Analysis Of The Isoforms Of FGF8 In The Tooth Of The Human And Mouse And The Effect Of FGF8 On Early Tooth Development

There are four signal molecular families to regulate tooth development, including:bone morphogenetic protein(BMP),fibroblast growth factor (FGF),hedgehog protein family(Hhs) and Wnt signaling.FGF8 is an important one of the FGF family.Stusies have found that there are four isoforms in the human body, named:FGF8a, FGF8b, FGF8e and FGF8f;and there are eight isoforms in the mouse body,named:FGF8a-h.FGF8 is expressed strongly from lamina stage to secreting stage in the molar tooth development,but in the E12 days of molar tooth developmet of mouse, FGF8 is strongly expressed,the expression began to decrease till E13,and there is no expression in the day of E14.But which isoform is expressed have not been know yet in the tooth development of human and mouse and what are the effects on tooth development of the different expression patterns, to address these issues, conducted the experiment. By RT-PCR, sequencing, comparative analysis found that, in both human and mouse tooth development FGF8a isoform is expressed.In order to study the impact on tooth development,constructed the lentiviral vector of pNL-IRES2-EGFP-FGF8a. Three plasmids and calcium phosphate were cotransfected in 293T cells to produce lentivirus. According to infection of FGF8a lentivirus to E13.5 molar mesenchymal cells to study its role.The result showed that the tooth which infected FGF8a lentivirus get to the bell stage of tooth development after implanted them under the mice kidney capsule for 8 days.Compared to the commen secretory stage,the development of tooth was delayed.The tooth get to the secretory stage,after implanted them under the mice kidney capsule for 14 days.Found that the enamel is thicker compared to the control group,and degradation appeared of the ameloblasts,the tooth is fully developed,while the ameloblasts are neatly arranged in the experimental group,and there is no degradation of the ameloblasts,so the tooth development is delayed.Therefore,overexpression of FGF8a to 14 days,FGF8a also play a role in inhibition of tooth development.