| OBP interacting with odor information, which has especial function and significance, was the first step for producing olfaction, seeking foods and spouses. The Bombyx mori has long been considered as a model system for studying chemosensory communication owing to the sufficiently sensitive olfactory. In recent years, it has put up comprehensive studies on olfactory-related proteins in the world, such as chemosensory proteins, odor receptors, etc. However, the temporal-spacial expression study on obps in silkworm lacks systematical research. Clarifying the expression rules of OBP not only could be helpful to promote the understanding behavior essence of silkworm and provide theories for controling pest and exploring new breeding techniques, but also has important revelation on studying creatural olfactory recognizing mechanism. Therefor, it has mensurated the difference of seven silkworm obps (gobp1,gobp2,abp,abpx,pbp1,pbp2,pbp3) of different developing stage,different tissues and organs and different feeding habit varieties from mRNA transcription level by using semi quantitative RT-PCR. Results as follows:⑴It has checked only the expression of abp and abpx in every larval tissue and organ of silkworm. There is no expession from mRNA transcription level of the other five obps. All of the seven obps have different extent expression in adult stage. The larval and adult expression difference of obps may have connection to the difference of olfactory reception chart and olfactory sensitive degree.⑵It has surveyed the expression of abp and abpx on larval head of three different developing stage. It has discovered obps comparatively expression quantities of 5th instar feeding stage and maturing stage higher than that of molting stage in 4th instar. This is likely to be related to the decline of olfactory sensitive degree in molting stage.⑶It has discussed obps expression on olfactory organs of larval head by extirpating antenna and maxipalp. Results indicate: the comparatively expression quantities of abp and abpx in 5th instar feeding stage and of abpx in maturing stage have declined significantly for extirpating antenna and maxipalp; but there has no evident impact on expression quantity in 4th instar molting stage. It has explained larval expression of obps not only on antenna and maxipalp being provided with olfactory organs, but also on other positions of head.⑷The expression of abp and abpx is not only on the head with olfactory organs, but also on non-olfactory organs, such as thoracic leg,abdominal leg,silk gland,midgut,fat body,malpighian tubule, etc. This expression is ubiquitously high.⑸To polyphagy, C108 and fengyi which have different feeding habits on artificial diet and nonmulberry plant, abp and abpx comparatively expression quantities on larval head of C108 that has moderate feeding habit are the lowest. It shows that feeding habit wide or narrow has no direct relation with obp expression quantity.⑹Seven obps expression of pupae and adult antenna has difference in different developing stage. There is no expression of gobp2 in female pupae and of pbp2 and pbp3 in male and femal pupae of five days fore-emergence. And there is less expression of pbp1. It has expression of other obps from pupae of five days fore-emergence to adult of four days after-emergence. The expression quantities of gobp and pbp are comparably high in one day fore/after-emergence. There is less difference on abp expression quantity in each stage. Most of seven obps comparatively expression quantities of male and female have no distinct diversity in different stage.⑺It has determined seven obps expression in antenna,thoracic leg and wing of male and female pupae in one day fore-emergence. It has discovered that each obp expresses entirely in antenna and its comparatively expression quantity is the uppermost, secondly is thoracic leg and then wing. There is no expression of two gobps,pbp2 and pbp3 in wing. Mostly there is no significantly difference in comparatively expression quantity of male and female.⑻It has inspected seven obps expression in antenna,head with de-antenna,thoracic leg,wing,abdominal body wall,abdominal end(including external reproductive organ) and fat body of male and female adult in one day after-emergence. It has detected all obps express in antenna and their comparatively expression quantities are topmost. The expression quantity of male higher than that of femal in different extent. Three obps(gobp1,abp and pbp1) express in all tested organs and tissues, and other four obps don't express in some tissues and organs. It has some difference with obp expression in one day fore-emergence.⑼It has examined obps expression in adult antenna of polyphagy, C108 and fengyi. Results indicate: comparatively expression quantities of gobp,abp and pbp1 have less difference in varieties and between male and female; but comparatively expression quantities of pbp2 and pbp3 in polyphagy and C108 are remarkably higher than that in fengyi.⑽It has detected that abp expresses quite highly in every tested developing stage,all tested tissues and organs and silkworm varieties, and there is no temporal-speciality and spacial-speciality. It is likely that abp possesses other functions. It demands further study on relation between obps expression and olfactory reaction,behavior and feeding habit.
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