Age-dependent oocyte aneuploidy, a major cause of Down syndrome, is associated with declining sister chromatid cohesion in postnatal oocytes. Here we show that cohesion in postnatal mouse oocytes is regulated by Tex19.1.
View Article and Find Full Text PDFMeiosis relies on the SPO11 endonuclease to generate the recombinogenic DNA double strand breaks (DSBs) required for homologous chromosome synapsis and segregation. The number of meiotic DSBs needs to be sufficient to allow chromosomes to search for and find their homologs, but not excessive to the point of causing genome instability. Here we report that the mammal-specific gene Tex19.
View Article and Find Full Text PDFAndrogens are required for normal male sex differentiation and development of male secondary sexual characteristics. Mutations in AR gene are known to cause defects in male sexual differentiation. In current study, we enrolled a 46,XY phenotypically female patient bearing testes in inguinal canal.
View Article and Find Full Text PDFBack Ground: Men with 47, XYY syndrome are presented with varying physical attributes and degrees of infertility. Little information has been documented regarding the meiotic progression in patients with extra Y chromosome along with the synapses and recombination between the two Y chromosomes.
Methods: Spermatocyte spreading and immunostaining were applied to study the behavior of the extra Y chromosome during meiosis I in an azoospermia patient with 47, XYY syndrome and results were compared with five healthy controls with proven fertility.
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December 2015
Folliculogenesis is an important part of ovarian function as it provides the oocytes for female reproductive life. Characterizing genes/proteins involved in folliculogenesis is fundamental for understanding the mechanisms associated with this biological function and to cure the diseases associated with folliculogenesis. A large number of genes/proteins associated with folliculogenesis have been identified from different species.
View Article and Find Full Text PDFSpermatocyte spreading and immunostaining were applied to detect meiotic prophase I progression, homologous chromosome pairing, synapsis and recombination in an azoospermic reciprocal translocation 46, XY, t(5;7;9;13)(5q11;7p11;7p15;9q12;13p12) carrier. Histological examination of the haematoxylin and eosin stained testicular sections revealed reduced germ cells with no spermatids or sperm in the patient. TdT (terminal deoxynucleotidyl transferase)-mediated dUDP nick-end labelling assay showed apoptotic cells in testicular sections of translocation carrier.
View Article and Find Full Text PDFCDH2 (cadherin 2, Neural-cadherin, or N-cadherin) is the predominant protein of testicular basal ectoplasmic specializations (basal ES; a testis-specific type of adhesion junction), one of the major cell junctions composing the blood-testis barrier (BTB). The BTB is found between adjacent Sertoli cells in seminiferous tubules, which divides the tubules into basal and adluminal compartments and prevents the deleterious exchange of macromolecules between blood and seminiferous tubules. However, the exact roles of basal ES protein CDH2 in BTB function and spermatogenesis is still unknown.
View Article and Find Full Text PDFSmall supernumerary marker chromosomes (sSMCs) are structurally abnormal rare chromosomes, difficult to characterize by karyotyping, and have been associated with minor dysmorphic features, azoospermia, and recurrent miscarriages. However, sSMC with a gonosomal trisomy has never been reported. Spermatocyte spreading and immunostaining were applied to detect meiotic prophase I progression, homologous chromosome pairing, synapsis, and recombination.
View Article and Find Full Text PDFDefective DNA damage response (DDR) is frequently associated with carcinogenesis. Abrogation of DDR leads to chromosomal instability, a most common characteristic of tumors. However, the molecular mechanisms underlying regulation of DDR are still elusive.
View Article and Find Full Text PDFZtbt20 is a POK family transcription factor and primarily functions through its conserved C2H2 Krüppel type zinc finger and BTB/POZ domains. The present study was designed to define the function of the Zbtb20, in vivo, during mouse spermatogenesis. Immunohistochemical studies revealed that ZBTB20 protein was localized specifically in the nuclei of Sertoli cells in seminiferous tubules.
View Article and Find Full Text PDFThe blood-testis barrier (BTB) is found between adjacent Sertoli cells in the testis where it creates a unique microenvironment for the development and maturation of meiotic and postmeiotic germ cells in seminiferous tubes. It is a compound proteinous structure, composed of several types of cell junctions including tight junctions (TJs), adhesion junctions and gap junctions (GJs). Some of the junctional proteins function as structural proteins of BTB and some have regulatory roles.
View Article and Find Full Text PDFIn mammals, the primordial follicle pool, providing all oocytes available to a female throughout her reproductive life, is established perinatally. Dysregulation of primordial follicle assembly results in female reproductive diseases, such as premature ovarian insufficiency and infertility. Female mice lacking Dicer1 (Dicer), a gene required for biogenesis of microRNAs, show abnormal morphology of follicles and infertility.
View Article and Find Full Text PDFElimination of uniparental chromosomes occurs frequently in interspecific hybrid cells. For example, human chromosomes are always eliminated during clone formation when human cells are fused with mouse cells. However, the underlying mechanisms are still elusive.
View Article and Find Full Text PDFBackground: MicroRNAs (miRNAs) are the class of small endogenous RNAs that play an important regulatory role in cells by negatively affecting gene expression at transcriptional and post-transcriptional levels. There have been extensive studies aiming to discover miRNAs and to analyze their functions in the cells from a variety of species. However, there are no published studies of miRNA profiles in human testis using next generation sequencing (NGS) technology.
View Article and Find Full Text PDFMeiosis is the process by which diploid germ cells produce haploid gametes. A key event is the formation of the synaptonemal complex. In the pachytene stage, the unpaired regions of X and Y chromosomes form a specialized structure, the XY body, within which gene expression is mostly silenced.
View Article and Find Full Text PDFHuman infertility affects 10-15% of couples, half of which is attributed to the male partner. Abnormal spermatogenesis is a major cause of male infertility. Characterizing the genes involved in spermatogenesis is fundamental to understand the mechanisms underlying this biological process and in developing treatments for male infertility.
View Article and Find Full Text PDFMost ovarian cancers originate from the ovarian surface epithelium and are characterized by aneuploid karyotypes. Aneuploidy, a consequence of chromosome instability, is an early event during the development of ovarian cancers. However, how aneuploid cells are evolved from normal diploid cells in ovarian cancers remains unknown.
View Article and Find Full Text PDFAneuploidy and chromosome instability (CIN) are hallmarks of the vast majority of solid tumors. However, the origins of aneuploid cells are unknown. The aim of this study is to improve our understanding of how aneuploidy and/or CIN arise and of karyotype evolution in cancer cells.
View Article and Find Full Text PDFUnlabelled: Next generation sequencing (NGS) techniques have been widely used to document the small ribonucleic acids (RNAs) implicated in a variety of biological, physiological and pathological processes. An integrated computational tool is needed for handling and analysing the enormous datasets from small RNA deep sequencing approach. Herein, we present a novel web server, CPSS (a computational platform for the analysis of small RNA deep sequencing data), designed to completely annotate and functionally analyse microRNAs (miRNAs) from NGS data on one platform with a single data submission.
View Article and Find Full Text PDFAlthough the relationship between meiotic recombination frequency and synaptonemal complex (SC) length has been of interest for a long time, how recombination frequency is related to SC length has not been carefully explored. To address this question, we have measured the meiotic recombination frequency as represented by MLH1 foci in 889 pachytene spermatocytes and measured the length of 19,558 autosomal SCs from 10 human males. A complex relationship between the number of MLH1 foci and total autosomal SC length per cell was observed.
View Article and Find Full Text PDFMammalian oocytes undergo an asymmetrical first meiotic division, extruding half of their chromosomes in a small polar body to preserve maternal resources for embryonic development. To divide asymmetrically, mammalian oocytes relocate chromosomes from the center of the cell to the cortex, but little is known about the underlying mechanisms. Here, we show that upon the elevation of intracellular cAMP level, mouse oocytes produced two daughter cells with similar sizes.
View Article and Find Full Text PDFMammalian male germ cells should be maintained below body temperature for proper development. Here, we investigated how male germ cells respond to heat stress. A short exposure of mouse testes to core body temperature induced phosphorylation of eIF2α and the formation of stress granules (SGs) in male germ cells.
View Article and Find Full Text PDFBackground: p53 abnormality and aneuploidy often coexist in human tumors, and tetraploidy is considered as an intermediate between normal diploidy and aneuploidy. The purpose of this study was to investigate whether and how p53 influences the transformation from tetraploidy to aneuploidy.
Principal Findings: Live cell imaging was performed to determine the fates and mitotic behaviors of several human and mouse tetraploid cells with different p53 status, and centrosome and spindle immunostaining was used to investigate centrosome behaviors.