RESUMO
OBJECTIVE: This study examined the expression pattern of the Deleted-in-colorectal-carcinoma (DCC) gene in developing rat tooth germs. METHODS: Rat pups at 4, 7 and 10 d postpartum were used in this study. Reverse transcription-polymerase chain reaction (RT-PCR) and immunofluorescent localization were used to determine the level of DCC expression during tooth development. RESULTS: There was more than 2-fold higher level of DCC mRNA in the rat 2nd maxillary molar tooth germs on 10 d postpartum, which was the root stage, than in the rat 3rd maxillary molar tooth germ, which was at the cap/early bell development stage. In addition, the levels of DCC mRNA in the 2nd maxillary molar germs at 4, 7 and 10 d postpartum increased gradually according to tooth development. Interestingly, immunoreactivity against DCC was specifically detected in the differentiating ameloblasts. DCC was observed in the lateral and apical sides of the newly differentiating and secretory stage ameloblasts. Afterwards, DCC was localized only in the apical side of the maturation stage ameloblasts, not in the lateral side. CONCLUSION: DCC is expressed in the differentiating ameloblasts, which suggests that this molecule plays a crucial role in amelogenesis.
Assuntos
Ameloblastos/citologia , Regulação da Expressão Gênica/genética , Genes DCC/genética , Odontogênese/genética , Receptores de Superfície Celular/análise , Germe de Dente/citologia , Proteínas Supressoras de Tumor/análise , Amelogênese/genética , Amelogenina/análise , Amelogenina/genética , Animais , Diferenciação Celular/genética , Receptor DCC , Proteínas do Esmalte Dentário/análise , Proteínas do Esmalte Dentário/genética , Saco Dentário/citologia , Órgão do Esmalte/citologia , Células Epiteliais/citologia , Imunofluorescência , Incisivo/citologia , Dente Molar/citologia , Ratos , Ratos Sprague-Dawley , Receptores de Superfície Celular/genética , Raiz Dentária/citologia , Proteínas Supressoras de Tumor/genéticaRESUMO
Basidiospores were isolated from the fruiting bodies of Ganoderma infecting oil palms from an estate in Johor and from ornamental palms (including oil palms) from Singapore. The spores were then germinated to obtain homokaryotic mycelia. Based on clamp connection formation in paired hyphal fusions, tester strains were identified from the homokaryons isolated. Compatibility tests were then carried out using these testers to determine the relatedness of the homokaryotic Ganoderma isolates, both from Johor and from Singapore. Results from the compatibility tests showed that Ganoderma from both locations belong to the same species, while the Ganoderma isolates from Singapore share some common alleles. The pathogenicity tests carried out on Chrysalidocarpus lutescens seedlings using inoculum growing on rubber wood blocks showed that dikaryotic mycelia can cause basal stem rot infection.