Screening for signatures of selection of Tianzhu white yak using genome-wide re-sequencing.

The Tianzhu white yak, a domestic yak indigenous to the Qilian Mountains, migrated inland from the Qinghai-Tibet Plateau. Specific ecological and long-term artificial selection influenced the evolution of its pure white coat and physiological characteristics. Therefore, it is not only a natural population that represents a genomic selective region of environmental adaptability but is also an animal model for studying the pigmentation of the yak coat. A total of 24 261 829 variants, including 22 445 252 SNPs, were obtained from 29 yaks by genome-wide re-sequencing. According to the results of a selective sweep analysis of Tianzhu white yak in comparison to Tibetan yaks, nine candidate genes under selection in Tianzhu white yak were identified by combining π, Tajima's D, πA/πB and FST statistics, with threshold standards of 5%. These genes include PDCD1, NUP210, ABCG8, NEU4, LOC102287650, D2HGDH, COL4A1, RTP5 and HDAC11. Five of the nine genes were classified into 12 molecular signaling pathways, and most of these signaling pathways are involved in environmental information processing, organismal systems and metabolism. A majority of these genes has not been implicated in previous studies of yak coat color and high-altitude animals. Our findings are helpful not only for explaining the molecular mechanism of yak coat pigmentation but also for exploring the genetic changes in Tianzhu white yak due to environmental adaptation.

Highly Conserved Keratin-Associated Protein 7-1 Gene in Yak, Taurine and Zebu Cattle.

Keratin-associated proteins (KRTAPs) play a critical role in cross-linking the keratin intermediate filaments to build a hair shaft. The genetic polymorphisms of the bovine KRTAP7-1 gene were investigated for the first time in this study. The complete coding sequence of the KRTAP7-1 gene in 108 domestic yak, taurine and zebu cattle from China and Indonesia were successfully amplified using polymerase chain reaction and then directly sequenced. Only two single-nucleotide polymorphisms (one nonsynonymous at c.7C/G and another synonymous at c.21C/T) and three haplotypes (BOVIN-KRTAP7-1*A, B and C) were identified in the complete coding sequence of the bovine KRTAP7-1 gene among all animals. There was no polymorphism across three Chinese indigenous yak breeds and one Indonesian zebu cattle population, all sharing the BOVINKRTAP71*A haplotype. The four taurine cattle populations also had BOVIN-KRTAP7-1*A as the most common haplotype with a frequency of 0.80. The frequency of novel haplotype BOVIN-KRTAP7-1*B was only 0.07 present in one heterozygous animal in each of the four taurine cattle populations, while BOVINKRTAP7- 1*C was only found in a Simmental and a local Chinese Yellow cattle population with frequencies of 0.17 and 0.36, respectively. The monomorphic yak KRTAP7-1 gene in particular, and highly conserved bovine, sheep and goat KRTAP7-1 genes in general, demonstrated its unique intrinsic structural property (e.g., > 21% high glycine content) and primary functional importance in supporting the mechanical strength and shape of hair.

Effect of ice on pain after corticosteroid injection in the hand and wrist: a randomized controlled trial.

This prospective, randomized controlled study was designed to determine if applying ice to the site of corticosteroid injections in the hand and wrist reduces post-injection pain. Patients receiving corticosteroid injections in the hand or wrist at a tertiary institution were enrolled. Subjects were randomized to apply ice to the injection site and take scheduled over-the-counter analgesics ( n = 36) or take scheduled over-the-counter analgesics alone ( n = 32). There were no significant differences in the mean pain score between the two groups at any time-point (pre-injection or 1-5 days post-injection). In regression modelling, the application of ice did not predict pain after injection. Visual analogue pain scores increased at least 2 points (0-10 scale) after injection in 17 out of 36 patients in the ice group versus ten out of 32 control patients. We conclude that the application of ice in addition to over-the-counter analgesics does not reduce post-injection pain after corticosteroid injection in the hand or wrist. LEVEL OF EVIDENCE: I Therapeutic Study.