Quantitative trait loci for white blood cell numbers in swine

Abstract

Differential white blood cell counts are essential diagnostic parameters in veterinary practice but knowledge on the genetic architecture controlling variability of leucocyte numbers and relationships is sparse, especially in swine. Total leucocyte numbers (Leu) and the differential leucocyte counts, i.e. the fractions of lymphocytes (Lym), polymorphonuclear leucocytes [neutrophils (Neu), eosinophils (Eos) and basophils (Bas)] and monocytes (Mon) were measured in 139 F(2) pigs from a Meishan/Pietrain family, before and after challenge with the protozoan pathogen Sarcocystis miescheriana for genome-wide quantitative trait loci (QTL) analysis. After infection, the pigs passed through three stages representing acute disease, reconvalescence and chronic disease. Nine genome-wide significant and 29 putative, single QTL controlling leucocyte traits were identified on 15 chromosomes. Because leucocyte traits varied with health and disease status, QTL influencing the leucocyte phenotypes showed specific health/disease patterns. Regions on SSC1, 8 and 12 contained QTL for baseline leucocyte traits. Other QTL regions reached control on leucocyte traits only at distinct stages of the disease model. Two-thirds of the QTL have not been described before. Single QTL explained up to 19% of the phenotypic variance in the F(2) animals. Related traits were partly under common genetic influence. Our analysis confirms that leucocyte trait variation is associated with multiple chromosomal regions.

Genome‐wide association study of periweaning failure‐to‐thrive syndrome (PFTS) in pigs

“…This region was only identified with CATT, possibly due to its property to detect non-additive effects of the SNP alleles. This region identified on SSC8 harbours several QTL already reported in swine: white blood cell counts (Reiner and others 2007a), bilirubin concentration (Reiner and others 2009), and time spent feeding and lying after infection with S miescheriana (Reiner and others 2007b). This region is surrounded by three genes: SLIT2 ( slit guidance ligand 2), PACRGL (PARK2 co-regulated-like), and KCNIP4 (Kv channel interacting protein 4).…”

A Whole Genome Association Study to Detect Single Nucleotide Polymorphisms for Blood Components (Immunity) in a Cross between Korean Native Pig and Yorkshire

“…We detected a neutrophil QTL at 106 Mb on the same chromosome (Table 3). For the same trait, Reiner et al (2008) reported two QTL in a Meishan×Pietrain cross, which were located at 8 cM on SSC4 and at 23 cM on SSC11, respectively. In the similar regions, two QTL were detected at 17 Mb and 18 Mb in the respective chromosomes (Table 3).…”

Identification of pleiotropic genes and gene sets underlying growth and immunity traits: a case study on Meishan pigs

“…We should note that many QTL mapping designs used families that were developed by crossing European Wild Boar with a commercial breed or crossing the Chinese Meishan breed with a commercial breed (Rothschild et al, 2007). For example, an overlap could be formed by a growth-related QTL identified in a family generated by cross-breeding of Duroc and Pietrain (Liu et al, 2007) and an immunity-related QTL in a family generated by cross-breeding of Pietrain and Meishan (Reiner et al, 2008). Therefore, to decrease false-positive findings, we set the threshold to be a conservative value -10 kb.…”