Kim Dae-Won, Chae Sung-Hwa, Kang Bo-Ra, Choi Sang-Haeng, Kim Aeri, Woo Seonock, Park Hong-Seog
Genome Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Korea.
Genome. 2008 Jun;51(6):452-64. doi: 10.1139/G08-029.
There have been many studies of the morphology, behavioral audiograms, and population structure of the false killer whale (Pseudorca crassidens), but sequencing, mapping, and functional and comparative genomics studies are still largely unknown. In this paper, we sequenced three novel BAC clones corresponding to a total length of 308 kb and spanning the PRNP, PRND, and RASSF2 loci, and conducted comparative genomic analysis to examine the genomic structure of the false killer whale PRNP locus. We determined that the three genes show a high degree of conservation in their syntenic regions with respect to gene order, gene orientation, and the predicted coding sequence (CDS) between human and whale, whereas PRNT was not detected in whale. Interestingly, the predicted CDS in whale PRNP contained a novel type of 4-copy octarepeat resulting from a 24 bp deletion when compared with the human sequence. In addition, we identified a novel 1869 bp repeat unit in a region that is non-syntenic to human and cow sequences and is therefore considered to be whale-specific sequence. Our results will provide novel insights into the genomic changes that have occurred during evolution of mammalian PRNP loci, and may also have implications for research into prion disease.
已经有许多关于伪虎鲸（Pseudorca crassidens）的形态学、行为听力图和种群结构的研究，但测序、图谱绘制以及功能和比较基因组学研究在很大程度上仍然未知。在本文中，我们对三个新的细菌人工染色体（BAC）克隆进行了测序，其总长为308 kb，跨越PRNP、PRND和RASSF2基因座，并进行了比较基因组分析，以研究伪虎鲸PRNP基因座的基因组结构。我们确定，这三个基因在其同线区域在基因顺序、基因方向以及人与鲸之间预测的编码序列（CDS）方面显示出高度保守性，而在鲸中未检测到PRNT。有趣的是，与人类序列相比，鲸PRNP中预测的CDS包含一种新型的4拷贝八肽重复序列，这是由24 bp的缺失导致的。此外，我们在一个与人类和牛序列非同线的区域中鉴定出一个新的1869 bp重复单元，因此被认为是鲸特异性序列。我们的结果将为哺乳动物PRNP基因座进化过程中发生的基因组变化提供新的见解，也可能对朊病毒疾病的研究产生影响。
