology Planning Project of Guangdong Province,China(2020B1212060052)High-level Hospital Construction Project(DFJHBF202110)Youth Innovation Promotion of the Chinese Academy of Sciences(2019348)Guangzhou Key Medical Disciplines(2021–2023)。
文摘The spatiotemporal relationships in high-resolution during odontogenesis remain poorly understood.We report a cell lineage and atlas of developing mouse teeth.We performed a large-scale(92,688 cells)single cell RNA sequencing,tracing the cell trajectories during odontogenesis from embryonic days 10.5 to 16.5.Combined with an assay for transposase-accessible chromatin with high-throughput sequencing,our results suggest that mesenchymal cells show the specific transcriptome profiles to distinguish the tooth types.Subsequently,we identified key gene regulatory networks in teeth and bone formation and uncovered spatiotemporal patterns of odontogenic mesenchymal cells.CD24^(+)and Plac8^(+)cells from the mesenchyme at the bell stage were distributed in the upper half and preodontoblast layer of the dental papilla,respectively,which could individually induce nonodontogenic epithelia to form tooth-like structures.Specifically,the Plac8^(+)tissue we discovered is the smallest piece with the most homogenous cells that could induce tooth regeneration to date.Our work reveals previously unknown heterogeneity and spatiotemporal patterns of tooth germs that may lead to tooth regeneration for regenerative dentistry.
文摘Gervais has already characterised finitely I--[q,k]-determinacy of C<sup>∞</sup> map-germs. It seems that Cao Yi’s expressions are in better form than Gervais’（cf. Ref. [2]）. This note will deal with the I-<sub>q,k</sub>-determinacy of C<sup>∞</sup> map-germs which develop the basic results in Refs. [1]and [2]. We shall adopt the notations in Ref. [3],if not specialized, and every map-germ is C<sup>∞</sup>.
基金National Natural Science Foundation of China,No.82173446the Youth Training Program of the Army Medical University,No.2018XQN01.
文摘Hair follicle stem cells(HFSCs)in the bulge are a multipotent adult stem cell population.They can periodically give rise to new HFs and even regenerate the epidermis and sebaceous glands during wound healing.An increasing number of biomarkers have been used to isolate,label,and trace HFSCs in recent years.Considering more detailed data from single-cell transcriptomics technology,we mainly focus on the important HFSC molecular markers and their regulatory roles in this review.
