This proposal is to study genetic factors that affect sperm function in fertilization. Previous work by the P.I. has identified a factor near the centromere of mouse chromosome 6 which plays a role in sperm maturation and function; this area was identified using Robertsonian translocations involving the Rb (6.16) junction. The current work will involve analysis of regions surrounding this junction to identify sequences involved in delay in sperm viability. DNA clones from the Rb (6.16) junction and the centromeres/telomeres of the normal 6 and 16 chromosomes will be prepared after microdissection. The clones will be characterized and unique sequences will be localized and amplified. Genetic mapping of unique sequences will be done using recombinant inbred strains and interspecies backcross. The presence or absence of telomeric repeats in the Rb junction will be determined, to try to understand the origin of Rb translocations. Information about the mechanism of centric fusions will also be obtained. %%% This proposal is to study genetic factors in sperm that are involved in fertilization. Chromosomes or chromosomal regions that play a role in mammalian sperm function are being identified, prior to identifying genes that influence sperm maturation and function. chromosomally different sperm in a predictable manner. Using mice bred to carry certain chromosomal translocations, a factor(s) near the centromere region of chromosome 6 has been identified which affects sperm maturation and function. This area, known as an Rb (6.16) junction, and the centromeres/telomeres of chromosomes 6 and 16, will be microdissected and cloned. Clones will be characterized and unique sequences will be amplified; genetic mapping of unique sequences will be done. The presence or absence of telomeric repeats in the Rb (6.16) junction will be assessed, to determine what is involved in the origin of Rb translocations. This will be the first molecular analysis of the junction of an Rb transloca- tion. This may help in the understanding of centric fusion and its role in sperm function.
