The human globin genes are among the most extensively characterized in the human genome, yet the details of the molecular events regulating normal human hemoglobin switching and the potential reactivation of fetal hemoglobin in adult hematopoietic cells remain elusive. Recent discoveries demonstrate physical interactions between the beta locus control region and the downstream structural gamma-...

Different models of gene family evolution have been proposed to explain the mechanism whereby gene copies created by gene duplications are maintained and diverge in function. Ohta proposed a model which predicts a burst of nonsynonymous substitutions following gene duplication and the preservation of duplicates through positive selection. An alternative model, the duplication-degeneration-compl...

A comprehensive dataset of 62 beta globin gene sequences from various vertebrates was compiled to test the molecular clock and to estimate dates of gene duplications. We found that evolution of the beta globin family of genes is not clock-like, a result that is at odds with the common use of this family as an example of a constant rate of evolution over time. Divergence dates were estimated eit...

We have examined the dynamics of nuclear repositioning and the establishment of a replication timing program for the actively transcribed dihydrofolate reductase (DHFR) locus and the silent beta-globin gene locus in Chinese hamster ovary cells. The DHFR locus was internally localized and replicated early, whereas the beta-globin locus was localized adjacent to the nuclear periphery and replicat...

M13 DNA probes labeled with biotinylated psoralen and a streptavidin-horseradish peroxidase conjugate provide nonradioactive detection of the sickle cell and normal alleles of the beta-globin locus. The two biotinylated probes contain single-stranded sequences complementary to two different Sau3AI restriction fragments from the 5' region of the beta-globin gene and double-stranded M13 vector se...

Background: The double heterozygous state of α/β thalassemia may alter the hematological indices and modify the phonotype. In addion, definite characterizaon of co-inheritance of α- and β-thalassemia heterozygous carriers may change the process of genec counseling. Materials and Methods: An Iranian couple with low hematological indices was analyzed for α-globin gene deleons using mulpl...

Active gene promoters are associated with covalent histone modifications, such as hyperacetylation, which can modulate chromatin structure and stabilize binding of transcription factors that recognize these modifications. At the beta-globin locus and several other loci, however, histone hyperacetylation extends beyond the promoter, over tens of kilobases; we term such patterns of histone modifi...

background: &beta-thalassemia; is the most common monogenic disorder in human. the (ct) polymorphism at -158 upstream region of the &gammag-globin; gene and pharmacological factors such as hydroxyurea have been reported to influence &gamma-globin; gene expression and the severity of clinical symptoms of &beta-thalassemia.; methods: in the present study, 51 &beta-thalassemia; intermediate patie...

background: the double heterozygous state of α/β thalassemia may alter the hematological indices and modify the phonotype. in addion, definite characterizaon of co-inheritance of α- and β-thalassemia heterozygous carriers may change the process of genec counseling. materials and methods: an iranian couple with low hematological indices was analyzed for α-globin gene deleons using mulplex g...

We have compared the rates of alpha- and beta-globin gene transcription with the rates of mature globin mRNA appearance in the cytoplasm during the course of chemically induced differentiation of mouse erythroleukemia cells by in vivo pulse-labeling experiments. The absolute rates for both processes were determined by simultaneously measuring incorporation into globin-specific transcripts and i...