title: Different autosomes evolved into sex chromosomes in the sister genera of Salix and Populus.
abstract: Willows (Salix) and poplars (Populus) are dioecious plants in Salicaceae family. Sex chromosome in poplar genome was consistently reported to be associated with chromosome XIX. In contrast to poplar, this study revealed that chromosome XV was sex chromosome in willow. Previous studies revealed that both ZZ/ZW and XX/XY sex-determining systems could be present in some species of Populus. In this study, sex of S. suchowensis was found to be determined by the ZW system in which the female was the heterogametic gender. Gene syntenic and collinear comparisons revealed macrosynteny between sex chromosomes and the corresponding autosomes between these two lineages. By contrast, no syntenic segments were found to be shared between poplar's and willow's sex chromosomes. Syntenic analysis also revealed substantial chromosome rearrangements between willow's alternate sex chromatids. Since willow and poplar originate from a common ancestor, we proposed that evolution of autosomes into sex chromosomes in these two lineages occurred after their divergence. Results of this study indicate that sex chromosomes in Salicaceae are still at the early stage of evolutionary divergence. Additionally, this study provided valuable information for better understanding the genetics and evolution of sex chromosome in dioecious plants.
authors.affiliation: The Southern Modern Forestry Collaborative Innovation Center, Nanjing Forestry University, Nanjing 210037, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Hou
authors.affiliation: The Southern Modern Forestry Collaborative Innovation Center, Nanjing Forestry University, Nanjing 210037, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Ye
authors.affiliation: The Southern Modern Forestry Collaborative Innovation Center, Nanjing Forestry University, Nanjing 210037, China.
authors.forename: Defang
authors.initials: D
authors.lastname: Zhang
authors.affiliation: The Southern Modern Forestry Collaborative Innovation Center, Nanjing Forestry University, Nanjing 210037, China.
authors.forename: Yingnan
authors.initials: Y
authors.lastname: Chen
authors.affiliation: The Southern Modern Forestry Collaborative Innovation Center, Nanjing Forestry University, Nanjing 210037, China.
authors.forename: Lecheng
authors.initials: L
authors.lastname: Fang
authors.affiliation: The Southern Modern Forestry Collaborative Innovation Center, Nanjing Forestry University, Nanjing 210037, China.
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Dai
authors.affiliation: The Southern Modern Forestry Collaborative Innovation Center, Nanjing Forestry University, Nanjing 210037, China.
authors.forename: Tongming
authors.initials: T
authors.lastname: Yin
mesh_terms: D032461:Chromosomes, Plant; D035264:Flowers; D056426:Genetic Loci; D018745:Genome, Plant; D010802:Phylogeny; D020161:Physical Chromosome Mapping; D032107:Populus / Q000145:classification / Q000235:genetics*; D032108:Salix / Q000145:classification / Q000235:genetics*; D012730:Sex Chromosomes