Quantitative trait loci segregating in crosses between <scp>N</scp>ew <scp>H</scp>ampshire and <scp>W</scp>hite <scp>L</scp>eghorn chicken lines: <scp>II</scp>. Muscle weight and carcass composition

<jats:title>Summary</jats:title><jats:p>In order to identify genetic factors influencing muscle weight and carcass composition in chicken, a linkage analysis was performed with 278 <jats:styled-content style="fixed-case">F</jats:styled-content><jats:sub>2</jats:sub> males of reciprocal crosses between the extremely different inbred lines <jats:styled-content style="fixed-case">N</jats:styled-content>ew <jats:styled-content style="fixed-case">H</jats:styled-content>ampshire (NHI) and <jats:styled-content style="fixed-case">W</jats:styled-content>hite <jats:styled-content style="fixed-case">L</jats:styled-content>eghorn (<jats:styled-content style="fixed-case">WL</jats:styled-content>77). The <jats:styled-content style="fixed-case">NHI</jats:styled-content> line had been selected for high meat yield and the <jats:styled-content style="fixed-case">WL</jats:styled-content>77 for low egg weight before inbreeding. Highly significant quantitative trait loci (<jats:styled-content style="fixed-case">QTL</jats:styled-content>) controlling body weight and the weights of carcass, breast muscle, drumsticks–thighs and wings were identified on <jats:styled-content style="fixed-case">GGA</jats:styled-content>4 between 151.5 and 160.5 <jats:styled-content style="fixed-case">cM</jats:styled-content> and on <jats:styled-content style="fixed-case">GGA</jats:styled-content>27 between 4 and 52 <jats:styled-content style="fixed-case">cM</jats:styled-content>. These genomic regions explained 13.7–40.2% and 5.3–13.8% of the phenotypic <jats:styled-content style="fixed-case">F</jats:styled-content><jats:sub>2</jats:sub> variances of the corresponding traits respectively. Additional genome‐wide highly significant <jats:styled-content style="fixed-case">QTL</jats:styled-content> for the weight of drumsticks–thighs were mapped on <jats:styled-content style="fixed-case">GGA</jats:styled-content>1, 5 and 7. Moreover, significant <jats:styled-content style="fixed-case">QTL</jats:styled-content> controlling body weight were found on <jats:styled-content style="fixed-case">GGA</jats:styled-content>2 and 11. The data obtained in this study can be used for increasing the mapping resolution and subsequent gene targeting on <jats:styled-content style="fixed-case">GGA</jats:styled-content>4 and 27 by combining data with other crosses where the same <jats:styled-content style="fixed-case">QTL</jats:styled-content> were found.</jats:p>