Multi-Locus control of MLC reactions in rhesus monkeys

Abstract

The genetic basis for MLC reactivity in rhesus monkeys was further investigated. Cells from anintra-RhLA recombinant monkey were MLC reactive with those of an SD-identical sib and with each of two sets of homozygous typing cells carrying either paternal haplotype. Also, cells from a pair ofRhLA- identical sibs reacted in MLC with each other, as well as with three genotypically different siblings. This excludes control of MLC reactivity by the conventionalD locus only. Thus the results selected for presentation provide formal evidence for the existence of at least one additional MLC locus, namedD'. The possibility thatD' exerts its influence on MLC reactivity only after alloimmunization is discussed.

The Major Histocompatibility Complex of Rhesus Monkeys XII: Cellular Typing for D Locus Antigens in Families1

“…Antigen TC 75'-1 is segregating with the paternal b haplotype. Interestingly, the response of GO was low with TC 2A and high with TC 2B; this aberrant reactivity of GO has been' described (Widmer & Balner 1978) and will be dealt with in more detail below. Antigen TC blank-1 segregates with the maternal haplotype c in family 9584.…”

“…It can be seen that there is responsiveness against all four 75'-1 (b/b) typing cells but that the response t o TC 2A was fairly low (cpm 596; SI = 2.4), while responses to TC's 2B, 2C and 2G were higher. Such differences were even more pronounced shortly after alloimmunization of animal GO (Widmer & Balner 1978).…”

Mixed lymphocyte reactivity in cattle

“…The results did suggest that MLR is controlled by one genetic system and this idea is consistent with results in other species. Generally, strong responses are raised by mismatching at one locus whereas weaker responses are raised against antigens of another locus, which is also MHC linked (Bijnen et al 1977, Goldman et al 1975, Gunther & Stark 1978, Widmer & Balner 1978. The exception to this is the cow where the existence of two strong MLR-controlling loci has been postulated (Usinger et al 1977).…”

The RhLA Complex of Rhesus Monkeys. XI: Positive MLC Reactions between Identical Sibs Caused by Alloimmunization1

“…This suggests that the D' and Ir genes in question, had recombined in coupling. This would imply that the D', Ir-GA and Ir-GL genes have a mapping position close to each other in the same region of RhLA (Widmer & Balner 1978).…”

“…Since recombination between the lal /D and the SDregion could be excluded, the existence of one or more other loci with an influence on MLC reactivity had to be assumed4. For reasons detailed elsewhere (Widmer & Balner 1978), these "aberrant" MLC reactivities were provisionally attributed to disparities for a second RhLA-linked locus, called D'. I t was speculated that the products of that D' locus exert their influence only after alloimmunization.…”