摘要：腺苷二磷酸葡萄糖焦磷酸化酶(AGPase)是淀粉生物合成的限速酶，在玉米淀粉合成过程中具有重要作用。本研究采用生物信息学方法分析了AGPase家族基因的系统发育关系和基因结构特征，并基于玉米B73参考基因组（AGPv4）新鉴定了玉米AGPase小亚基编码基因，同时根据序列比对结果重新注释了基因组中发生扩张的AGPS片段基因。新鉴定并重新注释的ZmAGPS2-3、ZmAGPS2-4、ZmAGPS2-5包含一个序列高度相似的外显子，由祖先基因ZmAGPS2-2的多个外显子（无内含子）序列拼接形成。其编码蛋白的保守结构域存在不同程度的缺失，且这三个基因在染色体上的位置无共线性关系，也不相邻。因此推测ZmAGPS2-3、ZmAGPS2-4和ZmAGPS2-5的起源方式为反转录转座复制，在演化过程中丢失了部分序列后，成为功能缺失的假基因。

Abstract: Adenosine diphosphate glucose pyrophosphorylase (AGPase) is the rate-limiting enzyme of starch biosynthesis, which plays an important role in the synthesis of maize starch. In this study, the phylogenetic relationship and gene structure characteristics of AGPase family genes were analyzed by bioinformatics method, and the coding gene of AGPase small subunit in maize was newly identified based on the reference genome of maize B73 (AGPv4). At the same time, according to the results of sequence alignment, the expanded AGPase fragment genes in the genome were re-annotated.The newly identified and re-annotated ZmAGPS2-3, ZmAGPS2-4 and ZmAGPS2-5 contain an exon with highly similar sequence, and are formed by splicing several exons (without introns) of the ancestral gene ZmAGPS2-2. The conserved domains of proteins are deleted in different degrees, and the locations of three genes on chromosomes are not collinear or adjacent. Therefore, it is speculated that the origin of ZmAGPS2-3, ZmAGPS2-4 and ZmAGPS2-5 is reverse transposed duplication, and losing some sequences in the evolution, they become pseudogenes missing the function.

青年科学(31601317)