Voss S R, Smith J J, Gardiner D M, Parichy D M
Department of Biology, Colorado State University, Fort Collins, CO 80523, USA.
Genetics. 2001 Jun;158(2):735-46. doi: 10.1093/genetics/158.2.735.
Urodele amphibians (salamanders) are important models for embryological, physiological, and natural history research and are also a biomedically important group because they are the only vertebrates capable of regenerating entire organ systems. To enhance the utility of salamanders for biomedical research and for understanding genome evolution, genetic linkage analysis was used to identify chromosome segments that are homologous between ambystomatid salamanders and distantly related vertebrate model organisms. A total of 347 loci (AFLPs, RAPDs, and protein-coding loci) were mapped using an interspecific meiotic mapping panel (Ambystoma mexicanum and A. tigrinum tigrinum; family Ambystomatidae). Genome size in Ambystoma was estimated to be 7291 cM, the largest linkage map estimate reported for any organism. However, the relatively large size of the salamander genome did not hinder efforts to map and identify conserved syntenies from a small sample of 24 protein-coding loci. Chromosomal segments that are conserved between fishes and mammals are also conserved in these salamanders. Thus, comparative gene mapping appears to be an efficient strategy for identifying orthologous loci between ambystomatid salamanders and genomically well-characterized vertebrate model organisms.
有尾两栖动物（蝾螈）是胚胎学、生理学和自然历史研究的重要模型，也是生物医学上的重要类群，因为它们是唯一能够再生整个器官系统的脊椎动物。为了提高蝾螈在生物医学研究和理解基因组进化方面的实用性，采用遗传连锁分析来鉴定美西钝口螈和远缘脊椎动物模型生物之间同源的染色体片段。使用种间减数分裂作图群体（墨西哥钝口螈和虎纹钝口螈虎纹亚种；钝口螈科）对总共347个基因座（扩增片段长度多态性、随机扩增多态性DNA和蛋白质编码基因座）进行了定位。钝口螈的基因组大小估计为7291厘摩，这是报道的任何生物体中最大的连锁图谱估计值。然而，蝾螈基因组相对较大的规模并未阻碍从小样本的24个蛋白质编码基因座中进行图谱绘制和鉴定保守同线性的努力。鱼类和哺乳动物之间保守的染色体片段在这些蝾螈中也保守。因此，比较基因图谱绘制似乎是鉴定钝口螈科蝾螈与基因组特征明确的脊椎动物模型生物之间直系同源基因座的有效策略。
