Molecular and immunogenetic analysis of major histocompatibility haplotypes in northern bobwhite enable direct identification of corresponding haplotypes in an endangered subspecies, the masked bobwhite

The major histocompatibility complex (MHC) is a group of genetic loci codin g for haplotypes that have been associated with fitness traits in mammals a nd birds. Such associations suggest that MHC diversity may be an indicator of overall genetic fitness of endangered or threatened species. The MHC hap lotypes of a captive population of 12 families of northern bobwhites (Colin us virginianus) were identified using a combination of immunogenetic and mo lecular techniques. Alloantisera were produced within families of northern bobwhites and were then tested for differential agglutination of erythrocyt es of all members of each family. The pattern of reactions determined from testing these alloantisera identified a single genetic system of alloantige ns in the northern bobwhites, resulting in the assignment of a tentative ge notype to each individual within the quail families. Restriction fragment p atterns of the DNA of each bird were determined using the chicken MHC B-G c DNA probe bg11. The concordance between the restriction fragment patterns a nd the alloantisera reactions showed that the alloantisera had identified t he MHC of the northern bobwhite and supported the tentative genotype assign ments, identifying at least 12 northern bobwhite MHC haplotypes. Eighteen n orthern bobwhite alloantisera were then used to detect a minimum of 17 mask ed bobwhite MHC haplotypes. Subsequent restriction fragment pattern analyse s using cDNA probes for chicken MHC genes were in agreement with agglutinat ion patterns displayed by the antisera, showing that the immunogenetically identified alloantigen system constituted the MHC of the masked bobwhite. T hese data demonstrate that a non-endangered species may be used to provide antisera for differentiating MHC haplotypes in a closely related endangered species, thus providing a practical basis for long-range monitoring of MHC haplotypes of birds surviving in their native habitats. Zoo Biol 18:279-29 4, 1999. (C) 1999 Wiley-Liss, Inc.