*3.1. Assessment of Genetic Links between Sheep Breeds within the Wool-Type Groups*

Principal Component Analysis performed for 15 coarse wool sheep populations (Figure 1A) showed that the first Principal Component (PC1) accounting for 13.34% of genetic variability clearly separated the Romanov and the Kuchugur breeds from the other populations which were clustered together. The Buubei (2) population was differentiated from the Buubei\_1 group as well as the other breeds by the second Principal Component (PC2). Besides the PC2 pierced the joined cluster into two slightly traceable subgroups

(Buubei (1) + Mongolian + Edilbai + Kalmyk + Karakul + Tuva and Andean + Karachaev + Tushin + Ossetin + Lezgin).

**Figure 1.** Principal component analysis for Russian sheep populations: (**A**) performed for coarse wool breeds; (**B**) performed for semi-fine wool breeds; (**C**) performed for fine wool breeds. For a description of the sheep breeds, see Table 1.

Based on PCA results for semi-fine wool breeds, the Russian longhaired breed was the most distant from the other breeds and located in the right down quadrant formed by the PC1 and PC2 (Figure 1B). The Kuibyshev and North Caucasian breeds occupied the left upper quadrant, while the Altai Mountain and Tsigai breeds were placed within the left down quadrant.

Within the fine wool group, the Volgograd breed was separated from the other breeds be the PC1, which accounts for 3.02% of genetic variability, while the Dagestan Mountain breed was differentiated by the PC2 (Figure 1C).
