RNA polymerases can be shared by a particular group of genes in a transcription "factory" in nuclei, where transcription may be coordinated in concert with the distribution of coexpressed genes in higher-eukaryote genomes. Moreover, gene expression can be modulated by regulatory elements working over a long distance. Here, we compared the conformation of a 130-kb chromatin region containing the...

The widespread occurrence of intergenic transcription in eukaryotes is increasingly evident. Intergenic transcription in the beta-globin gene cluster has been described in murine and human cells, and models for a role in gene and chromatin activation have been proposed. In this study, we analyze intergenic transcription and the chromatin state throughout the human beta-globin gene cluster and f...

BACKGROUND Thalassemia syndromes are the most prevalent single gene disorders in Iran. This study aimed to evaluate the effect of different types of beta-globin gene mutations, co-inheritance of alpha-globin gene mutations and/or Xmn1 SNP on disease phenotype in a large cohort of Iranian patients. SUBJECTS AND METHODS In total, 433 patients were clinically classified into β-thalassemia major ...

Background: β-thalassemia as a hereditary disease is defined as defective synthesis of   β-globin chains, resulting in erythropoiesis abnormalities and severe anemia. Different studies have shown that cytokines and cytokine gene polymorphisms play a major role in the pathogenesis of   β-thalassemia. Single nucleotide polymorphisms (SNPs) within the promoter region or other regulatory sequences ...

Background: The double heterozygous state of α/β thalassemia may alter the hematological indices and modify the phonotype. In addition, definite characterization of co-inheritance of αand β-thalassemia heterozygous carriers may change the process of genetic counseling. Materials and Methods: An Iranian couple with low hematological indices was analyzed for α-globin gene deletions using multiple...

BACKGROUND The clinical and hematologic features of β-thalassemia are modulated by different factors, resulting in a wide range of clinical severity. The main factors are the type of disease-causing mutation and the ability to produce α-globin and γ-globin chains. In the present study we investigated the respective contributions of known modifiers to the prediction of the clinical severity of β...

The alpha-like globin gene cluster in rabbits contains embryonic zeta-globin genes, an adult alpha-globin gene, and theta-globin genes of undetermined function. The basic arrangement of genes, deduced from analysis of cloned DNA fragments, is 5'-zeta 0-zeta 1-alpha 1-theta 1-zeta 2-zeta 3-theta 2-3'. However, the pattern of restriction fragments containing zeta- and theta-globin genes varies am...

of human red blood cells. Some of the genes were friendlier than others. For example, two -globin genes were about fi ve times more likely to be near each other than were two -globin genes. Next, the researchers tested whether a gene’s chromatin environment affects its tendency to cluster. In human cells, -globin sits in a tightly packaged chromatin region, whereas -globin’s neighborhood is loo...

The developmental switch from human fetal (gamma) to adult (beta) hemoglobin represents a clinically important example of developmental gene regulation. The transcription factor BCL11A is a central mediator of gamma-globin silencing and hemoglobin switching. Here we determine chromatin occupancy of BCL11A at the human beta-globin locus and other genomic regions in vivo by high-resolution chroma...

β-Thalassemia major results from severely reduced or absent expression of the β-chain of adult hemoglobin (α₂β₂;HbA). Increased levels of fetal hemoglobin (α₂γ₂;HbF), such as occurs with hereditary persistence of HbF, ameliorate the severity of β-thalassemia, raising the potential for genetic therapy directed at enhancing HbF. We used an in vitro model of human erythropoiesis to assay for enhan...