Polyrhachis The Thorn Ants Creb Gene Mrna Expression

Polyrhachis vicina Roger belongs to the genus Polyrhachis (Hymenoptera: Formicidae), which is a typical species of the eusocial insects characterized by castes differentiation, complex behaviors and specific responsibility . Consequently, P. vicina is a good material for the studies of the mechanisms of insect development and behavior.As is a central transcription factor. CREB (cAMP response element binding protein) belongs to one of house-keeping gene family . CREB possesses many physiological roles including the cell apoptosis , spermatogenesis and also involved in the neuronal plasticity and memory formation proved in Aplysia dactylomela,Drosophila,Mus musculus,Rattus norvegicus. The mRNA expression levels of CREB in the brain of different castes including Y maze trained and untrained worker were investigated by real-time RT-PCR and in situ hybridization methods in P. vicina. The results are offered as follows:1 The CREB mRNA expresses in the brains of three castes extensively. The prominent positive reactions are found in the Keyron cells of mushroom body, the optic lobes and the olfactory lobe. In the three castes, the relatively higher expression levels are found in the olfactory lobe and mushroom body of workers'brain as well as in the optic lobes of males'brain. These results suggest that the functions of CREB may involve in obtaining and integrating the visual and olfaction information in the nervous system, and may be relevant with their behavior in social community.2 The trained worker brain of the central complex body, optic lobes and olfactory lobe show more prominent positive reactions than the brain of untrained worker ant. These results suggest that CREB has some important function in learning and memory for P. Vicina.3 CREB mRNA expresses in all samples tested at the different levels. The expression of CREB is highest in the workers and first insdar. In the adults, the CREB expresses the highest in the workers.The expression analysis among the brains of the three castes have showed that the expression levels are higher in the heads of workers, and there is no significant difference between the male and female ants. The variant expression levels of CREB mRNA in the different castes and brains of different castes may reflect the functions of CREB in the behaviors of different caste. Different expression levels of CREB mRNA in the brain of trained and untrained worker ant suggest CREB may have some important roles in learning and memory for P. Vicina.4 making a comparison between the brain of trained and untrained worker ant by maze, experiment results indicated in the brain of trained worker ant have more positive reactions than in the brain of untrained worker ant. From these results, we speculated that the main physiological functions of CREB in the ant are involved in regulating the behaviors,development and other physiological activities in adults.Above these results may be vary useful for further inverstigation the functions of CREB ininsects.