STAT5A/AvaI polymorphism in Podolica bulls and its effect on growth performance traits

Analysis of Potential Genes and Economic Parameters Associated with Growth and Heat Tolerance in Sheep (Ovis aries)

This study explored the potential genes and economic factors that might be associated with growth and heat tolerance in two sheep breeds. Data on growth performance from the third month to six months of age were obtained based on records. In comparison to Aboudeleik lambs, Barki lambs developed considerably greater starting body weight, final body weight, final body weight gain, daily weight gain, and percentage increase in BW/month. Single nucleotide polymorphisms (SNPs) were found between lambs of the two breeds using PCR-DNA sequencing of CAST, LEP, MYLK4, MEF2B, STAT5A, TRPV1, HSP90AB1, HSPB6, HSF1, ST1P1, and ATP1A1 genes. Lambs from each breed were divided into groups based on detected SNPs in genes related to growth. The least squares means of the differentiated groups revealed a significant correlation of detected SNPs with growth and heat tolerance attributes (p ≤ 0.05). Barki lambs elicited greater total variable costs, total costs, total return, and net return values. The Barki sheep provided the best economic efficiency value when comparing the percentage difference between net profit and economic efficiency. Together with economic considerations, SNPs found may be used as proxies for marker-assisted selection of the best breed of sheep for traits related to growth and heat tolerance.

Genetic polymorphism of Pit-1 and CSN3 genes in Holstein calves and its associations with calf birth weight

Abstract. The aim of this study was to examine the polymorphic structures of Pit-1 and CSN3 genes of Holstein calves bred in Gümüşhane province of Türkiye, to determine the distribution of genotype and allele gene frequencies, as well as examine the effects of determined polymorphisms on birth weight of calves. HinfI polymorphisms of Pit-1 and CSN3 genes were identified in DNA isolated from blood samples of 100 Holstein calves used in the study, using the PCR-RFLP method. According to the Hardy–Weinberg genetic equilibrium test, it was observed that the distribution of genotype frequencies of HinfI polymorphisms of Pit-1 genes in the studied population was in equilibrium, but not in equilibrium in terms of CSN3 gene location. The AA, AB, and BB genotype frequencies of the Pit-1 gene in the population were 13.4 %, 40.2 %, and 46.3 %, respectively; the frequency of the A allele was 0.34, while for B allele it was 0.66. The AA, AB, and BB genotype frequencies of the CSN3 gene were found to be 24.5 %, 36.7 %, and 38.8 %, respectively; the frequency of the A allele was 0.43 and the frequency of the B allele was 0.57. According to the Hardy–Weinberg genetic equilibrium test, the distribution of genotype frequencies was in equilibrium in the Pit-1/HinfI polymorphism, but not in the CSN3/HinfI polymorphism. A statistically significant relationship was not found between the genotypes of both polymorphic regions and calf birth weight.

Influence of the Casein Composite Genotype on Milk Quality and Coagulation Properties in the Endangered Agerolese Cattle Breed

The aim of this study was the characterization of CSN1S1, CSN2 and CSN3 genetic variability in Agerolese cattle, and the investigation of the effect of casein composite genotypes (CSN1S1, CSN2 and CSN3) on quality and coagulation traits of the corresponding milk. To these purposes, blood and milk from 84 cows were sampled and analysed. Allele frequencies at CSN2 and CSN3 revealed no Hardy-Weinberg equilibrium in the population with a prevalence of allele A² for CSN2 and allele B for CSN3. BBA¹A²AB and BBA²A²AB composite genotypes were the most common in the population. BBA¹A²AB showed a higher total solids and fat content (12.70 ± 0.16 and 3.93 ± 0.10, respectively), while BBA²A²BB showed the best coagulation properties (RCT 12.62 ± 0.81; k₂₀ 5.84 ± 0.37; a₃₀ 23.72 ± 1.10). Interestingly, the A² allele of CSN2 was very widespread in the population; thus, it will be intriguing to verify if A²A² Agerolese cattle milk and the derived cheese may have better nutraceutical characteristics.

Association of STAT5A Gene Variants with Milk Production Traits in Agerolese Cattle

Two polymorphisms at STAT5A gene were investigated in a sample of Agerolese cows. The aims of the present study were to estimate the allele and genotype frequencies and to investigate the relationship among genotypes and milk production traits. Milk production traits were analyzed for each animal in the first, second, third, and fourth lactation. No genetic variability was found at STAT5A/AvaI locus. At STAT5A/MslI locus, the frequencies of T and C alleles were 0.875 and 0.125, respectively. Significant differences between genotypes were found: TT cow produced a milk with a higher content of fat and protein when compared with TC.

Bovine STAT5A gene polymorphism and its influence on growth traits in Podolica breed

Signal transducers and activators of transcription (STAT) are latent cytoplasmic transcription factors that mediate the actions of a variety of peptide hormones and cytokines within target cells. STAT5A is the main mediator of growth hormone action on target genes and plays a key role as intracellular mediator of prolactin signalling. In this study, the T→C nucleotide polymorphism at position 12 743 in exon 16 of the bovine STAT5A gene was investigated with polymerase chain reaction-restriction fragment length polymorphism in a sample of Podolica young bulls. The Podolica breed derives from Bos primigenius podolicus (forebears of the modern Bos taurus), it has been present in Italy for a very long time and represents yet another example of successful biological adaptation to a hostile environment. The aims of this study were to estimate the allele and genotype frequencies in Podolica breed and to investigate a possible relationship between this polymorphism and some growth performance traits. The observed frequencies of C and T alleles were 0.344 and 0.656, respectively. The TT genotype was the most frequent in the studied population followed by TC and CC ones. Moreover, the animals carrying TT genotypes seem to show an initial faster growth, which determined higher bodyweight at 90 and 270 days of age; conversely, CC individuals exhibit a faster growth in the post-weaning period achieving the higher bodyweight at 450 days of age.

PCR-SSCP variation of GH and STAT5A genes and their association with estimated breeding values of growth traits in Baluchi sheep

Growth hormone (GH) selected for its important role in economically relevant traits and signal transducers and activators of transcription 5A (STAT5A) is also known as a main mediator of growth hormone action on target genes. A total number of 190 lambs of Iranian purebred Baluchi sheep were genotyped at exon 5 of GH and exons 7 and 8 of STAT5A genes by using PCR-SSCP analysis. GH gene revealed three (G1, G2, and G3) conformational patterns; however, STAT5A loci were not polymorphic. Breeding values of growth traits including birth weight, weaning weight, 6 months weight, 9 months weight, and yearling weight were estimated by using the Best Linear Unbiased Prediction based on an animal model with a relationship matrix. Studied growth traits were examined for association analysis. Our findings suggest that animals with G2 genotype have highest breeding value for six month weight, while these animals have lowest breeding value for pre-weaning traits. Higher performance of G2 animals in adult ages may be related to the growth hormone role in puberty ages. The other traits showed no relationship to the genotypes examined.

Genetic polymorphism of STAT5A protein: relationships with production traits and milk composition in Italian Brown cattle

STATs are a group of transcription factors that mediate actions of a variety of peptide hormones and cytokines within target cells (for example, prolactin and growth hormone). Therefore, STAT5A gene is a candidate marker for quantitative traits in farm animals with respect to milk production traits. In this study the STAT5A/AvaI polymorphism was investigated with PCR-RFLP in a sample of 233 Italian Brown cattle. This polymorphism is localized in the coding region of the bovine STAT5A gene. It is a substitution C-->T at position 6853 within exon 7. All three possible genotypes for the C/T polymorphism were identified. The overall frequencies of alleles C and T were 0.83 and 0.17 respectively; the Hardy-Weinberg equilibrium was verified. In order to study the relationship between STAT5A/AvaI polymorphism and milk performance traits, the data for a 305-d milk production that included milk yield, protein and fat yield, fat and protein percentage were used. Significant differences between the two genotypes were found in yields of milk, fat and protein and protein percentage (P<0.01). CC cows produced more milk than CT (5418.68 v. 5149.54 kg). Protein content was higher in milk from CC compared with CT genotypes (3.40 v. 3.21%). No significant difference was found in fat content. Owing to the low number of TT cows in the studied population, this genotype was not included in the statistical analysis; in fact the number of TT cows was not enough to provide an accurate statistical analysis. Although more studies are needed to better clarify the role of this SNP on production traits, STAT5A/AvaI polymorphism appears to be a promising indirect marker to improve milk production traits in cattle.