Sequence of the t complex Tcp-10a t gene and examination of the Tcp-10 t gene family

Transmission ratio distortion (TRD) is a property of complete t haplotypes which results in the preferential transmission of the t haplotype chromosome from heterozygous t/+ males to the majority of the offspring. A candidate gene for one of the primary genetic elements in TRD, the t complex responder locus has recently been suggested to be Tcp-10b ^t. There are multiple, functional Tcp-10 ^t genes, but genetic data suggest the presence of the Tcp-10a ^t gene alone is compatible with normal transmission ratios. Here we present the complete sequence and genomic structure of the Tcp-10a ^t gene which is compared with sequence data from a number of cDNAs and genomic subclones representing all active Tcp-10 ^t family genes. A detailed table of all sequence variants discovered in the course of our investigation is presented, and we have clarified the extent of 5 untranslated alternative splicing patterns exhibited by this gene family. A 60 base pair (bp) in-frame deletion from the 5 end of exon 3 of the Tcp-10a ^t gene is also presented and compared with the equivalent region of Tcp-10b ^t and Tcp-10c ^t. A search of the University of Edinburgh database has revealed a significant homology between the Tcp-10b ^t open reading frame and several cytosolic filament proteins. Interestingly, the region of homology is involved in the deletion from the Tcp-10a ^t gene.