Glatt K, Glatt H, Lalande M
Genetics Division, Children's Hospital, Boston, Massachusetts 02115, USA.
Genomics. 1997 Apr 1;41(1):63-9. doi: 10.1006/geno.1997.4639.
The genes encoding the gamma-aminobutyric acid (GABA) type-A receptor subunits beta 3 (GABRB3), alpha 5 (GABRA5), and gamma 3 (GABRG3) map to chromosome 15q11-q13. The three genes are contained within roughly 800 kb of the distal part of the imprinted Prader-Willi and Angelman syndrome region. A 570-kb contig encompassing GABRB3 and GABRA5 has been constructed in P1, lambda phage, and PAC clones. GABRB3 spans 250 kb of DNA and is organized into 9 exons that range from 68 to 504 bp, while GABRA5 is encoded by 11 exons (65 to 924 bp in length) within 86 kb. The exon/intron borders for both genes have been characterized and, primers have been designed to amplify each of the individual exons. Two reference STR markers have been positioned in the contig. The reference STR for GABRB3 is in fact located at least 60 kb beyond the 3' terminus of GABRB3, while D15S97 is contained within intron 4 of GABRB3. The detailed physical map of this GABAA receptor subunit gene cluster should not only be useful in genetic studies of the 15q11-q13 region, but will also be important for investigating the evolution and expression of the GABAA receptor gene superfamily.
编码γ-氨基丁酸（GABA）A型受体亚基β3（GABRB3）、α5（GABRA5）和γ3（GABRG3）的基因定位于15号染色体q11-q13区域。这三个基因包含在印记普拉德-威利综合征和安吉尔曼综合征区域远端约800 kb的范围内。一个包含GABRB3和GABRA5的570 kb重叠群已在P1、λ噬菌体和PAC克隆中构建。GABRB3跨越250 kb的DNA，由9个外显子组成，长度从68到504 bp不等，而GABRA5由86 kb内的11个外显子（长度为65到924 bp）编码。这两个基因的外显子/内含子边界已被确定，并且已设计引物来扩增每个单独的外显子。两个参考STR标记已定位在重叠群中。GABRB3的参考STR实际上位于GABRB3 3'末端至少60 kb以外，而D15S97包含在GABRB3的第4内含子中。这个GABAA受体亚基基因簇的详细物理图谱不仅对15q11-q13区域的遗传学研究有用，而且对研究GABAA受体基因超家族的进化和表达也很重要。
