Serum Transferrins of Twin Sheep-Goat Hybrids

Abstract

Recently there has been renewed interest in the question of hybridization between sheep and goats. Dikov (1960, 1961) have claimed that live and fully viable hybrids· can be produced. Szumowski and TMret (1965) have summarized the results of their own and three other investigations on one particular individual suspected of being a hybrid; on .the basis of its morphological and serological characteristics they considered it to be a true hybrid. Bowerman and Hancock (1963) and Alexander and Williams (unpublished data) have obtained hybrid foetuses with the intermediate chromosome number of 57 (sheep 54, goat 60) but found that the foetuses invariably died, usually at about the 60th day of pregnancy. The purpose of this report is to describe the transferrin types of twin hybrid foetuses obtained by Caesarian section at 61 days. The material was obtained during the course of hybridization experiments of Alexander and Williams.Serum transferrin polymorphism has been described in both sheep (Ashton 1958a(Ashton , 1958bAshton and Ferguson 1963) and goats (Ashton and McDougall 1958;Millison and Pattison 1961). The limited family data availaple are in agreement with the hypothesis that in each species the difference between transferrin types are determined by a series of alleles at a single locus and which do not exhibit dominance. Starch gel electrophoresis followed by 59Fe radioautography (Bailey and Cooper, unpublished data) indicate that in both the sheep and the goat each transferrin allele determines the production of a characteristic pair of proteins electrophoretically separable in starch gel. It It has been shown (Cooper 1966; Stormont and co-workers, personal communication, 1965) that the Merino transferrins called F, A, H, J, and K by Ashton and Ferguson (1963) are indistinguishable from five of the transferrins found commonly in British breeds and called A, B, 0, D, and E by Khattab, Watson, and Axford (1964) and Hall (personal communication). The results of Cooper and Stormont and co-workers are in contrast to those of Ashton and Ferguson, who found transferrins F, H, and J only in Merinos.