Veterinary Research Forum

Abstract Genetic variations within a partial region of the growth hormone (GH) gene and their associations with growth traits were investigated in European sea bass (Dicentrarchus labrax) using DNA sequencing. Five haplotypes and ten novel single nucleotide polymorphisms were identified in the GH gene of European sea bass. In silico analysis revealed two amino acid substitutions between the reference and our partial protein sequence, specifically serine to leucine and serine to threonine. Both variations were located within the α1 helix, which also contains H34, a zinc-binding residue. The genotypes at the g.1611T>C locus of the GH gene were found to be significantly associated with total weight, fillet weight and head length. Additionally, the association between GH g.1557A>T genotypes and both preanal and abdominal lengths was statistically significant. Similarly, the genotypes of g. 1857 C>T loci having the synonymous mutation in phenylalanine amino acid were significantly associated with standard length. The haplotype 4 reported the highest weight and length traits than the other haplotypes. It was concluded that haplotype 4 could be used as a potential genetic marker for selective breeding programs of European sea bass under Mediterranean conditions.

Abstract Uterine infection is one of the reproductive diseases that can have disturbing postpartum uterine health in cattle. Therefore, identification of resistant genotypes to uterine infection is important. Lactoferrin (LF) is one of the major antimicrobial compounds in the normal uterine discharges of cows. We hypothesized that allelic diversity in LF gene may contribute to susceptibility or resistance to uterine infection. We investigated the single nucleotide polymorphism genes identified in the 5' untranslated region (5'-UTR, position +32) of the LF gene using Allele-specific PCR method in cows with and without uterine infection. Blood samples were collected from 89 multiparous Holstein dairy cows with a history of uterine infection (n = 51), and cows without disease as the control group (n= 38). The results indicated the presence of different proportion of polymorphisms (G > C) in the 5'-UTR area of cows in the all groups. The results of Allele specific PCR was in complete agreement with sequencing method. Statistical analysis did not show any statistically significant correlation between disease and SNP in 5'-UTR. While, there was a significant difference in the mean of reproductive parameters of cows without polymorphism compare to those of with SNP in 5'-UTR. Cows with +32:CC genotype and +32:GC genotype (cows with SNP in UTR) had lower average of services per conception and days open compared to cows with the +32:GG genotypes. However, no significant difference in the calving to first service was found between these genotypes. Further studies will be required to determine critical SNPs in LF gene and status of the risk of uterine infection and embryo survival in cows.