Dose-dependent nuclear ß-catenin response segregates endomesoderm along the sea star primary axis.
Development
; 142(1): 207-17, 2015 Jan 01.
Article
in En
| MEDLINE
| ID: mdl-25516976
ABSTRACT
In many invertebrates, the nuclearization of ß-catenin at one pole of the embryo initiates endomesoderm specification. An intriguing possibility is that a gradient of nuclear ß-catenin (nß-catenin), similar to that operating in vertebrate neural tube patterning, functions to distinguish cell fates in invertebrates. To test this hypothesis, we determined the function of nß-catenin during the early development of the sea star, which undergoes a basal deuterostomal mode of embryogenesis. We show that low levels of nß-catenin activity initiate bra, which is expressed in the future posterior endoderm-fated territory; intermediate levels are required for expression of foxa and gata4/5/6, which are later restricted to the endoderm; and activation of ets1 and erg in the mesoderm-fated territory requires the highest nß-catenin activity. Transcription factors acting downstream of high nß-catenin segregate the endoderm/mesoderm boundary, which is further reinforced by Delta/Notch signaling. Significantly, therefore, in sea stars, endomesoderm segregation arises through transcriptional responses to levels of nß-catenin activity. Here, we describe the first empirical evidence of a dose-dependent response to a dynamic spatiotemporal nß-catenin activity that patterns cell fates along the primary axis in an invertebrate.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Cell Nucleus
/
Body Patterning
/
Endoderm
/
Beta Catenin
/
Mesoderm
Type of study:
Prognostic_studies
Limits:
Animals
Language:
En
Journal:
Development
Journal subject:
BIOLOGIA
/
EMBRIOLOGIA
Year:
2015
Document type:
Article
Affiliation country:
United States