Abstract for presentation at 11th International Congress of Human Genetics

Gene expression profiling of murine spermatogenesis leads to the cloning and characterization of Ard2, a novel mouse Ard1 homologue that is preferentially expressed starting from meiosis

  • Lap-Yin Pang, National Institute of Child Health and Human Development, National Institutes of Health, United States
  • Stephanie Peacock, National Institute of Child Health and Human Development, National Institutes of Health, United States
  • Warren Johnson, National Institute of Child Health and Human Development, National Institutes of Health, United States
  • Deborah Bear, National Institute of Child Health and Human Development, National Institutes of Health, United States
  • Martin Dym, Department of Cell Biology, Georgetown University, United States
  • Owen Rennert, National Institute of Child Health and Human Development, National Institutes of Health, United States
  • Wai-Yee Chan, National Institute of Child Health and Human Development, National Institutes of Health, United States

    • Spermatogenesis is the developmental process of the male germ cells, which is believed to be mediated by a concerted global change in gene expression. To elucidate the functional differences of different stages of germ cells, we profiled the germ cell transcriptomes of male mouse germ cells at specific developmental stages. From that, the full-length sequence of an EST showing a differential expression pattern between meiotic and post-meiotic germ cells was cloned by RACE; and was named Ard2 since it encodes a putative homologue of the mouse N-acetyltransferase catalytic subunit Ard1. In silico analysis further revealed other conserved Ard1 homologues in the mouse genome, and potential miRNA recognition sites were predicted on the 3’ UTR of Ard2. These Ard1 homologues were expressed differentially in various tissues and different stages of male germ cells, with Ard2 demonstrating a testis-specific expression pattern and an elevated expression level during meiosis. We also identified the use of alternative transcriptional start sites and polyadenylation signals in Ard2 transcripts in different stages of germ cells. Ard2 displayed an expression pattern reciprocal to the X-linked Ard1 in Western blot analysis. Meanwhile, the highest level of Ard2 was detected only in post-meiotic germ cells, indicating Ard2 was translationally repressed during meiosis and became active afterwards. Our results suggest that Ard2 is responsible for a germ cell-specific function and its expression is subjected to an intricate regulation both at transcriptional and post-transcriptional levels. Ard1 had been implicated in cell cycle regulation and histone acetylation in yeasts, and was shown to be active by itself in mammalian cells. Further experiments are underway to test the involvement of Ard2 in such activities in germ cells and the role of miRNAs in regulating Ard2 translation.

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