Analysis of the adult and embryonic chicken globin genes in chromosomal DNA

Abstract

Globin-specific mRNA has been purified from the red blood cells of anemic adult hens and from those of 5-day and 7-day chick embryos. These RNA preparations were used to synthesize labeled cDNA for solution and filter hybridization (Southern blotting) experiments. Hybridization of cDNAs prepared with separated adult alpha- and beta-mRNAs and of rabbit globin-specific probes to restriction enzyme-digested, filter-bound chicken chromosomal DNA has shown that the adult globin genes of the chicken exist within EcoRI-cleaved chromosomal DNA fragments which are 4.3, 6.0, and 12.5 kilobase pairs (kbp) in size. These fragments contain the majority or entirety of the adult alpha D, beta, and alpha A genes, respectively. Furthermore, we present evidence that the predominant chicken embryonic globins are contained within EcoRI fragments 9.4 and 15 kbp in size. Evidence is also presented that the same globin organization exists in several different breeds of chickens and in several chicken culture cell types. Finally, it is demonstrated that the pattern of globin-specific hybridization to reticulocyte chromosomal DNA digested with several restriction enzymes is unchanged during erythropoietic development.