Hunter Linda S, Sidjanin Duska J, Hijar Manuel Villagrasa, Johnson Jennifer L, Kirkness Ewen, Acland Gregory M, Aguirre Gustavo D
J.A. Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA.
Mol Vis. 2007 Mar 26;13:431-42.
Mutations in PAX6 cause human aniridia. The small eye (sey) mouse represents an animal model for aniridia. However, no large animal model currently exists. We cloned and characterized canine PAX6, and evaluated PAX6 for causal associations with inherited aniridia in dogs.
Canine PAX6 was cloned from a canine retinal cDNA library using primers designed from human and mouse PAX6 consensus sequences. An RH3000 radiation hybrid panel was used to localize PAX6 within the canine genome. Genomic DNA was extracted from whole blood of dogs with inherited aniridia, and association testing was performed using markers on CFA18. Fourteen PAX6 exons were sequenced and scanned for mutations, and a Southern blot was used to test for large deletions.
Like the human gene, canine PAX6 has 13 exons and 12 introns, plus an alternatively spliced exon (5a). PAX6 nucleotide and amino acid sequences were highly conserved between dog, human, and mouse. The canine PAX6 cDNA sequence determined in this study spans 2 large gaps present in the current canine genomic sequence. Radiation hybrid mapping placed canine PAX6 on CFA18 in a region with synteny to HSA11p13. Exon-scanning revealed single nucleotide polymorphisms, but no pathological mutations, and Southern blot analysis revealed no differences between normal and affected animals.
Canine PAX6 was cloned and characterized, and results provide sequence information for gaps in the current canine genome sequence. Canine PAX6 nucleotide and amino acid sequences, as well as gene organization and map location, were highly homologous with that of the human gene. PAX6 was evaluated in dogs with an inherited form of aniridia, and sequence analysis indicated no pathological mutations in the coding regions or splice sites of aniridia-affected dogs, and Southern blot analysis showed no large deletions.
PAX6基因的突变会导致人类无虹膜症。小眼（sey）小鼠是无虹膜症的一种动物模型。然而，目前尚无大型动物模型。我们克隆并鉴定了犬类PAX6基因，并评估其与犬类遗传性无虹膜症的因果关联。
使用根据人类和小鼠PAX6共有序列设计的引物，从犬类视网膜cDNA文库中克隆犬类PAX6基因。利用RH3000辐射杂种细胞系将PAX6基因定位到犬类基因组中。从患有遗传性无虹膜症的犬类全血中提取基因组DNA，并使用CFA18上的标记进行关联测试。对14个PAX6外显子进行测序并扫描突变，使用Southern印迹法检测大片段缺失。
与人类基因一样，犬类PAX6基因有13个外显子和12个内含子，外加一个可变剪接外显子（5a）。犬类、人类和小鼠之间的PAX6核苷酸和氨基酸序列高度保守。本研究确定的犬类PAX6 cDNA序列跨越了当前犬类基因组序列中存在的2个大缺口。辐射杂种图谱将犬类PAX6基因定位在CFA18上与人类11号染色体短臂13区同源的区域。外显子扫描揭示了单核苷酸多态性，但未发现病理性突变，Southern印迹分析显示正常动物和患病动物之间没有差异。
克隆并鉴定了犬类PAX6基因，结果为当前犬类基因组序列中的缺口提供了序列信息。犬类PAX6核苷酸和氨基酸序列以及基因结构和图谱位置与人类基因高度同源。对患有遗传性无虹膜症的犬类进行了PAX6基因评估，序列分析表明无虹膜症患病犬的编码区或剪接位点没有病理性突变，Southern印迹分析显示没有大片段缺失。
