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Polymorphism of vitamin B 12 [ 57 Col binding proteins in rabbit serum
Author(s) -
Masina P.,
Ramunno L.,
Iannelli D.
Publication year - 1978
Publication title -
animal blood groups and biochemical genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.756
H-Index - 81
eISSN - 1365-2052
pISSN - 0003-3480
DOI - 10.1111/j.1365-2052.1978.tb01412.x
Subject(s) - vitamin b12 , biology , phenotype , locus (genetics) , allele , microbiology and biotechnology , genetics , biochemistry , gene
Summary When rabbit serum labelled with vitamin B 12 [ 57 Co] was subjected to starch gel electrophoresis and au;oradiography, three phenotypes of proteins capable of binding vitamin B 12 were observed. Family data revealed that these phenotypes (called TC‐A, TC‐AB and TC‐B) are controlied by two codominant alleles ( TC A and TC B ), at an autosomic locus. Proteins capable of binding vitamin B 12 both in vivo and in vitro are commonly referred to as Transcobalamins and can be found in the serum of numerous animal species (for a review, see Glass, 1974; Allen, 1975; Stenman, 1975). Furthermore, Daiger et al. (1975a) have described seven different patterns of vitamin B 12 binding proteins which occur in human plasma and which are presumably controlled by four alleles. The present paper describes experiments in which both starch gel electrophoresis and autoradiography are used to identify three phenotypes of rabbit serum proteins responsible for binding vitamin B 12 in vitro. It was found that these three phenotypes are controlled by two allelic codominant genes, at an autosomic locus. Individual serum samples (30 μl), obtained from 385 White New Zealand rabbits varying in age from one month to three years, were incubated with 0.1 ng of vitamin B 12 [ 57 Co] (specific activity: 180 μCi/μg; Lot 247; Radiochemical Centre, Amersham, England) at 37°C for 30 minutes. Starch gel electrophoresis and autoradiography were performed as described by Geldermann (1970) and Daiger et al. (1975b), respectively. Electrofocusing (pH range 3.5–9.5) was conducted in the 2117 Multiphor apparatus (LKB, Bromma, Sweden) according to the manufacturer's instructions. The resulting pH gradient was measured with a surface pH electrode (Ingold, Zürich, Switzerland).