Chromosomal arrangement of the duck α-globin genes and primary structure of the embryonic α-globin gene π′

Abstract

A recombinant λ Charon 4A bacteriophage, DαG-1, carrying the genes coding for the duck embryonic (π′) and adult (α A, α D) α-like globins was isolated from a previously constructed duck DNA recombinant library. The three globin genes are transcribed from the same DNA strand and are arranged in the order of their expression during development: 5′-π′-α D-α A-3′. We have determined the complete nucleotide sequence of the duck π′ -globin gene, including the flanking regions. Due to the unusual length of intron 1 (963 bp) and intron 2 (568 bp) the 2167-bp duck π′-globin gene is by far the largest among all known mammalian or avian α- and β-globin genes. For instance, the duck π′ -globin gene introns are amiost twice as long as those of the chicken π′-globin gene. A surprisingly high degree of nucleotide sequence homology (88%) has been found for the 5′ flanking region (positions −1 to −223) of the duck and chicken π′-globin gene.