Isolation of Xenopus FGF-8b and comparison with FGF-8a.
The Xenopus FGF-8a and FGF-8b isoforms have been reported to be neural crest and neuronal inducers, respectively. However, cloning of Xenopus FGF-8b (XFGF-8b) has not been reported previously and the two isoforms do not seem to have been clearly distinguished in Xenopus experiments. Here, we describe the cloning and expression of XFGF-8b and compare the effects of the two isoforms. XFGF-8b has an 11 amino acid insert in its N-terminal region compared with XFGF-8a. Both isoforms are expressed in the anterior neural regions of the early embryo, and in the apical ectodermal ridge of limb buds and tips of growing digits in the larval stages. However, XFGF-8b is more abundant than XFGF-8a throughout early development. The two isoforms are also regulated in similar fashion by retinoic acid in early development. However, although both XFGF-8a and XFGF-8b induce ectopic neurogenesis, only XFGF-8a appears to be involved in neural crest induction.
Shim
Sangwoo
S
Department of Life Science and Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang 790-784, Korea.
Bae
Narina
N
Park
Sang Yoon
SY
Kim
Won-Sun
WS
Han
Jin-Kwan
JK
D000595:Amino Acid Sequence; D000818:Animals; D051524:Fibroblast Growth Factor 8; D005346:Fibroblast Growth Factors / Q000096:biosynthesis* / Q000737:chemistry / Q000302:isolation & purification*; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D008969:Molecular Sequence Data; D020033:Protein Isoforms / Q000096:biosynthesis* / Q000737:chemistry; D016415:Sequence Alignment; D014212:Tretinoin / Q000494:pharmacology; D014404:Tubulin / Q000096:biosynthesis; D014982:Xenopus laevis / Q000196:embryology / Q000378:metabolism*
D020033:Protein Isoforms; D014404:Tubulin; D051524:Fibroblast Growth Factor 8; D014212:Tretinoin; D005346:Fibroblast Growth Factors