HAPLOID GENE-EXPRESSION - TEMPORAL ONSET AND STORAGE PATTERNS OF 13 NOVEL TRANSCRIPTS DURING RAT AND MOUSE SPERMIOGENESIS

The temporal and spatial expression of thirteen novel spermatid-specif ic genes corresponding to cDNA clones isolated from an adult mouse tes tis library was analyzed. Northern analysis of RNA from seminiferous t ubules at defined stages of the rat and mouse seminiferous epithelial cycle and in situ hybridization of testis sections revealed that these mRNAs were expressed in a stage-specific manner. The expression of al l mRNAs was first detected in early round spermatids, and it increased to abundance during stages VII-VIII of the epithelial cycle. Twelve o ut of thirteen mRNAs were found not only in round spermatids but also in transcriptionally inactive elongated spermatids, suggesting that th ey are stored and regulated at the translational level. The variation in the length of the poly(A) tail was detected for four of the transcr ipts, represented by cDNA clones MTEST70, MTEST627, MTEST641, and MTES T643 at defined stages of the cycle. Similarity in the stage-specific expression pattern displayed by this group of haploid-specific genes s trongly suggests the presence of common regulatory mechanisms that act during spermiogenesis, and these genes also provide a means for furth er studies of these mechanisms.