Mapping of an immotile short tail sperm defect in the Finnish Yorkshire on porcine Chromosome 16.

An immotile short tail sperm defect has recently been identified as a hereditary disorder present within the Finnish Yorkshire pig population. The syndrome is inherited as an autosomal recessive disease exclusively expressed in male individuals as shorter sperm tail length and immotile spermatozoa. Based on the assumption of a recent common origin of the disease-causing mutation, a genome-wide search was performed with 228 evenly spaced microsatellites by homozygosity mapping of affected and unaffected DNA pools. One locus, SW2411 on Chr 16, demonstrated a significantly skewed allele distribution between the two pools. Linkage analysis of five markers in this region mapped the disease-causing gene within a 6-cM confidence interval region with a highest LOD score of 7.7 at marker SW419. It appears that three-marker haplotypes can be used for marker-assisted selection within analyzed pedigrees. Furthermore, future fine mapping may reveal a more precise population-wide associated haplotype and facilitate identification of a new gene affecting sperm tail development.