PRNP gene polymorphisms in main indigenous Turkish goat breeds.

The polymorphisms of the PRNP gene influence the susceptibility to scrapie in goats. In this study, caprine PRNP gene was analysed in a total of 249 individuals from three main indigenous goat breeds of Turkey: Anatolian Black, Angora and Kilis. We focused on the Anatolian Black breed, which represents 97% of the goat population in Turkey and compared the data of samples originated from different geographical regions. Eight polymorphisms were determined, given rise to 12 haplotypes. Allele, genotype and haplotype frequencies of the polymorphisms at codons 142, 143, 146, 154, 171, 211, 222 and 240 were calculated. Alleles associated to resistance to scrapie were found to be relatively rare in all breeds. The resistance allele 222K was absent in Turkish breeds. Other resistance-associated alleles: 146D, 146S, 154H and 171R were observed with low frequencies. The results of this study, which cover the mainly bred indigenous goats in Turkey, present the distribution of PRNP polymorphisms. Very low frequencies of resistance-associated alleles show the susceptibility to scrapie. The resistance-associated alleles S and D of codon 146 might be accepted as candidate alleles, due to their relative higher frequencies observed in the present study. A breeding program aiming to increase particularly the frequency of 146S might be applied. Predictions about impacts of a long-term breeding programme based on low initial allele frequencies and regarding its possible adverse effects are warranted. Our results might be a database for future breeding programmes, which should be carefully designed with adequate levels of genetic resistance and acceptable timeframe.

Preparing and Analyzing Expressed Sequence Tags (ESTs) Library for the Mammary Tissue of Local Turkish Kivircik Sheep.

Kivircik sheep is an important local Turkish sheep according to its meat quality and milk productivity. The aim of this study was to analyze gene expression profiles of both prenatal and postnatal stages for the Kivircik sheep. Therefore, two different cDNA libraries, which were taken from the same Kivircik sheep mammary gland tissue at prenatal and postnatal stages, were constructed. Total 3072 colonies which were randomly selected from the two libraries were sequenced for developing a sheep ESTs collection. We used Phred/Phrap computer programs for analysis of the raw EST and readable EST sequences were assembled with the CAP3 software. Putative functions of all unique sequences and statistical analysis were determined by Geneious software. Total 422 ESTs have over 80% similarity to known sequences of other organisms in NCBI classified by Panther database for the Gene Ontology (GO) category. By comparing gene expression profiles, we observed some putative genes that may be relative to reproductive performance or play important roles in milk synthesis and secretion. A total of 2414 ESTs have been deposited to the NCBI GenBank database (GW996847-GW999260). EST data in this study have provided a new source of information to functional genome studies of sheep.

FASN gene polymorphism in indigenous cattle breeds of Turkey.

The aim of this study was to determine the variants of the thioesterase (TE) beta-ketoacyl reductase (KR) domains of the Fatty Acid Synthase (FASN) gene, in the East Anatolian Red (EAR) and South Anatolian Red (SAR) cattle breeds. It has been suggested that the FASN gene is effective on fatty acid composition of meat in cattle. In this study, the genotype and allele frequencies of g.17924 A>G, g.18440 G>A and g.16024 G>A, g.16039 T>C in TE and KR domains, respectively, were detected by using polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP) method. The g.18663 T>C polymorphism of the TE domain was determined by direct sequencing. The GG genotype of the g.17924 A>G polymorphism, which affects unsaturated fatty acid composition positively, has a high frequency in EAR and SAR breeds. The frequencies of the two haplotypes g.16024 G>A and g.16039 T>C in the KR domain were found to be significantly high in both breeds. These haplotypes also have positive effects on unsaturated fatty acid composition. The AA genotype of the g. 18440 G>A polymorphism, which is suggested to be absent in Bos taurus breeds, was detected in SAR and EAR breeds with frequencies close to those in Bos indicus breeds. In conclusion, we suggest that SAR and EAR cattle breeds have an advantage in terms of genotype and haplotype distribution of the polymorphisms in TE and KR domains of the FASN gene. Additionally g.18440 G>A polymorphism might be a potential marker for breed discrimination.

Detection of bovine spongiform encephalopathy-related prion protein gene promoter polymorphisms in local Turkish cattle.

Polymorphisms in open reading frames of the prion protein gene (PRNP) have been shown to be associated with prion disease susceptibility in humans, sheep, and mice. Studies in recent years have demonstrated a similar effect of PRNP promoter and intron-1 polymorphisms on bovine spongiform encephalopathy (BSE) susceptibility in cattle. In this study, the deletion/insertion (indel) polymorphisms of the bovine PRNP gene within the promoter sequence (23 bp) and intron 1 (12 bp) were analyzed in local Turkish cattle. For this, 150 animals belonging to three different local breeds--the South Anatolian red, the East Anatolian red, and the Turkish gray--were tested using DNA purification and polymerase chain reaction. The ins allele in the 12 bp indel, which is associated with low susceptibility to BSE, showed a high frequency in all three breeds. The low-susceptibility allele of the 23-bp indel was identified in Turkish gray cattle with a frequency of 0.80. Results of the study have shown that local Turkish cattle might have an important genetic value for selection against BSE.