Early H4

Function

The early H4 (EH4) gene is a member of the early histone genes subtype.
Early histone genes are reiterated several hundred-fold per haploid genome in a tandem array (Lee et al., 1991).

Protein

Histone protein
SWISS_PROT: P02306

Subcellular location

Unlike the bulk maternal mRNA pool, histone mRNA is located almost exclusively within the egg nucleus, suggesting that the egg selectively retains the stored pool of histone mRNPs within the nuclear membrane while allowing newly synthesized mRNAs, including histone transcripts, to pass into the egg cytoplasm (DeLeon et al., 1983; Showman et al., 1982; Venezky et al., 1981). The stored histone mRNPs remain within the egg nucleus until fertilization initiates egg cleavage (Maxson et al., 1983).

Expression Pattern

The amount of EH4 mRNA increases approximately 10-fold from the 16-cell stage to early blastula and then decreases rapidly so that little EH4 mRNA remains by the gastrula stage.
The levels of mRNA do not appear to be identical for each batch of embryos studied, making a generalization about exact level of increase impossible (Weinberg et al., 1983).

mRNA level

Temporal accumulation
Method 1: RNA blot hybridization
Reference: Weinberg et al., 1983

Stage Egg 2 hr 4 hr 6 hr 8 hr 10 hr 12 hr 14 hr

Level - + - + - + + + + + + + +