Hawkins J W, Van Keuren M L, Piatigorsky J, Law M L, Patterson D, Kao F T
Hum Genet. 1987 Aug;76(4):375-80. doi: 10.1007/BF00272448.
The crystallins are highly conserved structural proteins universally found in the eye lens of all vertebrate species. In mammals, three immunologically distinct classes are present, alpha-, beta-, and gamma-crystallins, and each class represents a multigene family. The alpha-crystallin gene family consists of alpha 1-crystallin (CRYA1) and alpha 2-crystallin (CRYA2) genes (previously designated alpha A- and alpha B-crystallin, respectively), which show extensive sequence homology. We constructed a synthetic oligonucleotide probe of 25 bases corresponding to a specific region of the human alpha 1-crystallin gene sequence. This 25-mer probe bears little sequence homology to human alpha 2-crystallin gene and does not cross-hybridize to alpha 2-crystallin sequences in Southern blot analysis. Using this unique synthetic probe, we have demonstrated the identity of the alpha 1-crystallin gene in human genomic DNA. In addition, we have also confirmed its chromosomal location on human chromosome 21. Finally, we have regionally localized the gene to q22.3 by using both Southern blot analysis of a panel of cell hybrids containing different parts of human chromosome 21, and in situ hybridization to metaphase chromosomes. The use of synthetic oligonucleotide probes specific for individual genes should be useful in identifying and mapping members of multigene families.
晶状体蛋白是高度保守的结构蛋白，普遍存在于所有脊椎动物的眼晶状体中。在哺乳动物中，存在三种免疫上不同的类型，即α-、β-和γ-晶状体蛋白，且每种类型都代表一个多基因家族。α-晶状体蛋白基因家族由α1-晶状体蛋白（CRYA1）和α2-晶状体蛋白（CRYA2）基因组成（以前分别称为αA-和αB-晶状体蛋白），它们显示出广泛的序列同源性。我们构建了一个与人类α1-晶状体蛋白基因序列的特定区域相对应的25个碱基的合成寡核苷酸探针。这个25聚体探针与人类α2-晶状体蛋白基因几乎没有序列同源性，并且在Southern印迹分析中不会与α2-晶状体蛋白序列发生交叉杂交。使用这个独特的合成探针，我们已经证明了人类基因组DNA中α1-晶状体蛋白基因的同一性。此外，我们还证实了它在人类21号染色体上的染色体定位。最后，我们通过对一组包含人类21号染色体不同部分的细胞杂种进行Southern印迹分析以及对中期染色体进行原位杂交，将该基因区域定位到q22.3。使用针对单个基因的合成寡核苷酸探针在鉴定和定位多基因家族的成员方面应该是有用的。
