Project description:Purpose: to construct a library of miRNAs in bovine sperm was constructed using Illumina high‐throughput sequencing technology. Result: Unique sequences that were 18–26 nucleotides in length were mapped to specific precursors in miRBase 20.0 using BLAST. A total of 951 known miRNAs and 8 novel, highly expressed miRNA candidates were identified.
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: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: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:To identify if the patterns of spermatic small non-coding RNAs (sncRNAs) are affected by paternal age and/or impact early embryogenesis, we generated sncRNAs libraries of sperm collected from same bulls at 10, 12, and 16 months of age, using 16 months as control for differential expression and functional analysis. miRNAs present in measurable quantity in oocytes were excluded. Of the remaining miRNAs, ten sperm-borne miRNAs were significantly differentially expressed in younger bulls (four in the 10 vs 16 months contrast and six in the 12 vs 16 months contrast). Targets of miRNAs were identified and compared to the transcriptomic database of two-cell embryos, to genes related to two-cell competence, and to the transcriptomic database of blastocysts. Ingenuity pathway analysis of the targets of these miRNAs suggested potential influence on the developmental competence of two-cell embryos and on metabolism and protein synthesis in blastocysts. The results showed that miRNA patterns in sperm are affected by the age of the bull and may mediate the effects of paternal age on early embryonic development.
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.
Project description:Spermatozoa harbor a complex and environment sensitive pool of small non-coding RNAs (sncRNA)1, which influences offspring development and adult phenotypes1-7. Whether spermatozoa in the epididymis are directly susceptible to environmental cues is not fully understood8. We used two distinct paradigms of preconception acute high fat diet to dissect epididymal vs testicular contributions to the sperm sncRNA pool and offspring health. We show that epididymal spermatozoa, but not developing germ cells, are sensitive to the environment and identify mitochondrial tRNAs and their fragments (mt-tsRNA) as sperm-borne factors. In humans, mt-tsRNAs in spermatozoa correlate with BMI and paternal overweight at conception doubles offspring obesity risk and compromises metabolic health. Sperm sncRNA-seq of mice mutant for genes involved in mitochondrial function, and metabolic phenotyping of their wild-type offspring, suggest that alterations of mt-tsRNAs are downstream of mitochondrial dysfunction. Most importantly, single embryo transcriptomics of genetically hybrid two-cell embryos demonstrated sperm-to-oocyte transfer of mt-tRNAs at fertilisation and implied them in the control of early embryo transcription. Our study supports the importance of paternal health at conception for offspring metabolism, shows that mt-tRNAs are diet-induced and sperm-borne and demonstrates, for the first time in a physiological setting, father-to-offspring transfer of sperm mitochondrial RNAs at fertilization.
Project description:Identification of bovine sperm surface carbohydrate-binding proteins relevant in two important aspects of fertilization: (i) formation of the sperm reservoir in the oviductal epithelium, and (ii) gamete recognition (oocyte-sperm interaction). Using whole sperm cells and a novel affinity capture method that combines proteolysis of protein-glycan complexes and mass spectrometry (i.e., CREDEX-MS), several lectins were enriched, identified by MS/MS proteomics, and mapped within the fertilization events in bovine species.
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.
Project description:Purpose: Screening the sperm sncRNAs that are responsible for dairy cattle fertility is of great interest, however, exploring the fertility-associated sncRNAs in sperm and linking them with the epigenetic inheritance in bovine has not been performed yet. Here in this study, we hypothesized that some sncRNAs in bovine sperm have a great potential to be linked with direct and immediate bull fertility data and could later influence the embryo and possibly impacting the daughter fertility. Methods: 12 bovine cryopreserved semen (high bull fertility, n=3 VS low bull fertility, n=3; high daughter fertility, n=3 vs low daughter fertility, n=3) that came from a pre-filtered 100 bull list (Figure 1) had been selected to extract total sperm RNA, the somatic cell lysis buffer had been added during the RNA extraction process to avoid the somatic cell pollution. The maternal and other confounding factors had been taken into consideration during the calculation of the phenotype criteria index.After the library construction, the library size that was smaller than 200 base pairs (adapter size around 125 nt) had been cut and sent for next-generation sequencing Results: bull fertility and daughter fertility related sncRNAs had been identified. Conclusions: providing promising epigenetic biomarker for cattle fertility improvement in the future, although these small non-coding RNAs need to be validated in larger sample sizes before being used as biomarkers.