荔枝椿平腹小蜂触角味觉受体基因的鉴定与表达分析

Identification and Expression Analysis of Antennal Gustatory Receptor Genes of Anastatus japonicus

昆虫具有极其敏锐的味觉感受系统,昆虫的味觉系统对其取食选择、交配和产卵等多种行为反应起到重要的作用。荔枝椿平腹小蜂(Anastatus japonicus)作为膜翅目中一种重要的寄生蜂,具有防治荔枝椿象的作用。研究对荔枝椿平腹小蜂触角进行转录组测序,从数据库进行筛选鉴定得到5个味觉受体基因。借助RT-PCR对荔枝椿平腹小蜂的雌性触角、雄性触角、胸、腹和腿部味觉受体的表达量进行比较,发现Ajap GR58,Ajap GR49和Ajap GR64f在成虫的各组织部位表达量一致并均较低,而Ajap GR38和Ajap GR2的表达量相对较高,同时,Ajap GR38只在雌性触角以及胸部特异性表达,Ajap GR2则是在雌性触角、雄性触角、胸部和腹部均有表达,而腿部却不表达。通过系统发育树可以看出,Ajap GR58和Ajap GR49同源,与DmelGR33a,Dmel GR43a聚在一起,Ajap GR38与Dmel GR28同源,与Dmel GR66a聚在一起,说明Ajap GR58、Ajap GR49以及Ajap GR38处于苦味受体家族中,可能也行使苦味感知功能。Ajap GR64f与Dme GRl5,DmelGR64f同源并与Dmel GR64a聚在一起,同时,Ajap GR2与Dmel GR64a,Dmel GR64b,Dmel GR64c,Dmel GR64f以及Dmel GR5所形成的一类并聚在一起,说明Ajap GR64f和Ajap GR2处于甜味受体家族中,可能也行使甜味感知功能。

The insect has extremely sharp taste perception system,and in insect feeding,mating and oviposition and other behavioral responses,it plays an important role.As an important parasitoid of Hymenoptera,Anastatus japonicus contributes to the prevention of Tessaratoma papillosa.Transcriptome sequencing of Anastatus japonicus antenna was conducted,and five gustatory receptor genes were obtained from the database by screening and identification.With RT-PCR,expressions of gustatory receptors of Anastatus japonicus female antennae,male antennae,thorax,abdomen and leg were compared.The results show that expressions of AjapGR58,AjapGR49 and AjapGR64f were identical and lower in different tissues of adults whereas expressions of AjapGR38 and AjapGR2 were relatively high.At the same time,AjapGR38 was expressed only in female antennae and thorax,AjapGR2 were expressed in female antennae,male antennae,thorax and abdomen,but was not expressed in legs.Judging by the phylogenetic tree,AjapGR58 and AjapGR49 were homologous and polymerized with DmelGR33a and DmelGR43a,DmelGR28 and AjapGR38 were homologous and polymerized with DmelGR66a,indicating that AjapGR58,AjapGR49 and AjapGR38 are in the bitter receptor family,and may also perform the function of bitter taste.AjapGR64f was homologous with DmeGR15 and DmelGR64f and polymerized with DmelGR64a,and at the same time,AjapGR2 and DmelGR64a,DmelGR64b,DmelGR64c,DmelGR64f and DmelGR5 formed a cluster together,indicating that AjapGR64f and AjapGR2 are in the sweet receptor family,and may also function as a function of sweet taste.