Molecular analysis of mouse spermatogenesis: isolation of the t-complex polypeptide-1 gene and related sequences.

The mouse f-complex is a region of chromosome 17, found in wild mouse populations, which is grossly rearranged when compared to those of normal laboratory strains. So far, two large, independent inversions have been demonstrated. The distal inversion includes the entire Major Histocompatibility Complex (MHC) (Artzt, Shin & Bennett, 1982; Shin etal. 1983; Pla & Condamine, 1984) and the recently discovered proximal inversion (Herrmann etal. 1986) also contains many genes, including the ^-complex polypeptide-1 gene (Tcp-1) discussed in this article. Using in situ hybridization, the MHC (Lader etal. 1985) and Tcp-1 (Lyon et al. 1986) genes have been positioned on chromosome 17 and the ^-complex would appear to occupy Giemsa bands 17B and 17A3, representing roughly 15 % of the chromosome. Presumably, in addition to those already mapped, many hundreds of genes are located in this region. The ^-complex has been extensively studied because independent f-haplotype chromosomes carry recessive embryonic lethal genes that result in embryonic death at different stages of development (Bennett, 1975). The different lethal genes map throughout the ^-complex (Artzt, McCormick & Bennett, 1982; Artzt, 1984) and it is suggested that they are related in function in the sense that they are sequentially required during early embryonic development (Shin, McCormick, Artzt & Bennett, 1983). This genetic model has not been proven, since none of the lethal genes, and there are at least sixteen independent recessive lethals carried by various different ^-chromosomes isolated from wild mouse populations around the world (Klein, Sipos & Figueroa, 1984), have been molecularly cloned. In one instance (t), a recessive lethal has been identified as combined lipase deficiency