Genetic Relationships and Phylogeny of Papua New Guinean Hylid Frogs Elucidated by Allozyme Analysis

Abstract

To elucidate the evolutionary relationships of Papua New Guinean hylid frogs, we conducted an allozyme analysis using a total of 70 individuals from nine species of Litoria and two species of Nyctimystes. Fourteen enzymes extracted from skeletal muscles and livers were analyzed by starch-gel electrophoresis. These enzymes were encoded by genes at 20 presumptive loci. There were 3-11 phenotypes produced by 3-9 alleles at these loci. The mean proportion of heterozygous loci per individual, mean proportion of polymorphic loci per population, and mean number of alleles per locus in 11 species were 4.5%, 12.5%, and 1.14 on average, respectively. Genetic distances were 0.036 between two populations of L. infrafrenata; 0.248-1.849 (x=1.135) between nine species of the genus Litoria; and 1.703 between two species from the genus Nyctimystes. The intergeneric genetic distances were 1.551-2.877 (x=1.944) between Litoria and Nyctimystes. The UPGMA dendrogram and NJ tree showed the primary dichotomy of the Papua New Guinean hylids Nyctimystes and Litoria. Our distance data confirmed the presence of several sibling species of Litoria, which are similar to each other in external morphology; i. e., L. arfakiana and L. wollastoni, and L. contrastens and L. bicolor group sp.