TFIIA alpha/beta-like factor is encoded by a germ cell-specific gene whoseexpression is up-regulated with other general transcription factors duringspermatogenesis in the mouse

TFIIA alpha/beta -like factor (ALF) is a testis-specific counterpart of the large subunit of human general transcription factor TFIIA. Northern analys is shows that ALF mRNA first appears in mouse testis at Postnatal Day 14. S imilarly, expression of the general transcription factors TBP, TRF2, TFIIA alpha/beta, TFIIA gamma, and TFIIIB90 is also increased beginning at Postna tal Day 14, suggesting that there is a coordinated induction of many genera l transcription factors during male germ cell differentiation. Analysis of male germ cells separated by Staput sedimentation shows that ALF is present in pachytene spermatocytes and haploid spermatids, In addition, in situ hy bridization experiments with adult mouse testis shows that ALF is present i n haploid spermatids, Searches of the human genome sequence database using the basic local alignment search tool reveal that the ALF and TFIIA alpha/b eta (GTF2A1) genes are both composed of nine exons, whereas the TFIIA gamma (GTF2A2) gene is composed of five exons. Furthermore, nucleotide and amino acid comparisons among human and mouse ALF, TFIIA alpha/beta, and TFIIA ga mma cDNA sequences show that ALF has diverged more rapidly than either TFII A alpha/beta or TFIIA gamma. Finally, the ALF and SBLF (Stoned B-Like Facto r) sequences present in the chimeric SALF cDNA are both present on human ch romosome 2, and an analysis of the corresponding genes suggests a model for the formation of SALF.