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1.
Nat Cell Biol ; 22(4): 380-388, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32231309

RESUMO

The importance of germline-inherited post-translational histone modifications on priming early mammalian development is just emerging1-4. Histone H3 lysine 9 (H3K9) trimethylation is associated with heterochromatin and gene repression during cell-fate change5, whereas histone H3 lysine 4 (H3K4) trimethylation marks active gene promoters6. Mature oocytes are transcriptionally quiescent and possess remarkably broad domains of H3K4me3 (bdH3K4me3)1,2. It is unknown which factors contribute to the maintenance of the bdH3K4me3 landscape. Lysine-specific demethylase 4A (KDM4A) demethylates H3K9me3 at promoters marked by H3K4me3 in actively transcribing somatic cells7. Here, we report that KDM4A-mediated H3K9me3 demethylation at bdH3K4me3 in oocytes is crucial for normal pre-implantation development and zygotic genome activation after fertilization. The loss of KDM4A in oocytes causes aberrant H3K9me3 spreading over bdH3K4me3, resulting in insufficient transcriptional activation of genes, endogenous retroviral elements and chimeric transcripts initiated from long terminal repeats during zygotic genome activation. The catalytic activity of KDM4A is essential for normal epigenetic reprogramming and pre-implantation development. Hence, KDM4A plays a crucial role in preserving the maternal epigenome integrity required for proper zygotic genome activation and transfer of developmental control to the embryo.


Assuntos
Histona Desmetilases/metabolismo , Histonas/metabolismo , Oócitos/metabolismo , Processamento de Proteína Pós-Traducional , Zigoto/metabolismo , Animais , Implantação do Embrião , Embrião de Mamíferos , Feminino , Fertilização/genética , Heterocromatina/química , Heterocromatina/metabolismo , Histona Desmetilases/genética , Histonas/genética , Masculino , Metáfase , Metilação , Camundongos , Camundongos Knockout , Oócitos/citologia , Oócitos/crescimento & desenvolvimento , Regiões Promotoras Genéticas , Transcrição Genética , Zigoto/citologia , Zigoto/crescimento & desenvolvimento
2.
PLoS One ; 15(4): e0229781, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32343699

RESUMO

Lamin C2 (LMN C2) is a short product of the lamin a gene. It is a germ cell-specific lamin and has been extensively studied in male germ cells. In this study, we focussed on the expression and localization of LMN C2 in fully-grown germinal vesicle (GV) oocytes. We detected LMN C2 in the fully-grown germinal vesicle oocytes of various mammalian species with confirmation done by immunoblotting the wild type and Lmnc2 gene deleted testes. Expression of LMN C2 tagged with GFP showed localization of LMN C2 to the nuclear membrane of the oocyte. Moreover, the LMN C2 protein notably disappeared after nuclear envelope breakdown (NEBD) and the expression of LMN C2 was significantly reduced in the oocytes from aged females and ceased altogether during meiotic maturation. These results provide new insights regarding LMN C2 expression in the oocytes of various mammalian species.


Assuntos
Laminina/genética , Oócitos/crescimento & desenvolvimento , Oogênese/genética , Ovário/crescimento & desenvolvimento , Animais , Feminino , Regulação da Expressão Gênica no Desenvolvimento/genética , Células Germinativas/crescimento & desenvolvimento , Masculino , Meiose/genética , Camundongos , Camundongos Knockout , Membrana Nuclear/genética , Oócitos/metabolismo , RNA Mensageiro/genética , Espermatócitos/crescimento & desenvolvimento , Testículo/crescimento & desenvolvimento
3.
PLoS One ; 15(3): e0229043, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32182244

RESUMO

Oocyte in vitro maturation can be improved by mimicking the intra-follicular environment. Oocyte, cumulus cells, granulosa cells, and circulating factors act as meiotic regulators in follicles and maintain oocyte in the meiotic phase until oocyte becomes competent and ready to be ovulated. In a randomized experimental design, an ovine model was used to optimize the standard in vitro maturation media by Granulosa secreted factors. At first, the development capacity of oocyte derived from medium (>4 to 6 mm) and small (2 to ≤4 mm) size follicles was determined. Differential gene expression of granulosa secreted factors and their receptors were compared between the cumulus cells of the two groups. Then, the best time and concentration for arresting oocytes at the germinal vesicle stage by natriuretic peptide type C (CNP) were determined by nuclear staining in both groups. Oocyte quality was further confirmed by calcein uptake and gene expression. The developmental competence of cumulus oocyte complexes derived from small size follicles that were cultured in the presence of CNP in combination with amphiregulin (AREG) and prostaglandin E2 (PGE2) for 24 h was determined. Finally, embryo quality was specified by assessing expressions of NANOG, SOX2, CDX2, OCT4, and TET1. The cumulus oocyte complexes derived from small size follicles had a lower capacity to form blastocyst in comparison with cumulus oocyte complexes derived from medium size follicles. Prostaglandin E receptor 2 and prostaglandin-endoperoxide synthase 2 had significantly lower expression in cumulus cells derived from small size follicles in comparison with cumulus cells derived from medium size follicles. Natriuretic peptide type C increased the percentage of cumulus oocyte complexes arresting at the germinal vesicle stage in both oocytes derived from medium and small follicles. Gap junction communication was also improved in the presence of natriuretic peptide type C. In oocytes derived from small size follicles; best blastocyst rates were achieved by sequential exposure of cumulus oocyte complexes in [TCM+CNP (6 h), then cultured in TCM+AREG+PGE2 (18h)] and [TCM+CNP (6 h), then cultured in conventional IVM supplements+AREG+PGE2 (18h)]. Increased SOX2 expression was observed in [TCM+CNP (6 h), then cultured in TCM+AREG+PGE2 (18h)], while decreased OCT4 expression was observed in [TCM+CNP (6 h), then cultured in conventional IVM supplements+AREG+PGE2 (18h)]. It seems that the natriuretic peptide type C modulates meiotic progression, and oocyte development is probably mediated by amphiregulin and prostaglandin E2. These results may provide an alternative IVM method to optimize in vitro embryo production in sheep and subsequently for humans.


Assuntos
Meios de Cultura/farmacologia , Células do Cúmulo/citologia , Técnicas de Maturação in Vitro de Oócitos/métodos , Oócitos/crescimento & desenvolvimento , Folículo Ovariano/citologia , Anfirregulina/farmacologia , Animais , Biomarcadores , Células Cultivadas , Meios de Cultura/química , Células do Cúmulo/metabolismo , Dinoprostona/farmacologia , Feminino , Fertilização In Vitro , Fluoresceínas/metabolismo , Meiose , Modelos Animais , Peptídeo Natriurético Tipo C/farmacologia , Oócitos/efeitos dos fármacos , Oócitos/metabolismo , Folículo Ovariano/efeitos dos fármacos , Ovinos
4.
Gene ; 741: 144495, 2020 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-32088244

RESUMO

As a member of the chromosomal passenger complex, CDCA8 (cell division cycle associated 8) plays an important role in human mitosis, but its roles in human meiosis are unknown. Here, we show that CDCA8 expression is increased and its encoded protein has dynamic localization in human oocytes from germinal vesicle breakdown (GVBD) to metaphase Ⅱ (MⅡ), and that there are multipolar spindles, disordered chromosomes, and that microtubule assembly is affected after CDCA8 RNA interference (RNAi) in GV-stage oocytes. The GVBD and polar body extrusion (PBE) rates were not affected following CDCA8 depletion, but the PBE time was extended. There was no statistical difference between CDCA8 expression of oocytes from older and younger women, but the first polar body from older women was prone to chromosome abnormalities, and oocytes with such abnormalities had lower CDCA8 expression than oocytes with normal polar bodies. These results indicate that CDCA8 is associated with bipolar spindle formation, chromosome segregation, PBE during human oocyte meiosis, and that it may affect the incidence of aneuploidy embryos in older women.


Assuntos
Proteínas de Ciclo Celular/genética , Meiose/genética , Oócitos/crescimento & desenvolvimento , Fuso Acromático/genética , Adulto , Segregação de Cromossomos , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Mitose/genética , Oócitos/metabolismo , Corpos Polares/metabolismo , Interferência de RNA
5.
Nucleic Acids Res ; 48(6): 3211-3227, 2020 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-31956907

RESUMO

Tens of thousands of rapidly evolving long non-coding RNA (lncRNA) genes have been identified, but functions were assigned to relatively few of them. The lncRNA contribution to the mouse oocyte physiology remains unknown. We report the evolutionary history and functional analysis of Sirena1, the most expressed lncRNA and the 10th most abundant poly(A) transcript in mouse oocytes. Sirena1 appeared in the common ancestor of mouse and rat and became engaged in two different post-transcriptional regulations. First, antisense oriented Elob pseudogene insertion into Sirena1 exon 1 is a source of small RNAs targeting Elob mRNA via RNA interference. Second, Sirena1 evolved functional cytoplasmic polyadenylation elements, an unexpected feature borrowed from translation control of specific maternal mRNAs. Sirena1 knock-out does not affect fertility, but causes minor dysregulation of the maternal transcriptome. This includes increased levels of Elob and mitochondrial mRNAs. Mitochondria in Sirena1-/- oocytes disperse from the perinuclear compartment, but do not change in number or ultrastructure. Taken together, Sirena1 contributes to RNA interference and mitochondrial aggregation in mouse oocytes. Sirena1 exemplifies how lncRNAs stochastically engage or even repurpose molecular mechanisms during evolution. Simultaneously, Sirena1 expression levels and unique functional features contrast with the lack of functional importance assessed under laboratory conditions.


Assuntos
Mitocôndrias/genética , Oócitos/metabolismo , RNA Longo não Codificante/genética , RNA Mensageiro/genética , RNA Mitocondrial/genética , Animais , Técnicas de Inativação de Genes , Camundongos , Mitocôndrias/ultraestrutura , Oócitos/crescimento & desenvolvimento , Oócitos/ultraestrutura , Poliadenilação/genética , Ratos , Transcriptoma/genética
6.
Environ Sci Pollut Res Int ; 27(7): 7729-7735, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31904101

RESUMO

Somatic cell nuclear transfer (SCNT) is a valuable technology tool with various uses in transgenic animals, regenerative medicine, and stem cell research. However, the efficiency of SCNT embryos appears to have poor developmental competency. Environmental issues may adversely affect SCNT embryos in buffalo. Thereafter, the present study aimed to explore the effect of season on the maturation of buffalo oocytes and subsequent developmental capability after parthenogenetic activation and SCNT in buffalo. Buffalo oocytes (n = 6353) were collected from local slaughterhouse at various seasons; spring (March-April), summer (May-August), autumn (September-November), and winter (December-January). A significant increase (p < 0.05) was recorded in the maturation rate (57.07%) at autumn compared with spring, summer, and winter (50.46, 50.93, and 50.66%, respectively). No significant differences were recorded in the fusion and the cleavage rates among all seasons. Blastocyst development rate was higher (p < 0.05) in autumn and winter (16.52 ± 8.45% and 15.98 ± 7.17%, respectively) than in spring and summer (9.47 ± 6.71% and 10.84 ± 6.58%, respectively) seasons. It could be concluded that the season had a significant effect on oocyte development competence which can be used for SCNT in buffalo.


Assuntos
Búfalos , Técnicas de Transferência Nuclear/veterinária , Oócitos/crescimento & desenvolvimento , Estações do Ano , Animais , Desenvolvimento Embrionário
7.
RNA ; 26(3): 324-344, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31896558

RESUMO

Most cells change patterns of gene expression through transcriptional regulation. In contrast, oocytes are transcriptionally silent and regulate mRNA poly(A) tail length to control protein production. However, the genome-wide relationship of poly(A) tail changes to mRNA translation during vertebrate oocyte maturation is not known. We used Tail-seq and polyribosome analysis to measure poly(A) tail and translational changes during oocyte maturation in Xenopus laevis We identified large-scale poly(A) and translational changes during oocyte maturation, with poly(A) tail length changes preceding translational changes. Proteins important for completion of the meiotic divisions and early development exhibited increased polyadenylation and translation during oocyte maturation. A family of U-rich sequence elements was enriched near the polyadenylation signal of polyadenylated and translationally activated mRNAs. We propose that changes in mRNA polyadenylation are a conserved mechanism regulating protein expression during vertebrate oocyte maturation and that these changes are controlled by a spatial code of cis-acting sequence elements.


Assuntos
Oogênese/genética , Poliadenilação/genética , Biossíntese de Proteínas/genética , RNA Mensageiro/genética , Animais , Regulação da Expressão Gênica no Desenvolvimento/genética , Genoma/genética , Oócitos/crescimento & desenvolvimento , Oócitos/metabolismo , Sequências Reguladoras de Ácido Nucleico/genética , Xenopus laevis/genética , Xenopus laevis/crescimento & desenvolvimento
8.
Nucleic Acids Res ; 48(6): 3257-3276, 2020 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-31970406

RESUMO

During oocyte maturation, changes in gene expression depend exclusively on translation and degradation of maternal mRNAs rather than transcription. Execution of this translation program is essential for assembling the molecular machinery required for meiotic progression, fertilization, and embryo development. With the present study, we used a RiboTag/RNA-Seq approach to explore the timing of maternal mRNA translation in quiescent oocytes as well as in oocytes progressing through the first meiotic division. This genome-wide analysis reveals a global switch in maternal mRNA translation coinciding with oocyte re-entry into the meiotic cell cycle. Messenger RNAs whose translation is highly active in quiescent oocytes invariably become repressed during meiotic re-entry, whereas transcripts repressed in quiescent oocytes become activated. Experimentally, we have defined the exact timing of the switch and the repressive function of CPE elements, and identified a novel role for CPEB1 in maintaining constitutive translation of a large group of maternal mRNAs during maturation.


Assuntos
Desenvolvimento Embrionário/genética , Meiose/genética , Oócitos/metabolismo , Oogênese/genética , Animais , Regulação da Expressão Gênica no Desenvolvimento/genética , Técnicas de Maturação in Vitro de Oócitos , Camundongos , Oócitos/crescimento & desenvolvimento , RNA Mensageiro/genética , RNA Mensageiro Estocado/genética , Proteínas de Ligação a RNA/genética , Fatores de Transcrição/genética
9.
Environ Toxicol ; 35(2): 152-158, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31696613

RESUMO

Fluorene-9-bisphenol (9,9-bis(4-hydroxyphenyl)-fluorene [BHPF]) is a bisphenol A (BPA) substitute used in the production of "BPA-free" plastics, now has been identified is harmful to living organisms. Our previous study showed that BHPF impaired mouse denuded oocyte in vitro maturation. However, there is a question that whether BHPF is still able to affect oocyte maturation in the presence of dense cumulus cells. In the present study, we checked the toxic effects of BHPF on porcine oocyte maturation which is derived from COCs in vitro culture. Our results showed that BHPF (50 µM) inhibited the expansion of cumulus cells, led to a significant decrease in polar body extrusion (PBE). Importantly, BHPF resulted in abnormal spindle assembly, ATP level decrease, reactive oxygen species (ROS) accumulation and early apoptosis in porcine oocytes, which are all negative to oocyte maturation. Furthermore, BHPF also declined porcine oocyte quality by disturbing the cortical granules (CGs) distribution. In conclusion, our study showed that BHPF still inhibited oocyte maturation even in the presence of cumulus cells leading to abnormal spindle assembly, ATP decrease, increased ROS level, early apoptosis, and disturbed CGs distribution in porcine oocytes, and also indicates that BHPF has a wide range toxic effects on oocyte in different species.


Assuntos
Apoptose/efeitos dos fármacos , Compostos Benzidrílicos/toxicidade , Disruptores Endócrinos/toxicidade , Oócitos/efeitos dos fármacos , Oogênese/efeitos dos fármacos , Fenóis/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Animais , Feminino , Técnicas de Maturação in Vitro de Oócitos , Camundongos , Oócitos/crescimento & desenvolvimento , Oócitos/metabolismo , Oócitos/patologia , Suínos
10.
Nucleic Acids Res ; 48(2): 879-894, 2020 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-31777931

RESUMO

An important event of the maternal-to-zygotic transition (MZT) in animal embryos is the elimination of a subset of the maternal transcripts that accumulated during oogenesis. In both invertebrates and vertebrates, a maternally encoded mRNA decay pathway (M-decay) acts before zygotic genome activation (ZGA) while a second pathway, which requires zygotic transcription, subsequently clears additional mRNAs (Z-decay). To date the mechanisms that activate the Z-decay pathway in mammalian early embryos have not been investigated. Here, we identify murine maternal transcripts that are degraded after ZGA and show that inhibition of de novo transcription stabilizes these mRNAs in mouse embryos. We show that YAP1-TEAD4 transcription factor-mediated transcription is essential for Z-decay in mouse embryos and that TEAD4-triggered zygotic expression of terminal uridylyltransferases TUT4 and TUT7 and mRNA 3'-oligouridylation direct Z-decay. Components of the M-decay pathway, including BTG4 and the CCR4-NOT deadenylase, continue to function in Z-decay but require reinforcement from the zygotic factors for timely removal of maternal mRNAs. A long 3'-UTR and active translation confer resistance of Z-decay transcripts to M-decay during oocyte meiotic maturation. The Z-decay pathway is required for mouse embryo development beyond the four-cell stage and contributes to the developmental competence of preimplantation embryos.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ligação a DNA/genética , Genoma/genética , Proteínas Musculares/genética , RNA Mensageiro/genética , Fatores de Transcrição/genética , Zigoto/crescimento & desenvolvimento , Animais , Embrião de Mamíferos , Desenvolvimento Embrionário/genética , Feminino , Regulação da Expressão Gênica no Desenvolvimento/genética , Proteínas de Homeodomínio/genética , Camundongos , Nucleotidiltransferases/genética , Oócitos/crescimento & desenvolvimento , Estabilidade de RNA/genética , Receptores CCR4/genética
11.
Chemosphere ; 240: 124935, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31563720

RESUMO

Increasing studies have established the toxic effects of BPA on development and reproduction in animals. In present study, we investigated epigenetic effects on the transcription of several ovarian steroidogenic genes in rare minnows Gobiocypris rarus after BPA exposure at 15 µgL-1 for 21, 42 and 63 d. Results showed that short term BPA exposure (21 d) caused significant increase of both estradiol and testerone levels whereas long term exposure (63 d) led to significant decrease of them. The oocytes development was hindered after BPA exposure. BPA treatments for 21 and 42 d resulted in significant increase of genome DNA methylation in ovary while 63-d exposure caused marked decrease. The histone trimethylation levels (H3K4me3, H3K9me3 and H3K27me3) in the ovary were also disturbed by BPA. H3K9me3 was significantly decreased after 21 d whereas it was markedly increased after 42 and 63 d. The 42-d exposure caused significant decrease for H3K4me3. Meanwhile, 42- and 63-d BPA exposure led to significant decrease of H3K27me3. DNA methylation could involve in gene expression regulation of cyp17a1 and cyp19a1a after BPA exposure. After short (21 d) and long term (63 d) BPA exposure, the respective mRNA expression down-regulation and up-regulation of star, cyp11a1, and cyp17a1 were mediated by H3K9me3. This study suggests that epigenetic modulation including DNA and histone methylation could be responsible for the detrimental effects on ovary development upon BPA exposure in G. rarus. It is speculated that BPA exposures for short or long term duration could disturb the steroidogenesis in entirely different mechanisms.


Assuntos
Compostos Benzidrílicos/toxicidade , Cyprinidae/genética , Metilação de DNA/efeitos dos fármacos , Estrogênios não Esteroides/toxicidade , Oócitos/crescimento & desenvolvimento , Ovário/crescimento & desenvolvimento , Fenóis/toxicidade , Animais , Cyprinidae/metabolismo , DNA/metabolismo , Estradiol/metabolismo , Feminino , Regulação da Expressão Gênica , Histonas/genética , Diferenciação Sexual/efeitos dos fármacos , Esteroide 17-alfa-Hidroxilase/genética , Testosterona/metabolismo
12.
Toxicol Ind Health ; 35(11-12): 714-725, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31818241

RESUMO

This study aimed to evaluate the mancozeb (MNZ) impact on oocyte maturation of first-generation mice pups as well as their fertilization rate, embryo development, and implantation along with the preventative effect of vitamins E and C. Pregnant mice were randomly divided into six groups: control, vehicle, and MNZ (500 mg/kg body weight (BW)), vitamin E (200 mg/kg BW), MNZ plus vitamin E, MNZ plus vitamin C (100 mg/kg BW), and MNZ plus two vitamins. All treatments were conducted by oral gavage every 2 days from the second day of gestation until the end of lactation. Vitamin treatment was initiated 30 min before receiving MNZ. After birth, first-generation mice pups were kept until adulthood (8-10 W). Adult female mice pups superovulated and then the collected oocytes were examined for nuclear maturity status. After in vitro fertilization of metaphase II oocytes with sperm of the first-generation male mice pups, fertilization rate and embryo development were evaluated over 24 h. Also, the fecundity rate and the number of implanted embryos in vivo were studied on the eighth day of pregnancy. MNZ exposure during embryo development and lactation significantly decreased the total number of collected oocytes, oocyte maturation, fertilization rate, implantation rate, fecundity rate, and embryo development compared with the control group in the first-generation pups. In contrast, vitamin treatments significantly increased these parameters compared to the MNZ group. Reduction in the quality of oocyte, the rate of fertilization, embryo implantation, and development following MNZ exposure could decrease female reproductive success, while coadministration of vitamins E and C could prevent these complications.


Assuntos
Ácido Ascórbico/farmacologia , Fungicidas Industriais/toxicidade , Maneb/toxicidade , Exposição Materna/efeitos adversos , Vitamina E/farmacologia , Zineb/toxicidade , Animais , Animais Recém-Nascidos , Antioxidantes/farmacologia , Implantação do Embrião , Desenvolvimento Embrionário/efeitos dos fármacos , Feminino , Fertilização/efeitos dos fármacos , Lactação/efeitos dos fármacos , Camundongos , Oócitos/efeitos dos fármacos , Oócitos/crescimento & desenvolvimento , Oogênese/efeitos dos fármacos , Gravidez
13.
PLoS Genet ; 15(12): e1008261, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31860668

RESUMO

Germline genome defense evolves to recognize and suppress retrotransposons. One of defensive mechanisms is the PIWI-associated RNA (piRNA) pathway, which employs small RNAs for sequence-specific repression. The loss of the piRNA pathway in mice causes male sterility while females remain fertile. Unlike spermatogenic cells, mouse oocytes posses also RNA interference (RNAi), another small RNA pathway capable of retrotransposon suppression. To examine whether RNAi compensates the loss of the piRNA pathway, we produced a new RNAi pathway mutant DicerSOM and crossed it with a catalytically-dead mutant of Mili, an essential piRNA gene. Normal follicular and oocyte development in double mutants showed that RNAi does not suppress a strong ovarian piRNA knock-out phenotype. However, we observed redundant and non-redundant targeting of specific retrotransposon families illustrating stochasticity of recognition and targeting of invading retrotransposons. Intracisternal A Particle retrotransposon was mainly targeted by the piRNA pathway, MaLR and RLTR10 retrotransposons were targeted mainly by RNAi. Double mutants showed accumulations of LINE-1 retrotransposon transcripts. However, we did not find strong evidence for transcriptional activation and mobilization of retrotransposition competent LINE-1 elements suggesting that while both defense pathways are simultaneously expendable for ovarian oocyte development, yet another transcriptional silencing mechanism prevents mobilization of LINE-1 elements.


Assuntos
Oócitos/crescimento & desenvolvimento , Interferência de RNA , RNA Interferente Pequeno/genética , Retroelementos , Animais , Proteínas Argonauta/genética , RNA Helicases DEAD-box/genética , Feminino , Camundongos , Mutação , Oócitos/química , Ribonuclease III/genética , Transdução de Sinais
14.
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
15.
Clin Epigenetics ; 11(1): 197, 2019 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-31856890

RESUMO

BACKGROUND: In vitro follicle culture (IFC), as applied in the mouse system, allows the growth and maturation of a large number of immature preantral follicles to become mature and competent oocytes. In the human oncofertility clinic, there is increasing interest in developing this technique as an alternative to ovarian cortical tissue transplantation and to preserve the fertility of prepubertal cancer patients. However, the effect of IFC and hormonal stimulation on DNA methylation in the oocyte is not fully known, and there is legitimate concern over epigenetic abnormalities that could be induced by procedures applied during assisted reproductive technology (ART). RESULTS: In this study, we present the first genome-wide analysis of DNA methylation in MII oocytes obtained after natural ovulation, after IFC and after superovulation. We also performed a comparison between prepubertal and adult hormonally stimulated oocytes. Globally, the distinctive methylation landscape of oocytes, comprising alternating hyper- and hypomethylated domains, is preserved irrespective of the procedure. The conservation of methylation extends to the germline differential methylated regions (DMRs) of imprinted genes, necessary for their monoallelic expression in the embryo. However, we do detect specific, consistent, and coherent differences in DNA methylation in IFC oocytes, and between oocytes obtained after superovulation from prepubertal compared with sexually mature females. Several methylation differences span entire transcription units. Among these, we found alterations in Tcf4, Sox5, Zfp521, and other genes related to nervous system development. CONCLUSIONS: Our observations show that IFC is associated with altered methylation at specific set of loci. DNA methylation of superovulated prepubertal oocytes differs from that of superovulated adult oocytes, whereas oocytes from superovulated adult females differ very little from naturally ovulated oocytes. Importantly, we show that regions other than imprinted gDMRs are susceptible to methylation changes associated with superovulation, IFC, and/or sexual immaturity in mouse oocytes. Our results provide an important reference for the use of in vitro growth and maturation of oocytes, particularly from prepubertal females, in assisted reproductive treatments or fertility preservation.


Assuntos
Metilação de DNA , Redes Reguladoras de Genes , Oócitos/crescimento & desenvolvimento , Técnicas de Reprodução Assistida/efeitos adversos , Animais , Modelos Animais de Doenças , Feminino , Impressão Genômica , Técnicas de Maturação in Vitro de Oócitos , Camundongos , Oócitos/química , Maturidade Sexual , Superovulação
16.
J Assist Reprod Genet ; 36(12): 2403-2418, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31705227

RESUMO

PURPOSE: Molecular cytogenetic analysis has confirmed that a proportion of apparently meiotic aneuploidy may be present in the germ cells prior to the onset of meiosis, but there is no clear perception of its frequency. The aim of this review is to assess the evidence for premeiotic aneuploidy from a variety of sources to arrive at an estimate of its overall contribution to oocyte aneuploidy in humans. METHODS: Relevant scientific literature was covered from 1985 to 2018 by searching PubMed databases with search terms: gonadal/germinal mosaicism, ovarian mosaicism, premeiotic aneuploidy, meiosis and trisomy 21. Additionally, a key reference from 1966 was included. RESULTS: Data from over 9000 cases of Down syndrome showed a bimodal maternal age distribution curve, indicating two overlapping distributions. One of these matched the pattern for the control population, with a peak at about 28 years and included all cases that had occurred independently of maternal age, including those due to germinal mosaicism, about 40% of the cohort. The first cytological proof of germinal mosaicism was obtained by fluorescence in situ hybridisation analysis. Comparative genomic hybridisation analysis of oocyte chromosomes suggests an incidence of up to 15% in premeiotic oocytes. Direct investigation of fetal ovarian cells led to variable results for chromosome 21 mosaicism. CONCLUSIONS: Oocytes with premeiotic errors will significantly contribute to the high level of preimplantation and prenatal death. Data so far available suggests that, depending upon the maternal age, up to 40% of aneuploidy that is present in oocytes at the end of meiosis I may be due to germinal mosaicism.


Assuntos
Aneuploidia , Cromossomos/genética , Meiose/genética , Mosaicismo , Hibridização Genômica Comparativa , Feminino , Células Germinativas/crescimento & desenvolvimento , Células Germinativas/patologia , Humanos , Idade Materna , Oócitos/crescimento & desenvolvimento , Oócitos/patologia , Gravidez
17.
J Assist Reprod Genet ; 36(12): 2593-2604, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31760547

RESUMO

PURPOSE: Women with early-stage breast cancer may still have a future child wish, while chemotherapy may impair fertility. To pursue on fertility preservation shortly after breast cancer diagnosis is complex. This review holds a critical reflection on all topics that need to be counseled to give them the opportunity to make a well-informed decision before starting any oncological treatment. METHODS: A comprehensive literature review was performed on papers published in English language on breast cancer in young women, risk of chemotherapy-induced infertility, fertility preservation techniques, impact of possible mutation carriership, and future pregnancy outcome. RESULTS: Below 40 years of age, the risk of permanent chemotherapy-induced ovarian function failure is approximately 20%, where taxanes do not significantly add to this risk. Overall, 23% of reported women who performed fertility preservation by cryopreserving oocytes or embryos returned for embryo transfer. Of these, 40% gave live birth. Both fertility preservation in women diagnosed with breast cancer and pregnancy after treatment seem safe with respect to breast cancer survival. Women who have a genetic predisposition for breast cancer like BRCA gene mutation should also be informed about the possibility of pre-implantation genetic diagnosis. CONCLUSIONS: Women with an early stage of breast cancer and a possible future child wish should be referred to an expertise center in breast cancer, fertility preservation, and genetics in this complex decision-making process, shortly after diagnosis.


Assuntos
Neoplasias da Mama/diagnóstico , Detecção Precoce de Câncer , Aconselhamento Genético , Infertilidade Feminina/fisiopatologia , Adulto , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Hidrocarbonetos Aromáticos com Pontes/uso terapêutico , Criança , Criopreservação , Feminino , Fertilidade/efeitos dos fármacos , Fertilidade/fisiologia , Preservação da Fertilidade/métodos , Humanos , Infertilidade Feminina/patologia , Infertilidade Feminina/prevenção & controle , Recuperação de Oócitos/métodos , Oócitos/crescimento & desenvolvimento , Oócitos/patologia , Indução da Ovulação/métodos , Gravidez , Taxoides/uso terapêutico , Adulto Jovem
18.
Braz. j. biol ; 79(4): 669-677, Nov. 2019. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1001474

RESUMO

Abstract Cheirodon interruptus is a ubiquitous small characid that inhabits the Pampean region and commonly used as bait. Its vast market is supplied from the wild population causing a significant environmental impact. In this study, we assess the effect of photoperiod on ovarian maturation in order to evaluate its potential as a tool to manipulate reproduction under artificial conditions. Four treatments in triplicate (light: dark, L: D) were tested: 24L: 0D, 12L: 12D, 0L: 24D and a progressive photoperiod corresponding to the daily photoperiod increments in wild during winter-spring transition, accelerated three times. The experiment was conducted for 45 days. Gonadosomatic index (GSI), oocyte mean diameter, vitellogenic oocyte proportions, plasma estradiol concentrations (E2), condition factor (Kn) and standard length were estimated. Values of mean GSI, oocyte diameter, vitellogenic oocyte proportions and E2 concentration were maximum in the progressive treatment indicating vitellogenesis stimulation. In turn the same parameters were minimum in the 24L: 0D, revealing the vitellogenesis inhibition. This study showed that photoperiodic regime play an important role in the onset of ovarian maturation in C. interruptus.


Resumo Cheirodon interruptus é um pequeno caracídeo amplamente distribuído na região Pampeana e comumente usado como isca. Seu vasto mercado se abastece de populações silvestres causando um impacto ambiental significativo. Neste estudo, investigamos o efeito do fotoperíodo no amadurecimento do ovário para avaliar o potencial deste fator como ferramenta para manipular a reprodução em condições artificiais. Quatro tratamentos foram testados por triplicado (luz: escuro, L: D): 24L: 0D, 12L: 12D, 0L: 24D e um fotoperíodo progressivo que simula as mudanças das horas luz na natureza e na transição de inverno a primavera, acelerado três vezes. O experimento se realizou durante 45 dias. O índice gonadossomático (GSI), o diâmetro médio dos ovócitos, a proporção de ovócitos vitelogênicos, as concentrações plasmáticas de estradiol (E2), o fator de condição (Kn) e o comprimento padrão foram estimados. Os valores médios de GSI, o diâmetro dos ovócitos, as proporções de ovócitos vitelogênicos e a concentração de E2 foram maximizados no fotoperíodo progressivo, indicando estimulação de vitelogênesis. Por outro lado, esses mesmos parâmetros resultaram mínimos no tratamento 24L: 0D, revelando um efeito inibidor da vitelogênesis. Este estudo mostrou que as variações de fotoperíodo exercem um papel importante no início vitelogênesis reprodutiva em C. interruptus .


Assuntos
Animais , Feminino , Oócitos/crescimento & desenvolvimento , Reprodução/fisiologia , Fotoperíodo , Characidae/fisiologia , Estações do Ano , Ritmo Circadiano , Estradiol/sangue
19.
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
20.
PLoS One ; 14(10): e0222390, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31647816

RESUMO

The size of oocytes was previously reported to be smaller in obese women with polycystic ovary syndrome (PCOS). In the present prospective cohort study, we sought to determine whether oocyte size and morphology are associated with patient characteristics in non-PCOS women. Oocyte and oolemmal diameter were measured, enlarged perivitelline space (PVS) and ooplasmic granulation were assessed in 308 MII oocytes from 77 IVF/ICSI couples. Statistical analysis was undertaken using SAS version 9.4 (SAS institute Inc., USA). Continuous values are presented as mean ± SD and compared using a two-sample t-test or Mann-Whitney U test as appropriate. Categorical parameters are presented as proportions and compared using a Fisher exact test. Logistic and linear regression models were used to control for the effect of age for categorical and continuous variables respectively. P-value < 0.05 was considered statistically significant. Patients presented with a mean age of 40.3±5.0 years, had a BMI of 25.1±6.1 kg/m2, median AMH levels of 0.6 ng/ml and produced a median of 4 oocytes. Mean total oocyte diameter was 163.2±7.4 µm (range 145.8-182.1 µm), while oolemmal diameter was 109.4±4.1 µm (range 98.5-122.3 µm). After adjusting for age and ovarian reserve increasing BMI was associated with decreased total oocyte diameter (p<0.05). Total oocyte diameter was also inversely associated with AMH levels (p = 0.03) and oocyte yield (p = 0.04). In contrast to total oocyte diameter, oolemmal diameter was not related to patient characteristics. Younger women and those with large oocyte yields demonstrated fewer oocytes with ooplasmic granulation (p<0.05 and p = 0.01). After adjustments for age, ooplasmic granulation was also less frequently observed in oocytes from women with higher AMH (p = 0.03) and increasing BMI (p<0.01). Fertilization was more likely in oocytes with larger oolemmal diameter (p = 0.008). Embryos from oocytes with larger total and ooplasmic diameters were more likely to be transferred or frozen (p = 0.004 and p = 0.01). In non-PCOS infertile women, BMI and ovarian function relate to total oocyte diameter. These results expand on previously observed associations between oocyte size and BMI in women with PCOS. They indicate the importance of detailed oocyte assessments, which may aid the currently used criteria for embryo selection and help to better understand how oocyte status is associated with later embryo development.


Assuntos
Tamanho Celular , Infertilidade Feminina/terapia , Oócitos/crescimento & desenvolvimento , Reserva Ovariana/fisiologia , Adulto , Índice de Massa Corporal , Desenvolvimento Embrionário/fisiologia , Feminino , Fertilização In Vitro , Humanos , Infertilidade Feminina/fisiopatologia , Masculino , Pessoa de Meia-Idade , Recuperação de Oócitos/métodos , Oócitos/patologia , Indução da Ovulação , Síndrome do Ovário Policístico/patologia , Gravidez , Taxa de Gravidez , Injeções de Esperma Intracitoplásmicas
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