We have determined the complete nucelotide sequence of two early embryonic β-globin genes of the BALB/c mouse: βh0 and βh1. βh1 codes for the embryonic z protein, while the βh0 gene may be a minor early embryonic β-globin gene. The general sequence organization of both genes in entirely analogous to other functional globin genes. There is, however, a 220-base pair insertion of unique sequence within the first intron of βh0. βh0 and βh1 are 96% homologous for 260 base pairs 5' to the AUG initiation codon, and 93% homologous throughout their coding regions. Analysis of the 5'-flanking sequence demonstrates that these genes are more nonadult-like than adult-like. The sequences show evidence for gene conversions among the mouse nonadult β-globin genes that were limited to individual exons, presumably by the presence of non-homologous introns. We propose that this arrangement has the beneficial evolutionary effect of allowing gene conversion to act independently on regions of the protein with different structural or functional responsibilities. βh0 and βh1 are evolutionary homologs to the human fetal and rabbit β3 genes, while their manner of expression is similar to rabbit β3 and dissimilar to human fetal expression. The evolutionary history of the human β-globin genes, therefore, includes the recruitment of an embryonic gene to fetal developmental control.
|Original language||English (US)|
|Number of pages||9|
|Journal||Journal of Biological Chemistry|
|State||Published - 1984|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology