THE USE OF IMMUNOLOGICAL TECHNIQUES IN 

 RACIAL STUDIES 



By 



George J . Ridgway-' 



1/ 



Races have been defined as populations 

 which are characterized by different frequencies 

 of variable genes and/or chromosome struc- 

 tures (Dobzhansky and Epling, 1944) . There is 

 much evidence from the work of geneticists, 

 systematists and physical anthropologists to 

 support this definition. It would appear then 

 that one of the best ways to distinguish between 

 races of any animal would be to find variable 

 characters which are genetically controlled and 

 determine their frequency within the populations 

 in question. Gordon (1947) has used this meth- 

 od in a study of isolated populations of the 

 Mexican platyfish, (Platypoecilus macula tus ). 

 The characters he studied, seven different pat- 

 terns of tail markings, were shown to be due to 

 a series of dominant allelic genes . Populations 

 from different geographic areas were shown to 

 have different and characteristic frequencies 

 for these genes, some of which have remained 

 fairly constant over a period of 70 years . 



The characters which have been found 

 most useful in studies on the races of man are 

 differences in the antigenic composition of red 

 cells. The first such differences, now known 

 as the ABO groups, were discovered by Land- 

 steiner (1900), shown to be genetically controlled 

 by Von Dungern and Hirszfeld (1910) and first 

 demonstrated to differ in their frequency of 

 occurrence in various races by L. and H. Hirsz- 

 feld (1919). Subsequently, many other antigenic 

 differences in human red cells have been found 

 and demonstrated to vary in frequency between 

 various populations or races. For recent re- 

 views concerning this subject, see Boyd (1950), 

 Race and Sanger (1954), Mourant (1954) and 

 Levine (1954). 



1/ Biochemist, Pacific Salmon Investigations, 

 U.S. Fish and Wildlife Service, 2725 Montlake 

 Blvd., Seattle, Washington. Formerly Bio- 

 chemist, Salmon Nutrition Laboratory, Cook, 

 Washington . 



Individual differences in red cell antigens 

 have been demonstrated in many animals in- 

 cluding the following: cattle (Stormont, Owen 

 and Irwin, 1951), sheep (Yeas, 1949), chickens 

 (Briles, McGibbon and Irwin, 1950), whales 

 (Fujino, 1953) and goldfish (Hildemann, 1954). 

 These antigenic differences have been shown to 

 be genetically controlled in cattle and in chickens 

 wherever they have been studied by genetic 

 techniques. Differences in the frequencies of 

 cellular antigens between breeds (races) have 

 been shown in dairy cattle (Owen, Stormont and 

 Irwin, 1947) . There is also some evidence that 

 isolated stocks of sheep (Dujarric de la Riviere 

 et_aL, 1952) and of whales (Fujino, 1953) differ 

 in the frequency of occurrence of various cellu- 

 lar antigens . 



Another serological property which shows 

 variation between individuals is the presence of 

 naturally occurring hemagglutinins or antibodies 

 which agglutinate red blood cells . These in- 

 variably occur in man in a reciprocal relation- 

 ship to the A and B antigens and with them define 

 the ABO blood groups. Of interest here are the 

 demonstrations of individual variations in the 

 occurrence of natural hemagglutinins in yellow - 

 fin tuna and skipjack bloods (Cushing, 1952) and 

 the bloods of several species of whales (Fujino, 

 1953). They have been tested for, but have not 

 been found in the blood of the cod, ( Gadus 

 morrhua) (Jensen, 1937). The usefulness of 

 natural hemagglutinins for racial studies is 

 limited by the fact that they occur irregularly 

 except in man and there is considerable doubt 

 that they are genetically controlled (Wiener, 1951) . 



The antigenic properties of serum proteins 

 have been extensively used to demonstrate phylo- 

 genetic relationships between animal species 

 (Nutall, 1904), including fish (Gemeroy, 1943). 

 However, intraspecific differences in the anti- 

 genic properties of serum proteins have been 

 demonstrated only once to the author's knowledge 



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