Etiology behind canine uterine inertia: Role of uterine expression of MLCK4, MYH2, and PKC genes.

Dystocia is an obstetrical emergency, and primary uterine inertia (PUI) is the major etiological reason among the more prevalent maternal causes in dogs. The present study involved the relative expression analysis of genes associated with myometrial contraction in medium-sized dog breeds with uterine inertia. Dogs without any progress in the parturition process even after four hours of the onset of labor and the absence of uterine contractions were considered to have complete primary uterine inertia (CPUI, n = 9). Dogs that had expelled at least one fetus and made no further progress in parturition in the absence of active uterine contraction were considered to be experiencing partial primary uterine inertia (PPUI, n = 6). Dogs with the fetal cause of dystocia (FCD), i.e., obstructive dystocia, were taken as the third (n = 7) group. Uterine tissue samples were collected during cesarean section in each group, RNA was isolated, and the relative expression of myometrial ACTA2, ACTG2, MLCK4, MYH2, and PKC genes was analyzed. The MLCK4 gene expression was downregulated in CPUI (P ≤ 0.05) and PPUI (P ≤ 0.01) when compared to FCD. The MYH2 gene expression was downregulated in PPUI in comparison to CPUI (P ≤ 0.01) and FCD (P ≤ 0.05). The PKC gene expression was upregulated in PPUI in comparison to FCD and CPUI (P ≤ 0.05). The downregulation of MLCK4 and MYH2 gene expressions recorded in PPUI indicated the possibility of myometrial defects. The possibility of myometrial defects was also observed in CPUI, but to a lesser degree, suggesting other etiologies.

High resolution melt curve analysis identifies a novel SNP (G21A) in butyrophilin gene having significant association with milk production traits in Holstein Friesian crossbreds of Kerala.

Butyrophilin (BTN1A1) gene is located in the neighborhood of a quantitative trait loci for milk production in bovine autosome 23. We verified the genetic variability of exon-3 in BTN1A1 and its association with milk production traits in Holstein Friesian crossbreds of Kerala. Genomic DNA was isolated and 94 bp fragment enclosing exon-3 was amplified by primers designed using PRIMER 3 based on reference sequence (GenBank NC_037350). Pooled amplicons were sequenced by Sanger's method and a novel single nucleotide polymorphism due to a transversion of guanine to adenine at position 21 of amplicon (G21A) leading to amino acid change arginine to glutamine was detected. The study population was genotyped by high-resolution melt curve analysis and revealed two genotypes with frequencies GG/0.84 and GA/0.14. The allele G was found to be the major one (G/0.93 and A/0.07). Moreover, association analysis of G21A with milk production traits was done using the General linear model-Analysis of Variance considering herd, season, and parity as non-genetic factors and milk production trait as a dependent variable. In analysis, animals with GA genotype were found to be having significantly higher (p ≤ 0.01) 305 day milk (GG:2720.74 ± 122.92 kg; GA:3250.20 ± 183.24 kg), fat (GG:106.55 ± 4.32 kg; GA:126.30 ± 13.35 kg), and SNF yield (GG: 211.52 ± 9.20 kg; GA: 246.90 ± 13.70 kg). However, GG (7.80 ± 0.04) genotype has significantly higher (p ≤ 0.05) SNF percent than GA (7.65 ± 0.07). Butyrophilin gene polymorphism G21A can be suggested as a molecular marker for future breeding programmes of cattle.