Developmental abnormalities in triploid hybrids between tetraploid and diploid tree frogs (genus Hyla)

Abstract

Crosses between tetraploid female grey tree frogs, Hyla versicolor, and diploid males of the same genus may provide information on developmental differences between the parental species. Crosses with Hyla cinerea males in 1988 produced a large number of vigorous offspring, but abnormalities in eye development indicated some incompatibility of the parental genomes. The degree of eye development of the hybrids varied, ranging from completely absent to fully functional. Repetition of this cross combination in 1989 resulted in similar variation in eye formation. Histological sections through developing eyes indicated that the abnormalities may be related to improper formation of the cornea, improper orientation of the lens, or lack of lens induction. This may reflect differences in the timing of development between the two parental species.