Electrophoretic and chromosomal variation in captive Asian elephants (Elephas maximus)

Abstract

AbstractTo investigate genetic diversity in captive Asian elephants (Elephas maximus), a total of 26 individuals from zoos in the German cities of Berlin, Hamburg, and Leipzig, and from Zürich, Switzerland, were investigated for electrophoretic variation at 44 presumptive blood protein and enzyme coding loci. The proportion of polymorphic loci (P = 4.6%) and average heterozygosity (H = 1.4%) in the specimens studied were very low. The distribution of alleles and genotypes suggested some genetic differentiation among the source populations of our elephants, most of which were wild born. Since our results are in accordance with those of a previous survey on wild populations, low genetic variation in the Asian elephant is not only associated with captive propagation. Together with differences in the incidence of alleles among populations, it is probably largely due to low effective sizes of wild Asian elephant stocks and to species‐specific breeding tactics. Standard karyotype analysis was carried out for 11 individuals, and in some cases, heterochromatin staining by Giemsa C‐banding and reverse fluorochrome staining were performed. Heterochromatin polymorphism was found in four chromosome pairs, including two satellited pairs, and is considered an important marker for population genetic investigations. One of the 11 individuals studied was found to be heterozygous for a centric fusion of two small acrocentrics. The implications of our results for breeding programs of Asian elephants are discussed. © 1995 Wiley‐Liss, Inc.