title: A New Nomenclature of Xenopus laevis Chromosomes Based on the Phylogenetic Relationship to Silurana/Xenopus tropicalis.
abstract: Xenopus laevis (XLA) is an allotetraploid species which appears to have undergone whole-genome duplication after the interspecific hybridization of 2 diploid species closely related to Silurana/Xenopus tropicalis (XTR). Previous cDNA fluorescence in situ hybridization (FISH) experiments have identified 9 sets of homoeologous chromosomes in X. laevis, in which 8 sets correspond to chromosomes 1-8 of X. tropicalis (XTR1-XTR8), and the last set corresponds to a fusion of XTR9 and XTR10. In addition, recent X. laevis genome sequencing and BAC-FISH experiments support this physiological relationship and show no gross chromosome translocation in the X. laevis karyotype. Therefore, for the benefit of both comparative cytogenetics and genome research, we here propose a new chromosome nomenclature for X. laevis based on the phylogenetic relationship and chromosome length, i.e. XLA1L, XLA1S, XLA2L, XLA2S, and so on, in which the numbering of XLA chromosomes corresponds to that in X. tropicalis and the postfixes 'L' and 'S' stand for 'long' and 'short' chromosomes in the homoeologous pairs, which can be distinguished cytologically by their relative size. The last chromosome set is named XLA9L and XLA9S, in which XLA9 corresponds to both XTR9 and XTR10, and hence, to emphasize the phylogenetic relationship to X. tropicalis, XLA9_10L and XLA9_10S are also used as synonyms.
authors: Laboratory of Animal Genetics, Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan.
authors: Yoichi
authors: Y
authors: Matsuda
authors: Yoshinobu
authors: Y
authors: Uno
authors: Mariko
authors: M
authors: Kondo
authors: Michael J
authors: MJ
authors: Gilchrist
authors: Aaron M
authors: AM
authors: Zorn
authors: Daniel S
authors: DS
authors: Rokhsar
authors: Michael
authors: M
authors: Schmid
authors: Masanori
authors: M
authors: Taira
mesh_terms: D000818:Animals; D002871:Chromosome Banding; D002875:Chromosomes / Q000145:classification* / Q000235:genetics / Q000648:ultrastructure; D005260:Female; D006824:Hybridization, Genetic / Q000235:genetics; D017404:In Situ Hybridization, Fluorescence; D008677:Metaphase; D010802:Phylogeny; D013045:Species Specificity; D009626:Terminology as Topic; D057891:Tetraploidy; D014981:Xenopus / Q000145:classification; D014982:Xenopus laevis / Q000145:classification / Q000235:genetics*