Project description:Prototypical micro RNAs (miRNAs) are 21~25-base-pair RNAs that regulate differentiation, carcinogenesis and pluripotency by eliminating mRNAs or blocking their translation, processes collectively termed RNA interference (RNAi). RNAi mediated by miRNAs regulates early development in zebrafish, and mouse embryos lacking the miRNA precursor processor, Dicer, are inviable. However, the role of miRNAs during mammalian fertilization is unknown. We here show using microarrays that miRNAs are present in mouse sperm structures that enter the oocyte at fertilization. Sperm contained a broad profile of miRNAs and a subset of potential mRNA targets were expressed in fertilizable, metaphase II (mII) oocytes. Oocytes contained transcripts for the RNAinduced silencing complex (RISC) catalytic subunit, EIF2C3 (formerly AGO3). However, levels of sperm-borne miRNA (measured by quantitative PCR) were apparently low relative to those of unfertilized, mII oocytes, and fertilization did not alter the part of the mII oocyte miRNA landscape that included the most abundant sperm-borne miRNAs. Coinjection of mII oocytes with sperm heads plus anti-miRNAs - to suppress miRNA function - did not perturb pronuclear activation or preimplantation development. Contrastingly, we provide evidence that nuclear transfer by microinjection alters the miRNA profile of enucleated oocytes. These data argue that sperm-borne prototypical miRNAs play a limited role, if any, in mammalian fertilization or early preimplantation development. Keywords: miRNA profiling
Project description:The objectives of our study were to identify microRNA (miRNA) present in bovine sperm and to evaluate the effects of fescue toxicosis on sperm miRNA expression.
Project description:Purpose: Sperm-borne RNA are particularly sensitive to degradation and methodology-induced bias, thus necessitating the use of a consistent, effective RNA extraction protocol for inter-species comparisons. To this end, we established SpermBase, an RNA expression database consisting of small and large RNA expression data obtained using consistent methodologies. Methods: Total RNA was extracted from total sperm and sperm head samples using an RNA extraction protocol that required only slight, species-specific alterations at the lysis stage. Total RNA was subjected to either RNA-Seq (large RNA) or sncRNA-Seq (small RNA). Results: By using a consistent methodology, we were able to perform a cross-species analysis on the conserved features of large and small sperm-borne RNAs. We identified conserved features in both populations of RNAs in the four mammalian species (i.e., mouse, rabbit, rat, and human) surveyed. Conclusions: Our study demonstrates an effective, near-universal approach to the study of sperm-borne RNAs, and identifies conserved characteristics in the large and small RNA populations of mammalian sperm.
Project description:Prototypical micro RNAs (miRNAs) are 21~25-base-pair RNAs that regulate differentiation, carcinogenesis and pluripotency by eliminating mRNAs or blocking their translation, processes collectively termed RNA interference (RNAi). RNAi mediated by miRNAs regulates early development in zebrafish, and mouse embryos lacking the miRNA precursor processor, Dicer, are inviable. However, the role of miRNAs during mammalian fertilization is unknown. We here show using microarrays that miRNAs are present in mouse sperm structures that enter the oocyte at fertilization. Sperm contained a broad profile of miRNAs and a subset of potential mRNA targets were expressed in fertilizable, metaphase II (mII) oocytes. Oocytes contained transcripts for the RNAinduced silencing complex (RISC) catalytic subunit, EIF2C3 (formerly AGO3). However, levels of sperm-borne miRNA (measured by quantitative PCR) were apparently low relative to those of unfertilized, mII oocytes, and fertilization did not alter the part of the mII oocyte miRNA landscape that included the most abundant sperm-borne miRNAs. Coinjection of mII oocytes with sperm heads plus anti-miRNAs - to suppress miRNA function - did not perturb pronuclear activation or preimplantation development. Contrastingly, we provide evidence that nuclear transfer by microinjection alters the miRNA profile of enucleated oocytes. These data argue that sperm-borne prototypical miRNAs play a limited role, if any, in mammalian fertilization or early preimplantation development. Keywords: miRNA profiling Seven samples were analyzed for the study.
Project description:microRNAs are a group of small RNAs that regulate target gene expression post transcriptionally. The roles of microRNAs in regulating sperm production and function have been implicated by previous studies. In clinical studies, samples from patient with defective sperm production or function have been shown to display a different microRNA expression profile. Disruption of microRNA biogenesis is shown to result in sperm production or function defects in previous studies. However, the roles of individual microRNAs are largely unknown. Here, we aim to identify microRNAs that are enriched in male germlines of C. elegans, and study their potential roles in regulating sperm production or function.
Project description:DNA from expanded bovine blastocysts and bovine sperm were extracted then subjected to methylation-sensitive enzymatic digestion and LM-PCR enrichment before being hybridized onto a microarray. Two-condition experiment, bovine blastocysts (pools of 10) vs bovine sperm. Four biological replicates of each tissue were hybridized to four two-color arrays in a dye-balanced design.