QTL analysis of white blood cell, platelet and red blood cell-related traits in an F2 intercross between Landrace and Korean native pigs

Abstract

Haematological traits play important roles in disease resistance and defence functions. The objective of this study was to locate quantitative trait loci (QTL) and the associated positional candidate genes influencing haematological traits in an F(2) intercross between Landrace and Korean native pigs. Eight blood-related traits (six erythrocyte traits, one leucocyte trait and one platelet trait) were measured in 816 F(2) progeny. All experimental animals were genotyped with 173 informative microsatellite markers located throughout the pig genome. We report that nine chromosomes harboured QTL for the baseline blood parameters: genomic regions on SSC 1, 4, 5, 6, 8, 9, 11, 13 and 17. Eight of twenty identified QTL reached genome-wide significance. In addition, we evaluated the KIT locus, an obvious candidate gene locus affecting variation in blood-related traits. Using dense single nucleotide polymorphism marker data on SSC 8 and the marker-assisted association test, the strong association of the KIT locus with blood phenotypes was confirmed. In conclusion, our study identified both previously reported and novel QTL affecting baseline haematological parameters in pigs. Additionally, the positional candidate genes identified here could play an important role in elucidating the genetic architecture of haematological phenotype variation in swine and in humans.

QTL analysis of clinical-chemical traits in an F2intercross between Landrace and Korean native pigs

“…A three-generation resource population was established and managed as described by Cho et al (11). In brief, eight KNP males were mated to nine Landrace females, and eight Landrace males were mated to 11 KNP females to produce each reciprocal half of the cross, i.e., L ϫ K and K ϫ L F 1 progeny.…”

“…Inversely, all cross LKKL F 2 progeny carry Landrace mitochondrial genotype, males carry the Y-chromosome from Landrace, and females can only be homozygous for KNP alleles on X-chromosome. All experimental breeding and feeding took place in the same houses on Jeju Island described by Cho et al (11). The experimental procedure was approved by the Animal Care Committee at the Jeju National University.…”

“…Because previous QTL studies of clinical-chemistry traits in pigs focused mostly on lipid levels in serum, it is imperative to identify QTL for other clinical-chemical traits in pigs and detect positional candidate genes, given the potential role of pigs as a genetic disease model. Korean native pigs (KNP) on Jeju Island have better robustness properties, compared with foreign pig breeds, as they have been accustomed to the local climate and environment of Jeju Island for more than 1,000 years (11). However, like many other indigenous breeds, KNP could also not avoid being introgressed with international breeds.…”

Identification of SNPs Affecting Porcine Carcass Weight with the 60K SNP Chip

“…The pig population used in this study is the same previously described by Cho et al (2011), which was the crossbred population between Landrace and KNP. This population was composed of 1,233 pigs from 79 full-sib F2 families.…”

“…However, the recent development of SNP chips enables GWAS analysis and the direct identification of linked SNPs (Balding, 2007). Examples of GWAS studies include those for backfat thickness and postmortem pH differences (Yoo et al, 2011), meat quality and biochemical traits in pork (Kim et al, 2011), body composition traits (including carcass weight) , blood composition traits , as well as teat numbers and growth traits Kim et al, 2005).…”