The establishment and application of positional cloning method for unknown gene in fish species of tetraploid origin.

为了定位克隆虹鱼常染色体显性眼皮肤白化病(OCA)相关基因，我们利用1004个被分析家系的样本进行了SSLP147标记连锁分析。发现SSLP147标记与显性白化基因座的遗传距离仅为0.2 cM。作为第二步，我们开始了利用虹鲑鱼BAC文库进行染色体步行的方法。因此，我们在1004个样本中检测到了一些表型和基因型之间没有重组的BAC克隆。我们测定了BAC克隆的全序列，并在该序列中寻找了候选基因。不幸的是，我们没有找到OCA的候选基因。通过候选基因逼近的方法，我们克隆了与斑马鱼色素模式突变体相关的虹鲑类c-kit基因。我们在转录调控区发现了一些碱基对替换，但在编码区没有发现。

As a first step towards the positional cloning of the gene responsible for autosomal dominant oculocutaneous albinism (OCA) in rainbow trout, we performed linkage analysis of SSLP147 markers associated with the dominant albino locus by using 1004 samples from analyzed family. And then, we found that the genetic distance between SSLP147 marker and the dominant albino locus was only 0.2 cM. As a second step, we started chromosome walking method using rainbow trout BAC libraries. As a results, we detected some BAC clones that have no recombinant between phenotypes and genotypes within 1004 samples. We determined whole sequences of the BAC clones and searched the candidate gene in the sequence. Unfortunately, we could not find the candidate gene of OCA. By candidate gene approach method, we isolated rainbow trout c-kit like gene that related with the pigment pattern mutant in zebrafish. We found some base pair substitutions in transcriptional regulatory region, but not in coding region.