Differential expression and regulation of olig genes in zebrafish.
The members of the Olig gene family encode for basic helix-loop-helix (bHLH) transcription factors involved in neural cell type specification. Three Olig genes (Olig1, Olig2 and Olig3) have been identified in all known vertebrate models and a fourth one in anamniotes (olig4). Here we have performed a global analysis of olig genes during zebrafish embryonic development and determined which signaling pathways control their induction and regionalization in the CNS. Interestingly, zebrafish olig3 and olig4 together establish most of the expression domains corresponding to mouse Olig3. According to our data, olig1 is specifically confined to the oligodendrocyte lineage, whereas the other members display stratified expression in diencephalon, hindbrain, and spinal cord. We observed differential expression of olig genes within specific motoneuron and interneuron domains of the spinal cord. olig2, olig3, and olig4 expression appears to be regulated by nodal and FGF signaling during gastrulation and early somitogenesis, by RA signaling in the hindbrain, and by BMP and Hh signals along the dorsoventral axis of the embryonic CNS. Our findings suggest a role for olig genes in CNS patterning as well as in multiple cell fate decisions during neural differentiation.
Department of Biology, University of Padova, I-35131 Padova, Italy. natascia.tiso@unipd.it
Natascia
N
Tiso
Alida
A
Filippi
Francesca
F
Benato
Enrico
E
Negrisolo
Nicola
N
Modena
Enrico
E
Vaccari
Wolfgang
W
Driever
Francesco
F
Argenton
D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics*; D015415:Biomarkers / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D053823:Hedgehog Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D020033:Protein Isoforms / Q000235:genetics*; D015398:Signal Transduction / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics*; D015027:Zebrafish / Q000196:embryology / Q000235:genetics; D029961:Zebrafish Proteins / Q000235:genetics*
D051792:Basic Helix-Loop-Helix Proteins; D015415:Biomarkers; D053823:Hedgehog Proteins; D020033:Protein Isoforms; D014157:Transcription Factors; D029961:Zebrafish Proteins; C540919:olig1 protein, zebrafish