Exploring Y-DNA haplogroup diversity in the British Isles

Abstract
The Yfiler™ Plus PCR Amplification Kit is a Y-chromosome STR kit designed for the specific amplification of male DNA samples. This makes it particularly useful in sexual assault cases and paternal lineage studies. Additionally, the high inter-population variability of Y-STRs makes the kit ideal for investigating biogeographical differences and migration patterns. The aim of this study was to investigate the haplogroups of the English, Irish, Welsh, and Scottish populations to support the development of population-specific Y-STR databases and advance our understanding of the genetics of the British Isles. Buccal swabs were collected from 888 unrelated male individuals: 461 English, 191 Irish, 124 Welsh, and 112 Scottish. DNA was extracted using Prep-n-Go™ Buffer and amplified with the Yfiler™ Plus kit. The resulting data passed the Y Chromosome Haplotype Reference Database (YHRD) quality checks and were uploaded to the database. Haplogroups were identified using the Y-DNA Haplogroup Predictor - NevGen online tool, and haplogroup diversity was calculated. A total of 46 haplogroups were observed, with R1b M269 being the most common haplogroup across all populations (64% in English, 85% in Irish, 92% in Welsh, and 73% in Scottish). I1 was the second most common haplogroup in both the English (13%) and Scottish (6%) populations, while I2a2a M223 was the second most common in the Welsh (2%) and Irish (6%) populations. R1a M198 and E1b1b > V13 were the other two most frequently observed haplogroups, while the remaining 41 haplogroups were found five or fewer times across all populations. Although the Scottish population showed a higher number of haplogroups relative to the sample size tested, greater diversity was observed in the English (0.57) and Scottish (0.46) populations compared to the Irish (0.28) and Welsh (0.14) populations. This study highlights genetic differences between the four populations, with the distribution of haplogroups supporting previous findings. However, further studies with more markers and larger sample sizes are needed to continue populating Y-marker databases.