SEROLOGICAL STUDIES ON THE BLOOD TYPE IN RED CRUCIAN CARP

This paper investigated erythrocytic antigen differences between individuals in R. C. Carp population using routine serlogical methods. This antigen system is nominated as S blood type (or group) system. Based on the results of isoagglutination and isoantibody and rabbit antiserum absorption tests, four blood phenotypes were revealed: no antigen(type Ⅰ, S0), two antigens(type Ⅱ, S1S2) and single antigen(type Ⅲ, S1 and type Ⅳ, S2). In serum, type Ⅰ has anti-S1 and anti-S2, type Ⅱ has no antibodies, type Ⅲ has anti-S2, and type Ⅳ has anti-S1. This blood type system is similar to the phenotype models of "A-B-O" type in tuna and ABO type in human being, but is different from the model in deer mouse which has only 3 phenotypes, A, AB and B, possibly controlled by two alleles alabelled PA and PB. It has been assumed that S blood type in R. C. Carp is determined by 3 multiple alleles labelled S1, S2 and S0 (here S1 and S2 are codominant, and S0 is most likely to be recessive). Although the genetic background of S system is possibly similar to that of human ABO. the results of agglutination test between human "A" and "B" serum and four types of S system in R.C.Carp showed that S system is a particular blood type independent of human ABO. The primary data present a much higher S1S2 ratio(6/16) in R.C.Carp than in human AB type. Further investigations of crossing between genotypes for S system are in process.