[Gene expression of transcription regulator LMO 4 in tooth morphogenesis].
OBJECTIVE
To investigate the expression of transcription regulator LMO4 mRNA in the developing mouse molar and compare the expression pattern of LMO4 with that of Shh signaling molecule.


METHODS
Wild-type embryos used in this study (E11.5-P1.5) were generated by mating Kun-Ming mice. The expression pattern of LMO4 during organ development was carried on by whole-mount in situ hybridization. The expression patterns of LMO4 and Shh mRNA during molar development were analysed by section in situ hybridization. Immunohistochemical staining of PCNA was carried on by SP method.


RESULTS
LMO4 mRNA was widespread at early embryonic stages (E11.5) with positive hybridization signal in the mandibular reason, limb bud, brain, epidermis and somites revealed by whole-mount in situ hybridization. Section in situ hybridization showed that LMO4 was expressed in the tooth bud, the two tips of the enamel organ and the cervical loop from E13.5 to E16.5. While Shh was localized in the enamel knot on E14.5. On E18.5-P1.5, LMO4 transcripts were distributed in the ameloblast and the stratum intermedium. On E13.5-E16.5, the tooth bud cells and the cervical loop cells were PCNA positive. These were the same regions that showed LMO4 mRNA expression.


CONCLUSIONS
LMO4 was confined to the dental epithelium and had spatial temporal expression patterns during tooth morphogenesis. The expression patterns of LMO4 and Shh were similar. In early tooth development, LMO4 might regulate cell proliferation. In late tooth development, it might participate in the ameloblast differentiation.
Zhang
Lu
L
Key Laboratory for Oral Biomedical Engineering of Ministry of Education, School of Stomatology, Wuhan University, Wuhan 430079, China.
Hua
Fang
F
Sun
Zhi-jun
ZJ
Zhang
Qi
Q
Fan
Ming-wen
MW
Chen
Zhi
Z
D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D000831:Animals, Newborn; D005260:Female; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000096:biosynthesis*; D060588:LIM Domain Proteins; D051379:Mice; D008815:Mice, Inbred Strains; D009024:Morphogenesis / Q000235:genetics*; D011247:Pregnancy; D014083:Tooth Germ / Q000378:metabolism*; D014157:Transcription Factors / Q000096:biosynthesis*; D014158:Transcription, Genetic
D048868:Adaptor Proteins, Signal Transducing; D018398:Homeodomain Proteins; D060588:LIM Domain Proteins; C491976:Lmo4 protein, mouse; D014157:Transcription Factors