title: Fibroblast growth factor 9: cloning and immunolocalisation during tooth development in Didelphis albiventris.
abstract: There are no reports in literature about functional roles of fibroblast growth factor 9 (FGF-9) in tooth development in animals with complete tooth pattern. The classical model for studying tooth development is the mouse, which has small number of teeth and distinctive incisor and molar patterns. The opossum Didelphis albiventris with five upper and four lower incisors, one canine, three premolars, and four molars, on each side of the jaw, seems to be a convenient model to test results obtained in the mouse. Molecular expression studies indicate that FGF-9 participates in murine tooth initiation and regulation of morphogenesis. Searching for similarities and differences in FGF-9 expression between the opossum and the mouse, amino acid sequence and expression pattern of FGF-9 in the developing first molars of D. albiventris were characterised. FGF-9 cDNA sequence was obtained using RT-PCR and expressed in bacterial system for recombinant protein production and analysis of immunoreactivity. FGF-9 expression during tooth development was investigated by immunoperoxidase method. FGF-9 protein consists in a 209-residue polypeptide with a predicted molecular mass of 23.5 kDa. FGF-9 amino acid sequence has 98% of sequence identity to human and 97% to rodents. During tooth development, epithelial FGF-9 expression was seen at the dental lamina stage. Mesenchymal expression was seen at the bud stage and at the cap stage. No significant expression was found in the enamel knot. While in rodents FGF-9 is involved in initiation and regulation of tooth shape, it is suggested that it is only involved in tooth initiation in D. albiventris.
authors.affiliation: Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, UFMG, Presidente Antônio Carlos Avenue 6627, 31270-901 Belo Horizonte, Minas Gerais, Brazil. cristianebbtorres@yahoo.com.br
authors.forename: Cristiane B B
authors.initials: CB
authors.lastname: Torres
authors.forename: Vinicius S
authors.initials: VS
authors.lastname: Goes
authors.forename: Alfredo M
authors.initials: AM
authors.lastname: Goes
authors.forename: Lucila G G
authors.initials: LG
authors.lastname: Pacífico
authors.forename: Gerluza A B
authors.initials: GA
authors.lastname: Silva
authors.forename: Nelson Lopes
authors.initials: NL
authors.lastname: Junior
authors.forename: José B
authors.initials: JB
authors.lastname: Alves
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004270:DNA, Circular / Q000032:analysis; D048293:Didelphis / Q000235:genetics / Q000502:physiology*; D004285:Dogs; D004848:Epithelium / Q000737:chemistry; D005260:Female; D051525:Fibroblast Growth Factor 9 / Q000032:analysis / Q000235:genetics*; D005786:Gene Expression Regulation / Q000235:genetics; D006801:Humans; D008648:Mesoderm / Q000737:chemistry; D051379:Mice; D008963:Molar / Q000254:growth & development*; D051381:Rats; D011994:Recombinant Proteins / Q000032:analysis; D017386:Sequence Homology, Amino Acid
chemical_list: D004270:DNA, Circular; D051525:Fibroblast Growth Factor 9; D011994:Recombinant Proteins