Genetic variability in the western lowland gorilla ({\it Gorilla gorilla gorilla\/}): Implications for captive management

Eloise Aita, Fordham University


An assessment of genetic variability within a population can be made by identifying and quantifying genetic polymorphisms. Electrophoretic analysis of red blood cell enzymes and plasma proteins was performed on a study group of 75 gorillas. Chromosomal analysis using G-band and C-band staining techniques were performed on a group of 33 gorillas. Within each study group gorillas were separated into two categories: wild-born and captive-born individuals. Genetic heterozygosity was assessed using electrophoretic polymorphisms identified at four of twenty loci studied. Genetic variability was also measured through analysis of C-band polymorphisms which were identified on all gorilla chromosomes. Frequencies for all identified polymorphisms were calculated.^ Electrophoretic data showed that total average heterozygosity (H) for the wild-born group equalled 0.042 and within the captive-born H equalled 0.031. These average heterozygosity values were not significantly different though the frequency of heterozygotes at the PGM-1 locus was significantly decreased in the captive-born group as compared to the wild-born group.^ Chromosomal data showed that total average heterozygosity values for wild-born gorillas and captive-born gorillas was virtually the same, 0.28 and 0.29 respectively. Seventeen low frequency polymorphisms ($\leq$0.13) identified within the wild-born group were not demonstrated in the captive-born group. Neither structural nor numerical abnormalities were observed for any of the individuals studied. C-band polymorphisms were shown to be useful in delineating familial relationships and may prove a suitable tool in determining paternity within large gorilla breeding groups.^ An overview of gorilla breeding status is presented. Heterozygosity levels are related to founder population size and recommendations are made to maximize the genetic input from the remaining wild-born group, especially those individuals that have not yet produced offspring. ^

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Recommended Citation

Aita, Eloise, "Genetic variability in the western lowland gorilla ({\it Gorilla gorilla gorilla\/}): Implications for captive management" (1990). ETD Collection for Fordham University. AAI9105785.