Journal of Genetics

The objective of this study was to investigate the effect of the polymorphism in the Myf5 gene on meat quality traits in the Ira and Tianfu Black rabbit breeds using polymerase chain reaction and DNA sequencing. A total of six SNPs and four haplotypes were found in Ira rabbits and only two SNPs were found in Tianfu Black rabbits. The two rabbit breeds had intermediate levels of genetic diversity according to their polymorphic information content values. The SNP association analysis in Ira indicated that SNP1-6 had a significant association with redness, yellowness and intramuscular fat values in the biceps femoris muscle, and also a significantly effect on redness in the longissimus dorsi muscle. The haplotype association analysis indicated that some haplotypes could be selected to get higher or lower meat redness, yellowness and intramuscular fat content in longissimus dorsi in Ira rabbits. Several SNPs and haplotypes of Myf5 identified here could be considered as molecular markers to improve the meat quality of Ira and Tianfu Black rabbits.

1. As a result of crossing-over between two differently invertedX-chromosomes anX-chromosome was obtained with a deficiency for a part of its genetically inert region. 2. In theXY males carrying this chromosome, theX andY-chromosomes synapse only in 61·4 per cent. of cases. Each of the unsynapsed chromosomes is lost during disjunction approximately in one-fourth of the cases, not reaching either of the daughter nuclei. 3.XYY males carrying this chromosome produce gametes almost exclusively of theXY andY types. 4. The case studied appears to confirm the views of Muller and Painter concerning the homology of the inert part of theX-chromosome with theY-chromosome, and supports the opinion that few or no gene mutations can at present arise in theY-chromosome (except those of the genebb).

Wilson disease (WD) is an autosomal recessive disorder of copper metabolism. The gene responsible for WD was discovered in 1993 and is located on chromosome 13 at 13q14.3. It encodes a copper-specific transporting P-type ATPase. Early diagnosis can improve treatment outcome and decrease the rate of disability or even mortality. We used Sanger sequencing to identify mutation hot spots in 55 northern Vietnamese with a clinical diagnosis of WD. Mutations were screened and detected by direct DNA sequencing. A total of 26 different ATP7B gene mutations were identified, including seven novel mutations (five nonsense and two missense mutations). The most frequent mutations were p.Ser105Ter (24.55%), p.Arg778Leu (5.45%) and p.Thr850Ile (4.55%). Mutation detection rate in exon 2 was 34.55% and ranked first, followed by exon 8 with 16.36%, and exon 18 with 10.91% each, thus, exons 2, 8 and 18 are the mutation hot spots for northern Vietnamese WD patients. These findings were different from previous studies in Asia. Our research established a suitable strategy for ATP7B gene testing in northern Vietnamese WD patients.