Gene Networks Database
purpuratus Genes in Development: Histone Genes
The H1-alpha gene codes for histone that interacts
with euchromatin and is synthesized during the earliest
stages of embryonic development (Chambers et al., 1987).
In the H1-alpha histone five contiguous repeats of the tetrapeptide SPBB (where
B is R or K) occur between positions 10 and 29.
Multiple seryl residues including SPBB are located in
the NH2-, and BBSP in the COOH-end of the protein.
They become phosphorylated by egg cytosol shortly after
insemination (Porter et al., 1989).
The amino acid sequence of the first 34 residues of
this histone shows striking similarity with sequences
from three South African species.
The measurement of H1-alpha peptide elongation rate in
cleaving embryos indicate an elongation rate (at 15
degrees C) of 0.80 codons per s. These values fall
within the range of values of average peptide
elongation rate for total protein in the cells (Goustin et al., 1982).
H1-alpha is expressed at the earliest stages of
It is distributed to both daughter cells at
mitosis, resulting in it being most concentrated in
cells that stop dividing shortly after H1-alpha
synthesis ends, while cells that continue to divide
dilute their H1-alpha content in proportion to the
number of cell divisions.
Thus, H1-alpha becomes segregated in dividing cells (Pehrson et al., 1985).
H1-alpha histone was detected in all three cell
types which comprise the 16-cell stage embryo:
micromeres, macromeres, and mesomeres, but micromeres
contain H1-alpha that migrates faster than that of
macromeres and mesomeres (Chambers et al., 1987).
- H1-gamma Strongylocentrotus purpuratus
- H1-alpha Lytechinus pictus
- H1-alpha Psammechinus miliaris
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Copyright © 1997 GeNet Team