Annotation and evolution of the antioxidant genes in the silkworm, Bombyx mori.
Annotation and evolution of the antioxidant genes in the silkworm, Bombyx mori.
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DOI：
10.1002/arch.21014
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发表时间：
2012-02
影响因子：
2.2
通讯作者：
Gui-Qin Shi;Q. Yu;Ze Zhang
中科院分区：
文献类型：
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作者：
Gui-Qin Shi;Q. Yu;Ze Zhang
抗氧化系统由多个基因家族组成，在减轻所有生物体的氧化损伤和外源性物质解毒方面发挥着重要作用。根据家蚕全基因组序列，我们从9个基因家族中鉴定出50个家蚕抗氧化基因。对家蚕与冈比亚按蚊、意大利蜜蜂、黑腹果蝇和赤拟谷盗的抗氧化基因进行了比较分析。我们发现，大多数抗氧化基因家族是高度保守的，但过氧化氢酶（CAT）和含血红素过氧化物酶（HPX）家族在家蚕中的谱系特异性扩展。利用已知的EST、基因芯片数据和RT-PCR技术，对家蚕抗氧化基因的表达模式进行了研究。在50个家蚕抗氧化基因中，有42个基因被转录，且大多数转录基因具有组织特异性表达模式。超过一半的谱系特异性扩增的BmCAT缺乏36个血红素结合残基中的15个或15个以上，并且可能失去过氧化氢酶活性。然而，编码这些BmCAT的基因显示出几乎无处不在的组织表达模式，表明它们可能已经进化出新的功能。此外，由于BmHPXs主要在家蚕丝腺中表达，因此BmHPXs在家蚕大量丝蛋白合成过程中具有维持细胞内环境稳定的功能。家蚕抗氧化基因家族的谱系特异性扩展为了解家蚕甚至鳞翅目昆虫抗氧化基因的进化和功能多样性提供了有用的信息。
Antioxidant system, which is composed of multiple gene families, plays a major role in reducing oxidative damage and xenobiotic detoxification in all living organisms. We identified 50 silkworm antioxidant genes from nine gene families based on the assembled genome sequence. A comparative analysis of the antioxidant genes of the silkworm with other order insects Anopheles gambiae, Apis mellifera, Drosophila melanogaster, and Tribolium castaneum, was performed. We found that most of the antioxidant gene families are highly conserved but Catalase (CAT) and heme-containing peroxidase (HPX) families were lineage-specifically expanded in the silkworm. The expression patterns of the silkworm antioxidant genes were investigated with the known ESTs, microarray data, and reverse transcription-polymerase chain reaction (RT-PCR). Forty two of the 50 silkworm antioxidant genes were transcribed and most of the transcribed genes showed tissue-specific expression patterns. More than a half of lineage-specifically expanded BmCATs lacked 15 or more than 15 of the 36 heme-binding residues and might lose catalase activities. However, the genes encoding these BmCATs showed almost a ubiquitous tissue expression pattern, indicating that they might have evolved new functions. In addition, the lineage-specifically expanded BmHPXs could function in maintaining cell homeostasis in the process of the synthesis of large amounts of silk proteins because they were predominantly expressed in silk gland of the silkworm. The lineage-specific expansion of antioxidant gene families in the silkworm provides useful information for understanding evolution and functional versatility of antioxidant genes in the silkworm even Lepidopteran insects.