Gene, secretor

Biochemical studies on ABO and Lewis antigens and the role of the secretor gene have been reviewed/ The Haworth Memorial Lecture given by R. U. Lemieux and entitled Human Blood Groups and Carbohydrate Chemistry has been published. ... 

Some people express antigens of these blood group systems on secretory glycoproteins, as well as upon their red cells, and this capacity is regulated by a distinct secretor gene. Those who are secretors are "Sd, those who are not are sd. Secretor type and red cell phenotype do not always correspond. 

The secretor gene Se does not control either the A-specific or B-specif-ic glycosyltransferases (see above) the available evidence indicates that... 

The presence of one antigenic determinant may reduce the extent of expression of another. Thus, in an A glycoprotein of a secretor, the expression of the H determinant is largely inhibited, and by using enzymes (30) which destroy A or B activity, H activity is greatly increased (3, 7). Also, gene interactions may occur as, for example, when the H and Le genes are both present, a new specificity termed Leb arises... 

In non-secretors, the a 1,2 fucosyltransferase is not found in epithelial tissues (Chester and Watkins, 1969), so the function of the 5egene must be to regulate the tissue specificity of the enzyme s expression (i.e. the tissue-specific activity of the H-gene). 

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