Seel ion 11 — Imnuuwgenetics 



pig-O antibodies are present in normal sera of 

 certain cattle, goats, and pigs. Reagents pre- 

 pared from these sources were used in hemolytic 

 tests to type the red cells of 961 Duroc, Yorkshire, 

 and Duroc-Yorkshire crossbred pigs and their 

 sires and dams. Three phenotypes, A, O, and - 

 ("dash", i.e. A-negative, O-negative), were 

 observed. Blood-typing results were in agree- 

 ment with the hypothesis that the allele for A is 

 dominant to that for O, and that the expression 

 of A and O phenotypes is prevented by a homo- 

 zygous recessive genotype at another locus, 

 resulting in — . Five matingsof — — gave 22 — 

 offspring; 33 matings of O > O gave 213 O and 

 3—; 23 matings of O -gave 18 A, 70 O and 

 56 — ; 27 matings of A . -gave 66 A, 29 O and 

 66—; 36 matings of A : O gave 147 A, 98 O 

 and 30 — ; and 23 matingsof A A gave 96 A, 

 21 O and 26 — . Red cells of some pigs reacted 

 only weakly with available A or O reagents, and 

 the normal serum of an occasional pig appeared 

 to react most often with red cells of — pigs, 

 suggesting additional complexities of A-O 

 genotypes in pigs. 



This work was supported in part by a research 

 grant, GM-08752, from the National Institutes 

 of Health, Public Health Service. 



11.10. Studies of Equine Blood Groups. Clyde 

 Stormont, Yoshiko Suzuki, and E. A. Rhode 

 (Davis, U.S.A.). 



Studies on equine blood groups have been 

 underway in our laboratory for the past several 

 years. Although there have been no published 

 reports of the data, some of the progress may 

 be mentioned here. Sixteen specifically different 

 equine blood-typing reagents have been produ- 

 ced, and the blood factors corresponding to 

 these reagents have been named Ai, A2, B, 

 C, D, E, F, G, H, J, K, L, M, N, O and X. 

 Our main interest is that of determining the 

 genetic systems in which these reagents act. It 

 is found that reagents for blood factors Ai, 

 A2, B and C react in a system named A in which 

 five heritable combinations (phenogroups) Ai, 

 A2C, B, A2BC and — v the negative alternative) 

 are established. A second system, named D, 

 involves blood factors D, M and X, and the 

 phenogroups DX, MX and — . Blood factors F 

 and G appear to be independent of each other 

 and of all the other blood factors. Consequently, 

 they have been assigned to respective systems 

 F and G. Likewise, H appears to be indepen- 



dent of all the others with the possible exception 

 of E. Although the remaining blood factors J, 

 K, L, N and O are excluded as members of the 

 systems A, D, F, G and H, their possible rela- 

 tionships with respect to one another have not 

 been fully ascertained. Thus, it would appear 

 that genes at a minimum of six loci are involved 

 in the control of equine blood groups. 



11.11. Genetic Polymorphism in the Transferrings of 

 the Horse. Mikael Braend (Oslo, Norway). 



Plasma samples from 220 horses belonging to 

 the Norwegian Dola breed have been subjected 

 to starch gel electrophoresis. Nine different 

 transferrin patterns were found. They could be 

 explained by a theory of five different alleles 

 at a single locus. These alleles were named Tf D , 

 Tf F , Tf H , Tf° and TF. The Tf R and TF alleles 

 were most common, the Tf D gene was very rare. 

 Results from studies of sire families, dam- 

 offspring pairs and gene frequency analyses were 

 in agreement with the genetic theory. 



In the Fjording breed 44 horses were investi- 

 gated. Three transferrin alleles only were 

 recognized in this breed, but two genotypes were 

 found which had not been seen in the Dola horse. 

 The gene frequencies in the Fjording material 

 were markedly different from those found in the 

 Dola breed. Most common was the TF allele, 

 but the Tf D and TF alleles were seen quite 

 frequently too. 



In horses of foreign origin additional trans- 

 ferrin patterns have been detected. Most im- 

 portant is the occurrence of a sixth transferrin 

 allele, Tf M . In total, 14 different transferrin 

 genotypes have been found in this study. 



11.12. The Inheritance of Bloodgroups in the B and 

 C Blood Group Systems in Cattle. J. Bouw 

 (Wageningen, The Netherlands). 



Investigations on blood groups in cattle have 

 demonstrated that these bloodgroups can be 

 classified into at least 1 1 genetic systems. 



Within the systems the blood groups are 

 composed of one or more serologically deter- 

 minable antigenic factors. 



In the so-called B- and C blood group systems 

 numbers of at least 240 and 50 blood groups, 

 composed of various antigenic factors, controlled 

 by these systems, have been established. 



Concerning the inheritance of these blood 

 groups mainly 2 explanations have been ad- 

 vanced: 



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