1. Identification of morc (microrchidia), a mutation that results in arrest of spermatogenesis at an early meotic stage in the mouse
- Author
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Watson, Mark L., Zinn, Andrew R., Inoue, Norimitsu, Hess, Kari D., Cobb, John, Handel, Mary Ann, Halaban, Ruth, Duchene, Clark C., Albright, George M., and Moreadith, Randall W.
- Subjects
Atherosclerosis -- Research ,Gene mutations -- Research ,Mice as laboratory animals -- Genetic aspects ,Science and technology - Abstract
The microrchidia, or morc, autosomal recessive mutation results in the arrest of spermatogenesis early in prophase I of meiosis. The morc mutation arose spontaneously during the development of a mouse strain transgenic for a tyrosinase cDNA construct. Morc -/- males are infertile and have grossly reduced testicular mass, whereas -/- females are normal, indicating that the Morc gene acts specifically during male gametogenesis. Immunofluorescence to synaptonemal complex antigens demonstrated that -/- male germ cells enter meiosis but fail to progress beyond zygotene or leptotene stage. An apoptosis assay revealed massive numbers of cells undergoing apoptosis in testes of -/- mice. No other abnormal phenotype was observed in mutant animals, with the exception of eye pigmentation caused by transgene expression in the retina. Spermatogenesis is normal in +/- males, despite significant transgene expression in germ cells. Genomic analysis of -/- animals indicates the presence of a deletion adjacent to the transgene. Identification of the gene inactivated by the transgene insertion may define a novel biochemical pathway involved in mammalian germ cell development and meiosis.
- Published
- 1998