Somatic cell mapping and in situ localization of the bovine uridine monophosphate synthase gene (UMPS).

Abstract

Uridine monophosphate synthase (UMPS) catalyzes the final two steps of de novo pyrimidine synthesis, converting orotic acid to uridine 5' monophosphate. In Holstein and Red Holstein cattle, deficiency of UMPS (DUMPS) is inherited as a monogenic autosomal recessive trait. Heterozygous animals are phenotypically normal but have decreased UMPS activity in a number of tissues, whereas the homozygous genotype is lethal in utero. The cDNA for UMPS has recently been cloned in cattle (Sch6ber et al. 1993). A C ~ T point mutation in codon 405 results in a premature stop codon in DUMPS cattle (Schwenger et al. 1993), providing a DNA test for the detection of heterozygous bulls prior to entry into artificial insemination programs. UMPS has previously been mapped to human Chromosome (Chr) 3q13 (Qumsiyeh et al. 1989), Chinese hamster Chr 4p2 (Qumsiyeh and Suttle 1990), and sheep Chr lq (Burkin et al. 1993). Using somatic celt hybrid analysis and fluorescence in situ hybridization (FISH), we have assigned UMPS to cattle syntenic group U10 and sublocalized the gene to bovine Chr (BTA) 1 band 31. This represents the first assignment of a U10 marker to cattle chromosomes. BUS 6, a 1.5-kb fragment of the bovine UMPS cDNA representing amino acids 133-480 and the 3' untranslated region, was isolated from the E c o R I site of the plasmid pTZl9R (Sch6ber et al. 1993). The insert was radiolabeled with a-32p-dCTP and hybridized to EcoRI -d iges t ed bovine rodent hybrid somatic cell DNAs under high strin-