The Putative Oncogene Pim-1 in the Mouse: Its Linkage and Variation Among t Haplotypes

Joseph H. Nadeau ¹ and Sandra J. Phillips ¹

¹ The Jackson Laboratory, Bar Harbor, Maine 04609

Pim-1, a putative oncogene involved in T-cell lymphomagenesis, was mapped between the pseudoalpha globin gene Hba-4ps and the alpha-crystallin gene Crya-1 on mouse chromosome 17 and therefore within the t complex. Pim-1 restriction fragment variants were identified among t haplotypes. Analysis of restriction fragment sizes obtained with 12 endonucleases demonstrated that the Pim-1 genes in some t haplotypes were indistinguishable from the sizes for the Pim-1^b allele in BALB/c inbred mice. There are now three genes, Pim-1, Crya-1 and H-2 I-E, that vary among independently derived t haplotypes and that have indistinguishable alleles in t haplotypes and inbred strains. These genes are closely linked within the distal inversion of the t complex. Because it is unlikely that these variants arose independently in t haplotypes and their wild-type homologues, we propose that an exchange of chromosomal segments, probably through double crossingover, was responsible for indistinguishable Pim-1 genes shared by certain t haplotypes and their wild-type homologues. There was, however, no apparent association between variant alleles of these three genes among t haplotypes as would be expected if a single exchange introduced these alleles into t haplotypes. If these variant alleles can be shown to be identical to the wild-type allele, then lack of association suggests that multiple exchanges have occurred during the evolution of the t complex.

This article has been cited by other articles:

				Y. Si and P. Olds-Clarke Mice Carrying Two t Haplotypes: Sperm Populations with Reduced Zona Pellucida Binding Are Deficient in Capacitation Biol Reprod, July 1, 1999; 61(1): 305 - 311. [Abstract] [Full Text]