Association of the exon 9 single nucleotide polymorphism of CAPN1 with beef tenderness

The document attached has been archived with permission from the Association for the Advancement of Animal Breeding and Genetics.Initial data analysis from both the University of Adelaide’s Davies Cattle Gene Mapping and the New Zealand AgResearch Cattle Gene Mapping Projects showed a tenderness quantitative trait locus (QTL) on BTA29. Based on its function and location, the gene for micromolar calcium-activated neutral protease or calpain gene (CAPN1) was considered to be a strong positional candidate for the observed QTL effects. The objective of this study was to assess the association of a previously reported single nucleotide polymorphism (SNP) in Exon 9 of CAPN1 with the tenderness of M. longissimus dorsi (LD) and M. semitendinosus (ST) muscles in Bos taurus. The SNP (base 5709) causes the amino acid substitution of alanine for glycine316 [superscript] in the μ-calpain enzyme. Results demonstrated that the Exon 9 SNP was significantly associated with tenderness of both ST and LD muscles (P<0.01). Animals with the GG genotype showed higher (P<0.01) shear force values compared with CC genotypes (15% and 11% on day 1 and 14% and 11% on day 26 in LD and ST, respectively). The paternal allele encoding glycine at position 316 was associated with decreased meat tenderness relative to the allele encoding alanine at position 316. The equivalent maternal allele for CAPN1 Exon 9 was significantly associated with decreased tenderness of LD at four cook times and ST at day 1

QTL for meat colour and pH IN Bos Taurus cattle

The document attached has been archived with permission from the Association for the Advancement of Animal Breeding and Genetics.An experimental cattle backcross between the Jersey and Limousin breeds was performed in Australia and New Zealand to map quantitative trait loci (QTL) for diverse production traits. Six crossbred sires and their progeny were genotyped for 253 informative microsatellite markers covering the 29 bovine autosomes. This study reports the results for meat colour and pH recorded on 355 backcross animals in Australia. Results of the genome scan using regression interval mapping revealed evidence for QTL (<5% chromosome-wise level) on BTA10, 18, 19, and 27 for meat colour and BTA2, 3, 5, 6, 11, 12, 13, 16, 24 and 27 for meat pH. A number of detected QTL were mapped to genomic regions likely to contain the 'RN' or 'RYR1' genes, which are known to affect meat quality traits in pigs

Combining information across traits using a factor analytic model increases the power of QTL detection

W.S. Pitchford, A. Esmailizadeh Koshkoih and A.R. Gilmou

Mapping multiple QTL for birth weight in cattle Using a mixed model approach

A mixed model approach was developed, allowing for the rapid detection of multiple QTL across the complete genome in half sib designs. The method fits all the markers simultaneously as independent random effects with common variance within linkage groups nested within sires. For the linkage groups with significant marker variance a QTL profile is predicted as a weighted function of the marker BLUP for each marker position and used to identify a putative QTL location. A putative QTL covariate was then calculated for that position from flanking markers and added to the model as a fixed effect nested within sires. If this did not explain all the marker variance, the process was repeated. The method was applied to analysis birth weight data from 356 animals representing three beef cattle half-sib families scored for 249 markers spread across 29 bovine autosomes. The results indicated significant evidence for QTL affecting birth weight on BTA1, 5, 13, 14, 21, 22 and 24