Mitf contributes to melanosome distribution and melanophore dendricity.
Mitf is a transcription factor of the basic/helix-loop-helix/leucine-zipper family which is indispensable for development of melanocytes and the retinal pigment epithelium. Our previous work using Xenopus laevis as a model system suggested that Mitf regulates melanosome dispersal in vivo though whether this was via melanosome transport or melanophore dendricity was not obvious. To better understand the role of Mitf, we have now characterized neural tube cultures from wild-type Mitf-injected or a dominant-negative Mitf-injected embryos and compared them with controls. In vitro, lower levels of Mitf activity induced less dendritic melanophores with aggregated melanosomes, whereas melanophores overexpressing Mitf had an extensive dendritic morphology with dispersed melanosomes. Moreover, immunorfluoresence assays reveal that expression of a dominant-negative Mitf leads to decreased Rab27a expression. These results suggest that Mitf is involved in the regulation of melanosome transport and the level of dendricity in melanophores.
Kawasaki
Akiha
A
Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Sendai, Japan.
Kumasaka
Mayuko
M
Satoh
Akira
A
Suzuki
Makoto
M
Tamura
Koji
K
Goto
Toshiyasu
T
Asashima
Makoto
M
Yamamoto
Hiroaki
H
D000818:Animals; D001692:Biological Transport; D048430:Cell Shape; D046149:Embryo Culture Techniques; D018507:Gene Expression Regulation, Developmental; D005838:Genotype; D008547:Melanophores / Q000378:metabolism*; D020460:Melanosomes / Q000378:metabolism*; D051739:Microphthalmia-Associated Transcription Factor / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D054259:Neural Tube / Q000166:cytology / Q000378:metabolism*; D010641:Phenotype; D014162:Transfection; D029867:Xenopus Proteins / Q000235:genetics / Q000378:metabolism*; D014982:Xenopus laevis / Q000196:embryology / Q000235:genetics / Q000378:metabolism; D020691:rab GTP-Binding Proteins / Q000378:metabolism
D051739:Microphthalmia-Associated Transcription Factor; D029867:Xenopus Proteins; D020691:rab GTP-Binding Proteins