Expression Of Gas7 In Septal Area Of Rat During Development

Objective: To observe the expression of growth arrest-specific protein 7(Gas7) in the septal are of rats at different developmental stages, exploring the possible biological functions of Gas7, molecular mechanism of enriching and perfecting the regulation of development of septal area. Methods: 60 adult SD rats, male or female in half, were caged in the 18:00 according to 1:1 proportion of male and female. At noon of the next day, if a vaginal plug was detected, that day was set as embryonic day 0.5(E0.5). We choose 7 time points(groups):E20.5, E20.5, postnatal day 0(P0), P7, P14, P21 and adult(2 months). 18 rats of each group were randomly selected, and a total of 126 rats were used for the experiment: 6 of each group were used for RT-PCR,Western blot and immunohistoche--mical method to study the expression and histological localization of Gas7 protein in most of septal area of rats at different developmental stages. Results: 1. RT-PCR:At E16.5 the expression of Gas7 mRNA in the septal area of rat is very low, then the expression intensity gradually increased and reached the peak at P21, and the expression intensity at the adult is weaker than that of P21(P<0.05);2. Western blot:Western blot analysis showed that the expression tendency of Gas7 protein in septal area of rats at different developmental stages was consistent with the results of RT-PCR;3. Immunohistochemistry: ①LS: At E16.5, E20.5 and P0 the Gas7 positive product were flocculent deposition; Gas7 positive cells appeared at P7; Gas7 positive cells at P14 are more than P7(p<0.05); The immunoreactivity at P14 is further strengthen than P7(p<0.05);Compared to P14, the number of Gas7 positive cells at P21 were increased significantly(P<0.05) and average gray degree were decreased evidently(P<0.05); At the adult the immunoreactivity decreased(p<0.05).②MS:Brown Gas7 immunoreactive product was observed at E16.5 and E20.5; the Gas7 positive cell shows at P0, the staining was light;Since then,the trend of average gray and number of cells is the same as LS. ③DB: The time of Gas7 immunoreactive neurons appeared and trends in the number and the average gray value is consistent with MS in HDB;At P0 the dim outline of Gas7 positive cells appeared in VDB, Gas7 positive cells at P14 are more than P7、P21 and adults(p<0.05) and average gray degree were decreased evidently(P<0.05),suggests that Gas7 may be involved in the development process nuclei adjust each compartment area.○4 SFI and TS: The typical morphology Gas7 positive neurons were not seen from E16.5 to adults.Conclusion: 1.The expression of Gas7 gene nucleic acid and protein in thalamus of rat showed both position and time dependency, the specificity correlated with the development and maturation of septal area neurons, suggesting that Gas7 gene may be involved in regulating the structure formation and function maturing of septal area.2. The Gas7 positive neurons in most septal area appeared not consistent in different nucle, and the time point when the number and average gray degree reaches a peak and valley is different too,VDB first, HDB and MS the second, positive neurons at LS appeared later. There is no Gas7 immunoreactive neurons in SFI and TS.The difference expression may realated to the characteristics of nuclear sub group in septal area upon its own developments,but also suggests that the regulatory role of Gas7 is not exactly the same in defferent nuclei in septal area.