Chromosome Banding in Amphibia. XXXVI. Multimorphic Sex Chromosomes and an Enigmatic Sex Determination in Eleutherodactylus johnstonei (Anura, Eleutherodactylidae)

摘要

A detailed cytogenetic study on the leaf litter frog Eleutherodactylus johnstonei from 14 different Caribbean islands and the mainlands of Venezuela and Guyana revealed the existence of multimorphic XY♂/XX♀ sex chromosomes 14. Their male sex determination and development depends either on the presence of 2 telocentric chromosomes 14 (X_(t)Y_(t)), or on 1 submetacentric chromosome 14 (X_(sm)) plus 1 telocentric chromosome 14 (Y_(t)), or on the presence of 2 submetacentric chromosomes 14 (X_(sm)Y_(sm)). The female sex determination and development requires either the presence of 2 telocentric chromosomes 14 (X_(t)X_(t)) or 2 submetacentric chromosomes 14 (X_(sm)X_(sm)). In all individuals analyzed, the sex chromosomes 14 carry a prominent nucleolus organizer region in their long arms. An explanation is given for the origin of the (X_(t)Y_(t))♂, (X_(sm)Y_(t))♂, (X_(sm)Y_(sm))♂, (X_(t)X_(t))♀, and (X_(sm)X_(sm))♀ in the different populations of E. johnstonei. Furthermore, the present study gives detailed data on the chromosome banding patterns, in situ hybridization experiments, and the genome size of E. johnstonei.