Gene Networks Database


Strongylocentrotus purpuratus Genes in Development: Cell-type specific genes


Spec3


Function

Spec3 is a single copy gene whose product is involved in ectodermal ciliogenesis (Eldon et al., 1987).

Protein

Spec3 is an ectoderm-specific ciliary structural protein.
It is a hydrophobic protein with the molecular mass of 21.6 kD.
The carboxy-terminal part of this protein contains two long hydrophobic stretches, 31 and 37 residues long, separated by short hydrophilic regions of six to eight residues.
The presence of these two distinct hydrophobic stretches suggests that the Spec3 protein contains two alpha-helical domains that either span the lipid bilayer or are associated with some other hydrophobic environment (Eldon et al., 1987).
SWISS_PROT: P16537

Subcellular location

Cytoplasm of hatching blastula stage embryos (Eldon et al., 1990).

Expression Pattern

mRNA level

Temporal accumulation

Method: in situ hybridization
Reference: Eldon et al., 1987

StageEgg
Cleavage
Hatching blastula
Mesenchyme blastula
Gastrula
Prism
Pluteus
LevelLow level
Accumulate rapidly
Increase 50-fold Decline abruptly Remain constant IncreaseIncrease again

The Spec3 mRNA, 2.0 kb in length, is present at low levels in unfertilized eggs but accumulates rapidly during cleavage, increasing 50-fold by hatching blastula stage. Message levels then decline abruptly, remain constant during mesenchyme blastula and gastrula stages, and increase again during prism and pluteus stages.
Deciliation and regeneration of cilia in gastrula-stage embryos results in a four- to fivefold increase in Spec3 mRNA levels, implying that the Spec3 gene product is associated with ciliogenesis (Eldon et al., 1987).

Spatial localization

Method: in situ hybridization
Reference: Eldon et al., 1987

Stage
Early blastula
Late blastula
Gastrula
Pluteus
TissueAll blastomeres Ectoderm (animal hemisphere) Ectoderm Ciliary band, other ectoderm cells

In situ hybridization shows that although Spec3 message accumulates in all blastomeres at early blastula stages, it later becomes restricted to ectoderm. By late blastula stage, hybridization is strongest in the animal hemisphere.
At gastrula, signals are variable over ectoderm, and by pluteus, grains are concentrated in the ciliary band, though present in other ectodermal cells as well (Eldon et al., 1987).


Sequences

GenBank

Regulatory Regions

Regions

Regulatory Connections

Upstream Genes

Spec3

Downstream Genes


Evolutionary Homologues


Links


Bibliography


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