Detection of quantitative trait loci for teat number and female reproductive traits in Meishan × Large White F2 pigs

Abstract

A quantitative trait locus (QTL) analysis of female reproductive data from a three-generation experimental cross between Meishan (MS) and Large White (LW) pig breeds is presented. Six F1 boars and 23 F1 sows, progeny of six LW boars and six MS sows, produced 573 F2 females and 530 F2 males. Six traits, i.e. teat number (TN), age at puberty (AP), ovulation rate (OR), weight at mating (WTM), number of viable embryos (NVE) and embryo survival (ES) at 30 days of gestation were analysed. Animals were genotyped for a total of 137 markers covering the entire porcine genome. Analyses were carried out based on interval mapping methods, using a line-cross (LC) regression and a half-full sib (HFS) maximum likelihood test. Genome-wide (GW) highly significant (P , 0.001) QTL were detected for WTM on SSC 7 and for AP on SSC 13. They explained, respectively, 14.5% and 8.9% of the trait phenotypic variance. Other GW significant (P , 0.05) QTL were detected for TN on SSC 3, 7, 8, 16 and 17, for OR on SSC 4 and 5, and for ES on SSC 9. Two additional chromosome-wide significant (P , 0.05) QTL were detected for TN, three for WTM, four for AP, three for OR, three for NVE and two for ES. With the exception of the two above-mentioned loci, the QTL explained from 1.2% to 4.6% of trait phenotypic variance. QTL alleles were in most cases not fixed in the grand-parental populations and Meishan alleles were not systematically associated with higher reproductive performance.

Identification of loci affecting teat number by genome-wide association studies on three pig populations

“…We have previously identified 11 genome-wide significant QTLs for teat number by a genome scan on the White Duroc×Erhualian F 2 resource population [6]. These loci were distributed on SSC1, 3, 4, 5, 6, 7, 8, and 12, which were consistent with previous reports [1, 23–29]. Of the 11 significant loci, the loci on SSC1, SSC7 and SSC12 were replicated in this study (Table 2 and Figure 1).…”

“…Unlike most reproductive traits, teat number is an inborn trait that is less affected by environmental factors [1]. Different pig breeds have variable teat, numbers, ranging from 8 to 25.…”

Genetic and metabolic aspects of androstenone and skatole deposition in pig adipose tissue: A review(Open Access publication)

“…Each team identified QTL on different chromosomes i.e. for skatole SSC6, SSC13 and SSC14 [21] versus SSC7, SSC12 and SSCX [4] and for indole SSC13 and SSC14 [21] versus SSC2, SSC6 and SSC7 [4]. The results of the assessment of lean and fat samples by a sensory panel [21] resulted in the detection of a QTL on SSC14 for skatole scores, half way between the QTL identified for skatole and indole levels.…”

“…Lee et al [21] and Bidanel et al [4], worked on subgroups of the Large White × Meishan pig population used in the French study [33] and measured skatole and indole accumulation in fat at slaughter (80-85 kg live weight). Each team identified QTL on different chromosomes i.e.…”

Microsatellite mapping of quantitative trait loci affecting female reproductive tract characteristics in Meishan × Large White F2 pigs1

“…The physiological and genetic bases of this increased prolificacy remain largely unknown. Sev-eral studies have been implemented to search for QTL explaining the difference in reproductive traits between Meishan and Western breeds (e.g., Rohrer et al, 1999;Bidanel et al, 2008;Noguera et al, 2009). Yet, the number of QTL affecting reproduction traits identified so far is limited compared with other traits of interest (Bidanel and Rothschild, 2002), and most of them are only suggestive QTL.…”