The CYP21 (steroid 21-hydroxylase) gene is involved in the synthesis of steroid hormones. Bov-A2 is a retroposon that is common in ruminant genomes. The promoter region of bovine CYP21 contains a short interspersed nucleotide element of Bov-A2, which overlaps a putative Sp1 binding site. We looked for RFLP/HpaII polymorphism in the Bov-A2 element in bovine Zebu breeds by PCR-RFLP, and examined whether polymorphism in this element is associated with methylation.
Investigation of molecular marker effects on production traits is essential to define marker assisted selection strategies in beef cattle. We looked for a possible association of molecular markers and backfat thickness (BFT) and rib eye area (REA) in Canchim (5/8 Charolais + 3/8 Zebu) and MA (offspring of Charolais bulls and 1/2 Canchim + 1/2 Zebu cows) animals raised exclusively on pasture. Traits were measured on 987 individuals from seven herds from two Brazilian States (São Paulo and Goiás), in March and April from 2005 to 2007, when animals were, on average, 19 months of age.
Cyclin-dependent kinase 6 (CDK6) is a key element of D-type cyclin holoenzymes. It is involved in the regulation of the G1-phase of the cell cycle and is considered to be an important candidate gene for selection of body measurement traits through marker-assisted selection. We cloned the promoter sequence of this gene in bovines and found it to share high similarity with that of the human CDK6 promoter.
We analyzed two single nucleotide polymorphisms (SNPs) of the IGF2 and CYP21 genes in Nellore cattle participating in the Brazilian Animal Breeding Program. The SNPs were found in exon 6 of the IGF2 (insulin-like growth factor 2) gene (RFLP/MboII) as well as in the promoter region of the CYP21 (steroid 21-hydroxylase) gene (RFLP/HpaII) of these animals. The TC heterozygotes were significantly more frequent than CC and TT homozygotes in the RFLP/MboII polymorphism.
Acyl-coenzyme A oxidase 1 (ACOX1) is the first enzyme in peroxisomal fatty acid β-oxidation; it is rate-limiting and plays a key role in fatty acid metabolism and fat deposition. ACOX1 is an important candidate gene for meat quality selection through marker-assisted selection. Genomic structural analysis showed that bovine ACOX1 shares 86% identity with human ACOX1. Using PCR-SSCP technology, we discovered a single nucleotide polymorphism (SNP) (A1865C) in exon 13 of the ACOX1 gene.
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.
Bovine leukemia virus (BLV), the causative agent of enzootic bovine leukosis, is an exogenous, B lymphotropic retrovirus belonging to the Retroviridae family that induces persistent lymphocytosis in cattle and sheep. PCR has proven to be particularly suitable for investigating herds of cattle with a very low incidence of BLV infection and for clarifying doubtful serological results obtained by immunodiffusion or ELISA. The native Iranian and Russian cattle have a series of valuable traits that discriminate them as unique breeds that are well able to compete with western analogues.
Using PCR-SSCP and DNA sequencing technology, we examined the association of single nucleotide polymorphisms (SNPs) in the bovine MyoG gene with body measurement traits in 779 individuals of six native Chinese cattle breeds, namely Luxi, Luxi × Simmental crossbred, Nanyang, Xia’nan, Jiaxian red, and Qinchuan. A novel SNP, T314C, was detected. Allelic frequencies of MyoG-T/C in the six breeds were 0.8308/0.1692, 0.8774/0.1226, 0.8021/0.1979, 0.8209/0.1791, 0.8630/0.1370, 0.8044/0.1956, respectively.
The testis-specific protein Y-encoded gene (TSPY) is a Y-specific gene present in variable copy number in many mammalian species, including cattle. We tested the applicability of the TSPY gene as a Y-specific marker to predict preimplantation embryo sex in Nelore (Bos indicus) cattle. Two blastomeres were removed from each embryo. A total of 36 single blastomeres and the remaining cells of their 18 matched in vitro conceived embryos were screened for TSPY amplification by nested-PCR.
Cloning by nuclear transfer is often associated with poor results due to abnormal nuclear reprogramming of somatic donor cells and altered gene expression patterns. We investigated the expression patterns of imprinted genes IGF2 and IGF2R in 33- to 36-day bovine embryos and chorio-allantoic membranes derived from in vivo- and in vitro-produced embryos by somatic cell nuclear transfer (SCNT), parthenogenetic activation, and in vitro fertilization (IVF).