Ptc, Smo, Sufu, and the Hedgehog signaling pathway in amphioxus.
The Hedgehog (Hh) signaling pathway regulates many developmental processes both in vertebrates and in invertebrates. However, little is known about this pathway in the cephalochordate amphioxus. In this paper, we focus on the Ptc, Smo, and Sufu homologs in amphioxus, which are the key members of the Hh signaling pathway. Their genomic structures show their comparability with homologs in vertebrates. In situ hybridization reveals that amphioxus Ptc, Smo, and Sufu have similar expression patterns in embryogenesis. They are expressed in the neural plate at early neurula stage, and then down-regulated in dorsal neural ectoderm. During development, their transcripts appear and persist in the notochord, the wall of the head cavity, the epithelium of the pharynx, and the gut. The data show that the expression patterns of these three genes are overlapping with Hh and Gli during the embryonic development in amphioxus. Moreover, injection of amphioxus Hh RNA into zebrafish-fertilized eggs can expand the expression domains of Ptc1 and Nk2.2a, the target genes of the Hh signaling pathway, which is similar to the injection of zebrafish Sonic hh a (zShha) and Sonic hh b (zShhb). Our results suggest that amphioxus may possess a conserved and functional Hh signaling pathway similar to that of vertebrates.
Lin
Yushuang
Y
Institute of Developmental Biology, Life Science College, Shandong University, Jinan 250100, China.
Cai
Zhaoping
Z
Huang
Shuhong
S
Yang
Ling
L
Wang
Chengdong
C
Liu
Zhongzhen
Z
Cao
Jianmeng
J
An
Yunhe
Y
Zhang
Hongwei
H
D000818:Animals; D043344:Chordata / Q000235:genetics* / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental; D053823:Hedgehog Proteins / Q000378:metabolism*; D006801:Humans; D017403:In Situ Hybridization; D008565:Membrane Proteins; D000072079:Patched Receptors; D000072081:Patched-1 Receptor; D010802:Phylogeny; D011956:Receptors, Cell Surface / Q000378:metabolism*; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000378:metabolism*; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D000072086:Smoothened Receptor; D015027:Zebrafish; D029961:Zebrafish Proteins
D053823:Hedgehog Proteins; D008565:Membrane Proteins; D000072079:Patched Receptors; D000072081:Patched-1 Receptor; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; D012097:Repressor Proteins; C491023:SMO protein, human; C490764:SUFU protein, human; D000072086:Smoothened Receptor; D029961:Zebrafish Proteins; C491715:ptch1 protein, zebrafish