Molecular genetics of wool fibre structure in sheep

Methods for mapping quantitative trait loci (QTL) are actively used in the sheep to identify chromosomal regions contributing to variation in wool traits. Therefore, this paper summarises and integrates QTL studies in the sheep to identify basic information on the genetic architecture of quantitative traits relating to wool’s important traits from viewpoint of the textile industry. The number of traits, number of QTL/associations and number of related chromosomes for categories of “Fibre” and “Fleece” were 6, 78 and 18, and 5, 97 and 23, respectively. QTL list and associated single nucleotide polymorphisms (SNPs) and genes relating to fibre curvature, fibre diameter coefficient of variance, fibre diameter standard deviation, mean fibres diameter, primary fibre diameter and primary fibre diameter coefficient of variance, fleece yield, greasy fleece weight, staple length, staple strength and wool crimp are presented. This information can be helpful in identifying genes or SNPs underlying the QTL and in the application of molecular genetic information in marker-assisted breeding programs. There is complexity in identifying relationships between wool genes. Part of this complexity in the relationships between wool traits is probably related to the pleiotropic phenomenon. In general, some researchers have found markers that have not been confirmed in other published papers. False positives and false negatives in the statistical methods used can be the reason for the differences in the distinguished genes for the desired traits of wool.