The Clone And Expression Of Gene Fragment About Human's Early Tooth Development

A lot of research work have been done to the molecular biological mechanism about mouse's tooth development, but there is no report on human tooth germ. In this study, we firstly examine the expression of a few key signal factors in human tooth germ. We designed specifical primers of Shox2 Msxl Pax9 Pitx2 and Fgf8, then cloned the fragments of these genes directly from genomic DNA. The mRNA probes of Shox2 Pitx2 and Fgf8 were transcripted. The expression of Shox2 Pitx2 and Fgf8 in 9 weeks' human first molar germ were examined and Shox2 were examined in 6 weeks' human palate by in situ hybridization. It was shown that Fgf8 express in epithelia of milk tooth and limit in enamel knot, but it doesn't express in permanent tooth. Pitx2 express in epithelia of both milk tooth and permanent tooth. Shox2 express both in epithelia and mesenchyme of milk tooth, it express also in permanent tooth. The expression of Pitx2 and Shox2 is the same with it in mouse. The expression of Fgf8 in the bud of permanent tooth is the same with it in mouse, but in milk tooth it's different from mouse. Shox2 is expressed in 6 weeks' prior palate but not in posterior palate. It's the same with it in mouse.