A transcriptional enhancer located between adult beta-globin and embryonic epsilon-globin genes in chicken and duck.
We have detected a transcriptional enhancer sequence downstream from the adult beta-globin (beta A-globin) genes of chicken and duck. DNA segments from the beta-globin coding and flanking sequences were cloned into expression vectors containing the SV40 promoter linked to either the T antigen gene or the cat gene. The expression of these genes was measured in a chicken erythroid cell line transfected with the recombinant plasmids. We found that segments located about 400 bp downstream from the poly(A) site of both the chicken and duck beta A-globin genes (and about 1.5 kb upstream from the embryonic epsilon-globin gene) stimulate transcription of the test genes about five-fold. In chicken essentially the same segment was also found by others to act as an erythroid cell-specific enhancer [Hesse et al., Proc. Natl. Acad. Sci. USA 83 (1986) 4312-4316; Choi and Engel, Nature 323 (1986) 731-734]. The sequence containing this enhancer is conserved in evolution. A high degree of homology, reaching 84% in a segment 180 bp in length, was found between chicken and duck despite an evolutionary divergence of 70 myr.
Institute Jacques Monod, Paris, France.
A
A
Kretsovali
M M
MM
Müller
F
F
Weber
L
L
Marcaud
G
G
Farache
E
E
Schreiber
W
W
Schaffner
K
K
Scherrer
D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D002460:Cell Line; D002645:Chickens; D004372:Ducks; D004742:Enhancer Elements, Genetic; D004900:Erythroblasts / Q000378:metabolism; D005796:Genes; D005914:Globins / Q000235:genetics*; D008969:Molecular Sequence Data; D010957:Plasmids; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity; D014158:Transcription, Genetic
D005914:Globins