Expression of Cellular Protooncogenes in the Mouse Male Germ Line: A Distinctive 2.4-Kilobase pim-1 Transcript is Expressed in Haploid Postmeiotic Cells

• Published in: Proceedings of the National Academy of Sciences - PNAS 1988-04, Vol.85 (7), p.2191-2195
• Main Authors: Sorrentino, Vincenzo, McKinney, Martin D., Giorgi, Mauro, Geremia, Raffaele, Fleissner, Erwin
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Developmental biology; Fundamental and applied biological sciences. Psychology; Gene expression; Gene Expression Regulation; Genes; Germ cells; Haploidy; Infertility, Male - genetics; Male; Mice; Mice, Mutant Strains - genetics; Mice, Quaking - genetics; Molecular and cellular biology; Molecular genetics; Pachytene stage; Protein-Serine-Threonine Kinases; Proto-Oncogene Proteins - biosynthesis; Proto-Oncogene Proteins - genetics; Proto-Oncogene Proteins c-abl; Proto-Oncogene Proteins c-fos; Proto-Oncogene Proteins c-mos; Proto-Oncogene Proteins c-pim-1; Proto-Oncogene Proteins p21(ras); Proto-Oncogenes; ras genes; RNA; RNA, Messenger - biosynthesis; Spermatids; Spermatids - metabolism; Spermatogenesis; Testes
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.85.7.2191

We report that a 2.4-kilobase (kb) pim-1 transcript is expressed in the germ cells of mouse testis. Analysis of purified populations of spermatogenic cell types indicates that the 2.4-kb transcript is selectively expressed in haploid postmeiotic early spermatids. The evidence for a developmentally regulated expression of pim-1 in haploid spermatids suggests a possible developmental role for this protooncogene product. The 2.4-kb pim-1 transcript present in postmeiotic cells differs in size from the 2.8-kb transcript usually detected in somatic tissues. Similar testis-specific transcripts have been seen for mos and abl genes. These data suggest specificity in transcription or processing of certain genes in haploid male germ cells. We have also analyzed other representative protooncogenes, including examples of protein kinases, the ras family, and the ``nuclear'' protooncogenes. The results indicate that additional protooncogenes are preferentially expressed in either meiotic pachytene cells or postmeiotic early spermatids. These findings suggest a differential regulation of gene expression in these two developmental stages of germ cells. In particular, analysis of expression of the three members of the ras gene family indicates a distinct temporal differential regulation in the expression of the Harvey, Kirsten, and N-ras genes in these germ cells.