Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 180
Protein & Cell ; (12): 51-63, 2023.
Article in English | WPRIM | ID: wpr-971605


RBM46 is a germ cell-specific RNA-binding protein required for gametogenesis, but the targets and molecular functions of RBM46 remain unknown. Here, we demonstrate that RBM46 binds at specific motifs in the 3'UTRs of mRNAs encoding multiple meiotic cohesin subunits and show that RBM46 is required for normal synaptonemal complex formation during meiosis initiation. Using a recently reported, high-resolution technique known as LACE-seq and working with low-input cells, we profiled the targets of RBM46 at single-nucleotide resolution in leptotene and zygotene stage gametes. We found that RBM46 preferentially binds target mRNAs containing GCCUAU/GUUCGA motifs in their 3'UTRs regions. In Rbm46 knockout mice, the RBM46-target cohesin subunits displayed unaltered mRNA levels but had reduced translation, resulting in the failed assembly of axial elements, synapsis disruption, and meiotic arrest. Our study thus provides mechanistic insights into the molecular functions of RBM46 in gametogenesis and illustrates the power of LACE-seq for investigations of RNA-binding protein functions when working with low-abundance input materials.

Animals , Mice , 3' Untranslated Regions/genetics , Cell Cycle Proteins/metabolism , Gametogenesis/genetics , Meiosis/genetics , Nuclear Proteins/genetics , RNA-Binding Proteins/genetics
Chinese Journal of Biotechnology ; (12): 4108-4122, 2023.
Article in Chinese | WPRIM | ID: wpr-1008015


Meiotic initiation is a critical step in gametogenesis. Recently, some genes required for meiotic initiation have been identified. However, meiosis-initiating factors and the underlying mechanisms are far from being fully understood. We have established a long-term culture system of spermatogonial stem cells (SSCs) and an in vitro model of meiotic initiation using mouse SSCs. Our previous study revealed that the RNA-binding protein RBFOX2 may regulate meiotic initiation, but the role and the mechanism need to be further elucidated. In this study, we constructed RBFOX2 knockdown SSC lines by using lentivirus-mediated gene delivery method, and found that the knockdown SSCs underwent normal self-renewal, mitosis and differentiation. However, they were unable to initiate meiosis when treated with retinoic acid, and they underwent apoptosis. These results indicate that RBFOX2 plays an essential role in meiotic initiation of spermatogonia. This work provides new clues for understanding the functions of RNA-binding proteins in meiotic initiation.

Mice , Male , Animals , Spermatogonia/metabolism , Meiosis/genetics , Cell Differentiation , Tretinoin/pharmacology , Mitosis , Testis/metabolism
Acta Academiae Medicinae Sinicae ; (6): 142-148, 2022.
Article in Chinese | WPRIM | ID: wpr-927858


Aurora kinase A (AURKA),a family member of aurora kinases,is involved in mitotic entry,maturation and separation of centrosome,assembly and stabilization of bipolar spindle,and condensation and separation of chromosome.Studies have demonstrated that AURKA plays a similar role in meiosis,while the specific mechanism and the similarities and differences in its role between meiosis and mitosis remain unclear.Therefore,we reviewed the studies about the localization and activation of AURKA in oocyte meiosis,and compared the role of AURKA in regulating spindle formation,activating spindle assembly checkpoint,and correcting the kinetochore-microtubule attachment between the meiosis of oocytes and the mitosis of somatic cells.This review will lay a theoretical foundation for revealing the mechanism of AURKA in the regulation of cell division and for the clinical research related to cancer and reproduction.

Humans , Aurora Kinase A/genetics , Cell Cycle Proteins/genetics , Chromosome Segregation , Meiosis , Oocytes
Rev. bras. ginecol. obstet ; 43(6): 480-486, June 2021. graf
Article in English | LILACS | ID: biblio-1341135


Abstract The process of ovulation involves multiple and iterrelated genetic, biochemical, and morphological events: cessation of the proliferation of granulosa cells, resumption of oocyte meiosis, expansion of cumulus cell-oocyte complexes, digestion of the follicle wall, and extrusion of the metaphase-II oocyte. The present narrative review examines these interrelated steps in detail. The combined or isolated roles of the folliclestimulating hormone (FSH) and luteinizing hormone (LH) are highlighted. Genes indiced by the FSH genes are relevant in the cumulus expansion, and LH-induced genes are critical for the resumption ofmeiosis and digestion of the follicle wall. A nonhuman model for follicle-wall digestion and oocyte release was provided.

Resumo O processo de ovulação envolve modificações genéticas, bioquímicas e morfológicas múltiplas e interrelacionadas: suspensão da proliferação das células da granulosa, reinício da meiose do oócito, expansão das células do complexo cumulus-oócito, digestão da parede folicular, e extrusão do oócito. Esta revisão narrativa examina em detalhes cada um desses eventos e os principais genes e proteínas envolvidos. Mais importante, a ação combinada ou isolada do hormônio folículo-estimulante (HFE) e do hormônio luteinizante (HL) é destacada. Detalha-se o papel do HFE na expansão do cumulus e do HL na digestão da parede folicular, permitindo a extrusão do oócito na superfície ovariana. Proveu-se um modelo não humano para explicar a digestão da parede folicular.

Humans , Animals , Female , Ovulation/physiology , Luteinizing Hormone/physiology , Oocytes/growth & development , Ovulation/genetics , Luteinizing Hormone/genetics , Signal Transduction , Models, Animal , Cumulus Cells/physiology , Follicle Stimulating Hormone/physiology , Follicle Stimulating Hormone/genetics , Ovarian Follicle/growth & development , Granulosa Cells/physiology , Meiosis/physiology , Meiosis/genetics
Asian Journal of Andrology ; (6): 580-589, 2021.
Article in English | WPRIM | ID: wpr-922375


The synaptonemal complex (SC) is a meiosis-specific proteinaceous macromolecular structure that assembles between paired homologous chromosomes during meiosis in various eukaryotes. The SC has a highly conserved ultrastructure and plays critical roles in controlling multiple steps in meiotic recombination and crossover formation, ensuring accurate meiotic chromosome segregation. Recent studies in different organisms, facilitated by advances in super-resolution microscopy, have provided insights into the macromolecular structure of the SC, including the internal organization of the meiotic chromosome axis and SC central region, the regulatory pathways that control SC assembly and dynamics, and the biological functions exerted by the SC and its substructures. This review summarizes recent discoveries about how the SC is organized and regulated that help to explain the biological functions associated with this meiosis-specific structure.

Animals , Chromosome Segregation , Meiosis/physiology , Synaptonemal Complex/physiology
Asian Journal of Andrology ; (6): 549-554, 2021.
Article in English | WPRIM | ID: wpr-922374


Male meiosis is a complex process whereby spermatocytes undergo cell division to form haploid cells. This review focuses on the role of retinoic acid (RA) in meiosis, as well as several processes regulated by RA before cell entry into meiosis that are critical for proper meiotic entry and completion. Here, we discuss RA metabolism in the testis as well as the roles of stimulated by retinoic acid gene 8 (STRA8) and MEIOSIN, which are responsive to RA and are critical for meiosis. We assert that transcriptional regulation in the spermatogonia is critical for successful meiosis.

Animals , Humans , Cell Differentiation/genetics , Meiosis/drug effects , Spermatogenesis/physiology , Tretinoin/metabolism
Asian Journal of Andrology ; (6): 555-561, 2021.
Article in English | WPRIM | ID: wpr-922362


Meiosis is an essential step in gametogenesis which is the key process in sexually reproducing organisms as meiotic aberrations may result in infertility. In meiosis, programmed DNA double-strand break (DSB) formation is one of the fundamental processes that are essential for maintaining homolog interactions and correcting segregation of chromosomes. Although the number and distribution of meiotic DSBs are tightly regulated, still abnormalities in DSB formation are known to cause meiotic arrest and infertility. This review is a detailed account of molecular bases of meiotic DSB formation, its evolutionary conservation, and variations in different species. We further reviewed the mutations of DSB formation genes in association with human infertility and also proposed the future directions and strategies about the study of meiotic DSB formation.

Humans , DNA Breaks, Double-Stranded , DNA Repair/genetics , Infertility/genetics , Meiosis/physiology
Asian Journal of Andrology ; (6): 562-571, 2021.
Article in English | WPRIM | ID: wpr-922359


Repairing DNA double-strand breaks (DSBs) with homologous chromosomes as templates is the hallmark of meiosis. The critical outcome of meiotic homologous recombination is crossovers, which ensure faithful chromosome segregation and promote genetic diversity of progenies. Crossover patterns are tightly controlled and exhibit three characteristics: obligatory crossover, crossover interference, and crossover homeostasis. Aberrant crossover patterns are the leading cause of infertility, miscarriage, and congenital disease. Crossover recombination occurs in the context of meiotic chromosomes, and it is tightly integrated with and regulated by meiotic chromosome structure both locally and globally. Meiotic chromosomes are organized in a loop-axis architecture. Diverse evidence shows that chromosome axis length determines crossover frequency. Interestingly, short chromosomes show different crossover patterns compared to long chromosomes. A high frequency of human embryos are aneuploid, primarily derived from female meiosis errors. Dramatically increased aneuploidy in older women is the well-known "maternal age effect." However, a high frequency of aneuploidy also occurs in young women, derived from crossover maturation inefficiency in human females. In addition, frequency of human aneuploidy also shows other age-dependent alterations. Here, current advances in the understanding of these issues are reviewed, regulation of crossover patterns by meiotic chromosomes are discussed, and issues that remain to be investigated are suggested.

Humans , Cell Division/physiology , Chromosome Segregation/physiology , Meiosis/genetics , Recombination, Genetic
Acta Physiologica Sinica ; (6): 518-526, 2021.
Article in Chinese | WPRIM | ID: wpr-887687


Cyclic adenosine monophosphate (cAMP) is one of the significant and conserved second messengers in mammals, and it participates in regulating the developmental and physiological functions of various organs and tissues through transducting extracellular signals. Studies have shown that the process of meiosis in female mammalian oocytes is closely related to the level of cAMP and strictly regulated. In oocytes, cAMP is mainly synthesized by adenylate cyclase 3 (AC3) and degraded by phosphodiesterase 3A (PDE3A), both of which jointly regulate the level of cAMP in oocytes and play important roles in the follicular development and oogenesis of female ovaries. It has been well illuminated that high level of cAMP in the cytoplasm of oocytes in growing follicles could maintain the arrest of the first meiotic of oocytes for a long time. The oocytes will resume meiosis and mature either when the synthesis of cAMP is down-regulated, or when cAMP is degraded by PDE3A. In recent years, the novo physiological functions of cAMP in oogenesis have been reported. To better understand the regulatory role and mechanism of cAMP in mammalian gametogenesis, this paper reviews the relevant research regarding the relationship between cAMP and germ cell development.

Animals , Female , Adenosine Monophosphate , Cyclic AMP , Mammals , Meiosis , Oocytes , Oogenesis
Chinese Journal of Medical Genetics ; (6): 286-289, 2021.
Article in Chinese | WPRIM | ID: wpr-879573


The development of female germ cells can be mainly divided into two stages: fetal germ cells and oocytes in folliculogenesis after puberty. Mitosis-meiosis transition, meiosis arrest and re-activation are the key phases of the development. Several phases may be characterized by their distinct molecular events, which involve precise regulation of gene expression and interaction with corresponding gonadal niche cells. In recent years, single-cell transcriptome studies have clarified phase-specific patterns of gene expression, signaling pathways and epigenetic modification during oogenesis and folliculogenesis. These works have provided important insights into the development of female germ cells and pathogenesis of germ-cell related diseases, which may promote clinical application of reproductive genetic research.

Female , Humans , Germ Cells , Meiosis , Oocytes , Oogenesis/genetics , Signal Transduction
Acta Physiologica Sinica ; (6): 513-522, 2020.
Article in Chinese | WPRIM | ID: wpr-827035


Mammalian oocytes within Graafian follicles are arrested at prophase I of meiosis. C-type natriuretic peptide (NPPC), secreted by mural granulosa cells (MGCs), maintains oocyte meiotic arrest via binding to its cognate receptor natriuretic peptide receptor 2 (NPR2) and producing cyclic guanosine monophosphate (cGMP). NPR2 is most concentrated in the cumulus cells. In addition, cAMP, gap junction, inosine monophosphate dehydrogenase (IMPDH) and other important regulatory factors are also involved in meiotic arrest. Luteinizing hormone (LH) then rapidly decreases cGMP and induces oocyte meiotic resumption. In this paper, advances in the molecular mechanisms of meiotic arrest and LH-induced meiotic resumption were reviewed. This paper may provide new ideas for the prevention, diagnosis and treatment of related reproductive diseases.

Animals , Female , Cumulus Cells , Luteinizing Hormone , Meiosis , Natriuretic Peptide, C-Type , Genetics , Oocytes
Chinese Journal of Biotechnology ; (12): 612-621, 2020.
Article in Chinese | WPRIM | ID: wpr-827007


Apomixis has been widely concerned because of its great potential in heterosis fixation. Artificial apomixis is an important direction of current apomixis research. Mitosis instead of Meiosis (MIME) produces diploid gametes that is identical with the maternal genetic composition and is a key step in the artificial creation of apomixes. This paper reviews the occurrence of MIME and its application in crop apomixis and the problems encountered, in an aim to provide reference for expanding the application of MIME in crop apomixis.

Apomixis , Crops, Agricultural , Genetics , Diploidy , Germ Cells , Meiosis , Mitosis
Asian Journal of Andrology ; (6): 79-87, 2020.
Article in English | WPRIM | ID: wpr-1009754


The transition from spermatogonia to spermatocytes and the initiation of meiosis are key steps in spermatogenesis and are precisely regulated by a plethora of proteins. However, the underlying molecular mechanism remains largely unknown. Here, we report that Src homology domain tyrosine phosphatase 2 (Shp2; encoded by the protein tyrosine phosphatase, nonreceptor type 11 [Ptpn11] gene) is abundant in spermatogonia but markedly decreases in meiotic spermatocytes. Conditional knockout of Shp2 in spermatogonia in mice using stimulated by retinoic acid gene 8 (Stra8)-cre enhanced spermatogonial differentiation and disturbed the meiotic process. Depletion of Shp2 in spermatogonia caused many meiotic spermatocytes to die; moreover, the surviving spermatocytes reached the leptotene stage early at postnatal day 9 (PN9) and the pachytene stage at PN11-13. In preleptotene spermatocytes, Shp2 deletion disrupted the expression of meiotic genes, such as disrupted meiotic cDNA 1 (Dmc1), DNA repair recombinase rad51 (Rad51), and structural maintenance of chromosome 3 (Smc3), and these deficiencies interrupted spermatocyte meiosis. In GC-1 cells cultured in vitro, Shp2 knockdown suppressed the retinoic acid (RA)-induced phosphorylation of extracellular-regulated protein kinase (Erk) and protein kinase B (Akt/PKB) and the expression of target genes such as synaptonemal complex protein 3 (Sycp3) and Dmc1. Together, these data suggest that Shp2 plays a crucial role in spermatogenesis by governing the transition from spermatogonia to spermatocytes and by mediating meiotic progression through regulating gene transcription, thus providing a potential treatment target for male infertility.

Animals , Male , Mice , Cell Cycle Proteins/genetics , Cell Line , Cell Survival , Chondroitin Sulfate Proteoglycans/genetics , Chromosomal Proteins, Non-Histone/genetics , Gene Expression Regulation , Gene Knockdown Techniques , Infertility, Male , Meiosis/genetics , Mice, Knockout , Mice, Transgenic , Phosphate-Binding Proteins/genetics , Protein Tyrosine Phosphatase, Non-Receptor Type 11/genetics , Rad51 Recombinase/genetics , Real-Time Polymerase Chain Reaction , Spermatocytes/metabolism , Spermatogenesis/genetics , Spermatogonia/metabolism
Semina cienc. biol. saude ; 39(2): 171-180, jul 2018.
Article in Portuguese | LILACS | ID: biblio-994905


A reprodução sexuada já foi considerada universal, e posteriormente, a forma mais perfeita de reprodução. Todavia, a partir de meados do século XIX, pesquisas no nível celular colocaram em xeque a ideia de que tipos de reprodução assexuadas fossem primitivos ou inferiores. Ao longo do século XX, e adentrando no XXI, hipóteses foram levantadas para explicar as vantagens da reprodução sexuada sobre a assexuada assim como o que permitiria a reprodução sexuada se manter quando seria mais vantajoso se reproduzir de forma assexuada. A mais importante e conhecida é a hipótese da Rainha Vermelha. Paralelamente, vários trabalhos procuraram entrever as pressões ecológicas que permitiram e favoreceram o aparecimento da reprodução sexuada em um cenário situado há cerca de dois bilhões de anos. O objetivo desse trabalho é revisar respostas históricas que marcaram o estudo da origem, da evolução e da manutenção da reprodução sexuada, identificando algumas das principais questões que a comunidade científica elaborou nos últimos duzentos anos.

Sexual reproduction has already been considered universal, and subsequently, the most perfect form of reproduction. However, since the mid-nineteenth century, research at the cellular level has questioned the idea that asexual reproduction types are primitive or inferior. During the twentieth century, and entering the XXI, hypotheses were raised to explain the advantages of sexual reproduction over the asexual as well as what would allow sexual reproduction to be maintained when it would be more advantageous to reproduce asexually. The most important and known is the Red Queen hypothesis. At the same time, several studies have sought to understand the ecological pressures that allowed and favored the appearance of sexual reproduction in a scenario that was around two billion years ago. The aim of this work is to review historical responses that marked the study of the origin, evolution and maintenance of sexual reproduction, identifying some of the main questions that the scientific community has elaborated over the last two hundred years.

Developmental Biology , Meiosis , Reproduction , Sexuality/classification
National Journal of Andrology ; (12): 558-561, 2018.
Article in Chinese | WPRIM | ID: wpr-689691


Nanos2, a member of the Nanos2 gene family, is a specific gene in male germ cells and encodes an evolutionarily conserved RNA binding protein expressed in male primordial germ cells (PGCs) during the embryonic period as well as in the spermatogonial stem cells (SSCs) of the testis. In the embryonic period, Nanos2 promotes the development of male PGCs and inhibits them from meiosis. In the process of spermatogenesis, Nanos2 suppresses the differentiation of SSCs in the testis and maintains the stability of the SSC pool. The knockout of Nanos2 may cause the disappearance of germ cells and sterility in male mice while its overexpression in the testis may lead to accumulation of SSCs in seminiferous tubules. Besides, Nanos2 is involved in the degradation of specific RNAs and possibly associated with some diseases of the male reproductive system. This review focuses on the recent progress in the studies of Nanos2 in the male reproductive system.

Animals , Male , Mice , Cell Differentiation , Gene Knockout Techniques , Meiosis , RNA , Metabolism , RNA-Binding Proteins , Genetics , Metabolism , Spermatogenesis , Physiology , Spermatogonia , Spermatozoa , Testis , Cell Biology
Article in English | LILACS, VETINDEX | ID: biblio-911895


The aim of this study was to evaluate the influence of epidermal growth factor (EGF) on in vitro maturation of canine oocytes at different times of the process. Ovaries were collected from 55 bitches considered healthy and aseptically isolated, immersed in physiological solution (0.9% NaCl) and transported under refrigeration. Grade 1 cumulus-oocyte complexes (COCs) were selected and divided into two groups: control group (CG) and treatment group (TG). In CG 698 grade I COCs were placed in 4-well plates containing TCM-199 medium supplemented with 25 mM HEPES, 100 IU/mL penicillin, 100 mg/mL streptomycin, 26 mM sodium bicarbonate, 1.5 mM sodium pyruvate, 2.9 mM sodium lactate pentahydrate, 0.6 mM cysteine, 0.03 IU/mL hCG, 0.5 µg/mL FSH, 20 µg/mL estrogen at 38.5ºC in a humidified atmosphere of 5% CO2 in times of 24 h, 48 h, and 72 h. In TG 547 COCs received the same maturation medium plus 10 ηg/mL EGF. Logistic regression models (SAS, 2011) were constructed in order to estimate the chances of oocytes being observed at nuclear maturation stages in different culture times (24 h, 48 h, and 72 h). Based on the results found EGF-supplemented medium showed 2.56 times more chances of having an oocyte at metaphase I (M-I) than medium without EGF (p < 0.0001). The results of this study demonstrated that the time of 72 h showed 5.88 times more chances of having an oocyte at metaphase II (M-II) compared to time of 24 h (p = 0.0001) and 7.69 times more chance than time of 48 h (p = 0.0001). The chances of finding an oocyte at M-II were also 9.09 times higher in medium supplemented with EGF than in medium without EGF (p = 0.0001). Thus, these results demonstrated the essential importance of EGF at different moments of oocyte maturation, being a key component for the acquisition of meiotic competence in bitches, increasing the M-I and M-II rates.(AU)

O objetivo deste estudo foi avaliar a influência do fator de crescimento epidermal (EGF) em diferentes momentos da maturação in vitro de oócitos caninos. Os ovários foram coletados de 55 cadelas consideradas sadias e isolados assepticamente, imersos em solução fisiológica e transportados refrigerados. Os complexos cumulus-oócito (COCs) grau 1 foram selecionados e divididos em dois grupos, denominados grupo controle (GC) e grupo tratamento (GT). No GC, 698 COCs grau I foram cultivados em placas de quatro poços contendo meio TCM-199 suplementado com 25 mM de HEPES, 100 UI/mL de penicilina, 100 mg/mL de estreptomicina, 26 mM de bicarbonato de sódio, 1,5 mM de piruvato de sódio, 2,9 mM de lactato de sódio penta hidratado, 0,6 mM de cisteína, 0,03 UI/mL de hCG, 0,5 µg/mL de FSH, 20 µg/mL de estrógeno em estufa úmida a 38ºC, 5% de CO2 nos períodos de 24h, 48 h e 72 h . Já no GT, 547 COCs receberam o mesmo meio de maturação acrescido de 10 ηg/mL do EGF. Modelos de regressão logística foram elaborados para estimar as chances do oócito ser observado nos estágios de maturação nuclear em diferentes tempos de cultivo. Com base nos resultados encontrados, o meio suplementado com EGF demonstrou 2,56 vezes mais chances de ter um oócito no estágio de metáfase I (M-I) do que o meio sem EGF (p < 0,0001). Os resultados desse estudo demonstraram também que o tempo de 72 h mostrou 5,88 vezes mais chances de ter um oócito no estágio de metáfase II (M-II) do que o tempo de 2 h (p = 0,0001) e 7,69 vezes mais chance do que o tempo de 48h (p = 0,0001). As chances de se encontrar um oócito em M-II também foram 9,09 vezes maiores no meio suplementado com EGF do que no meio sem EGF (p = 0,0001). Dessa forma, estes resultados demonstraram a importância essencial do EGF em diferentes momentos da maturação oocitária, sendo componente chave para a aquisição da competência meiótica nas cadelas, aumentando os índices de M-I e M-II.(AU)

Animals , Female , Dogs , Epidermal Growth Factor/analysis , In Vitro Oocyte Maturation Techniques/methods , In Vitro Oocyte Maturation Techniques/veterinary , Meiosis
National Journal of Andrology ; (12): 468-472, 2017.
Article in Chinese | WPRIM | ID: wpr-812739


Pluripotent stem cells (PSCs), including embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), have the potential of differentiating into all types of adult cells. Today, mature functional sperm can be derived from mouse PSCs in vitro, and meanwhile primordial germ cells (PGCs) and meiotic prophase sperm cells can be generated from human ESCs/iPSCs (hESCs/hiPSCs). It is proposed that non-genetic azoospermia might be cured if functional sperm could be obtained from human PSCs (hPSCs) in vitro. It is also possible that healthy functional sperm could be derived from the patient with genetic factor-induced azoospermia by combining iPSCs and gene editing technology. IPSC-derived functional sperm have a higher clinical value for the avoidance of the sperm source and the issue of medical ethics. This article summarizes recent advances in the differentiation of PSCs into male germ cells in vitro, aiming to provide some reference for the treatment of male infertility with PSCs.

Animals , Humans , Male , Mice , Cell Differentiation , Embryonic Stem Cells , Cell Biology , Induced Pluripotent Stem Cells , Cell Biology , Infertility, Male , Therapeutics , Meiosis , Pluripotent Stem Cells , Cell Biology , Spermatozoa , Cell Biology
Chinese Journal of Medical Genetics ; (6): 284-288, 2017.
Article in Chinese | WPRIM | ID: wpr-335136


Primary ovarian insuffiency (POI), which accounts for female infertility, is characterized by amenorrhea before the age of 40 and high serum level of follicular stimulating hormone (>40 U/L) at two measurements taken at least one month apart. The disorder is believed to have a strong genetic component. A large number of candidate genes have been proposed, though few of them were extensively studied. With the rapid evolvement of genome sequencing technology, recent research raised the possibility that the genes involved in essential steps of meiosis such as chromosome synapsis and recombination play an important role in the pathogenesis of POI. Clarifying the genetic pathogenesis of POI not only can enhance understanding of the molecular mechanism of reproductive functions and infertility, but also provide accurate information for genetic counseling for such patients.

Female , Humans , Follicle Stimulating Hormone , Metabolism , Infertility, Female , Genetics , Meiosis , Primary Ovarian Insufficiency , Genetics , Metabolism
Clinical and Experimental Reproductive Medicine ; : 15-21, 2017.
Article in English | WPRIM | ID: wpr-165799


OBJECTIVE: The aims of this study were to investigate whether fertilization could induce the resumption of meiosis in mouse oocytes arrested at metaphase I (MI) after in vitro maturation (IVM), and to investigate the effect of Ca²⁺ chelator treatment at the time of fertilization on the transition from MI to metaphase II (MII). METHODS: MII-stage and arrested MI-stage mouse oocytes after IVM were fertilized, and then embryonic development was monitored. Blastocysts from each group were transferred into 2.5 days post-coitum pseudo-pregnant ICR mice. MI oocytes after IVM were treated with a Ca²⁺ chelator to investigate the effect of Ca²⁺ oscillations on their maturation. RESULTS: As insemination time increased, the number of oocytes in the MI group that reached the MII stage also increased. The blastocyst rates and total cell numbers in the MII group were significantly higher than in the MI group. No pregnancy occurred in the MI group, but 10 pregnancies were achieved (10 of 12) in the MII group. The proportion of MI oocytes that matured to MII oocytes after fertilization was significantly higher in the non-treated group than in the Ca²⁺ chelator-treated group. CONCLUSION: The findings that a higher proportion of MI-arrested oocytes progressed to MII after fertilization and that the MI-to-MII transition was blocked by Ca2+ chelator treatments before fertilization indicate that the maturation of MI oocytes to MII oocytes is associated with intracellular Ca²⁺ oscillations driven by fertilization.

Animals , Female , Mice , Pregnancy , Blastocyst , Calcium Signaling , Cell Count , Embryonic Development , Fertilization , In Vitro Oocyte Maturation Techniques , In Vitro Techniques , Insemination , Meiosis , Metaphase , Mice, Inbred ICR , Oocytes , Spermatozoa
Cell Journal [Yakhteh]. 2017; 18 (4): 503-513
in English | IMEMR | ID: emr-185776


Objective: Phthalates, which are commonly used to render plastics into soft and flexible materials, have also been determined as developmental and reproductive toxicants in human and animals. The purpose of this study was to evaluate the effect of mono-[2-ethylhexyl] phthalate [MEHP] and di-[2-ethylhexyl] phthalate [DEHP] oral administrations on maturation of mouse oocytes, apoptosis and gene transcription levels

Materials and Methods: In this experimental study, immature oocytes recovered from Naval Medical Research Institute [NMRI] mouse strain [6-8 weeks], were divided into seven different experimental and control groups. Control group oocytes were retrieved from mice that received only normal saline. The experimental groups I, II or III oocytes were retrieved from mice treated with 50, 100 or 200 micro l DEHP [2.56 micro M] solution, respectively. The experimental groups IV, V or VI oocytes were retrieved from mouse exposed to 50, 100 or 200 micro l MEHP [2.56 micro M] solution, respectively. Fertilization and embryonic development were carried out in OMM and T6 medium. Apoptosis was assessed by annexin V-FITC/Dead Cell Apoptosis Kit, with PI staining. In addition, the mRNA levels of Pou5f1, Ccna1 and Asah1 were examined in oocytes. Finally, mouse embryo at early blastocyst stage was stained with acridine-orange [AO] and ethidium-bromide [EB], in order to access their viability

Results: The proportion of oocytes that progressed up to metaphase II [MII] and 2-cells embryo formation stage was significantly decreased by exposure to MEHP or DEHP, in a dose-dependent manner. Annexin V and PI positive oocytes showed greater quantity in the treated mice than control. Quantitative reverse transcriptase-polymerase chain reaction [qRT-PCR] revealed that expression levels of Pou5f1, Asah1 and Ccna1 were significantly lower in the treated mouse oocytes than control. The total cell count for blastocyst developed from the treated mouse oocytes was lower than the controls

Conclusion: These results indicate that oral administration of MEHP and DEHP could negatively affect mouse oocyte meiotic maturation and development in vivo, suggesting that phthalates could be risk factors for mammalians' reproductive health. Additionally, phthalate-induced changes in Pou5f1, Asah1 and Ccna1 transcription level could explain in part, the reduced developmental ability of mouse-treated oocytes

Animals, Laboratory , Diethylhexyl Phthalate/adverse effects , Oocyte Retrieval , Models, Animal , Meiosis/drug effects , Gene Expression Profiling , Apoptosis