Jaworski C, Sperbeck S, Graham C, Wistow G
Section on Molecular Structure and Function, National Eye Institute, Bethesda, Maryland 20892, USA.
Biochem Biophys Res Commun. 1997 Nov 7;240(1):196-202. doi: 10.1006/bbrc.1997.7623.
Pax-6 is essential for eye development and for tissue-specific gene expression within the eye. Splicing of an alternative exon (5a) leads to variant DNA binding specificity in Pax6. Here we show that in the mature bovine eye the relative abundance of the alternative Pax6-5a mRNA varies markedly, particularly between the lens and iris. Additional alternative splicing products were identified which may lead to "domain swapping" or truncation of Pax6 proteins. Comparison of amphibian (Xenopus) and mammalian (bovine) Pax-6 genes revealed highly conserved intronic sequences flanking exon 5a, including potential lariat sites which may have a role in the mechanism of alternative splicing.
Pax-6对于眼睛发育以及眼内组织特异性基因表达至关重要。一个可变外显子（5a）的剪接导致Pax6中DNA结合特异性发生变化。在此我们表明，在成熟的牛眼中，可变的Pax6-5a mRNA的相对丰度有显著差异，尤其是在晶状体和虹膜之间。还鉴定出了其他可变剪接产物，它们可能导致Pax6蛋白的“结构域交换”或截短。对两栖动物（非洲爪蟾）和哺乳动物（牛）的Pax-6基因进行比较，发现外显子5a两侧有高度保守的内含子序列，包括可能在可变剪接机制中起作用的潜在套索位点。
