Myelin basic protein is temporospatially expressed in developing rat molars.
Tooth development occurs through a complex and intricate set of gene-expression cascades. Although its early events have been examined extensively, there are fewer reports on the late events, such as dental hard-tissue formation. This study searched for genes involved in the late stages of tooth development. Differential display-polymerase chain reaction revealed myelin basic protein (MBP) mRNA to be expressed differentially in the second molar root stage germs compared with the third molar cap/early bell stage germs. The MBP expressed during hard tissue formation was confirmed to be a 21.5 kDa molecule by Western blotting. Immunoreactivity of MBP in the third molar (cap/early bell stage) germs was barely detectable in the dental papilla and inner enamel epithelia, whereas strong reactivity was noted in the differentiating and differentiated ameloblasts and odontoblasts in a temporospatial pattern. However, after complete formation of the full-thickness enamel, no reactivity was observed in the maturation-stage and protection stage ameloblasts. Myelin basic protein immunoreactive nerve fibers were also observed near the developing molar germs. This is the first report showing the presence of MBP in dental hard tissue cells, and its functional implications should be studied further.
Kim
Hyun-Jin
HJ
Department of Oral Anatomy, School of Dentistry, Wonkwang University, Iksan, South Korea.
Kim
Young-Ju
YJ
Kang
Jee-Hae
JH
Jung
Ji-Yeon
JY
Kim
Min-Seok
MS
Kim
Won-Jae
WJ
Oh
Won-Man
WM
Hwang
Yun-Chan
YC
Hwang
In-Nam
IN
Choi
Nam-Ki
NK
Lee
Eun-Ju
EJ
Kim
Sun-Hun
SH
D000565:Ameloblasts / Q000378:metabolism; D000818:Animals; D005455:Fluorescent Antibody Technique; D018507:Gene Expression Regulation, Developmental; D008963:Molar / Q000166:cytology; D008970:Molecular Weight; D004676:Myelin Basic Protein / Q000096:biosynthesis* / Q000235:genetics*; D009412:Nerve Fibers / Q000378:metabolism; D009804:Odontoblasts / Q000378:metabolism; D009805:Odontogenesis / Q000235:genetics*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014083:Tooth Germ / Q000166:cytology / Q000378:metabolism*
D004676:Myelin Basic Protein