Learn More
We used a mouse model in which sperm DNA damage was induced to understand the relationship of double-stranded DNA (dsDNA) breaks to sperm chromatin structure and to the Comet assay. Sperm chromatin fragmentation (SCF) produces dsDNA breaks located on the matrix attachment regions, between protamine toroids. In this model, epididymal sperm induced to undergo(More)
We have recently presented evidence that the structural integrity of the mouse sperm nuclear matrix may be necessary for the proper unpackaging of sperm DNA for participation in embryogenesis. It is likely that the sperm nuclear matrix contributes to the organisation of the sperm DNA and its disturbance can seriously damage the paternal genome or its(More)
The origin recognition complex (ORC) proteins, ORC1-6, are the first known proteins that bind DNA replication origins to mark the competency for the initiation of DNA synthesis. These proteins have complex mechanisms of assembly into the ORC complex and unexpected localizations in the mitotic chromosomes, cytoplasm, and nuclear structures. The mammalian(More)
We have been interested in determining the minimally required elements in the sperm head that are necessary in order for the paternal genome to participate in embryogenesis. We used an ionic detergent, mixed alkyltrimethylammonium bromide (ATAB), plus dithiothreitol (DTT) to remove the acrosome and almost all of the perinuclear theca, leaving only the sperm(More)
Mouse zygotes do not activate apoptosis in response to DNA damage. We previously reported a unique form of inducible sperm DNA damage termed sperm chromatin fragmentation (SCF). SCF mirrors some aspects of somatic cell apoptosis in that the DNA degradation is mediated by reversible double strand breaks caused by topoisomerase 2B (TOP2B) followed by(More)
Three stable monoclonal antibody-producing mouse hybridoma lines have been developed which produce high-titer, immunoglobulin M antibodies specific for the Novikoff ascites hepatoma (NAH) Mr 39,000 cytokeratin antigen (p39). Immunotransfer assays of cytoskeletal protein-enriched fractions indicated p39 to be present in a range of rat tissues, including(More)
Alus and B1s are short interspersed repeat elements (SINEs) indirectly derived from the 7SL RNA gene. While most researchers recognize that there exists extensive variability between individual elements, the extent of this variability has never been systematically tested. We examined all Alu elements over 200 nucleotides and all B1 elements over 100(More)
STUDY QUESTION Do the luminal fluids of the epididymis and the vas deferens contribute to sperm chromatin fragmentation (SCF) in mice? SUMMARY ANSWER The luminal fluids of both organs are required for activating SCF in mice, but the vas deferens luminal fluid does this more efficiently than that of the epididymis. WHAT IS KNOWN ALREADY Mice sperm have(More)
We have recently demonstrated that mammalian spermatozoa have the ability to degrade their DNA by a mechanism that is similar to apoptosis in somatic cells. When this mechanism is activated, the DNA is first degraded into loop-sized fragments by TOP2B (topoisomerase IIB). This degradation, termed sperm chromatin fragmentation, can be reversed by EDTA, which(More)