Genome-wide identification of QTL for age at puberty in gilts using a large intercross F2 population between White Duroc × Erhualian

Abstract

-Puberty is a fundamental development process experienced by all reproductively competent adults, yet the specific factors regulating age at puberty remain elusive in pigs. In this study, we performed a genome scan to identify quantitative trait loci (QTL) affecting age at puberty in gilts using a White Duroc · Erhualian intercross. A total of 183 microsatellites covering 19 porcine chromosomes were genotyped in 454 F 2 gilts and their parents and grandparents in the White Duroc · Erhualian intercross. A linear regression method was used to map QTL for age at puberty via QTLexpress. One 1% genome-wise significant QTL and one 0.1% genome-wise significant QTL were detected at 114 cM (centimorgan) on SSC1 and at 54 cM on SSC7, respectively. Moreover, two suggestive QTL were found on SSC8 and SSC17, respectively. This study confirmed the QTL for age at puberty previously identified on SSC1, 7 and 8, and reports for the first time a QTL for age at puberty in gilts on SSC17. Interestingly, the Chinese Erhualian alleles were not systematically favourable for younger age at puberty.age at puberty / quantitative trait loci / White Duroc / Erhualian

Mapping QTL for porcine muscle fibre traits in a White Duroc × Erhualian F2 resource population

“…In this population, two White Duroc boars and 17 Chinese Erhualian sows were mated to breed F 1 pigs, from which nine F 1 males and 59 F 1 females were intercrossed to produce six batches of 1912 F 2 pigs as described previously (Yang et al 2008). In this population, two White Duroc boars and 17 Chinese Erhualian sows were mated to breed F 1 pigs, from which nine F 1 males and 59 F 1 females were intercrossed to produce six batches of 1912 F 2 pigs as described previously (Yang et al 2008).…”

“…A three-generation resource population was bred at the experimental pig farm of Jiangxi Agricultural University in Nanchang, China. In this population, two White Duroc boars and 17 Chinese Erhualian sows were mated to breed F 1 pigs, from which nine F 1 males and 59 F 1 females were intercrossed to produce six batches of 1912 F 2 pigs as described previously (Yang et al 2008). All pigs were weaned at 46 days and provided with identical feed containing 21% of crude protein, 3300 kJ digestible energy and 1.25% of lysine before 120 days of age.…”

Detection of quantitative trait loci for porcine susceptibility to enterotoxigenic Escherichia coli F41 in a White Duroc × Chinese Erhualian resource population

“…All piglets were weaned at 46 days of age and the male were castrated at 90 days. The management of the resource population was described in detail by Yang et al (2008). In this study, 835 F 2 animals at 240 days of age were recorded for their F41 adhesion phenotypes and used for the quantitative trait loci (QTL) analysis.…”

A whole genome sequence association study for puberty in a large Duroc × Erhualian F2 population

“…; Yang et al . ; Li et al . ); however, practical use of these results in swine breeding programs is limited due primarily to low mapping resolution, lack of power from the structure of family‐based QTL studies and lack of segregation of the QTL in different breeds.…”

“…However, Eliasson () reported that accurate estrous symptoms require twice daily observations (Yang et al . ), which makes it too laborious to be measured routinely. With the availability of molecular genetic predictors, identifying and selecting individuals that tend to show early onset of puberty can be greatly simplified.…”