Werner P, Raducha M G, Prociuk U, Henthorn P S, Patterson D F
Center for Comparative Medical Genetics, School of Veterinary Medicine, University of Pennsylvania, Philadelphia 19104-6010, USA.
J Hered. 1999 Jan-Feb;90(1):39-42. doi: 10.1093/jhered/90.1.39.
We describe and illustrate a comparative approach to creating physical and linkage maps of genes on dog chromosomes. The approach is particularly useful in species, like the dog, which have a rudimentary gene map not integrated with microsatellite loci. Human or mouse cDNAs for genes to be mapped are used to isolate cosmid or phage clones from dog genomic libraries. Clones verified to contain the homologous canine gene coding sequences are screened for "gene-associated" simple sequence repeat polymorphisms (SSRPs). The unique sequences flanking the repeats are used to design PCR primers to amplify the repeat and gene-associated SSR length differences that are informative for linkage analysis used in canine pedigrees to study linkage between loci or with diseases. The same canine clones are employed as probes in fluorescence in situ hybridization (FISH) studies to physically map the loci to specific sites on dog chromosomes. This approach creates a combined gene and gene-associated microsatellite anchor locus framework map. In this article we review our recent use of this approach to map a series of genes found on human chromosome 17 (HSA17) to two dog chromosomes. Canine chromosome 9 (CFA9) contains 11 loci found on HSA17q, while two genes from HSA17p map to CFA5, demonstrating disruption of HSA17 synteny at the centromere. The order of 11 HSA17q genes on CFA9 was conserved in the dog, but the entire group is inverted with respect to the centromere when compared to human and mouse. Maps created by this approach can be used to advantage for integrating anonymous microsatellites with gene maps, including microsatellites found in genome scans to be linked to canine diseases. This makes it possible to identify the homologous chromosomal region in the human or mouse genome and to make use of this information in formulating hypotheses regarding candidate genes, as has recently been illustrated by other investigators.
我们描述并举例说明了一种用于构建犬类染色体上基因的物理图谱和连锁图谱的比较方法。该方法在像犬类这样的物种中特别有用，因为它们的基因图谱不完善且未与微卫星位点整合。用于定位的人类或小鼠基因的cDNA被用于从犬类基因组文库中分离黏粒或噬菌体克隆。经证实含有同源犬类基因编码序列的克隆被筛选用于“基因相关”简单序列重复多态性（SSRP）分析。重复序列两侧的独特序列被用于设计PCR引物，以扩增重复序列以及基因相关的SS长度差异，这些差异对于犬类家系连锁分析中研究基因座之间或与疾病的连锁关系具有参考价值。同样的犬类克隆被用作荧光原位杂交（FISH）研究中的探针，以将基因座物理定位到犬类染色体的特定位点。这种方法创建了一个基因和基因相关微卫星锚定基因座框架图谱。在本文中，我们回顾了我们最近使用这种方法将人类17号染色体（HSA17）上发现的一系列基因定位到两条犬类染色体上的情况。犬类9号染色体（CFA9）包含在HSA17q上发现的11个基因座，而来自HSA17p的两个基因定位到CFA5，这表明HSA17在着丝粒处的同线性被破坏。CFA9上11个HSA17q基因的顺序在犬类中是保守的，但与人类和小鼠相比，整个基因群相对于着丝粒是倒置的。通过这种方法创建的图谱可用于将匿名微卫星与基因图谱整合，包括在基因组扫描中发现的与犬类疾病相关的微卫星。这使得能够识别人类或小鼠基因组中的同源染色体区域，并利用这些信息来制定关于候选基因的假设，其他研究人员最近已经对此进行了说明。
