鯉魚Y類水晶蛋白基因之分析與探討

Abstract

以鯉魚γ水晶蛋白的γ ml cDNA作探針篩選含有鯉魚γ 類水晶蛋白基因的基因庫，得到的genomic clone作enzyme mapping, southern hybridization，再subclone到pUC19載體，反覆用enzyme mapping, southern hybridization，最後完成DNA序列分析。 γ m12整段核酸序列長度大約是1.2Kb，其中能翻譯成蛋白質的序列（coding regions）為exonl(9個核?酸）exon2(240個核?酸）,exon3(273個核?酸）：可以encode 174個胺基酸。 γ m 12含有兩個TATA box。比較鯉魚γ m12與γ m1及 γ m2 CDNA的胺基酸序列，其中γ m12有16個胺基酸與γ m1 CDNA相同，有15個胺基酸與 γ m2 cDNA相同，而與γ ml及γ m2 cDNA共同有的胺基酸有117個，因此，γ m12 genomic DNA不同於 γ m1或γ m2的水晶蛋白基因，為一新的水晶蛋白基因。

The recombinant phage clone, 101 ,containing the carp γm12 crystallin gene was isolated from an EMBL3 carp genomic library using theγm1 cDNA as probe. The restriction enzyme map of this phage clone was determined by multiple enzyme digestions .The region containing the γm12 crystallin gene was identified by southern blot hybridization analysis,and then subjected to subcloning and sequencing. The length of γm12 crystallin gene was 1.2kb. The coding region of theγm12 crystallin contain: exon1, 9 nucleotides, exon2, 240 nucleotides and exon3, 273 nucleotides . The γm12 crystallin gene encoded a protein with 174 amino acid residues. Theγm12 genomic DNA has two TATA boxes. Comparison ofγm1 andγ m2 cDNA withγm12 genomic sequence reveals thatγm12 crystallin have 15 amino acid residues homologous toγ m1 and 16 amino acid residues homologous to r m2 and 117 amino acid residues homologous toγ m1 andγ m2 sequence. Theγm12 genomic sequence is a newγ-crystallin gene of carp.