HpEts, an ets-related transcription factor implicated in primary mesenchyme cell differentiation in the sea urchin embryo.
The mechanism of micromere specification is one of the central issues in sea urchin development. In this study we have identified a sea urchin homologue of ets 1 + 2. HpEts, which is maternally expressed ubiquitously during the cleavage stage and which expression becomes restricted to the skeletogenic primary mesenchyme cells (PMC) after the hatching blastula stage. The overexpression of HpEts by mRNA injection into fertilized eggs alters the cell fate of non-PMC to migratory PMC. HpEts induces the expression of a PMC-specific spicule matrix protein, SM50, but suppresses of aboral ectoderm-specific arylsulfatase and endoderm-specific HpEndo16. The overexpression of dominant negative delta HpEts which lacks the N terminal domain, in contrast, specifically represses SM50 expression and development of the spicule. In the upstream region of the SM50 gene there exists an ets binding site that functions as a positive cis-regulatory element. The results suggest that HpEts plays a key role in the differentiation of PMCs in sea urchin embryogenesis.
Kurokawa
D
D
Graduate Department of Gene Science, Faculty of Science, Hiroshima University, Japan.
Kitajima
T
T
Mitsunaga-Nakatsubo
K
K
Amemiya
S
S
Shimada
H
H
Akasaka
K
K
D000595:Amino Acid Sequence; D000818:Animals; D001192:Arylsulfatases / Q000378:metabolism; D015152:Blotting, Northern; D015139:Blotting, Southern; D015815:Cell Adhesion Molecules / Q000378:metabolism; D002452:Cell Count; D002454:Cell Differentiation; D003598:Cytoskeletal Proteins / Q000378:metabolism; D016326:Extracellular Matrix Proteins; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008648:Mesoderm / Q000378:metabolism*; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010063:Ovum / Q000378:metabolism; D010641:Phenotype; D011506:Proteins / Q000378:metabolism; D012617:Sea Urchins / Q000196:embryology*; D017386:Sequence Homology, Amino Acid; D013997:Time Factors; D014157:Transcription Factors / Q000502:physiology*; D014452:Ubiquitins / Q000378:metabolism
D015815:Cell Adhesion Molecules; D003598:Cytoskeletal Proteins; D016326:Extracellular Matrix Proteins; C119263:HpEts protein, Hemicentrotus pulcherrimus; D011506:Proteins; C051691:SM50 protein, sea urchin; D014157:Transcription Factors; D014452:Ubiquitins; C061515:endo16 protein, sea urchin; D001192:Arylsulfatases