Project description:Proteomic investigations of spermatozoa provide practical tools for distinguishing normal, functional spermatozoa from abnormal spermatozoa. Indeed, two-dimensional gel electrophoresis (2-DE) coupled with mass spectrometry (MS) applies high-throughput industrial applications to identify sperm-specific proteins indicative of chemical exposure. As such, a direct comparison of protein expression profiles between control and exposed cells returned a set of protein markers. Because mature mammalian spermatozoa are virtually incapable of protein synthesis, the predicted protein biomarkers in spermatozoa offer considerable stability for use in clinical application. In the current study, we applied 2-DE coupled with ESI-MS/MS to investigate the modified protein profile in F1 capacitated spermatozoa due to gestational bisphenol-A (BPA) exposure to ascertain whether these proteomic modifications could explain the observed functional alterations in spermatozoa.
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:We reported RNA profiles of mice spermatozoa, a total of 35,288,825 reads matching 33,039 transcripts, including 27,310 coding transcripts, were obtained. RNA profiles of the spermatozoa of 9-10 weeks adult mice were sequenced by RNA-seq,using Illumina GAIIx.
Project description:The buffalo sperm surface proteins which are bound by either non-covalent (electrostatic)interactions or by a GPI-anchor were extracted and subjected to LC-MS/MS. The results revealed that proteins involved in the immune response and reproductive processes adorn the buffalo sperm surface.
Project description:Chromatin immunoprecipitation (ChIP) has been a cornerstone for epigenetic analyses over the last decades, but even coupled to sequencing approaches (ChIP-seq), it is ultimately limited to one protein at a time. In a complementary effort, we here combined ChIP with label-free quantitative (LFQ) mass spectrometry (ChIP-MS) to interrogate local chromatin compositions. We demonstrate the versality of our approach at telomeres, with transcription factors, in tissue and by dCas9-driven locus-specific enrichment.
Project description:Chromatin immunoprecipitation (ChIP) has been a cornerstone for epigenetic analyses over the last decades, but even coupled to sequencing approaches (ChIP-seq), it is ultimately limited to one protein at a time. In a complementary effort, we here combined ChIP with label-free quantitative (LFQ) mass spectrometry (ChIP-MS) to interrogate local chromatin compositions. We demonstrate the versality of our approach at telomeres, with transcription factors, in tissue and by dCas9-driven locus-specific enrichment.
Project description:In recent years considerable effort has been devoted to understanding the epigenetic control of sperm development leading to an increased appreciation of the importance of RNA interference pathways, and in particular microRNAs (miRNAs), as key regulators of spermatogenesis and epididymal maturation. It has also been shown that sperm are endowed with an impressive array of miRNA that have been implicated in various aspects of fertilization and embryo development. However, to date there have been no reports on whether the sperm miRNA signature is static or whether it is influenced by their prolonged maturation within the male reproductive tract. To investigate this phenomenon we employed next generation sequencing to systematically profile the miRNA signature of maturing mouse spermatozoa. In so doing we have provided the first evidence for the dynamic post-testicular modification of the sperm miRNA profile under normal physiological conditions. Such modifications include the apparent loss and acquisition of an impressive cohort of some 113 and 115 miRNAs, respectively between the proximal and distal epididymal segments. Interestingly, the majority of these changes occur late in maturation and include the uptake of novel miRNA species in addition to a significant increase in many miRNAs natively expressed in immature sperm. Since sperm are not capable of de novo transcription these findings identify the epididymis as an important site in establishing the sperm epigenome with the potential to condition the peri-conceptual environment of the female reproductive tract, contribute to the inheritance of acquired characteristics, and/or alter the developmental trajectory of the resulting offspring. Examination of the microRNA expression profile in sperm thoughout the mouse epididymis and mouse using next generation sequencing in duplicate.
Project description:Laminopathies are caused by mutations in components of the nuclear envelope (NE). While most NE components are widely expressed, laminopathies affect only a subset of tissues. However, the understanding of the molecular mechanisms that explain this phenomenon is still elusive. Here we have performed a genome wide DamID analysis in adult C. elegans nematodes comparing the DNA association profile of two components of the NE, Lamin/LMN-1 and Emerin/EMR-1. Although both proteins were associated to silent DNA, EMR-1 showed a predominant role in the anchoring of muscle and neuronal promoters to the nuclear periphery. Deletion of either EMR-1 or LEM-2, another integral NE protein, caused local changes in nuclear architecture with both increased and decreased LMN-1 association. Comparison of Dam::LMN-1 and Dam::EMR-1 DNA assotiation in wild type strains and Dam::LMN-1 DNA association in wild type, lem-2(tm1582) and emr-1(gk119) mutant backgrounds.