Identifying QTL and genetic correlations between fur quality traits in mink (Neovison vison)

Abstract

Mapping of QTL affecting fur quality traits (guard hair length, guard hair thickness, density of wool, surface of the fur and quality) and skin length was performed in a three-generation mink population (F2 design). In the parental generation, Nordic Brown mink were crossed reciprocally with American Black short nap mink. In all, 1082 mink encompassing three generations were used for the analyses. The mink were genotyped for 104 microsatellites covering all 14 autosomes. The QTL analyses were performed by least-square regression implemented in gridqtl software. Genetic and phenotypic correlations and heritabilities were estimated using the average information-restricted maximum-likelihood method. Evidence was found for QTL affecting fur quality traits on nine autosomes. QTL were detected for guard hair thickness on chromosomes 1, 2, 3, 6 and 13; for guard hair length on chromosomes 2, 3 and 6; for wool density on chromosomes 6 and 13; for surface on chromosomes 7, 12 and 13; for quality on chromosomes 6, 7, 11 and 13; and for skin length on chromosomes 7 and 9. Proximity of locations of QTL for guard hair length, guard hair thickness and for wool density and quality suggests that some of the traits are in part under the influence of the same genes. Traits under the influence of QTL at close or identical positions also were traits that were strongly genotypically correlated. Based on the results of correlation analyses, the most important single traits influencing the quality were found to be density of wool, guard hair thickness and appearance of the surface.

Genetic parameters for fur quality graded on live animals and dried pelts of American mink (Neovison vison)

“…The traits included fur quality and body size measurements. Former studies merged males and females and adjusted for effects of sex when analysing fur quality traits (Kołodziejczyk & Socha, ; Lagerkvist & Lundeheim, ; Lagerkvist et al., ; Socha & Kołodziejczyk, ; Socha et al., ; Thirstrup et al., ). However, in the present study, we tested if quality traits measured on males and females were influenced by the same set(s) of genes.…”

“…Thirstrup et al. () reported pelt quality heritability estimates in the range 0.15–0.43 for Black and Brown Danish mink crosses. In addition, our weight and skin size heritability estimates were consistent or higher than previous reports; Kenttämies and Vilva () estimated male Pastel mink body weight heritability in November at h 2 = 0.08.…”

“…These analyses were performed over a long time period and applied to different breeding populations, which might explain the inconsistencies, but also different trait definitions and varying statistical analyses might be responsible. The most recent studies used restricted maximum‐likelihood (REML) methods implemented in DMU software (Koivula et al., , ; Kołodziejczyk & Socha, ; Thirstrup et al., ), while least squares (LS) analyses (Kenttämies & Vilva, ), general linear models (GLM) procedure (Lagerkvist & Lundeheim, ) and REML (Lagerkvist et al., ) were employed in older studies. Nevertheless, for all fur quality traits analysed during the almost 30‐year period reviewed here, heritability estimates were medium to high, indicating good potential for use of genetic selection to increase fur quality and skin size in fur production.…”

“…Thirstrup et al. () reported correlation estimates between pelt quality traits in the range 0.10–0.88, where wool density was also shown to have more importance in overall pelt quality compared with silky appearance. Male and female skin size were negatively correlated with the three pelt quality traits and ranged from −0.55 to −0.34, the lowest between male skin size and pelt quality and the highest between female skin size and silky appearance.…”

“…Peura, Strand en, and M€ antysaari (2005) conducted a study of pelt character and live grading traits on Finnish blue fox and reported high genetic correlations between pelt and live fox grading traits. However, several studies estimated genetic parameters for pelt or skin quality traits in mink (Kentt€ amies & Vilva, 1988;Kołodziejczyk & Socha, 2012;Lagerkvist & Lundeheim, 1990;Lagerkvist et al, 1994;Socha & Kołodziejczyk, 2006;Socha, Kołodziejczyk, & Konopna, 2008;Thirstrup et al, 2013). All but one study (Kentt€ amies & Vilva, 1988) combined males and females and adjusted for sex effects by using sex as a fixed effect in the models.…”