Translational activation of developmental mRNAs during neonatal mouse testis development. Mus musculus

The sequence of gene regulatory events that drive neonatal germ cell development in the mammalian testis is not yet clear. We assessed changes in mRNA utilization in the neonatal testis at 1 and 4 dpp, times when the testis contains quiescent gonocytes (1 dpp) and proliferating spermatogonia (4 dpp). There are not thought to be major changes in the nature or number of somatic cells over that interval. We used microarrays to detail the global expression levels of mRNA distribution between non-translating mRNAs and efficiently translating mRNAs during testis development at 1 dpp and 4 dpp Overall design: Extracts of mouse testes from 1 dpp and 4 dpp CD-1 mice were fractionated over a sucrose gradient in triplicate. Gradients were fractionated using an ISCO gradient fractionation system equipped with a UA-6 detector. The position of the 80S peak defined the boundary between translating and non-translating mRNAs. Pooled non-polysomal (non-translating; fractions 1-3) and heavy polysomal (efficiently translating, fractions 7-13) RNAs were isolated from sucrose gradient fractions for hybridization on Affymetrix 420 2.0 microarrays.