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1.
Sheng Wu Gong Cheng Xue Bao ; 36(4): 632-642, 2020 Apr 25.
Artigo em Chinês | MEDLINE | ID: mdl-32347058

RESUMO

Extracellular vesicles (EVs) refer to bilayer membrane transport vesicles secreted by cells. EVs can take macromolecules from cells and transfer them to receptor cells. Among these macromolecular substances, the most studied are microRNAs (miRNAs). miRNA is non-coding RNA involved in the regulation of gene expression. It has been confirmed that there are different non-coding RNAs in mammalian follicular fluid EVs. EVs carrying miRNA can act as an alternative mechanism for autocrine and paracrine, affecting follicular development. This paper systematically introduced the kinds, characteristics and methods of isolation and identification of EVs, focusing on the effects of EVs and miRNAs on follicular development, including early follicular development, oocyte maturation, follicular dominance and effects on granulosa cell function. At the same time, the authors prospected the future research of EVs and microRNAs in follicular fluid, and provided ideas and directions for the research and application of EVs and miRNA functions in follicular fluid.


Assuntos
Vesículas Extracelulares , Líquido Folicular , MicroRNAs , Oogênese , Animais , Vesículas Extracelulares/metabolismo , Feminino , Líquido Folicular/química , Células da Granulosa/efeitos dos fármacos , MicroRNAs/farmacologia , Oogênese/efeitos dos fármacos
2.
Sheng Li Xue Bao ; 72(1): 48-62, 2020 Feb 25.
Artigo em Chinês | MEDLINE | ID: mdl-32099983

RESUMO

The mitogen-activated protein kinase (MAPK) signaling pathway is a highly conserved signal transduction pathway from yeast to human species, and is widely distributed in various eukaryotic cells. In almost all of the species studied over the past three decades, this signaling pathway plays a crucial role in the development of female germ cells and meiotic maturation. Especially in a variety of mammalian species including primates, rodents, and domestic animals, the MAPK signaling pathway is activated during the resumption of first oocyte meiosis and plays an indispensable role in meiotic spindle assembly and cell cycle progression. In granulosa cells of fully grown ovarian follicles, the MAPK pathway also mediates the physiological action of gonadotropins, including cumulus expansion, ovulation, and corpus luteum formation. Although the MAPK signaling pathway plays a wide range of physiological functions during the female reproduction process, and these functions are highly conserved in evolution, their underlying mechanisms, especially their direct and physiological target molecules, have not been sufficiently studied for a long time. In recent years, based on some new gene-editing mouse models and theoretical findings, as well as the wide application of various omics techniques, it has been further revealed that MAPK directly phosphorylates and activates the RNA binding protein cytoplasmic polyadenylation element-binding protein-1 (CPEB1), promoting poly(A) tail extension of maternal mRNA to regulate protein translation during meiotic recovery. These findings not only constitute the current basic mechanism of mammalian oocyte maturation and ovulation, but also provide useful research ideas for other related research in this field. In this review, we summarize the research findings in our laboratory and from other groups regarding the role of MAPK cascade in regulating oocyte maturation and ovulation. We also discuss the latest research progress on MAPK regulation of mRNA translation and degradation by directly activating the translation initiation complex and mRNA poly(A) polymerase by phosphorylation in the granulosa cells.


Assuntos
Sistema de Sinalização das MAP Quinases , Meiose , Proteínas Quinases Ativadas por Mitógeno/fisiologia , Oócitos/fisiologia , Oogênese , Ovulação , Animais , Feminino , Humanos , Camundongos , Fatores de Transcrição/genética , Fatores de Poliadenilação e Clivagem de mRNA/genética
3.
Sheng Li Xue Bao ; 72(1): 63-74, 2020 Feb 25.
Artigo em Chinês | MEDLINE | ID: mdl-32099984

RESUMO

Ovary, the female gonad in mammals, is a heterogeneous organ consisting of oocytes and various types of somatic cells. The functions of ovary is not only governing the health of individual female by regulating endocrine status, but also determining the production of mature oocytes which allow the continuation of species. As the fundamental unit of female reproduction, ovarian follicle consists of germline oocyte and follicle somatic cells, and the folliculogenesis is an accurate and orderly process of internal coordination and external regulation in mammals. The gonadotropin-dependent stage of follicle development, from early antral follicle to ovulation, directly regulates the reproductive cycles of the female, has been extensively investigated. Recently, increased lines of evidence show that the fine tuned early folliculogenesis plays a pivotal role in the maintenance of female reproductive lifespan. Further exploration of the mechanism of follicular development could lead to a more comprehensive understanding about how females maintain their proper reproductive lifespan in mammals, which may provide the possibility to design new therapeutic approaches against female reproductive ageing in future. With the advances of technologies and methods, especially the widespread application of genetically modified animals and novel microscopic technology, the research on regulating mechanisms of in vivo follicular development, especially the early stage development of follicles, has made great progress. In this review, we summarized the regulating mechanisms of in vivo folliculogenesis around the key developmental events under physiological conditions, with a focus on the research progress of the early development of follicles in recent years.


Assuntos
Oogênese , Folículo Ovariano/fisiologia , Animais , Feminino , Mamíferos , Oócitos
4.
Science ; 367(6482)2020 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-32054698

RESUMO

Sex determination of germ cells is vital to creating the sexual dichotomy of germ cell development, thereby ensuring sexual reproduction. However, the underlying mechanisms remain unclear. Here, we show that ZGLP1, a conserved transcriptional regulator with GATA-like zinc fingers, determines the oogenic fate in mice. ZGLP1 acts downstream of bone morphogenetic protein, but not retinoic acid (RA), and is essential for the oogenic program and meiotic entry. ZGLP1 overexpression induces differentiation of in vitro primordial germ cell-like cells (PGCLCs) into fetal oocytes by activating the oogenic programs repressed by Polycomb activities, whereas RA signaling contributes to oogenic program maturation and PGC program repression. Our findings elucidate the mechanism for mammalian oogenic fate determination, providing a foundation for promoting in vitro gametogenesis and reproductive medicine.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Oócitos/fisiologia , Oogênese/genética , Diferenciação Sexual/genética , Fatores de Transcrição/fisiologia , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/fisiologia , Animais , Proteínas Morfogenéticas Ósseas/metabolismo , Feminino , Feto/citologia , Masculino , Meiose/genética , Camundongos , Camundongos Knockout , Oócitos/citologia , Proteínas do Grupo Polycomb/metabolismo , Processos de Determinação Sexual , Transdução de Sinais , Fatores de Transcrição/genética , Transcriptoma , Tretinoína/fisiologia
5.
Chemosphere ; 249: 126182, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32078850

RESUMO

An adverse tendency induced by the environmental estrogens in female reproductive health is one serious problem worldwide. Diethylstilbestrol (DES), as a synthetic estrogen, is still used as an animal growth stimulant in terrestrial livestock and aquaculture illegally. It has been reported to negatively affect ovarian function and oogenesis. Nevertheless, the mechanism and toxicity of DES on oocyte meiotic maturation are largely unknown. Herein, we found that DES (40 µM) intervened in mouse oocyte maturation and first polar body extrusion (PBE) was decreased in vitro. Cell cycle analysis showed meiotic process was disturbed with oocytes arrested at metaphase I (MI) stage after DES exposure. Further study showed that DES exposure disrupted the spindle assembly and chromosome alignment, which then continuously provoke the spindle assemble checkpoint (SAC). We also observed that the acetylation levels of α-tubulin were dramatically increased in DES-treated oocytes. In addition, the dynamics of actin were also affected. Moreover, the distribution patterns of estrogen receptor α (ERα) were altered in DES-treated oocyte, as indicated by the significant signals accumulation in the spindle area. However, ERα inhibitor failed to rescue the defects of oocyte maturation caused by DES. Of note, the same phenomenon was observed in estrogen-treated oocytes. Collectively, we showed that DES exposure lead to the oocyte meiotic failure via impairing the spindle assembly and chromosome alignment. Our research is helpful to understand how environmental estrogen affects female germ cells and contribute to design the potential therapies to preserve fertility especially for occupational exposure.


Assuntos
Dietilestilbestrol/toxicidade , Estrogênios não Esteroides/toxicidade , Animais , Processos de Crescimento Celular , Cromossomos , Feminino , Pontos de Checagem da Fase M do Ciclo Celular , Meiose/efeitos dos fármacos , Metáfase , Camundongos , Oócitos/metabolismo , Oogênese/efeitos dos fármacos , Fuso Acromático , Testes de Toxicidade , Tubulina (Proteína)/metabolismo
6.
PLoS One ; 15(1): e0227690, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31999691

RESUMO

Fish oogenesis is characterised by a massive growth of oocytes each reproductive season. This growth requires the stockpiling of certain molecules, such as ribosomal RNAs to assist the rapid ribosomal assembly and protein synthesis required to allow developmental processes in the newly formed embryo. Massive 5S rRNA expression in oocytes, facilitated by transcription factor 3A (Gtf3a), serves as marker of intersex condition in fish exposed to xenoestrogens. Our present work on Gtf3a gene evolution has been analysed in silico in teleost genomes and functionally in the case of the zebrafish Danio rerio. Synteny-analysis of fish genomes has allowed the identification of two gtf3a paralog genes, probably emerged from the teleost specific genome duplication event. Functional analyses demonstrated that gtf3ab has evolved as a gene specially transcribed in oocytes as observed in Danio rerio, and also in Oreochromis niloticus. Instead, gtf3aa was observed to be ubiquitously expressed. In addition, in zebrafish embryos gtf3aa transcription began with the activation of the zygotic genome (~8 hpf), while gtf3ab transcription began only at the onset of oogenesis. Under exposure to 100 ng/L 17ß-estradiol, fully feminised 61 dpf zebrafish showed transcription of ovarian gtf3ab, while masculinised (100 ng/L 17α-methyltestosterone treated) zebrafish only transcribed gtf3aa. Sex related transcription of gtf3ab coincided with that of cyp19a1a being opposite to that of amh and dmrt1. Such sex dimorphic pattern of gtf3ab transcription was not observed earlier in larvae that had not yet shown any signs of gonad formation after 26 days of oestradiol exposure. Thus, gtf3ab transcription is a consequence of oocyte differentiation and not a direct result of estrogen exposure, and could constitute a useful marker of gonad feminisation and intersex condition.


Assuntos
Ovário/metabolismo , Fator de Transcrição TFIIIA/genética , Proteínas de Peixe-Zebra/genética , Peixe-Zebra/genética , Animais , Ciclídeos/genética , Ciclídeos/crescimento & desenvolvimento , Ciclídeos/metabolismo , Transtornos do Desenvolvimento Sexual/genética , Evolução Molecular , Feminino , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismo , Duplicação Gênica , Masculino , Oogênese/genética , Filogenia , Caracteres Sexuais , Diferenciação Sexual/genética , Sintenia , Fator de Transcrição TFIIIA/metabolismo , Peixe-Zebra/crescimento & desenvolvimento , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/metabolismo
7.
Nat Commun ; 11(1): 330, 2020 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-31949138

RESUMO

Female reproductive success critically depends on the size and quality of a finite ovarian reserve. Paradoxically, mammals eliminate up to 80% of the initial oocyte pool through the enigmatic process of fetal oocyte attrition (FOA). Here, we interrogate the striking correlation of FOA with retrotransposon LINE-1 (L1) expression in mice to understand how L1 activity influences FOA and its biological relevance. We report that L1 activity triggers FOA through DNA damage-driven apoptosis and the complement system of immunity. We demonstrate this by combined inhibition of L1 reverse transcriptase activity and the Chk2-dependent DNA damage checkpoint to prevent FOA. Remarkably, reverse transcriptase inhibitor AZT-treated Chk2 mutant oocytes that evade FOA initially accumulate, but subsequently resolve, L1-instigated genotoxic threats independent of piRNAs and differentiate, resulting in an increased functional ovarian reserve. We conclude that FOA serves as quality control for oocyte genome integrity, and is not obligatory for oogenesis nor fertility.


Assuntos
Reserva Ovariana/efeitos dos fármacos , Reserva Ovariana/fisiologia , Proteínas de Ligação a RNA/metabolismo , Proteínas de Ligação a RNA/toxicidade , Animais , Apoptose , Proteínas Argonauta/genética , Quinase do Ponto de Checagem 2/genética , Quinase do Ponto de Checagem 2/metabolismo , Dano ao DNA , Feminino , Fertilidade , Feto , Elementos Nucleotídeos Longos e Dispersos/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Testes de Mutagenicidade , Oócitos/metabolismo , Oogênese , Reserva Ovariana/genética
8.
PLoS Genet ; 16(1): e1008529, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31917788

RESUMO

Exposure to diethylhexyl phthalate (DEHP), the most abundant plasticizer used in the production of polyvinyl-containing plastics, has been associated to adverse reproductive health outcomes in both males and females. While the effects of DEHP on reproductive health have been widely investigated, the molecular mechanisms by which exposure to environmentally-relevant levels of DEHP and its metabolites impact the female germline in the context of a multicellular organism have remained elusive. Using the Caenorhabditis elegans germline as a model for studying reprotoxicity, we show that exposure to environmentally-relevant levels of DEHP and its metabolites results in increased meiotic double-strand breaks (DSBs), altered DSB repair progression, activation of p53/CEP-1-dependent germ cell apoptosis, defects in chromosome remodeling at late prophase I, aberrant chromosome morphology in diakinesis oocytes, increased chromosome non-disjunction and defects during early embryogenesis. Exposure to DEHP results in a subset of nuclei held in a DSB permissive state in mid to late pachytene that exhibit defects in crossover (CO) designation/formation. In addition, these nuclei show reduced Polo-like kinase-1/2 (PLK-1/2)-dependent phosphorylation of SYP-4, a synaptonemal complex (SC) protein. Moreover, DEHP exposure leads to germline-specific change in the expression of prmt-5, which encodes for an arginine methyltransferase, and both increased SC length and altered CO designation levels on the X chromosome. Taken together, our data suggest a model by which impairment of a PLK-1/2-dependent negative feedback loop set in place to shut down meiotic DSBs, together with alterations in chromosome structure, contribute to the formation of an excess number of DSBs and altered CO designation levels, leading to genomic instability.


Assuntos
Troca Genética , Quebras de DNA de Cadeia Dupla , Dietilexilftalato/toxicidade , Oogênese , Oogônios/efeitos dos fármacos , Plastificantes/toxicidade , Animais , Apoptose , Caenorhabditis elegans , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Instabilidade Genômica , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Oogônios/citologia , Oogônios/metabolismo , Proteína-Arginina N-Metiltransferases/genética , Proteína-Arginina N-Metiltransferases/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
9.
Genes Dev ; 34(3-4): 166-178, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-31919188

RESUMO

Oocytes are indispensable for mammalian life. Thus, it is important to understand how mature oocytes are generated. As a critical stage of oocytes development, meiosis has been extensively studied, yet how chromatin remodeling contributes to this process is largely unknown. Here, we demonstrate that the ATP-dependent chromatin remodeling factor Snf2h (also known as Smarca5) plays a critical role in regulating meiotic cell cycle progression. Females with oocyte-specific depletion of Snf2h are infertile and oocytes lacking Snf2h fail to undergo meiotic resumption. Mechanistically, depletion of Snf2h results in dysregulation of meiosis-related genes, which causes failure of maturation-promoting factor (MPF) activation. ATAC-seq analysis in oocytes revealed that Snf2h regulates transcription of key meiotic genes, such as Prkar2b, by increasing its promoter chromatin accessibility. Thus, our studies not only demonstrate the importance of Snf2h in oocyte meiotic resumption, but also reveal the mechanism underlying how a chromatin remodeling factor can regulate oocyte meiosis.


Assuntos
Adenosina Trifosfatases/genética , Adenosina Trifosfatases/metabolismo , Montagem e Desmontagem da Cromatina/genética , Proteínas Cromossômicas não Histona/genética , Proteínas Cromossômicas não Histona/metabolismo , Fator Promotor de Maturação/genética , Meiose/genética , Oogênese/genética , Animais , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Técnicas de Inativação de Genes , Camundongos , Oócitos/citologia , Transcriptoma
10.
Gen Comp Endocrinol ; 285: 113270, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31525374

RESUMO

Metazoans have evolved a complexity of sexual system and gonad development, however, sexual reproduction of scleractinian corals is not well understood. This study aimed to address the sexual system and gametogenesis in Porites lichen, a common species in the Indo-West Pacific. This study represents the first description of sexual system, which were determined by histological analysis of the samples collected in northern Taiwan. In addition, female and hermaphroditic colonies were separately cultured in aquarium to further monitor the release of eggs/larvae and thereby confirm the breeding system. The results demonstrate that P. lichen is a polygamodioecious brooder and displays seasonal gametogenesis and embryogenesis that ends in late summer. In hermaphroditic colonies, male polyps are predominant and hermaphroditic polyps make up a very small percent (1%-19.3%). In addition, two new gametogenic features were observed from the histological analysis: 1) oocytes developed within the spermaries in hermaphroditic polyps during the early stage of gametogenesis and 2) melanin granular cells were clustered in spermaries in both male and hermaphroditic colonies. This study demonstrated the plasticity of gametogenesis and melanin related cells appeared in corals, which provides an important information to explore hormones and molecular mechanism involving in gonadal arrangement and production of melanin for further studies.


Assuntos
Antozoários/crescimento & desenvolvimento , Antozoários/fisiologia , Gônadas/crescimento & desenvolvimento , Animais , Feminino , Geografia , Células Germinativas/metabolismo , Masculino , Melaninas/metabolismo , Oogênese , Reprodução/fisiologia , Espermatogênese , Taiwan
11.
Gen Comp Endocrinol ; 285: 113275, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31536721

RESUMO

The progestin receptor membrane components (Pgrmcs) contain two paralogs, Pgrmc1 and Pgrmc2. Our previous research into single knockout of Pgrmc1 or Pgrmc2 suggests that Pgrmc1 and Pgrmc2 regulate membrane progestin receptor or steroid synthesis and therefore female fertility in zebrafish. Additional roles of Pgrmcs may not be determined in using single Pgrmc knockouts due to compensatory roles between Pgrmc1 and Pgrmc2. To address this question, we crossed single knockout pgrmc1 (pgrmc1-/-) with pgrmc2 (pgrmc2-/-), and generated double knockouts for both pgrmc1 and pgrmc2 (pgrmc1/2-/-) in a vertebrate model, zebrafish. In addition to the delayed oocyte maturation and reduced female fertility, significant reduced ovulation was found in double knockout (pgrmc1/2-/-) in vivo, though not detected in either single knockout of Pgrmc (pgrmc1-/- or pgrmc2-/-). We also found significant down regulation of nuclear progestin receptor (Pgr) protein expression only in pgrmc1/2-/-, which was most likely the cause of reduced ovulation. Lower protein expression of Pgr also resulted in reduced expression of metalloproteinase in pgrmc1/2-/-. With this study, we have provided new evidence for the physiological functions of Pgrmcs in the regulation of female fertility by regulation of ovulation, likely via regulation of Pgr, which affects regulation of metalloproteinase expression and oocyte ovulation.


Assuntos
Núcleo Celular/metabolismo , Regulação para Baixo , Técnicas de Inativação de Genes , Infertilidade/genética , Proteínas de Membrana/deficiência , Receptores de Progesterona/genética , Proteínas de Peixe-Zebra/deficiência , Peixe-Zebra/genética , Animais , Feminino , Proteínas de Membrana/metabolismo , Metaloproteases/metabolismo , Oócitos/metabolismo , Oogênese , Ovário/metabolismo , Ovulação , Receptores de Progesterona/deficiência , Receptores de Progesterona/metabolismo , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/metabolismo
12.
Nat Commun ; 10(1): 5719, 2019 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-31844300

RESUMO

It is known that granulosa cells (GCs) mediate gonadotropin-induced oocyte meiosis resumption by releasing EGF-like factors in mammals, however, the detailed molecular mechanisms remain unclear. Here, we demonstrate that luteinizing hormone (LH) surge-induced histone deacetylase 3 (HDAC3) downregulation in GCs is essential for oocyte maturation. Before the LH surge, HDAC3 is highly expressed in GCs. Transcription factors, such as FOXO1, mediate recruitment of HDAC3 to the amphiregulin (Areg) promoter, which suppresses AREG expression. With the LH surge, decreased HDAC3 in GCs enables histone H3K14 acetylation and binding of the SP1 transcription factor to the Areg promoter to initiate AREG transcription and oocyte maturation. Conditional knockout of Hdac3 in granulosa cells in vivo or inhibition of HDAC3 activity in vitro promotes the maturation of oocytes independent of LH. Taking together, HDAC3 in GCs within ovarian follicles acts as a negative regulator of EGF-like growth factor expression before the LH surge.


Assuntos
Anfirregulina/genética , Regulação da Expressão Gênica no Desenvolvimento , Histona Desacetilases/metabolismo , Meiose/genética , Oócitos/crescimento & desenvolvimento , Oogênese/genética , Acetilação , Animais , Células Cultivadas , Feminino , Proteína Forkhead Box O1/metabolismo , Técnicas de Inativação de Genes , Células da Granulosa/metabolismo , Inibidores de Histona Desacetilases/farmacologia , Histona Desacetilases/genética , Histonas/metabolismo , Hormônio Luteinizante/metabolismo , Camundongos , Oogênese/efeitos dos fármacos , Cultura Primária de Células , Regiões Promotoras Genéticas/genética , Fator de Transcrição Sp1/metabolismo
13.
PLoS One ; 14(12): e0226061, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31856229

RESUMO

Collective migration plays critical roles in animal development, physiological events, and cancer metastasis. However, the molecular mechanisms of collective cell migration are not well understood. Drosophila border cells represent an excellent in vivo genetic model to study collective cell migration and identify novel regulatory genes for cell migration. Using the Mosaic Analysis with a Repressible Cell Marker (MARCM) system, we screened 240 P-element insertion lines to identify essential genes for border cell migration. Two genes were uncovered, including dlg5 (discs large 5) and CG31689. Further analysis showed that Dlg5 regulates the apical-basal polarity and cluster integrity in border cell clusters. Dlg5 is enriched in lateral surfaces between border cells and central polar cells but also shows punctate localization between border cells. We found that the distribution of Dlg5 in border cell clusters is regulated by Armadillo. Structure-function analysis revealed that the N-terminal Coiled-coil domain and the C-terminal PDZ3-PDZ4-SH3-GUK domains but not the PDZ1-PDZ2 domains of Dlg5 are required for BC migration. The Coiled-coil domain and the PDZ4-SH3-GUK domains are critical for Dlg5's cell surface localization in border cell clusters.


Assuntos
Proteínas de Drosophila/metabolismo , Drosophila/metabolismo , Guanilato Quinases/metabolismo , Oogênese , Animais , Proteínas do Domínio Armadillo/metabolismo , Membrana Celular/metabolismo , Movimento Celular , Polaridade Celular , Drosophila/crescimento & desenvolvimento , Proteínas de Drosophila/antagonistas & inibidores , Proteínas de Drosophila/química , Genes Reporter , Guanilato Quinases/antagonistas & inibidores , Guanilato Quinases/química , Óvulo/crescimento & desenvolvimento , Óvulo/metabolismo , Domínios Proteicos , Proteína Quinase C/metabolismo , Interferência de RNA , Proteínas de Ligação a RNA/metabolismo , Fatores de Transcrição/metabolismo
14.
Results Probl Cell Differ ; 68: 477-494, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31598868

RESUMO

The subphylum Chelicerata represents one of the oldest groups among arthropods and comprises more than a dozen orders. Representatives of particular orders differ significantly in their external morphology, reproductive biology, behavior, and structure of internal organs, e.g. of the respiratory system. However, in almost all chelicerates (excluding some mites) the female gonads show a similar architecture. In this chapter, the chelicerate-type ovary structure and the course of oogenesis are described. Structural and functional diversities of the chelicerate-type ovary in non-matrotrophic and matrotrophic arachnids are also presented.


Assuntos
Artrópodes/anatomia & histologia , Artrópodes/citologia , Oogênese , Ovário/anatomia & histologia , Ovário/citologia , Animais , Aracnídeos/anatomia & histologia , Aracnídeos/citologia , Feminino
15.
Results Probl Cell Differ ; 68: 495-513, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31598869

RESUMO

Even though tardigrades have been known since 1772, their phylogenetic position is still controversial. Tardigrades are regarded as either the sister group of arthropods, onychophorans, or onychophorans plus arthropods. Furthermore, the knowledge about their gametogenesis, especially oogenesis, is still poor and needs further analysis. The process of oogenesis has been studied solely for several eutardigradan species. Moreover, the spatial organization of the female germ-line clusters has been described for three species only. Meroistic ovaries characterize all analyzed species. In species of the Parachela, one cell per germ-cell cluster differentiates into the oocyte, while the remaining cells become the trophocytes. In Apochela several cells in the cluster differentiate into oocytes. Vitellogenesis is of a mixed type. The eggs are covered with the egg capsule that is composed of two shells: the thin vitelline envelope that adheres to the oolemma and the thick three-layered chorion. Chorion is formed as a first followed by vitelline envelope. Several features related to the oogenesis and structure of the ovary confirm the hypothesis that tardigrades are the sister group rather for arthropods than for onychophorans.


Assuntos
Oócitos/citologia , Oogênese , Ovário/anatomia & histologia , Tardígrados/anatomia & histologia , Tardígrados/fisiologia , Animais , Feminino , Ovário/citologia , Filogenia , Tardígrados/classificação
16.
Results Probl Cell Differ ; 68: 515-551, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31598870

RESUMO

Animal female and male germ-line cells often form syncytial units termed cysts, clusters, or clones. Within these cysts, the cells remain interconnected by specific cell junctions known as intercellular bridges or ring canals, which enable cytoplasm to be shared and macromolecules and organelles to be exchanged between cells. Numerous analyses have shown that the spatial organization of cysts and their functioning may differ between the sexes and taxa. The vast majority of our knowledge about the formation and functioning of germ-line cysts comes from studies of model species (mainly Drosophila melanogaster); the other systems of the cyst organization and functioning are much less known and are sometimes overlooked. Here, we present the current state of the knowledge of female germ-line cysts in clitellate annelids (Clitellata), which is a monophyletic taxon of segmented worms (Annelida). The organization of germ-line cysts in clitellates differs markedly from that of the fruit fly and vertebrates. In Clitellata, germ cells are not directly connected one to another, but, as a rule, each cell has one ring canal that connects it to an anuclear central cytoplasmic core, a cytophore. Thus, this pattern of cell distribution is similar to the germ-line cysts of Caenorhabditis elegans. The last decade of studies has revealed that although clitellate female germ-line cysts have a strong morphological plasticity, e.g., cysts may contain from 16 to as many as 2500 cells, the oogenesis always shows a meroistic mode, i.e., the interconnected cells take on different fates; a few (sometimes only one) become oocytes, whereas the rest play the role of supporting (nurse) cells and do not continue oogenesis.This is the first comprehensive summary of the current knowledge on the organization and functioning of female germ-line cysts in clitellate annelids.


Assuntos
Anelídeos/citologia , Células Germinativas/citologia , Células Gigantes/citologia , Células Gigantes/fisiologia , Animais , Feminino , Oócitos/citologia , Oócitos/crescimento & desenvolvimento , Oogênese
18.
Nat Commun ; 10(1): 3940, 2019 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-31477736

RESUMO

Collective cell migration is involved in development, wound healing and metastasis. In the Drosophila ovary, border cells (BC) form a small cluster that migrates collectively through the egg chamber. To achieve directed motility, the BC cluster coordinates the formation of protrusions in its leader cell and contractility at the rear. Restricting protrusions to leader cells requires the actin and plasma membrane linker Moesin. Herein, we show that the Ste20-like kinase Misshapen phosphorylates Moesin in vitro and in BC. Depletion of Misshapen disrupts protrusion restriction, thereby allowing other cells within the cluster to protrude. In addition, we show that Misshapen is critical to generate contractile forces both at the rear of the cluster and at the base of protrusions. Together, our results indicate that Misshapen is a key regulator of BC migration as it coordinates two independent pathways that restrict protrusion formation to the leader cells and induces contractile forces.


Assuntos
Actomiosina/genética , Movimento Celular/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Regulação da Expressão Gênica no Desenvolvimento , Oogênese/genética , Proteínas Serina-Treonina Quinases/genética , Citoesqueleto de Actina/metabolismo , Actomiosina/metabolismo , Algoritmos , Animais , Animais Geneticamente Modificados , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Feminino , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Modelos Genéticos , Proteínas Serina-Treonina Quinases/metabolismo , Interferência de RNA
19.
Adv Exp Med Biol ; 1169: 213-223, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31487026

RESUMO

Every organ in the body is thought to harbor two populations of stem cells, including the quiescent and the actively dividing, that leads to heterogeneity among them. It is generally believed that the ovary harbors a fixed number of follicles at birth that differentiate during fetal development from the primordial germ cells. The numbers of follicles decrease by age, leading to menopause. However, in 2004, it was suggested that ovary may harbor stem cells that are possibly involved in the formation of new follicles throughout reproductive life. Research over little more than a decade shows that ovarian stem cells include a quiescent population of very small embryonic-like stem cells (VSELs) and slightly bigger, actively dividing ovarian stem cells (OSCs). This heterogeneity among ovarian stem cells is similar to the presence of VSELs along with spermatogonial stem cells (SSCs) in the testis or hematopoietic stem cells (HSCs) in the hematopoietic system. VSELs express embryonic markers, including nuclear OCT-4, and are lodged in the ovary surface epithelium (OSE). Ovarian VSELs undergo asymmetric cell division to self-renew and give rise to OSCs that in turn undergo symmetric cell divisions and clonal expansion (germ cell nest) followed by meiosis to form an oocyte that gets assembled as a primordial follicle. Both VSELs and OSCs also express receptors for follicle-stimulating hormone (FSHR) and are directly activated by FSH to undergo neo-oogenesis and primordial follicle assembly. Whether stimulation of ovaries by FSH in Infertility Clinics activates the stem cells leading to the formation of multiple follicles needs further investigation. Epithelial cells lining the surface of ovary provide a niche to the stem cells under normal circumstances and undergo epithelial-mesenchymal transition (EMT) to form granulosa cells for primordial follicle assembly. Compromised function of the epithelial cells with age possibly leads to inability of stem cells to form follicles, leading to menopause. More than 90% of ovarian cancers arise in the OSE, possibly due to excessive self-renewal of VSELs. Altered biology of the OSE cells results in the formation of myofibroblasts by EMT and may provide a cancerous niche that supports excessive expansion of the stem cells lodged in the OSE, leading to ovarian cancer. Ovarian cancer cells express markers like OCT-4 and FSHR, which are also expressed by the VSELs lodged in the OSE, whereas the epithelial cells are distinctly negative for the same. Lot more research is required in the field to gain further understanding of ovarian stem cell biology.


Assuntos
Células-Tronco Embrionárias , Folículo Ovariano , Células-Tronco Embrionárias/citologia , Feminino , Humanos , Masculino , Oogênese , Folículo Ovariano/citologia
20.
Environ Pollut ; 255(Pt 1): 113194, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31520902

RESUMO

Heavy metal cadmium (Cd) is a widespread environmental contaminant with a potential toxicity that might adversely influence the health of experimental animals and humans. It has been known that Cd might accumulate in vertebrates for many years and thus leads to the hepatic and renal toxicity. Additionally, Cd concentration in the ovary increases with age and is highly related to the reproductive hazard. However, the underlying mechanisms regarding how Cd affects the female reproductive system especially the oocyte quality have not yet fully defined. Here, we reported that Cd exposure led to the defective nuclear maturation of oocytes via the impairment of cytoskeleton assembly, displaying the aberrant spindle organization, chromosome alignment and actin polymerization. In the meantime, Cd exposure caused the impaired cytoplasmic maturation by showing the disrupted dynamics of mitochondrial integrity and cortical granules, and thereby resulting in the compromised sperm binding ability and fertilization capacity of oocytes. More importantly, we found that glutathione (GSH) supplementation was able to recover the meiotic failure induced by Cd exposure through suppressing the excessive ROS level, DNA damage accumulation and apoptotic incidence. Taken together, our findings demonstrate that Cd exposure has the adverse effects on the oocyte meiotic maturation as well as subsequent fertilization, and provide a potential effective strategy to improve the quality of Cd-exposed oocytes.


Assuntos
Cádmio/toxicidade , Mitocôndrias/patologia , Oócitos/citologia , Oogênese/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Animais , Citoesqueleto/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Feminino , Glutationa/metabolismo , Humanos , Masculino , Meiose/efeitos dos fármacos , Oócitos/patologia , Suínos
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