昆虫orthodenticle基因研究进展

Progress in Research of Insect orthodenticle Gene

昆虫胚胎发育受一系列基因调控,这些基因按照时间、空间顺序启动或关闭,对胚胎细胞的生长和分化进行调节.orthodenticle(otd)是间隙基因,编码含同源结构域的转录因子,是昆虫胚胎发育的关键基因.在没有bicoid基因的昆虫中,otd基因取代了bicoid的部分功能,建立胚胎前后轴的极性.在昆虫原头体节形成过程中,otd等间隙基因直接激活体节极性基因的表达,而对控基因不起作用.此外,otd还与昆虫中枢神经和光感受器的形成有关.从进化方面来看,otd基因可能是从调控后生动物的光感受、脑发育和昼夜节律的基因中逐渐演变形成,并随着昆虫的系统发育而演化,其表达模式和功能既具有保守性又具有变异性.本文就昆虫otd基因的结构、功能和进化等方面的研究进展进行了综述.

The embryogenesis ofi nsect is controlled by a series of genes,which are turned on or off according to a precise time and spatial sequence to regulate the growth and differentiation of embryonic cells.Among these genes,orthodenticle （otd） is a gap gene which encodesa homeobox transcription factor and plays a key role in embryogenesis of insect.In some insects without bicoid gene,otd partially substitutes for bicoid function and establishes the polarity of anterior-posterior axis in early embryogenesis.In the cephalic segmentation in insects,the pair-rule genes do not play function,but gap genes,like otd,directly activate the expression of segment polarity genes.Furthermore,otd gene also involves in the process of developments of eyes and nervous system.otd possibly originates from those genes that regulate the photoreception,brain development and circadian rhythms in metazoan organisms,and then gradually differentiates with the phylogenetic evolution of insects,so the function of otd shows diversities in different insect groups.In this paper,the otd gene is reviewed,including its structure,function and evolution.Fig 1,Ref 62