Premium
Isolation and developmental expression of Mitf in Xenopus laevis
Author(s) -
Kumasaka Mayuko,
Sato Hiraku,
Sato Shigeru,
Yajima Ichiro,
Yamamoto Hiroaki
Publication year - 2004
Publication title -
developmental dynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.634
H-Index - 141
eISSN - 1097-0177
pISSN - 1058-8388
DOI - 10.1002/dvdy.20019
Subject(s) - microphthalmia associated transcription factor , biology , xenopus , microbiology and biotechnology , transcription factor , gene isoform , chromatophore , melanocyte , melanin , basic helix loop helix , genetics , gene , dna binding protein , melanoma
Mitf (gene for microphthalmia‐associated transcription factor) encodes a transcription factor of the basic/helix‐loop‐helix/leucine‐zipper family and is a key regulator during the development of two different types of melanin‐producing cell lineages, namely neural crest‐derived melanocytes/melanophores, and the retinal pigment epithelium (RPE) differentiated from the outer layer of the eye cup. Mitf ‐deficient mice show a lack of melanocytes and small eyes caused by abnormal RPE development. An interesting feature of Mitf is the existence of multiple isoforms with different amino termini and their functions in the development of these melanin‐producing pigment cells. In this study, we isolated two Mitf homologues ( XlMitfα and XlMitfβ ) and their isoforms from Xenopus laevis . Alignment analysis of the amino acid sequences of the N‐termini suggests that these isoforms are homologues of mouse Mitf‐M (expressed specifically in the melanocyte lineage) and Mitf‐A (strongly expressed in the RPE, although this expression is ubiquitous). In Xenopus , XlMitfα is strongly expressed in the melanophore lineage (especially in premigratory melanoblasts) and the presumptive RPE and the epiphysis, in which melanin‐producing cells differentiate in some vertebrates. Conservation of the Mitf isoforms expected to possess specific functions in the development of melanin‐producing cells and of the expressions in such cell types in Xenopus suggest that Xl Mitf plays a central role in the development of melanin‐producing cell lineages, and that, as in mice and humans, most of the signaling molecules or transcription factors implicated genetically in the development of melanin‐producing cell lineages affect either Mitf expression or its function (Goding [2000] Genes Dev. 14:1712–1728). Developmental Dynamics 230:107–113, 2004. © 2004 Wiley‐Liss, Inc.