Location: Livestock Bio-SystemsTitle: A study of vertebra number in pigs confirms the effect of vertnin and reveals additional QTL
Submitted to: Plant and Animal Genome Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 10/29/2014
Publication Date: 1/14/2015
Citation: Rohrer, G.A., Nonneman, D., Schneider, J.F. 2015. A study of vertebra number in pigs confirms the effect of vertnin and reveals additional QTL [abstract]. Plant and Animal Genome XXIII Conference Proceedings. Abstract #P0370.
Technical Abstract: Formation of the vertebral column is a critical developmental stage in mammals that is strictly controlled in most species. The pig is quite unique as considerable variation exists in number of thoracic vertebra as well as number of lumbar vertebra. At least two genes have been identified that affect number of vertebra in pigs yet considerable genetic variation still exists. Therefore, a genome-wide association (GWA) analysis was conducted to identify additional genomic regions that affect this trait. A total of 1,883 animals were phenotyped for the number of ribs (RIB) and thoracolumbar vertebra (TC) and successfully genotyped with the Illumina Porcine SNP60 BeadChip. Number of lumbar vertebra (LUM) was considered the difference of TC-RIB. After data editing, 41,148 SNP markers were included in the GWA analysis implementing the Bayes C option of GENSEL (version 4.61) and 1 Mb windows. Fixed effects fitted in the model were season of birth and genotype at the vertnin locus. The number of 1 Mb windows explaining more than 1% of the genetic variation detected was 13 for RIB, 14 for LUM and 18 for TC. The percentage of genetic variation explained by these windows was 81% for RIB, 82% for LUM and 59% for TC. Despite adjustment for vertnin on SSC7 at 103 M (regression coefficients of 0.69, 0.20 and 0.48 for RIB, LUM and TC, respectively), this region was associated with RIB and LUM indicating that either additional genetic variation within the vertnin locus exists in this population or that other genes affect vertebra numbers. Five other regions affected more than one trait; SSC6:98-99 Mb affected RIB and TC, SSC12:26 Mb affected LUM and TC, SSC16:18-19 Mb affected LUM and TC, SSC17:49 Mb affected LUM and TC, and SSC18:50 affected RIB and LUM. While most of these multiple association regions altered the number of ribs or lumbar vertebra which subsequently altered TC, the region on SSC18 increased the number of ribs at the expense of a lumbar vertebra, holding TC constant. These results yield novel information on number of vertebra in pigs and will eventually increase our knowledge on the development of vertebra in mammals.