Project description:Microarray analysis of purified pachytene spermatocytes and round spermatids. Each stage was examined in wild type and RNF8 knockout mice in two biological replicates. We performed microarray analysis using Affymetrix Gene 1.0 ST Arrays with purified pachytene spermatocytes and round spermatids. Pachytene spermatocytes and round spermatids were enriched from 3 to 4 males from the WT or Rnf8-KO via BSA gravity sedimentation according to the previous publication [PMID 8231890] and >95% (PS, RS) enrichments were verified after DAPI staining under a fluorescent microscope. For microarray analysis, total RNAs from purified pachytene spermatocytes or round spermatids were examined.
Project description:To further understand the effects of chronic cyclophosphamide treatment on spermatogenesis, we used whole genome microarrays to identify differentially expressed genes in pachytene spermatocytes and round spermatids from treated and control male rats. Pachytene spermatocytes and round spermatids from rats treated chronically with cyclophosphamide were isolated and profiled for changes in gene expression.
Project description:Although numerous miRNAs have been identified in the testis, their roles in regulating the highly specific events that occur in the different germ cell types throughout spermatogenesis remain largely unknown. Furthermore, whether male germ cell miRNA expression is altered in response to or as a consequence of exposure to a toxic agent is unknown. Here we examine miRNA expression profiles in pachytene spermatocytes and round spermatids obtained from control rats and from rats treated with a chronic low dose of cyclophosphamide, a male germ cell toxicant. We observed that pachytene spermatocytes and round spermatids display vastly different miRNA expression profiles, reflecting their different developmental stages and possibly influencing the cellular response to toxic insult. Chronic low dose cyclophosphamide treatment altered the miRNA profiles in both pachytene spermatocytes and round spermatids. Target prediction analyses revealed that miRNAs altered by cyclophosphamide treatment may be involved in the response to cellular stress and damage. However, many are also involved in processes that are crucial for proper germ cell development. This study suggests that pachytene spermatocytes and round spermatids display distinct miRNA profiles that can be altered by cyclophosphamide treatment. The observed changes may be part of a response and repair mechanism to cyclophosphamide-induced damage or a dysregulation that disrupts normal germ cell development.
Project description:Microarray analysis of purified pachytene spermatocytes and round spermatids. Each stage was examined in wild type and RNF8 knockout mice in two biological replicates.
Project description:Pachytene piRNAs are PIWI-interacting small RNAs abundantly expressed in pachytene spermatocytes and spermatids in adult mouse testes. Both MIWI and MILI-bound pachytene piRNAs have been found enriched in round spermatids. Miwi-null male mice are sterile due to spermiogenic arrest. In C. elegans, sperm-borne piRNAs appear to have an epigenetic role during fertilization and development because progeny of offspring derived from piRNA-deficient sperm display a progressive fertility loss after several generations. In mice, it remains unknown whether MIWI-bound pachytene piRNA-deficient round spermatids can produce offspring, and whether the progeny of offspring derived from MIWI-bound pachytene piRNA-deficient round spermatids also exhibit transgenerational loss of fertility. Here, we report that Miwi KO round spermatids could fertilize both wild type (WT) and Miwi KO oocytes through round spermatid microinjection (ROSI), and produce healthy and fertile offspring despite the aberrant pachytene piRNA profiles in those Miwi KO spermatids. Progeny of ROSI-derived heterozygotes, both male and female, displayed normal fertility for at least three generations when bred with either WT or Miwi KO females. Our data indicate that aberrant MIWI-bound pachytene piRNAs profiles in spermatids do not affect fertilization, early embryonic development, or fertility of the offspring, suggesting a normal pachytene piRNAs profile is not required for paternal transgenerational epigenetic inheritance in mice. Method: Round spermatids were purified from WT and Miwi KO adult testes using a mini-STA-PUT method[Methods Enzymol 1993; 225:84-113.],the purity of round spermatids was >90% based on our previous report[ J Biol Chem 2012; 287:25173-25190.]. Small RNA was isolated from round spermatids using the mirVana RNA isolation kit (Ambion) according to the manufacturer’s instructions. RNA quality and quantity were assessed using the Agilent 2100 Bioanalyzer. Small RNA-Seq was performed on an Ion Proton sequencer (Life Technologies). Libraries were prepared using the Ion Total RNA-Seq Kit v2 (Invitrogen) with biological triplicates for WT and Miwi KO samples. Resutls:Our data indicate that aberrant MIWI-bound pachytene piRNAs profiles in spermatids do not affect fertilization, early embryonic development, or fertility of the offspring, suggesting a normal pachytene piRNAs profile is not required for paternal transgenerational epigenetic inheritance in mice.
Project description:To further understand the effects of chronic cyclophosphamide treatment on spermatogenesis, we used whole genome microarrays to identify differentially expressed genes in pachytene spermatocytes and round spermatids from treated and control male rats.
Project description:ChIP-seq for H3K27 acetylation and RNA-seq were performed during spermatogenesis. We analyzed two representative stages of spermatogenesis: purified pachytene spermatocytes (PS) undergoing meiosis; and postmeiotic round spermatids (RS) from adult testes.
Project description:BRDT, a member of the BET family of double bromodomain-containing proteins, is expressed uniquely in the testis from pachytene spermatocytes through round spermatids, and is essential for spermatogenesis in the mouse. Although BRDT is known to bind to acetylated lysines in chromatin, it is not known where in the genome BRDT binds or whether the sites vary during the complex stages of differentiation in which it is expressed. Herein, we use ChIP-Seq to identify genome-wide BRDT binding sites in chromatin from mouse male germ cells at two distinct stages of differentiation. We identified 5452 BRDT-bound genomic loci in pachytene spermatocytes and 5618 BRDT-bound genomic loci in round spermatids. Roughly two thirds of BRDT binding sites were located in genes and BRDT binding correlated with highly transcribed genes. BRDT binding sites also overlapped with several histone modifications or variants that are associated with active transcription. Motif analysis revealed that BRDT-bound regions are enriched for consensus sequences for the MYB, RFX, ETS and ELF1 in pachytene spermatocytes, and JunD, c-Jun, CRE and RFX in round spermatids. Taken together, our data suggest that BRDT regulates distinct downstream target genes and may have unique functions in the meiotic and spermiogenic transcription programs.