A Novel Multiplex Polymerase Chain Reaction Method for the Identification of Brachyspina Syndrome Carriers in Chinese Holstein Cattle

A Novel Multiplex Polymerase Chain Reaction Method for the Identification of Brachyspina Syndrome Carriers in Chinese Holstein Cattle

Brachyspina syndrome (BS) is a monogenic autosomal recessive hereditary defect in Holstein dairy cattle. It is caused by a 3.3-kb deletion in the Fanconi anemia complementation group I (FANCI) gene on BTA21, which removes exons 25 to 27 and leads to a frame-shift and premature stop codon in exon 28. A consequence of BS is reduced reproduction efficiency and milk production in the dams due to loss of homozygous fetuses. In this study, we successfully developed a novel single-tube multiplex PCR assay to identify the recessive allele of BS with the bovine mitochondrial ATP synthase F0 subunit 8 (ATP8) genes as an internal positive control. We used this technique to detect BS alleles in a total of 63 Holstein bulls and 500 Chinese Holstein cows born between 2013 and 2015. Among them, 42 carriers were found (two sires and 40 cows). Combined with our previous study that assayed 206 Holstein bulls and 136 cows (born between 1996 and 2012) and identified 10 bull carriers and three cow carriers, the overall observed carrier frequency is 4.5% in bulls (269 assayed), and 6.8% in cows (636 assayed). Our method provides not only a reliable, economic, and practical diagnostic technique for BS carrier detection, but also promotes BS detection and monitoring system for the genetic improvement project of Chinese Holstein cattle.