关键词: 绿豆象, 触角, 气味受体, 基因克隆, 组织特异性表达

Abstract: 【Aim】 This study aims to clone four antennal odorant receptors (OR) genes and analyze their expression profiles in tissues of different dayold female and male adults of Callosobruchus chinensis, so as to lay the foundation for further investigation of gene function. 【Methods】 The candidate OR genes of C. chinensis were predicted based on the antennal transcriptome data of C. chinensis adults. The full-length cDNA sequences of four OR genes of C. chinensis were cloned by RT-PCR, and subjected to bioinformatic analysis. qPCR was used to detect the expression levels of the four OR genes in female and male adult tissues (antenna, head without antenna, abdomen, leg and wing) and antennae of 1-, 3- and 5-day-old female and male adults of C. chinensis. 【Results】 Based on the predicted gene sequences, the full-length cDNA sequences of four OR genes of C. chinensis were cloned, and named CchiOR8, CchiOR10, CchiOR16 and CchiOR39 with the GenBank accession numbers of MW732665, MN832705, MW732664 and MN832706, respectively, encoding 369, 352, 400 and 367 amino acids, respectively. CchiOR8, CchiOR10 and CchiOR16 are highly related to the homologous proteins of Colaphellus bowringi, while CchiOR39 clusters into a clade with the homologous proteins of Drosophila biarmipes and D. simulans. The qPCR result showed that the four OR genes were expressed in various tissues of female and male adults and highly expressed in antennae of C. chinensis. The expression levels of CchiOR10 and CchiOR39 in antennae of female adults were significantly higher than those in antennae of male adults. The expression level of CchiOR16 in antennae of male adults was significantly higher than that in antennae of female adults. The expression levels of CchiOR8 in antennae showed no significant difference between female and male adults. In addition, the expression levels of the four OR genes in antennae of different day-old adults were different to some degree. The expression levels of CchiOR8, CchiOR16 and CchiOR39 in antennae of male adults increased first and then decreased, all reaching the peak at the 3-day-old. The expression level of CchiOR10 in antennae of male adults was low and had no significant difference in different day-old adults. The expression levels of both CchiOR8 and CchiOR16 in antennae of the 5-day-old female adults reached the highest level, while the expression levels of CchiOR39 and CchiOR10 in antennae of the 1-day-old female adults were significantly higher than those in antennae of the other day-old female adults. 【Conclusion】 Four CchiOR genes of C. chinensis are highly expressed in the adult antennae, and are speculated to play an important role in the olfactory recognition of C. chinensis.

Key words: Callosobruchus chinensis, antennae, odorant receptor, gene cloning, tissue-specific expression