Genetic Diversity of Kıvırcık Sheep Breed Reared in Different Regions and its Relationship with Other Sheep Breeds in Turkey

Review of sheep breeding and genetic research in Türkiye

The livestock industry in Türkiye is vital to the country's agricultural sector and economy. In particular, sheep products are an important source of income and livelihood for many Turkish smallholder farmers in semi-arid and highland areas. Türkiye is one of the largest sheep producers in the world and its sheep production system is heavily dependent on indigenous breeds. Given the importance of the sheep industry in Türkiye, a systematic literature review on sheep breeding and genetic improvement in the country is needed for the development and optimization of sheep breeding programs using modern approaches, such as genomic selection. Therefore, we conducted a comprehensive literature review on the current characteristics of sheep populations and farms based on the most up-to-date census data and breeding and genetic studies obtained from scientific articles. The number of sheep has increased in recent years, mainly due to the state's policy of supporting livestock farming and the increase in consumer demand for sheep dairy products with high nutritional and health benefits. Most of the genetic studies on indigenous Turkish sheep have been limited to specific traits and breeds. The use of genomics was found to be incipient, with genomic analysis applied to only two major breeds for heritability or genome-wide association studies. The scope of heritability and genome-wide association studies should be expanded to include traits and breeds that have received little or no attention. It is also worth revisiting genetic diversity studies using genome-wide single nucleotide polymorphism markers. Although there was no report of genomic selection in Turkish sheep to date, genomics could contribute to overcoming the difficulties of implementing traditional pedigree-based breeding programs that require accurate pedigree recording. As indigenous sheep breeds are better adapted to the local environmental conditions, the proper use of breeding strategies will contribute to increased income, food security, and reduced environmental footprint in a sustainable manner.

Verification of pedigree information with paternity testing in Karacabey Merino sheep

Complex tests of DNA sequences, genetic research, and the use of specific DNA polymorphisms as genetic markers have all advanced rapidly in recent years. It is widely used in DNA-based parental testing. Therefore, it has replaced the blood types routinely used in pedigree tests. The study aimed to evaluate the 14 microsatellite loci in the study in terms of paternity test parameters and to investigate the usability of the relevant loci in determining the parentage of the Karacabey Merino breed. In this study, paternity testing was performed on 5 rams of the Karacabey Merino breed and their probable 98 offspring using 14 microsatellite loci. A total of 290 alleles were observed in the study. The observed heterozygosity ratio (Ho) based on loci was between 0.82 and 0.98, and the expected heterozygosity ratio (He) was between 0.87 and 0.93. Individual exclusion probability (PE) values for the loci were calculated to be between 0.596 and 0.761, with combined exclusion probability (CPE) values of 0.99999995. According to the results of the study, paternity tests using 14 microsatellite markers in Karacabey Merino sheep can be used with high accuracy.

Genetic Diversity of Montenegrin Local Sheep Breeds Based on Microsatellite Markers

The Montenegrin sheep population mostly consists of local breeds and their crossbreeds that are very valuable from their genome preservation point of view. The aim of this study was the investigation of the genetic diversity of seven Montenegrin sheep breeds (Jezeropivska-JP, Sora-SOR, Zetska zuja-ZZ, Bardoka-BAR, Sjenička-SJ, Ljaba-Lj, and Piperska zuja-PIP) using 18 microsatellite sets of markers. The genotyping was done for 291 samples from seven populations using the multiplex amplification of sequences with polymerase chain reaction (PCR). The parameters of genetic diversity were estimated using several software tools. In total, 243 alleles were found, with a range of 6 to 25 by locus. The mean observed heterozygosity (Ho), polymorphism information content (PIC), and Fis values (fixation index) per marker were 0.728, 0.781, and -0.007, respectively. The mean number of alleles per breed varied from 4.889 in ZZ to 10.056 in JP. The highest Ho was estimated for JP (0.763) and the lowest for ZZ (0.640). The genetic structure showed close relations between SOR and JP, and both of them with SJ, while ZZ, LJ, and PIP were more distanced. This study provides useful indicators for the development of further in-depth studies and the creation of appropriate conservation programs.