488
JOHN E. CUSHING
system, independent of sex and size, is postulated to be based on six
codominant alleles determining 15 phenotypes. These are differentiated
by seven reagents. Rigorous statistical analysis of frequencies of the
various phenotyes among almost loo0 fish, taken over the summer of
1965, showed that the frequencies of the hypothetical genes determining
these conformed to the expectation for a population in Hardy-Weinberg
equilibrium. The development of the understanding of this system provides an excellent basis for subpopulation investigation in this and
other species of tuna. Such population studies will assume added significance as they continue to be combined with those on serum esterase
(Fujino and Kang, 1968a) and transferrin (Fujino and Kang, 1968b)
groups in tuna. In fact, when one considers the additional parameters provided by all other researches on subpopulations of tunas, it looks as
though the next few years should provide a fascinating story, concerning
as it does the vast reaches of the major ocean systems and the biological
magnificence of the tunas with all their associated fisheries (cf. Cushing,
1964, for additional references on tuna blood group research).
Another recent involvement of fish with blood group research is
that concerned with the production of antibodies for human red cells
in the brown bullhead catfish, Ictalurus nebulosus (Chuba et al., 1968;
Wiener et al., 1969). As noted in the section on antibody specificity,
antibodies were produced by the injection of saliva from human secretors. The most striking of the results obtained was a reagent, anti-Z,
that detected a new specificity on human cells. This reacted equally
with all human cells irrespective of type except that of Bombay. It also
reacted with the cells of anthropoid apes but failed to react with those
of monkeys. Additional observations are reported that lead the authors
to postulate a basic blood group substance A on which the genes A and
B and the gene H superimpose their specificities.
Of interest in connection with the above studies is the fact that
the brown bullhead is the first species in which a system of erythrocyte
antigens and natural agglutinins analogous to that of the human ABO
system was detected (Cushing and Durall, 1957). Additional intraspecific agglutinations between the channel catfish, Zctalurus p . punctatus,
and the brown bullhead were also observed at this time, as was the
occurrence of rare isoagglutinations among the white croakers, Genyonemus lineatw. An isoagglutinin in the skipjack, Katsuwonis pelamis, was
also found in this period (cf. Cushing, 1956). Recently, Kuhns and
Chuba (1968) have reported on other intrageneric blood group differences among freshwater catfish (Ictalurids). These include a Forssmanlike antigen present not only on red cells but also on epithelial cells and
in the gastric mucus, and a second non-Forssman-like antigen recognized
JOHN E. CUSHING
system, independent of sex and size, is postulated to be based on six
codominant alleles determining 15 phenotypes. These are differentiated
by seven reagents. Rigorous statistical analysis of frequencies of the
various phenotyes among almost loo0 fish, taken over the summer of
1965, showed that the frequencies of the hypothetical genes determining
these conformed to the expectation for a population in Hardy-Weinberg
equilibrium. The development of the understanding of this system provides an excellent basis for subpopulation investigation in this and
other species of tuna. Such population studies will assume added significance as they continue to be combined with those on serum esterase
(Fujino and Kang, 1968a) and transferrin (Fujino and Kang, 1968b)
groups in tuna. In fact, when one considers the additional parameters provided by all other researches on subpopulations of tunas, it looks as
though the next few years should provide a fascinating story, concerning
as it does the vast reaches of the major ocean systems and the biological
magnificence of the tunas with all their associated fisheries (cf. Cushing,
1964, for additional references on tuna blood group research).
Another recent involvement of fish with blood group research is
that concerned with the production of antibodies for human red cells
in the brown bullhead catfish, Ictalurus nebulosus (Chuba et al., 1968;
Wiener et al., 1969). As noted in the section on antibody specificity,
antibodies were produced by the injection of saliva from human secretors. The most striking of the results obtained was a reagent, anti-Z,
that detected a new specificity on human cells. This reacted equally
with all human cells irrespective of type except that of Bombay. It also
reacted with the cells of anthropoid apes but failed to react with those
of monkeys. Additional observations are reported that lead the authors
to postulate a basic blood group substance A on which the genes A and
B and the gene H superimpose their specificities.
Of interest in connection with the above studies is the fact that
the brown bullhead is the first species in which a system of erythrocyte
antigens and natural agglutinins analogous to that of the human ABO
system was detected (Cushing and Durall, 1957). Additional intraspecific agglutinations between the channel catfish, Zctalurus p . punctatus,
and the brown bullhead were also observed at this time, as was the
occurrence of rare isoagglutinations among the white croakers, Genyonemus lineatw. An isoagglutinin in the skipjack, Katsuwonis pelamis, was
also found in this period (cf. Cushing, 1956). Recently, Kuhns and
Chuba (1968) have reported on other intrageneric blood group differences among freshwater catfish (Ictalurids). These include a Forssmanlike antigen present not only on red cells but also on epithelial cells and
in the gastric mucus, and a second non-Forssman-like antigen recognized