Screening of peste des petits ruminants virus in a population of district Khairpur, Pakistan.

Goats are the Pakistan's fastest growing ruminants, and Pakistan is the third largest goat producer in the world after India and China. Goat meat preference is the main reason for its increased demand. In the country, there are 25 goat breeds and two wild relatives such as Mark and Goats. At present, Pakistan has 53.8 million goats, according to the 2006 GOP report, and their population growth rate was more than 3% per year (37, 23, 22, and 18% of the goat population in Punjab, Sindh, Balochistan, and NWFP, respectively). Peste des petits ruminants virus (PPRV) belongs to the family Paramyxoviridae and is considered to be one of the major constraints on increasing the productivity of goats and sheep in the areas where they exist and become local. It is closely related to cattle and buffalo rinderpest virus, dogs and other wild predator distemper virus, human measles virus, and marine mammalian measles virus. The present study aimed to determine the screening of the PPRV, Capra Hircus Lin. population, in the Khairpur Mirs District, Sindh, Pakistan. We selected 290 goats for serum sample collection and analysis using competitive ELISA kits according to the manufacturer's instructions. Our results showed that 59 (64%) of the 92 clinical cases were positive and 33 (36%) were seronegative. The study concluded that PPR might be more prevalent in the Khairpur District. Furthermore, it is highly recommended to use homologous PPR-attenuated vaccines to prevent lethal virus attacks that control PPR in the country.

Back fat thickness and meat tenderness are associated with a 526 T→A mutation in the exon 1 promoter region of the MyF-5 gene in Chinese Bos taurus.

Qualitative trait loci (QTL) for growth and meat quality traits in cattle (Bos taurus) have been previously mapped to three chromosome regions, 0 to 30, 55 to 70, and 70 to 80 cM on chromosome 5. We evaluated the allele frequencies and gene-specific single nucleotide polymorphisms (SNPs) of bovine myogenic factor 5 (MyF-5) in the QTL regions and their associations with live weight and meat characteristics in indigenous Chinese cattle breeds. PCR-SSCP methodology showed a T>A mutation at 526 bp. Least square analysis revealed a significant association of this SNP with backfat thickness and meat tenderness (P < 0.05), while no significant association was found with live weight, loin eye height, loin eye area, rib area, or water holding capacity. Allele frequencies of MyF-5-A/B in the five breeds were 0.760/0.239, 0.752/0.247, 0.629/0.370, 0.715/0.284, and 0.750/0.250, for JiaXian red, Luxi, Nanyang, Qinchuan, and XiaNan crossbreed, respectively. The genotype distributions for these alleles in two of the Chinese cattle breeds (Luxi and Qinchuan) were not in Hardy-Weinberg equilibrium (P < 0.05); while those for the other three breeds (JiaXian red, Nanyang, and XiaNan) were in agreement with Hardy-Weinberg equilibrium (P > 0.05). The genotypic frequencies among all five cattle breeds showed moderate diversity (0.25 < polymorphism information content < 0.5). Based on our findings, we suggest that the MyF-5 gene influences back fat thickness and meat tenderness in Chinese Bos taurus. This SNP could be useful for marker-assisted selection for meat quality traits in these cattle.

Association between a single nucleotide polymorphism in the bovine chemerin gene and carcass traits in Qinchuan cattle.

Qinchuan is a red or yellow draft and beef breed in China. In order to identify a predictor of carcass traits on the basis of associations between carcass traits and gene polymorphism, variation in the bovine chemerin gene was investigated using PCR-single-strand conformational polymorphism and DNA sequencing. An SNP of A868G located in exon 2 of the Bos taurus chemerin gene was detected in 716 samples of six breeds (Jiaxian red, Luxi, Nan yang, Qinchuan, Simmental and Luxi crossbred steers, and Xia'nan), all in China, and three genotypes (AA, AG and GG) were found. Based on the χ(2) test, the AA/AG/GG genotype frequencies of all six breeds were found to be in Hardy-Weinberg equilibrium. A possible association of A868G with some carcass traits was investigated in 106 Qinchuan cattle. Animals with the AG genotype were found to have significantly lower mean loin eye area and meat tenderness compared to those with the AA and GG genotypes. However, there was no significant association between any individual haplotype and backfat thickness, water holding capacity or marbling score. We suggest that A868G could be used as a molecular marker in marker-assisted selection for carcass traits.

Lack of an association between a single nucleotide polymorphism in the bovine myogenic determination 1 (MyoD1) gene and meat quality traits in indigenous Chinese cattle breeds.

The myogenic determination 1 (MyoD1) gene is a member of the MyoD gene family. It encodes for skeletal muscle-specific transcription factors containing highly conserved basic helix-loop-helix regions that perform important roles in the initiation, maintenance, and regulation of phenotypic traits. We investigated a new single nucleotide polymorphism (SNP) in the MyoD1 gene to evaluate whether this polymorphism affects meat quality traits in five Chinese indigenous cattle breeds, namely Qinchuan (QC), Xia-Nan (XN), Nan-yang (NY), Luxi (LX), and Jia-xian red (JXR). A C→G transversion at position 624 was detected in exon 1 of the MyoD1 gene; it causes an amino acid substitution ((624)serine/(624)cysteine). Least squares analysis showed that this SNP is not significantly associated with back fat thickness, eye muscle area, intramuscular fat, or marbling. The A/B allelic frequencies in the five breeds were 0.810/0.189, 0.779/0.220, 0.768/0.231, 0.820/0.180, and 0.801/0.198, respectively. Based on the χ(2) test, the genotype distributions of four cattle breeds (LX, NY, QC, and XN) did not agree with Hardy-Weinberg equilibrium (P < 0.05); one breed (JXR) did not deviate significantly from Hardy-Weinberg equilibrium (P > 0.05). The genotypic frequencies among all five cattle breeds showed moderate diversity (0.25 < polymorphism information content < 0.5). We concluded that the C624G SNP of the MyoD1 gene does not influence meat quality traits in indigenous Chinese cattle breeds; however, this SNP could be included in breed composition and population admixture analyses due to the marked differences in allelic frequencies among these five breeds.