In situ expression of ribosomal protein L21 in developing tooth germ of the mouse lower first molar

Abstract

We previously performed cDNA subtraction between the mouse mandibles at embryonic day 10.5 (E10.5) in the pre-initiation stage of the odontogenesis and E12.0 in the late initiation stage to investigate the key regulator genes in odontogenesis. Ribosomal protein L21 (Rpl21) is one of differentially expressed genes in the E12.0 mandible. This study examined the precise expression pattern of Rpl21 mRNA in the mouse mandibular first molar by in situ hybridization. Rpl21 mRNA was expressed in the presumptive dental epithelium and the underlying mesenchyme at E10.5, and in the thickened dental epithelium at E12.0. Strong in situ signals were observed in the epithelial bud at E14.0, and in the enamel organ at E15.0. However, either no (E14.0) or only a weak (E15.0) in situ signal was found in the primary enamel knot at these gestational days. Rpl21 was strongly expressed in the inner enamel epithelium, cervical loop and dental lamina from E16.0 to E18.0. In addition, Rpl21 mRNA was also demonstrated in various developing cranio-facial organs. These results suggest that Rpl21 participates in the synthesis of various polypeptides which might be related to the initiation and the development of such tooth germ, and also in the synthesis of enamel components in the presecretory stage of the ameloblast. Rpl21 for protein synthesis might also be related to the morphogenesis of the developing cranio-facial organs.

In situ expression of 15 kDa interferon alpha responsive gene in the developing tooth germ of the mouse lower first molar

“…The signal patterns of Ifrg15 were very similar to those of these genes from the thickened epithelium to the bell stages of the tooth germ development (Akhter et al 2005;Honda et al 2008;Wada et al 2002;Xie et al 2009Xie et al , 2007Yamaza et al 2001a, b). The Ifrg15 might therefore participate in site-and stage-specific molecular networks of these genes throughout the development of the tooth germ.…”

“…The probes were labeled with digoxigenin (DIG)-11-UTP using the DIG RNA Labeling Kit (Sp6/T7) (Roche Molecular Biochemicals, Mannheim, Germany). In situ hybridization using the antisense RNA probe was performed according to our previous studies (Akhter et al 2005;Honda et al 2008;Kobayashi et al 2006;Wada et al 2002;Xie et al 2009Xie et al , 2007Yamaza et al 2001a, b). The specific day-old embryos were fixed in 4% paraformaldehyde (PFA) in diethylpyrocarbonate (DEPC)-treated phosphate buffered saline (PBS, pH 7.4) for 12 h. Heads dissected from the fixed embryos were embedded in the OCT compound (Sakura Finetechnical Co. Ltd, Tokyo, Japan).…”

“…In addition, 47 highlyexpressed positive clones were also obtained from the E12.0 mandible (Yamaza et al 2001a). Minute in situ expression patterns of the thymosin beta 4 (Tb4), phosphoglycerate kinase 1 (Pgk1), heat shock proteins (Hsc73, Hsj2, Hsp86), nucleolin, ribosomal protein L21 (Rpl21), and Set-a were the highly expressed genes in the developing lower first molar tooth germ (Akhter et al 2005;Honda et al 2008;Wada et al 2002;Xie et al 2009Xie et al , 2007Yamaza et al 2001a, b). Furthermore, we demonstrated that tooth germ development was disturbed by treatment with nucleolin anti-sense sulfur-substituted oligodeoxynucleotide (AS-S-ODN) in the cultured E11.0 mandible (Xie et al 2007).…”

In situ expression of the mitochondrial ATPase6 gene in the developing tooth germ of the mouse lower first molar

“…In situ hybridization using the antisense RNA probe was performed according to the protocol described in our previous studies (Akhter et al 2005(Akhter et al , 2010Honda et al 2008;Kobayashi et al 2006;Wada et al 2002;Xie et al 2007Xie et al , 2009Yamaza et al 2001aYamaza et al , 2001b. The embryos were fixed in 4% paraformaldehyde (PFA) in diethylpyrocarbonate (DEPC)-treated phosphate buffered saline (PBS, pH 7.4) for 12 h. Heads dissected from the fixed embryos were embedded in OCT compound (Sakura Finetechnical Co. Ltd, Tokyo, Japan).…”

“…In addition, 47 highly expressed positive clones were also obtained from the E12.0 mandible (Yamaza et al 2001a). Minute in situ expression patterns of the thymosin beta-4 (Tb4), 15-kDa interferon alpha responsive gene (Ifrg15), phosphoglycerate kinase 1 (Pgk1), heat shock protein (Hsc73, Hsj2 and Hsp86), nucleolin and Set-a genes were observed in the developing lower first molar tooth germs (Akhter et al 2005(Akhter et al , 2010Honda et al 2008;Wada et al 2002;Xie et al 2007Xie et al , 2009Yamaza et al 2001b). Furthermore, tooth germ development was disturbed by the treatment with nucleolin anti-sense sulfursubstituted oligodeoxynucleotide (AS-S-ODN) in the cultured E11.0 mandible (Xie et al 2007).…”