Section 11 — Immunugenetics 



bonito with a specificity related to human Ai. 

 The second concerns the exchange of blood 

 samples between individual sipunculids (Den- 

 drostomum zostericolurri) as a techniuue for the 

 investigation of potential immunological in- 

 compatibilities involving hemerythrocytes and 

 other hemocytes of this species. 



11.4. Immunogenetic Relationships of Trout. James 



E. Wright, Robert Sklenarik, and Suzanne 

 M. James (University Park, Pennsylvania, 

 U.S.A.). 



Antisera were prepared in rabbits and chickens 

 against erythrocytes of individuals of four trout 

 species— brook (Salvelinus fontinalis), lake (Sal- 

 velinus namaycush), brown {Salmo trutta), and 

 rainbow (Salmo gairdneri). Agglutination tests 

 show cross reactions of any of these sera with 

 erythrocytes of any of the trout species. Compa- 

 rative studies of dilutions of each serum provided 

 evidence of extensive antigenic homology be- 

 tween the two Salvelinus species. Also, marked 

 similarities in the cellular antigens of rainbows 

 and the two Salvelinus species were found. In 

 contrast, brown trout apparently lacked practi- 

 cally all antigens common to any of the other 

 three species. 



Absorptions of each serum by erythrocytes 

 from individuals of each species provided anti- 

 sera specific to each species; cross-match aggluti- 

 nation tests confirmed the antigenic relatedness 

 of brook, lake, and rainbow trout and the lack 

 of homology between brown trout and any of the 

 other three species, even rainbow trout, the other 

 Salmo species. 



Although genetic blood group systems pre- 

 viously identified in brown and in rainbow trout 

 are species-specific, these results suggest that 

 blood groups may be identified that are common 

 to rainbow, brook and lake. Absorptions of 

 anti-brook trout sera with cells of individual 

 rainbows produced reagents that identify several 

 blood types in rainbows, but these reagents 

 failed to differentiate among brook trout. Ab- 

 sorptions of anti-lake or anti-brook sera have 

 produced reagents that identify a major blood 

 group system in lake trout; these reagents also 

 agglutinate erythrocytes of some individuals 

 among brook trout. 



11.5. Sex-linked "Histocompatibility Reactions" 

 in the Salamander Triturus (diemictylus) 

 viridescens. Alexander Wolsky, C. Edward 

 Quinn, Jose Squadroni S.J. and Maria de 

 Issekutzi Wolsky (New York, U.S.A.). 



In these salamanders female skin grafts are 



better tolerated than male ones (Pizzarello and 

 Wolsky, Squadroni and Wolsky). This was 

 interpreted by assuming the existence of histo- 

 compatibility genes on the sex chromosomes 

 (although no sex chromosome dimorphism is 

 known in the species). Recent work, however, 

 indicates that the phenomenon may be due, 

 at least partly, to histological and histochemical 

 rather than immunological differences between 

 the sexes. 



Male and female skin grafts behave differently 

 even on the same host (Squadroni and Wolsky). 

 Female grafts, when alone on a host, remain 

 histologically normal, whereas male grafts 

 quickly lose their structure; especially the break- 

 down of the epidermis and the skin glands is 

 characteristic (Pizzarello). A double graft 

 elicits typical lymphocyte accumulation around 

 both grafts but the female skin structures are not 

 attacked immediately and appear normal at a 

 time when the male graft has been resorbed 

 (Squadroni). Studies with the Ouchterlony tech- 

 nique, involving rabbit sera immunized against 

 Triturus skin homogenates, indicate no difference 

 in the antigenicity of the male and female 

 skin (Quinn). 



The situation in the female Triturus skin seems 

 thus comparable to that found in the cheek 

 pouch skin of the golden hamster by Billingham 

 and co-workers, except that in the case of Tritu- 

 rus one must assume a double barrier in the 

 path of histocompatibility reactions (both to 

 and from the site of the antigenic stimulus) 

 whereas in the hamster only the latter seems to 

 exist. 



11.6. Different Degree of Compatibility between 

 Several Stocks of Drosophila melanogaster, 

 tested with Ovary Grafting. Carla Halfer 

 (Milan, Italy). 



Since it is generally known that grafting of 

 organs in Drosophila is successful, I have tried 

 to analyse the degree of compatibility between 

 genotypically different stocks of Drosophila 

 melanogaster, using the method of ovary grafting. 

 The compatibility between grafted ovary and 

 recipient has been measured as percentage of 

 flies where the grafted ovary was able to deliver 

 viable eggs, flies which allowed the ovary to 

 develop without becoming functional, and flies 

 which rejected the graft. As recipients, two dif- 

 ferent wild tumorous stocks have been used 

 (tu A 2 and tu B 3 ), one tumourless (Varese); 

 as donors: Chieti— vermilion, vermilion and 

 yellow white. The first data show a different 



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