Previous Article | Next Article ![]()
Mol. Cell. Biol., 03 1997, 1189-1200, Vol 17, No. 3
B Mandl, WF Brandt, G Superti-Furga, PG Graninger, ML Birnstiel and M Busslinger
The cleavage-stage (CS) histones of the sea urchin are known to be
maternally expressed in the egg, have been implicated in chromatin
remodeling of the male pronucleus following fertilization, and are the only
histone variants present in embryonic chromatin up to the four- cell stage.
With the help of partial peptide sequence information, we have isolated and
identified CS H1, H2A, H2B, H3, and H4 cDNAs from egg poly(A)+ mRNA of the
sea urchin Psammechinus miliaris. All five CS proteins correspond to
replacement histone variants which are encoded by replication-independent
genes containing introns, poly(A) addition signals, and long nontranslated
sequences. Transcripts of the CS histone genes could be detected only
during oogenesis and in development up to the early blastula stage. The CS
proteins, with the exception of H4, are unique histones which are distantly
related in sequence to the early, late, and sperm histone subtypes of the
sea urchin. In contrast, the CS H1 protein displays highest sequence
homology with the H1M (B4) histone of Xenopus laevis. Both H1 proteins are
replacement histone variants with very similar developmental expression
profiles in their respective species, thus indicating that the frog H1M
(B4) gene is a vertebrate homolog of the CS H1 gene. These data furthermore
suggest that the CS histones are of ancient evolutionary origin and may
perform similar conserved functions during oogenesis and early development
in different species.
Copyright © 1997, American Society for Microbiology
The five cleavage-stage (CS) histones of the sea urchin are encoded by a maternally expressed family of replacement histone genes: functional equivalence of the CS H1 and frog H1M (B4) proteins
Research Institute of Molecular Pathology, Vienna, Austria.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»