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2.
Zoolog Sci ; 38(5): 436-443, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34664918

RESUMO

Here, we report that the gross morphology of the testes changes under 'non-mating' or 'mating' conditions in medaka (Oryzias latipes). During these conditions, an efferent duct expands and a histological unit of spermatogenesis, the lobule, increases its number under 'non-mating' conditions. Based on BrdU labeling experiments, lower mitotic activity occurs in gonial cells under 'non-mating' conditions, which is consistent with the reduced number of germ cell cysts. Interestingly, the total number of type A spermatogonia was maintained, regardless of the mating conditions. In addition, the transition from mitosis to meiosis may have been retarded under the 'non-mating' conditions. The minimum time required for germ cells to become sperm, from the onset of commitment to spermatogenesis, was approximately 14 days in vivo. The time was not found to significantly differ between 'non-mating' and 'mating' conditions. The collective data suggest the presence of a mechanism wherein the homeostasis of spermatogenesis is altered in response to the mating conditions.


Assuntos
Oryzias/fisiologia , Espermatogênese/fisiologia , Testículo/fisiologia , Animais , Copulação , Feminino , Masculino , Meiose , Mitose , Oryzias/anatomia & histologia , Testículo/anatomia & histologia
3.
J Agric Food Chem ; 69(40): 11847-11855, 2021 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-34609142

RESUMO

Estrogen and its analogues are ubiquitous in agricultural environments, with large biological functions of oocyte development. Gap junction intercellular communications (GJICs) are the structural basis in cumulus-oocyte complexes (COCs) and regulate oocyte maturation and developmental material transport through a number of pathways. This study mainly determines the effect and potential mechanism of estrogen (17ß-estradiol) in regulating GJICs in porcine COCs. In our study, 17ß-estradiol increased porcine nuclear maturation in a time-dependent manner. The analysis revealed that 17ß-estradiol upregulated the autophagy in COCs during in vitro maturation. In contrast with the control, 17ß-estradiol decreased GJICs in a time-dependent manner between cumulus cells and oocytes, while it was consistent with the control group at 24 h. Carbenoxolone (CBX) blocks GJICs as a negative control group used in our system. Autophagy inhibitor autophinib decreased oocyte maturation, and the reduced nuclear maturation treated with autophinib was abolished by 17ß-estradiol. Besides, the upregulation effect of autophinib on GJICs and transzonal projections (TZPs) was decreased by 17ß-estradiol. 17ß-Estradiol could reduce serine 368 phosphorylation of connexin 43 (Cx43) protein by autophinib in porcine COCs. These results were dependent upon the MEK/ERK signaling pathway. Furthermore, 17ß-estradiol-induced GJICs and Cx43 phosphorylation were inhibited by autophinib or the MEK/ERK pathway inhibitors (Trametinib and FR 180204), indicating that 17ß-estradiol regulated GJICs through the MEK/ERK signaling pathway. In conclusion, 17ß-estradiol improves the autophagy-mediated nuclear maturation with downregulating GJICs and TZPs in porcine COCs. Such an effect occurs by phosphorylation of Cx43, which was regulated via the MEK/ERK signaling pathway.


Assuntos
Conexina 43 , Sistema de Sinalização das MAP Quinases , Animais , Autofagia , Conexina 43/genética , Conexina 43/metabolismo , Estradiol/metabolismo , Estradiol/farmacologia , Feminino , Junções Comunicantes/metabolismo , Meiose , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Oócitos/metabolismo , Fosforilação , Transdução de Sinais , Suínos
4.
Curr Opin Plant Biol ; 63: 102118, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34625367

RESUMO

Male germline development in flowering plants involves two distinct and successive phases, microsporogenesis and microgametogenesis, which involve one meiosis followed by two rounds of mitosis. Many aspects of distinctions after mitosis between the vegetative cell and the male germ cells are seen, from morphology to structure, and the differential functions of the two cell types in the male gametophyte are differentially needed and required for double fertilization. The two sperm cells, carriers of the hereditary substances, depend on the vegetative cell/pollen tube to be delivered to the female gametophyte for double fertilization. Thus, the intercellular communication and coordinated activity within the male gametophyte probably represent the most subtle regulation in flowering plants to guarantee the success of reproduction. This review will focus on what we have known about the differentiation process and the functional diversification of the vegetative cell and the male germ cell, the most crucial cell types for plant fertility and crop production.


Assuntos
Magnoliopsida , Magnoliopsida/genética , Meiose , Óvulo Vegetal/genética , Pólen/genética , Tubo Polínico
5.
Nat Commun ; 12(1): 5827, 2021 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-34625553

RESUMO

During meiosis, chromosomes exhibit dramatic changes in morphology and intranuclear positioning. How these changes influence homolog pairing, alignment, and recombination remain elusive. Using Hi-C, we systematically mapped 3D genome architecture throughout all meiotic prophase substages during mouse spermatogenesis. Our data uncover two major chromosome organizational features varying along the chromosome axis during early meiotic prophase, when homolog alignment occurs. First, transcriptionally active and inactive genomic regions form alternating domains consisting of shorter and longer chromatin loops, respectively. Second, the force-transmitting LINC complex promotes the alignment of ends of different chromosomes over a range of up to 20% of chromosome length. Both features correlate with the pattern of homolog interactions and the distribution of recombination events. Collectively, our data reveal the influences of transcription and force on meiotic chromosome structure and suggest chromosome organization may provide an infrastructure for the modulation of meiotic recombination in higher eukaryotes.


Assuntos
Meiose/fisiologia , Animais , Pareamento Cromossômico/genética , Pareamento Cromossômico/fisiologia , Citometria de Fluxo , Recombinação Homóloga/genética , Recombinação Homóloga/fisiologia , Humanos , Hibridização in Situ Fluorescente , Masculino , Meiose/genética , Camundongos , Camundongos Endogâmicos C57BL , RNA-Seq , Espermatócitos/metabolismo
6.
Biochem J ; 478(20): 3791-3805, 2021 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-34709374

RESUMO

Meiosis facilitates diversity across individuals and serves as a major driver of evolution. However, understanding how meiosis begins is complicated by fundamental differences that exist between sexes and species. Fundamental meiotic research is further hampered by a current lack of human meiotic cells lines. Consequently, much of what we know relies on data from model organisms. However, contextualising findings from yeast, worms, flies and mice can be challenging, due to marked differences in both nomenclature and the relative timing of meiosis. In this review, we set out to combine current knowledge of signalling and transcriptional pathways that control meiosis initiation across the sexes in a variety of organisms. Furthermore, we highlight the emerging links between meiosis initiation and oncogenesis, which might explain the frequent re-expression of normally silent meiotic genes in a variety of human cancers.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Meiose , Oogênese/genética , Espermatogênese/genética , Animais , Caenorhabditis elegans/citologia , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Caenorhabditis elegans/metabolismo , Carcinogênese/genética , Carcinogênese/metabolismo , Carcinogênese/patologia , Drosophila melanogaster/citologia , Drosophila melanogaster/genética , Drosophila melanogaster/crescimento & desenvolvimento , Drosophila melanogaster/metabolismo , Feminino , Humanos , Masculino , Camundongos , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/patologia , Saccharomyces cerevisiae/citologia , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento , Saccharomyces cerevisiae/metabolismo , Fatores Sexuais , Transdução de Sinais , Fatores de Tempo , Xenopus laevis/genética , Xenopus laevis/crescimento & desenvolvimento , Xenopus laevis/metabolismo
7.
Nat Methods ; 18(9): 1060-1067, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34480159

RESUMO

N6-methyladenosine (m6A) is the most prevalent modification of messenger RNA in mammals. To interrogate its functions and dynamics, there is a critical need to quantify m6A at three levels: site, gene and sample. Current approaches address these needs in a limited manner. Here we develop m6A-seq2, relying on multiplexed m6A-immunoprecipitation of barcoded and pooled samples. m6A-seq2 allows a big increase in throughput while reducing technical variability, requirements of input material and cost. m6A-seq2 is furthermore uniquely capable of providing sample-level relative quantitations of m6A, serving as an orthogonal alternative to mass spectrometry-based approaches. Finally, we develop a computational approach for gene-level quantitation of m6A. We demonstrate that using this metric, roughly 30% of the variability in RNA half life in mouse embryonic stem cells can be explained, establishing m6A as a main driver of RNA stability. m6A-seq2 thus provides an experimental and analytic framework for dissecting m6A-mediated regulation at three different levels.


Assuntos
Adenosina/análogos & derivados , Estabilidade de RNA/genética , Análise de Sequência de RNA/métodos , Adenosina/análise , Adenosina/genética , Animais , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Expressão Gênica , Meia-Vida , Meiose , Metiltransferases/genética , Metiltransferases/metabolismo , Camundongos , Camundongos Knockout , Células-Tronco Embrionárias Murinas/citologia , Células-Tronco Embrionárias Murinas/fisiologia , Fatores de Processamento de RNA/genética , Fatores de Processamento de RNA/metabolismo , Leveduras/genética
8.
Ecotoxicol Environ Saf ; 225: 112783, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34544023

RESUMO

Sudan I is one of the industry dyes and widely used in cosmetics, wax agent, solvent and textile. Sudan I has multiple toxicity such as carcinogenicity, mutagenicity, genotoxicity and oxidative damage. However, Sudan I has been illegally used as colorant in food products, triggering worldwide attention about food safety. Nevertheless, the toxicity of Sudan I on reproduction, particularly on oocyte maturation is still unclear. In the present study, using mouse in vivo models, we report the toxicity effects of Sudan I on mouse oocyte. The results reflect that Sudan I exposure disrupts spindle organization and chromosomes alignment as well as cortical actin distribution, thus leading to the failure of polar body extrusion. Based on the transcriptome results, it is found that the exposure of Sudan I leads to the change in expression of 764 genes. Moreover, it's further reflected that the damaging effects of Sudan I are mediated by the destruction of mitochondrial functions, which induces the accumulated ROS to stimulate oxidative stress-induced apoptosis. As an endogenous hormone, melatonin within the ovarian follicle plays function on improving oocyte quality and female reproduction by efficiently suppressing oxidative stress. Moreover, melatonin supplementation also improves oocyte quality and increases fertilization rate during in vitro culture. Consistent with these, we find that in vivo supplementation of melatonin efficaciously suppresses mitochondrial dysfunction and the accompanying apoptosis, thus reverses oocyte meiotic deteriorations. Collectively, our results prove the reproduction toxicity of Sudan I for the exposure of Sudan I reduces the oocyte quality, and demonstrate the protective effects of melatonin against Sudan I-induced meiotic deteriorations.


Assuntos
Melatonina , Animais , Apoptose , Feminino , Meiose , Melatonina/metabolismo , Melatonina/farmacologia , Camundongos , Mitocôndrias , Naftóis , Oócitos/metabolismo , Estresse Oxidativo
9.
J Vis Exp ; (175)2021 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-34542534

RESUMO

Female fertility and reproductive lifespan depend on the quality and quantity of the ovarian oocyte reserve. An estimated 80% of female germ cells entering meiotic prophase I are eliminated during Fetal Oocyte Attrition (FOA) and the first week of postnatal life. Three major mechanisms regulate the number of oocytes that survive during development and establish the ovarian reserve in females entering puberty. In the first wave of oocyte loss, 30-50% of the oocytes are eliminated during early FOA, a phenomenon that is attributed to high Long interspersed nuclear element-1 (LINE-1) expression. The second wave of oocyte loss is the elimination of oocytes with meiotic defects by a meiotic quality checkpoint. The third wave of oocyte loss occurs perinatally during primordial follicle formation when some oocytes fail to form follicles. It remains unclear what regulates each of these three waves of oocyte loss and how they shape the ovarian reserve in either mice or humans. Immunofluorescence and 3D visualization have opened a new avenue to image and analyze oocyte development in the context of the whole ovary rather than in less informative 2D sections. This article provides a comprehensive protocol for whole ovary immunostaining and optical clearing, yielding preparations for imaging using multiphoton microscopy and 3D modeling using commercially available software. It shows how this method can be used to show the dynamics of oocyte attrition during ovarian development in C57BL/6J mice and quantify oocyte loss during the three waves of oocyte elimination. This protocol can be applied to prenatal and early postnatal ovaries for oocyte visualization and quantification, as well as other quantitative approaches. Importantly, the protocol was strategically developed to accommodate high-throughput, reliable, and repeatable processing that can meet the needs in toxicology, clinical diagnostics, and genomic assays of ovarian function.


Assuntos
Reserva Ovariana , Ovário , Animais , Feminino , Imunofluorescência , Meiose , Camundongos , Camundongos Endogâmicos C57BL , Microscopia , Oócitos , Gravidez , Maturidade Sexual
10.
Cell Prolif ; 54(11): e13127, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34546582

RESUMO

OBJECTIVES: The alteration of bioenergetics by oocytes in response to the demands of various biological processes plays a critical role in maintaining normal cellular physiology. However, little is known about the association between energy sensing and energy production with energy-dependent cellular processes like meiosis. MATERIALS AND METHODS: We demonstrated that cell cycle-dependent mitochondrial Ca2+ connects energy sensing to mitochondrial activity in meiosis progression within mouse oocytes. Further, we established a model in mouse oocytes using siRNA knockdowns that target mitochondrial calcium uniporters (MCUs) in order to inhibit mitochondrial Ca2+ concentrations. RESULTS: Decreased numbers of oocytes successfully progressed to the germinal vesicle stage and extruded the first polar body during in vitro culture after inhibition, while spindle checkpoint-dependent meiosis was also delayed. Mitochondrial Ca2+ levels changed, and this was followed by altered mitochondrial masses and ATP levels within oocytes during the entirety of meiosis progression. Abnormal mitochondrial Ca2+ concentrations in oocytes then hindered meiotic progress and activated AMP-activated protein kinase (AMPK) signalling that is associated with gene expression. CONCLUSIONS: These data provide new insight into the protective role that MCU-dependent mitochondrial Ca2+ signalling plays in meiotic progress, in addition to demonstrating a new mechanism of mitochondrial energy regulation by AMPK signalling that influences meiotic maturation.


Assuntos
Canais de Cálcio/metabolismo , Meiose/fisiologia , Mitocôndrias/metabolismo , Oócitos/citologia , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Núcleo Celular/metabolismo , Metabolismo Energético/fisiologia , Camundongos , Fosforilação
11.
PLoS One ; 16(9): e0257248, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34507348

RESUMO

Meiosis is a complex process involving the expression and interaction of numerous genes in a series of highly orchestrated molecular events. Fam9b localized in Xp22.3 has been found to be expressed in testes. However, FAM9B expression, localization, and its role in meiosis have not been previously reported. In this study, FAM9B expression was evaluated in the human testes and ovaries by RT-PCR, qPCR, and western blotting. FAM9B was found in the nuclei of primary spermatocytes in testes and specifically localized in the synaptonemal complex (SC) region of spermatocytes. FAM9B was also evident in the follicle cell nuclei and diffusely dispersed in the granular cell cytoplasm. FAM9B was partly co-localized with SYCP3, which is essential for both formation and maintenance of lateral SC elements. In addition, FAM9B had a similar distribution pattern and co-localization as γH2AX, which is a novel biomarker for DNA double-strand breaks during meiosis. All results indicate that FAM9B is a novel meiosis-associated protein that is co-localized with SYCP3 and γH2AX and may play an important role in SC formation and DNA recombination during meiosis. These findings offer a new perspective for understanding the molecular mechanisms involved in meiosis of human gametogenesis.


Assuntos
Meiose/fisiologia , Proteínas Nucleares/metabolismo , Espermatócitos/metabolismo , Complexo Sinaptonêmico/metabolismo , Adulto , Feminino , Humanos , Imuno-Histoquímica , Masculino , Meiose/genética , Proteínas Nucleares/genética , Ovário/metabolismo , RNA-Seq , Reação em Cadeia da Polimerase em Tempo Real , Complexo Sinaptonêmico/genética , Testículo/metabolismo
12.
G3 (Bethesda) ; 11(10)2021 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-34568932

RESUMO

In Neurospora crassa, expression from an unpaired gene is suppressed by a mechanism known as meiotic silencing by unpaired DNA (MSUD). MSUD utilizes common RNA interference (RNAi) factors to silence target mRNAs. Here, we report that Neurospora CAR-1 and CGH-1, homologs of two Caenorhabditis elegans RNA granule components, are involved in MSUD. These fungal proteins are found in the perinuclear region and P-bodies, much like their worm counterparts. They interact with components of the meiotic silencing complex (MSC), including the SMS-2 Argonaute. This is the first time MSUD has been linked to RNA granule proteins.


Assuntos
Inativação Gênica , Neurospora crassa , DNA Fúngico , Meiose , Neurospora crassa/genética , RNA , Interferência de RNA
13.
Cells ; 10(9)2021 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-34571960

RESUMO

Meiosis involves a series of specific chromosome events, namely homologous synapsis, recombination, and segregation. Disruption of either recombination or synapsis in mammals results in the interruption of meiosis progression during the first meiotic prophase. This is usually accompanied by a defective transcriptional inactivation of the X and Y chromosomes, which triggers a meiosis breakdown in many mutant models. However, epigenetic changes and transcriptional regulation are also expected to affect autosomes. In this work, we studied the dynamics of epigenetic markers related to chromatin silencing, transcriptional regulation, and meiotic sex chromosome inactivation throughout meiosis in knockout mice for genes encoding for recombination proteins SPO11, DMC1, HOP2 and MLH1, and the synaptonemal complex proteins SYCP1 and SYCP3. These models are defective in recombination and/or synapsis and promote apoptosis at different stages of progression. Our results indicate that impairment of recombination and synapsis alter the dynamics and localization pattern of epigenetic marks, as well as the transcriptional regulation of both autosomes and sex chromosomes throughout prophase-I progression. We also observed that the morphological progression of spermatocytes throughout meiosis and the dynamics of epigenetic marks are processes that can be desynchronized upon synapsis or recombination alteration. Moreover, we detected an overlap of early and late epigenetic signatures in most mutants, indicating that the normal epigenetic transitions are disrupted. This can alter the transcriptional shift that occurs in spermatocytes in mid prophase-I and suggest that the epigenetic regulation of sex chromosomes, but also of autosomes, is an important factor in the impairment of meiosis progression in mammals.


Assuntos
Pareamento Cromossômico/genética , Epigênese Genética/genética , Mamíferos/genética , Meiose/genética , Proteínas Recombinantes/genética , Recombinação Genética/genética , Animais , Apoptose/genética , Marcadores Genéticos/genética , Masculino , Camundongos , Cromossomos Sexuais/genética , Espermatócitos/fisiologia , Transcrição Genética/genética
14.
PLoS Biol ; 19(9): e3001376, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34491981

RESUMO

Mammalian oocyte meiotic divisions are highly asymmetric and produce a large haploid gamete and 2 small polar bodies. This relies on the ability of the cell to break symmetry and position its spindle close to the cortex before anaphase occurs. In metaphase II-arrested mouse oocytes, the spindle is actively maintained close and parallel to the cortex, until fertilization triggers sister chromatid segregation and the rotation of the spindle. The latter must indeed reorient perpendicular to the cortex to enable cytokinesis ring closure at the base of the polar body. However, the mechanisms underlying symmetry breaking and spindle rotation have remained elusive. In this study, we show that spindle rotation results from 2 antagonistic forces. First, an inward contraction of the cytokinesis furrow dependent on RhoA signaling, and second, an outward attraction exerted on both sets of chromatids by a Ran/Cdc42-dependent polarization of the actomyosin cortex. By combining live segmentation and tracking with numerical modeling, we demonstrate that this configuration becomes unstable as the ingression progresses. This leads to spontaneous symmetry breaking, which implies that neither the rotation direction nor the set of chromatids that eventually gets discarded are biologically predetermined.


Assuntos
Segregação de Cromossomos , Meiose , Oócitos/citologia , Fuso Acromático , Actinas/metabolismo , Animais , Feminino , Camundongos , Proteína cdc42 de Ligação ao GTP , Proteína rhoA de Ligação ao GTP
15.
Int J Mol Sci ; 22(17)2021 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-34502253

RESUMO

In the past, major findings in meiosis have been achieved, but questions towards the global understanding of meiosis remain concealed. In plants, one of these questions covers the need for two diverse meiotic active SPO11 proteins. In Arabidopsis and other plants, both meiotic SPO11 are indispensable in a functional form for double strand break induction during meiotic prophase I. This stands in contrast to mammals and fungi, where a single SPO11 is present and sufficient. We aimed to investigate the specific function and evolution of both meiotic SPO11 paralogs in land plants. By performing immunostaining of both SPO11-1 and -2, an investigation of the spatiotemporal localization of each SPO11 during meiosis was achieved. We further exchanged SPO11-1 and -2 in Arabidopsis and could show a species-specific function of the respective SPO11. By additional changes of regions between SPO11-1 and -2, a sequence-specific function for both the SPO11 proteins was revealed. Furthermore, the previous findings about the aberrant splicing of each SPO11 were refined by narrowing them down to a specific developmental phase. These findings let us suggest that the function of both SPO11 paralogs is highly sequence specific and that the orthologs are species specific.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Endodesoxirribonucleases/genética , Splicing de RNA/genética , Arabidopsis/química , Arabidopsis/metabolismo , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/fisiologia , Quebras de DNA de Cadeia Dupla , Proteínas de Ligação a DNA/metabolismo , Endodesoxirribonucleases/química , Endodesoxirribonucleases/metabolismo , Endodesoxirribonucleases/fisiologia , Meiose/fisiologia , Rad51 Recombinase/metabolismo , Recombinação Genética , Especificidade da Espécie
16.
G3 (Bethesda) ; 11(9)2021 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-34544118

RESUMO

DNA topoisomerase I (Top1) maintains chromatin conformation during transcription. While Top1 is not essential in simple eukaryotic organisms such as yeast, it is required for the development of multicellular organisms. In fact, tissue and cell-type-specific functions of Top1 have been suggested in the fruit fly Drosophila. A better understanding of Top1's function in the context of development is important as Top1 inhibitors are among the most widely used anticancer drugs. As a step toward such a better understanding, we studied its localization in live cells of Drosophila. Consistent with prior results, Top1 is highly enriched at the nucleolus in transcriptionally active polyploid cells, and this enrichment responds to perturbation of transcription. In diploid cells, we uncovered evidence for Top1 foci formation at genomic regions not limited to the active rDNA locus, suggestive of novel regulation of Top1 recruitment. In the male germline, Top1 is highly enriched at the paired rDNA loci on sex chromosomes suggesting that it might participate in regulating their segregation during meiosis. Results from RNAi-mediated Top1 knockdown lend support to this hypothesis. Our study has provided one of the most comprehensive descriptions of Top1 localization during animal development.


Assuntos
DNA Topoisomerases Tipo I , Drosophila , Animais , DNA Topoisomerases Tipo I/genética , DNA Topoisomerases Tipo I/metabolismo , DNA Ribossômico/genética , Drosophila/genética , Drosophila/metabolismo , Meiose , Saccharomyces cerevisiae/genética , Inibidores da Topoisomerase I
17.
Int J Mol Sci ; 22(18)2021 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-34575966

RESUMO

Meiotic defects derived from incorrect DNA repair during gametogenesis can lead to mutations, aneuploidies and infertility. The coordinated resolution of meiotic recombination intermediates is required for crossover formation, ultimately necessary for the accurate completion of both rounds of chromosome segregation. Numerous master kinases orchestrate the correct assembly and activity of the repair machinery. Although much less is known, the reversal of phosphorylation events in meiosis must also be key to coordinate the timing and functionality of repair enzymes. Cdc14 is a crucial phosphatase required for the dephosphorylation of multiple CDK1 targets in many eukaryotes. Mutations that inactivate this phosphatase lead to meiotic failure, but until now it was unknown if Cdc14 plays a direct role in meiotic recombination. Here, we show that the elimination of Cdc14 leads to severe defects in the processing and resolution of recombination intermediates, causing a drastic depletion in crossovers when other repair pathways are compromised. We also show that Cdc14 is required for the correct activity and localization of the Holliday Junction resolvase Yen1/GEN1. We reveal that Cdc14 regulates Yen1 activity from meiosis I onwards, and this function is essential for crossover resolution in the absence of other repair pathways. We also demonstrate that Cdc14 and Yen1 are required to safeguard sister chromatid segregation during the second meiotic division, a late action that is independent of the earlier role in crossover formation. Thus, this work uncovers previously undescribed functions of the evolutionary conserved Cdc14 phosphatase in the regulation of meiotic recombination.


Assuntos
Proteína Quinase CDC2/genética , Proteínas de Ciclo Celular/genética , Resolvases de Junção Holliday/genética , Meiose/genética , Proteínas Tirosina Fosfatases/genética , Proteínas de Saccharomyces cerevisiae/genética , Segregação de Cromossomos/genética , Troca Genética/genética , Reparo do DNA/genética , DNA Cruciforme/genética , Gametogênese/genética , Recombinação Homóloga/genética , Mutação/genética , Fosforilação/genética , Saccharomyces cerevisiae/genética
18.
Elife ; 102021 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-34586062

RESUMO

During meiosis, protein ensembles in the nuclear envelope (NE) containing SUN- and KASH-domain proteins, called linker nucleocytoskeleton and cytoskeleton (LINC) complex, promote the chromosome motion. Yeast SUN-domain protein, Mps3, forms multiple meiosis-specific ensembles on NE, which show dynamic localisation for chromosome motion; however, the mechanism by which these Mps3 ensembles are formed during meiosis remains largely unknown. Here, we showed that the cyclin-dependent protein kinase (CDK) and Dbf4-dependent Cdc7 protein kinase (DDK) regulate meiosis-specific dynamics of Mps3 on NE, particularly by mediating the resolution of Mps3 clusters and telomere clustering. We also found that the luminal region of Mps3 juxtaposed to the inner nuclear membrane is required for meiosis-specific localisation of Mps3 on NE. Negative charges introduced by meiosis-specific phosphorylation in the luminal region of Mps3 alter its interaction with negatively charged lipids by electric repulsion in reconstituted liposomes. Phospho-mimetic substitution in the luminal region suppresses the localisation of Mps3 via the inactivation of CDK or DDK. Our study revealed multi-layered phosphorylation-dependent regulation of the localisation of Mps3 on NE for meiotic chromosome motion and NE remodelling.


Assuntos
Meiose , Proteínas de Membrana/genética , Membrana Nuclear/metabolismo , Proteínas Nucleares/genética , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Quinases Ciclina-Dependentes/genética , Quinases Ciclina-Dependentes/metabolismo , Proteínas de Membrana/metabolismo , Proteínas Nucleares/metabolismo , Fosforilação , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo
19.
Theriogenology ; 176: 35-42, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34571396

RESUMO

G protein-coupled estrogen receptor (GPER), which is different from traditional estrogen nuclear receptors (ERs), mediates the rapid transduction of nongenomic signals in cells, and works by regulating transcription and intracellular second messengers. Studies have shown that GPER may regulate oocyte maturation, but the relevant mechanism is not entirely clear. Here, goat cumulus-oocyte complexes (COCs) were used as a model to explore the regulation and mechanism of GPER on oocyte maturation. Our study showed that 17ß-estradiol (E2) significantly reduced cyclic guanosine monophosphate (cGMP) synthesis in COCs and accelerated the meiotic resumption of goat oocytes via GPER. Further investigation found that GPER mediated the downregulation of natriuretic peptide receptor 2 (NPR2) protein expression in goat cumulus cells by E2. In addition, we found that E2 significantly upregulated the mRNA levels of epidermal growth (EGF)-like factors in goat cumulus cells through GPER, and activated the downstream EGF receptor (EGFR) and extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathways. Both AG1478 (EGFR inhibitor) and U0126 (ERK1/2 inhibitor) abolished the inhibitory effect of E2 on the protein expression of NPR2. These results indicate that, through GPER, E2 upregulates the mRNA levels of EGF-like factors in goat cumulus cells and activates the downstream EGF signaling network to suppress the expression of NPR2 protein, which results in a decrease in cGMP synthesis and acceleration of meiotic resumption in goat oocytes.


Assuntos
Fator de Crescimento Epidérmico/metabolismo , Cabras , Receptores do Fator Natriurético Atrial/metabolismo , Receptores de Estrogênio , Receptores Acoplados a Proteínas G/metabolismo , Animais , Células do Cúmulo/metabolismo , Feminino , Proteínas de Ligação ao GTP , Cabras/metabolismo , Meiose , Oócitos/metabolismo , Receptores de Estrogênio/genética , Receptores de Estrogênio/metabolismo
20.
Elife ; 102021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34545808

RESUMO

In fluctuating environments, switching between different growth strategies, such as those affecting cell size and proliferation, can be advantageous to an organism. Trade-offs arise, however. Mechanisms that aberrantly increase cell size or proliferation-such as mutations or chemicals that interfere with growth regulatory pathways-can also shorten lifespan. Here we report a natural example of how the interplay between growth and lifespan can be epigenetically controlled. We find that a highly conserved RNA-modifying enzyme, the pseudouridine synthase Pus4/TruB, can act as a prion, endowing yeast with greater proliferation rates at the cost of a shortened lifespan. Cells harboring the prion grow larger and exhibit altered protein synthesis. This epigenetic state, [BIG+] (better in growth), allows cells to heritably yet reversibly alter their translational program, leading to the differential synthesis of dozens of proteins, including many that regulate proliferation and aging. Our data reveal a new role for prion-based control of an RNA-modifying enzyme in driving heritable epigenetic states that transform cell growth and survival.


Assuntos
Proliferação de Células , Transferases Intramoleculares/metabolismo , Meiose , Proteínas Priônicas/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/enzimologia , Crescimento Celular , Epigênese Genética , Regulação Enzimológica da Expressão Gênica , Regulação Fúngica da Expressão Gênica , Proteínas de Choque Térmico HSP70/genética , Proteínas de Choque Térmico HSP70/metabolismo , Transferases Intramoleculares/genética , Longevidade , Proteínas Priônicas/genética , Biossíntese de Proteínas , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento , Proteínas de Saccharomyces cerevisiae/genética , Fatores de Tempo
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