SGER: The Fate of Duplicated Genes in an Invasive Polyploid Species

同源基因，或那些被多倍体事件复制的基因，可能在反映其复制的水平上表达，或者它们的表达可能发生显著变化。本文提出的技术最近在异源多倍体物种的基因表达分化中得到了应用。为了评估异源多倍体入侵种英国米草属（Spartina anglica）蜡质基因的动态，需要解决的具体问题有：1)；米草属（Spartina anglica）蜡质（Waxy）的不同拷贝间是否存在序列差异？其二倍体祖系海苔、互花苔；英国金缕梅产生的不育F1杂种S. xtownsendii；以及新发现的F1混合动力车s.x neyrautii？2.） 蜡质位点的表达在米草属及其亲本种或二倍体祖先之间是否有差异？3)。英国米草属中蜡质是否存在差异变异？PCR、DNA的克隆和测序以及cDNA单链构象多态性（SSCP）的结合将比以前使用的技术更精确地提供入侵异源多倍体物种的基因组织和功能数据。将对RT-PCR产物进行直接测序以确认所有结果。所进行的分析将提供洞察动力学和随后的基因型和表型变化，这是由于历史上异域分类群、同源基因和异源多倍体之间的杂交。

Homeologous genes, or those genes duplicated by polyploid events, may be expressed at levels reflective of their duplication, or their expression may be changed dramatically. The techniquesproposed here have been very recently described with the application toward the differentiationof gene expression in allopolyploid species. Specific questions to be addressed to assess thedynamics of the Waxy gene in the allopolyploid invasive species, Spartina anglica are: 1.) Arethere sequence differences between the different copies of Waxy in: Spartina anglica; its diploidprogenitors S. maritima, S. alterniflora; the sterile F1 hybrid from which S. anglica arose, S. xtownsendii; and the newly discovered F1 hybrid, S. x neyrautii? 2.) Does variation in expressionof the Waxy locus vary between Spartina anglica, its parental species or diploid ancestors? 3.) Isthere differential variation of Waxy within Spartina anglica? A combination of PCR, cloning andsequencing of DNA and single stranded conformation polymorphisms (SSCP) of cDNA willprovide more precision than previously used techniques to provide data on genic organization and function in an invasive allopolyploid species. Direct sequencing of RT-PCR products will beperformed for confirmation of all results. The analyses performed will provide insight into thedynamics and subsequent genotypic and phenotypic changes due to the hybridization betweenhistorically allopatric taxa, homeologous genes, and allopolyploidization.