Variation of Y-chromosomal STRs in Yezidi and Chaldean populations in Iraqi Kurdistan

Background: Many ethnic groups live in the northern part of Iraq which represents the Iraqi part of Kurdistan. Short tandem repeats are widely used in population genetics and forensic science. Objective: This research aims to analyze the Y-chromosomal STR markers of two ethnic groups living in Iraqi Kurdistan, Yezidi, and Chaldean groups. Methodology: Samples of peripheral blood from a total of 44 unrelated males (22 for each ethnic group) were taken. DNA was extracted by using a DNA Extraction kit and analyzed for eight Y-chromosomal short tandem repeats (Y-GATA-H4, Y-GATA-C4, DYS458, DYS456, DYS448, DYS437, DYS392, and DYS19). Then, the PCR products were run on 10% polyacrylamide gel and stained by silver nitrate. The results were analyzed by Power marker V3.25 and the dendrogram was created by Mega X software. Results: The highest diversity was observed at Y-GATA-C4 (GD: 0.81) while the lowest diversity was observed at DYS456 (GD: 0.64) in the Yezidi group. In the Chaldean group, DYS458 (GD: 0.88) was the most diverse, while the least diverse marker was Y-GATA-H4 (GD:0.66). The marker Y-GATA-C4 was found to be the most informative marker in both groups with a PIC value of 0.8605. Conclusions: The study confirmed the high discrimination ability of the Y-chromosomal STRs analysis and provided a dataset on these two ethnic groups of Iraqi Kurdistan. The dendrogram of Yezidi and Chaldean datasets reveals that the Yezidi individuals are more closely related to each other as compared to the Chaldean group because intermarriage among Yezidi people is more than that among the Chaldean individuals .