Gene Networks Database
purpuratus Genes in Development: Primary mesenchyme-
The msp130 gene codes for a primary mesenchyme lineage-specific
cell surface protein in the embryo.
Experiments with the monoclonal antibodies suggested
this protein to be a major cell surface antigen of primary
mesenchyme cells (Anstrom et al., 1987).
The function of msp130 remains unclear, however it is evident
that it has been implicated in major primary mesenchyme cell functions (Parr et al., 1989).
There is also some experimental evidence that msp130
may play a role in the entrance of calcium ions into the
PMCs (Carson et al., 1985; Kabakoff et all., 1992).
The msp130 sequence predicts a protein of relative molecular
weight 81000, which contrasts with the observed Mr = 130000
on standard polyacrilamide gel (Parr et al., 1990).
The msp130 protein possesses two novel glycine-rich
domains and a signal peptide, but lacks a transmembrane domain.
Digestion of msp130 with endonuclease F reveals that this
protein contains N-linked carbohtdrate groups.
msp130 is apparently a sulphated glycoprotein;
two-dimensional immunoblots showed
that msp130 is an acidic protein that becomes
substantially less acidic in the absence of sulphate
in the sea water (Anstrom et al., 1987).
The carboxyl-terminal sequence suggests that msp130 may be
phosphatidylinositol-linked to the cell membrane and experiments
with phospholipases support this conclusion (Parr et al., 1990).
Immunoelectron microscopy shows that msp130 is present on the
trans side of the Golgi apparatus and extracellular surface of
primary mesenchyme cells (Anstrom et al., 1987).
The transcript encoding msp130 is undetectable in egg RNA
or 16-cell RNA (Leaf et al., 1987).
The msp130 transcripts are first detected at the
blastula stage, in micromere-lineage cells just prior
Appearance of msp130 transcripts remains strictly
limited to this lineage through the pluteus stage (Harkey et al., 1992).
The relative abundance of msp130
transcripts is uniform among the 32 cells of this
lineage in secondary mesenchyme blastulae and in
gastrulae. It indicates that expression is homogeneous
among these cells up to the early prism stage.
However, number of transcripts increases dramatically
in the PMCs of an embryo during prism and pluteus stages, suggesting that these
cells switch from an autonomous mode of regulation of
the msp130 gene to an inductive mode.
In the pluteus larva, the highest
levels of transcript expression occur in the cells associated
with the rapidly growing tips of the spicular skeleton (Harkey et al.,1992).
The msp130 protein is first detectable soon after
primary mesenchyme cell ingression into the blastocoel.
It is present at the mesenchyme blastula, gastrula and pluteus stages (Leaf et al., 1987).
Method: RNA gel blot hybridization
Reference: Leaf et al., 1987
Method: in situ hybridization
Reference: Harkey et al., 1992
||micromere-lineage cells prior to ingression
with the tips of the spicular skeleton
- msp130 Heliocidaris erytrogramma
- msp130 Heliocidaris tuberculata
- msp130 Eucidaris tribuloides
- msp130 Phyllacanthus parvispinus
- msp130 Asthenosoma ijimai
- msp130 Dendraster excentricus
- msp130 Mellita isometra
- msp130 Arabicia punctulata
- msp130 Strongylocentrotus droebachiensis
- msp130 Lutechinus variegatus
- msp130 Lutechinus pictus
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