Gene Networks Database


Strongylocentrotus purpuratus Genes in Development: VEB genes


SpHE


Function

The SpHE gene is one of a set of genes expressed zygotically only at the very early blastula (VEB) stage.
SpHE encodes hatching enzyme, a member of the collagenase family (Reynolds et al., 1992).

Protein

SpHE is a metalloendoprotease (Reynolds et al., 1992).

Subcellular location

Cytoplasmic

Expression Pattern

The VEB genes are the earliest activated genes identified that encode strictly zygotic products.
SpHE mRNA is undetectable in the egg.
RNAase protection assay, which can detect as few as 10 transcripts per embryo indicated that SpHE transcripts begin to accumulate at 4-8-cell stage.
RNA blot analysis demonstrate that the SpHE transcripts reach peak abundance from 9 hours (128 cells) to 15 hours (250 cells) post-fertilization and disappear by mesenchyme blastula stage (25 hours postfertilization).
Solution titration indicates that there are approximately 150,000 SpHE transcripts per embryo at 12 hours.
In situ hybridization showes that in 12-hour embryos the VEB transcripts always accumulate in presumptive ectoderm but to a variable extent in cells of the endoderm and mesenchymal lineages (Reynolds et al., 1992).

mRNA level

Temporal accumulation

Method: RNAase protection assay (up to 64 cells)
Reference: Reynolds et al., 1992
Method: RNA blot analysis
Reference: Reynolds et al., 1992

Stage
Egg
4-8 cells
16 cells
32 cells
64 cells
9h
12h
15h
25h
Level
-
+
+
+
+
+
+
+
-


Sequences

GenBank:

Regulatory Regions

Promoter structure

Regulatory Connections

Upstream Genes

SpOtx
SpEts4

SpHE

Downstream Genes


Evolutionary Homologues

HE6 Paracentrotus lividus

Links

Urchin Web

Bibliography


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