Zath3, a neural basic helix-loop-helix gene, regulates early neurogenesis in the zebrafish.
We have isolated a basic helix-loop-helix (bHLH) gene homologous to the Drosophila proneural gene atonal, termed zath3, from zebrafish. zath3 is expressed in neurons of the central nervous system and in subsets of cranial ganglia. Zebrafish mindbomb (mib) mutants have a higher density of zath3 expressing cells and narrowminded (nrd) mutants lack zath3 expression in a domain corresponding to primary sensory neurons showing that the expression of zath3 is regulated by both mib and nrd. Injection of synthetic zath3 RNA into zebrafish embryos expands the neural plate size, promotes ectopic expression of neuronal markers, and partially rescues the deficit of sensory neurons seen in nrd mutants. Interfering with zath3 function using antisense morpholino oligonucleotides (MO) has no significant effect on early neurogenesis. However, a double knock down of zath3 and neurogenin1 (ngn1), another atonal homologue, with morpholinos (MOs) leads to more severe defects in neurogenesis than are seen with ngn1 MO alone: a subtle reduction of motor and inter-neurons, and an almost complete loss all cranial ganglia. This study suggests that zath3 and ngn1 have partially overlapping roles in early neurogenesis.
Park
Su-Hyeon
SH
Department of Biology, Chungnam National University, Daejeon 305-764, South Korea.
Yeo
Sang-Yeob
SY
Yoo
Kyeong-Won
KW
Hong
Sung-Kook
SK
Lee
Suman
S
Rhee
Myungchull
M
Chitnis
Ajay B
AB
Kim
Cheol-Hee
CH
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D051792:Basic Helix-Loop-Helix Proteins; D003001:Cloning, Molecular; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics*; D018257:Helix-Loop-Helix Motifs; D006801:Humans; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000235:genetics*; D009420:Nervous System / Q000196:embryology*; D012333:RNA, Messenger / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D015027:Zebrafish / Q000196:embryology*; D029961:Zebrafish Proteins / Q000737:chemistry / Q000235:genetics*
D051792:Basic Helix-Loop-Helix Proteins; D017931:DNA Primers; D004268:DNA-Binding Proteins; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; D029961:Zebrafish Proteins; C476737:neurod4 protein, zebrafish