Regulation of amelogenin gene expression during tooth development

✍ Scribed by Enhong Chen; Ronald Piddington; Sylvia Decker; Jonathan Park; Zhi-An Yuan; William R. Abrams; Joel Rosenbloom; George Feldman; Dr. Carolyn W. Gibson

• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 1010 KB
• Volume: 199
• Category: Article
• ISSN: 1058-8388
• DOI: 10.1002/aja.1001990304

✦ Synopsis

Abstract

The amelogenins are the predominant matrix proteins in developing enamel and are crucial for proper enamel mineralization. Transgenic mice were constructed in order to identify the segment of the amelogenin gene required for specific expression in enamel organ cells. A 3.5 kb fragment of the bovine X‐chromosomal amelogenin gene that includes a TATA box, the transcription initiation site, and 32 bp of exon 1 was linked to the β__galactosidase__ gene and injected into fertilized mouse eggs. Newborn transgene positive mice expressed βgalactosidase activity in developing teeth treated with the chromogenic substrate Xgal. Foci of ameloblasts were positive in newborn mice; stain intensity and number of positive ameloblasts increased in 1‐day and 2‐day postnatal mice. Some of the adjacent stratum intermedium cells also were positive in the later stages. Targeting of the transgene to the enamel organ was specific; the only other cells observed to be positive were macrophages, which have endogenous βgalactosidase activity. © 1994 Wiley‐Liss, Inc.