Distinct expression and shared activities of members of the hedgehog gene family of Xenopus laevis.
The hedgehog family of signaling proteins is associated with a variety of spatial patterning activities in insects and vertebrates. Here we show that new members of this family isolated from Xenopus laevis are expressed embryonically in patterns suggestive of roles in patterning in the ectoderm, nervous system and somites. Banded hedgehog is expressed throughout the neural plate and subsequently in both the nervous system and in the dermatome of somites. Cephalic hedgehog is expressed in anterior ectoderm and endodermal structures, and sonic hedgehog is expressed in patterns which parallel those in other species. Injection of RNAs encoding Xenopus hedgehogs induces ectopic cement gland formation in embryos. Similar to reported activities of noggin and follistatin, Xenopus hedgehogs share a common ability to induce cement glands in animal cap explants. However, hedgehog activities in naive ectoderm appear capable of acting independently of noggin and follistatin since, although all three are induced by activin in animal cap explants, X-hh expression does not induce noggin or follistatin.
Ekker
S C
SC
Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
McGrew
L L
LL
Lai
C J
CJ
Lee
J J
JJ
von Kessler
D P
DP
Moon
R T
RT
Beachy
P A
PA
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins; D017931:DNA Primers; D004475:Ectoderm / Q000502:physiology; D004627:Embryonic Induction / Q000502:physiology; D005088:Exocrine Glands / Q000196:embryology; D038681:Follistatin; D018507:Gene Expression Regulation, Developmental; D006023:Glycoproteins / Q000235:genetics; D053823:Hedgehog Proteins; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D009420:Nervous System / Q000196:embryology*; D010903:Pituitary Gland, Anterior / Q000196:embryology; D016133:Polymerase Chain Reaction; D011506:Proteins / Q000235:genetics*; D015534:Trans-Activators; D029867:Xenopus Proteins; D014982:Xenopus laevis; D000099176:Noggin Protein
D002352:Carrier Proteins; D017931:DNA Primers; D038681:Follistatin; D006023:Glycoproteins; D053823:Hedgehog Proteins; D011506:Proteins; D015534:Trans-Activators; D029867:Xenopus Proteins; D000099176:Noggin Protein; C509232:IHH protein, Xenopus