Mapping of QTL on chromosome X for fat deposition, muscling and growth traits in a wild boar x Meishan F2 family using a high-density gene map

Quantitative trait loci (QTL) for fat deposition, growth and muscling traits have been previously mapped on the basis of low-density linkage maps in a wild boar × Meishan F₂ family to the chromosome X region flanked by SW2456 and SW1943 . Improved QTL resolution was possible using data for F₂ animals with a marker density of 2.7 cM distance in the SW2456 to SW1943 region, including AR , SERPINA7 and ACSL4 as candidate genes. The resolution of the QTL scan was increased substantially, as evidenced by the higher F -ratio values for all QTL. Maxima of F -ratio values for fat deposition, muscling and growth traits were 28.6, 18.2 and 16.5 respectively, and those QTL positions accounted for 7.9%, 5.0% and 4.5% of the F₂ phenotypic variance (VF₂) respectively. QTL for fatness and growth and for most muscling traits mapped near ACSL4 , with the exception of the QTL for ham traits that mapped proximally, in the vicinity of AR . An analysis performed separately for F₂ male animals showed the predominant QTL affecting fat deposition traits (up to 13.6% VF₂) near AR and two QTL for muscling traits (up to 9.9% VF₂) mapped close to ACSL4 . In the F₂ female animals, QTL affecting muscling (up to 12.1% VF₂) mapped at ACSL4 and SW2456 , and QTL for fat deposition (10% VF₂) and growth (up to 10.5% VF₂) mapped at ACSL4 .