Epistatic interactions between at least three loci determine the “rat-tail” phenotype in cattle

Table 1 Segregation analysis of 598 F₂ and backcross (BC) SEGFAM calves based on the RTS classification score (RT)

Coat colour	MC1R	PMEL	F₂			BC
Coat colour	MC1R	PMEL	Non-affected RT 1	RT 3–4	RT 2	Non-affected RT 1	RT 3–4	RT 2
Black, no dilution	E ^D/*	dc+/dc+	40	0	0	0	0	0
Black, moderate dilution	E ^D/*	Dc/dc+	85	36	58	81	48	76
Black, strong dilution	E ^D/*	Dc/Dc	75	0	2	0	0	0
Red, no dilution	e/e	dc+/dc+	21	0	0	0	0	0
Red, moderate dilution	e/e	Dc/dc+	57	0	0	0	0	0
Red, strong dilution	e/e	Dc/Dc	22	0	0	0	0	0

* Either allele E ^D (dominant allele for black basic coat colour) or e (recessive, red allele) at the extension (MC1R) locus; dc+ recessive wild type allele (no coat colour dilution) and Dc dominant allele (coat colour dilution) at the dilution (PMEL c.64G>A) locus

ISSN: 1297-9686