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Updated: Jul 20, 2026

Studying Proteolysis of Cyclin B at the Single Cell Level in Whole Cell Populations
Published on: September 17, 2012
Misexpression of cyclin B3 leads to aberrant spermatogenesis
Jale Refik-Rogers1, Katia Manova, Andrew Koff
1Program in Molecular Biology, Weill Graduate School of Medical Sciences, Cornell University, Ithaca, New York, USA.
Abstract:
Mus musculus cyclin B3 is an early meiotic cyclin that is expressed in leptotene and zygotene phases during gametogenesis. In order to determine whether downregulation of cyclin B3 at zygotene-pachytene transition was important for normal spermatogenesis, we investigated the consequences of expressing H. sapiens cyclin B3 after zygotene in mouse testes. Prolonging expression of cyclin B3 until the end of meiosis led to a reduction in sperm counts and disruption of spermatogenesis in four independent lines of transgenic mice. There were three distinct morphological defects associated with the ectopic expression of cyclin B3. Seminiferous tubules were either depleted of germ cells, had an abnormal cell mass in the lumen, or were characterized by the presence of abnormal round spermatids. These defects were associated with increased apoptosis in the testes. These results suggest that downregulation of cyclin B3 at the zygotene-pachytene transition is required to ensure normal spermatogenesis.
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