应用BXD小鼠鉴定肾脏发育相关QTLs

Identification of kidney development related QTLs in BXD mouse population

[目的]利用BXD小鼠群体定位肾脏发育相关QTLs及筛选QTLs区段内的候选功能基因。[方法]高脂饲喂BXD小鼠29w龄后,获取各品系小鼠肾脏重量和体重,结合该小鼠群体基因型信息,利用webQTL定位肾重比相关QTLs。为进一步筛选QTLs区段内的功能基因,首先,通过皮尔逊相关性分析,鉴定肾脏mRNA表达水平与肾重比显著相关(P<0.05)的基因;其次,通过比较C57BL/6J和DBA/2J亲本品系的DNA序列信息,鉴定含有非同义突变的蛋白编码基因;最后,将上述基因导入到Phenolyzer在线分析数据库,并以“kidney”为表型关键词进行检索,优选QTLs区段内的候选功能基因。[结果]BXD小鼠肾重比存在显著差异。经QTL作图,在基因组上共鉴定3个与肾重比相关的QTLs,分别位于四号和X染色体上。在QTLs区段内,共发现45个基因的肾脏mRNA表达水平与肾重比显著相关(P<0.05),65个基因含有非同义突变,经Phenolyzer在线数据库分析,发现51个基因可能与肾脏发育或肾脏疾病相关。[结论]通过QTL作图,在小鼠基因组上鉴定了3个影响肾脏发育的QTLs,筛选了部分候选基因,后续可做进一步的功能验证来阐明其参与肾脏发育的调控机制。

[Objective] Identification of kidney development related QTLs and candidate genes in BXD mouse population.[Methods]Kidney and body weight were measured for BXD male mice which fed with high fat diet for 29 weeks. Web QTL was used for QTL mapping to locate the genomic loci that regulating kidney development. For the identified QTLs,first,pearson correlation were used to identify QTLs genes whose mRNA expression level in kidney were significantly correlated with kidney mass( P < 0. 05). Second,protein coding genes with missense variants were identified through the comparation between C57 BL/6 J and DBA/2 J DNA sequence. Last,the above genes were submitted to "Phenolyzer"online database coupled with"kidney"as phenotype key words to prioritize the candidate functional genes.[Results]Kidney mass has large variability in BXD mouse population. Three kidney mass related QTLs were identified through QTL mapping in which one is located on chromosome 4 and the other two on chromosome X. A total of 45 genes which mRNA expression levels in kidney are significantly correlated with kidney mass( P < 0. 05) and 65 protein coding genes contain missense variants. In addition,51 genes are indicated have functional roles in kidney development or disease through"Phenolyzer"analysis.[Conclusion]Three kidney mass regulating QTLs were identified on mouse genome,and several candidate genes were prioritized which can be used for further functional validation and elucidate the regulating mechanism.