Genomics Research Unit, Faculty of Sciences and Philosophy, Universidad Peruana Cayetano Heredia, Lima, Peru.
PLoS One. 2012;7(4):e34775. doi: 10.1371/journal.pone.0034775. Epub 2012 Apr 6.
The majority of disease resistance (R) genes identified to date in plants encode a nucleotide-binding site (NBS) and leucine-rich repeat (LRR) domain containing protein. Additional domains such as coiled-coil (CC) and TOLL/interleukin-1 receptor (TIR) domains can also be present. In the recently sequenced Solanum tuberosum group phureja genome we used HMM models and manual curation to annotate 435 NBS-encoding R gene homologs and 142 NBS-derived genes that lack the NBS domain. Highly similar homologs for most previously documented Solanaceae R genes were identified. A surprising ∼41% (179) of the 435 NBS-encoding genes are pseudogenes primarily caused by premature stop codons or frameshift mutations. Alignment of 81.80% of the 577 homologs to S. tuberosum group phureja pseudomolecules revealed non-random distribution of the R-genes; 362 of 470 genes were found in high density clusters on 11 chromosomes.
迄今为止，在植物中鉴定出的大多数抗病（R）基因编码一种含有核苷酸结合位点（NBS）和富含亮氨酸重复（LRR）结构域的蛋白质。其他结构域，如卷曲螺旋（CC）和 Toll/白细胞介素-1 受体（TIR）结构域，也可能存在。在最近测序的马铃薯族块茎基因组中，我们使用 HMM 模型和手动注释来注释 435 个编码 NBS 的 R 基因同源物和 142 个缺乏 NBS 结构域的 NBS 衍生基因。鉴定出了大多数先前记录的茄科 R 基因的高度相似同源物。令人惊讶的是，在 435 个编码 NBS 的基因中，约有 41%（179 个）是假基因，主要是由于过早的终止密码子或移码突变。对 577 个同源物中的 81.80%与马铃薯族块茎假染色体进行比对，揭示了 R 基因的非随机分布；在 11 条染色体上发现了 470 个基因中的 362 个高密度簇。
