Devos Katrien M
Department of Crop and Soil Sciences, and Department of Plant Biology, University of Georgia, Athens, Georgia 30602, USA.
Curr Opin Plant Biol. 2005 Apr;8(2):155-62. doi: 10.1016/j.pbi.2005.01.005.
Comparative analyses unravel the relationships between genomes of related species. The most comprehensive comparative dataset obtained to date is from the grass family, which contains all of the major cereals. Early studies aimed to identify chromosomal regions that have remained conserved over long evolutionary time periods, but in recent years, researchers have focused more on the extent of colinearity at the DNA-sequence level. The latter studies have uncovered many small rearrangements that disturb colinearity in orthologous chromosome regions. In part, genomes derive their plasticity from genome- and gene-amplification processes. Duplicated gene copies are more likely to escape selective constraints and thus move to other regions of the genome, where they might acquire new functions or become deleted. These rearrangements will affect map applications. The most popular applications, especially since the complete rice genomic sequence has been available, are the use of comparative data in the generation of new markers to tag traits in other species and to identify candidate genes for these traits. The isolation of genes underlying orthologous traits is the first step in conducting comparative functional studies.
比较分析揭示了相关物种基因组之间的关系。迄今为止获得的最全面的比较数据集来自禾本科植物，其中包含所有主要谷物。早期研究旨在识别在漫长进化时期内保持保守的染色体区域，但近年来，研究人员更多地关注DNA序列水平上的共线性程度。后一类研究发现了许多扰乱直系同源染色体区域共线性的小重排。部分基因组的可塑性源于基因组和基因扩增过程。复制的基因拷贝更有可能逃脱选择限制，从而转移到基因组的其他区域，在那里它们可能获得新功能或被删除。这些重排将影响图谱应用。最受欢迎的应用，尤其是自水稻全基因组序列可用以来，是在生成新标记以标记其他物种的性状并识别这些性状的候选基因时使用比较数据。分离直系同源性状背后的基因是进行比较功能研究的第一步。
