Fascinating insights into the Xenopus genome have come to light in the course of the past 20 years. This issue summarizes the knowledge about extant polyploid amphibian species and gives an update on sexual differentiation and gene expression as well as the neuroendocrinological basis for courtship songs. New resources and associated studies unavailable or only in their infancy in the 1990s are described and include a web portal for all Xenopus-related issues (Xenbase), informatics approaches for studying duplicate gene expression and molecular polymorphism. Additionally, the articles reflect upon novel discoveries related to the complex cytogenetics of this group, such as the origins of sex chromosomes and transposable element evolution. A new official nomenclature of Xenopus laevis chromosomes based on the phylogenetic relationship to Silurana (Xenopus) tropicalis is presented for the first time. Providing a wealth of updates, Xenopus Genomics is recommended for specialists in the fields of zoology, herpetology, embryology and cytogenetics as well as for students with an interest in vertebrate cytogenetics.weiterlesen