N Blood Group System of Pigs

Abstract

THE N blood group system of pigs has been identified by Hála and Hojný¹ by means of an antiserum called anti-Na. The corresponding antigen, Na, was considered to be the product of a gene, N^a. They describe a system of two alleles, N^a and N^(c∣l)—the latter symbol denotes the absence of N^a. Two additional factors of the N system, Nb and Nc, defined by the antisera anti-Nb and anti-Nc, have been identified in this laboratory. Inheritance studies show that there are three genes: N^a, producing factor Na, N^b, producing factor Nb, and N^bc, producing factors Nb and Nc. N^a and N^b are a pair of contrasting alleles, forming a closed system; Nc is a sub-group of Nb, and has not been found in its absence. It was not possible to verify Hála and Hojný's claim that Na is a soluble antigenic substance.