Disease relevance of HBA2

• To understand what role this splice sequence plays in the processing and maturation of nuclear RNA to cytoplasmic RNA, we have analyzed the intron processing of the alpha D-globin transcript in both heterologous (monkey) and homologous (chicken) cells using simian virus 40 and retrovirus vectors, respectively [1].

High impact information on HBA2

• In both cell types, both introns of the alpha D-globin gene are efficiently and precisely removed [1].
• We mapped at high resolution and as a function of development the hypersensitive domain in the 5'-flanking region of the chicken alpha D-globin gene and determined the specific protein-binding sites within the domain [2].
• Comparison of our sequence data with the nucleotide sequence of the alpha D globin gene suggests that a single gene encodes both the embryonic and adult alpha D globin polypeptides [3].
• Our results show that the overall genome organization is not disturbed in the immediate neighbourhood of the adult globin genes; the observed restriction fragments are identical for both DNAs after EcoRI, HindIII, BamHI and XbaI digestion, using the beta, alpha A and alpha D globin cDNA probes [4].
• With respect to globin gene expression, however, we find that all but one of the globin genes studied (alpha D-globin) undergo dramatic developmental regulation [5].

Biological context of HBA2

• The divergence between the alpha A and alpha D globin within a same species point to individual functional specificity and hence independent evolution and suggest that a mechanism of 'gene conversion' did not operate in between the avian alpha globin genes [6].
• Screening of the DNA library resulted in the isolation of a recombinant, D alpha G-1, which carries both the adult duck alpha A- and alpha D-globin genes [7].
• This silencer element can autonomously reduce the activity of promoters for thymidine kinase and alpha D globin [8].

References