PubMed Health⌕ Search

Biomedical subjects

B G Forget

Publications and source records attributed to B G Forget.

At least 145 records · Page 8Linked to original sources
PubMed1980

Nucleotide sequence of the coding portion of human alpha globin messenger RNA.

The nucleotide sequence of the coding portion of human alpha globin mRNA has been determined by sequence analysis using human alpha globin cDNA cloned in bacterial plasmids. The sequence was obtained by a combination of direct sequence analysis of the cloned cDNA and analysis of cDNA obtained by primer extension, using short restriction endonuclease fragments of cloned alpha cDNA that were hybridized to human globin mRNA and elongated on the mRNA template by viral reverse transcriptase. The human alpha globin mRNA has an unexpectedly high G + C base composition (64.7%), similar to that observed for rabbit globin alpha mRNA, and displays a striking bias in the use of synonym codons for various amino acids. The bias in codon usage of human alpha globin mRNA is similar, with some exceptions, to that previously observed for rabbit alpha globin mRNA as well as for human and rabbit beta globin mRNAs. A detailed restriction endonuclease map of the human alpha globin cDNA is presented.

Amino Acid Sequence↗
PubMed1980

Complete nucleotide sequence of the human delta-globin gene.

We present the complete nucleotide sequence of the human delta-globin gene. The general DNA sequence organization of the delta-globin gene is similar to that of other known globin genes. We have been unable to identify unambiguously the structural basis of the low level of expression characteristic of the delta-globin gene.

Amino Acid Sequence↗
PubMed1980

The structure and evolution of the human beta-globin gene family.

We present the results of a detailed comparison of the primary structure of human beta-like globin genes and their flanking sequences. Among the sequences located 5' to these genes are two highly conserved regions which include the sequences ATA and CCAAT located 31 +/- 1 and 77 +/- 10 bp, respectively, 5' to the mRNA capping site. Similar sequences are found in the corresponding locations in most other eucaryotic structural genes. Calculation of the divergence times of individual beta-like globin gene pairs provides the first description of the evolutionary relationships within a gene family based entirely on direct nucleotide sequence comparisons. In addition, the evolutionary relationship of the embryonic epsilon-globin gene to the other human beta-like globin genes is defined for the first time. Finally, we describe a model for the involvement of short direct repeat sequences in the generation of deletions in the noncoding and coding regions of beta-like globin genes during evolution.

Animals↗
PubMed1980

Nucleotide sequence of human G gamma globin messenger RNA.

The nucleotide sequences of the entire coding portion and 3'-untranslated portion of the human G gamma globin mRNA have been determined by direct nucleotide sequence analysis of cloned human G gamma globin cDNAs. These nucleotides sequences have been compared to the previously published sequences of the human beta globin mRNA and A gamma globin mRNA. No differences were detected between the coding sequences of G gamma and A gamma globin mRNAs except for the expected difference at codon No. 136, but a number of differences were detected in the 3'-untranslated sequences of the two mRNAs. Codon usage of G gamma globin mRNA, although similar to that of the related beta globin mRNA, displays a few notable differences such as the use of UUG for leucine and GGA for glycine that are not utilized in beta globin mRNA.

Base Sequence↗
PubMed1980

Embryonic-fetal erythroid characteristics of a human leukemic cell line.

We have studied a number of cell surface, enzyme, and protein markers in the human leukemic K562 cell line. We have confirmed previous observations that these cells accumulate human embryonic hemoglobins after exposure to hemin. In addition, our results demonstrated that these cells possess in the "ininduced" state i surface antigen, lactate dehydrogenase isoenzymes characteristic of embryonic or fetal erythroid cells, fetal and embryonic globin chains, and globin mRNAs. The levels if i antigen, embryonic globin chains, and embryonic globin mRNA increased substantially after exposure of the cells to hemin in suspension culture. In contrast, K562 cells lacked several surface, enzymatic, and functional properties typical of granulocytes, lymphocytes, monocytes, or adult erythroblasts, including HLA surface antigens, surface immunoglobulins, sheep erythrocyte rosetting, phagocytosis, terminal deoxynucleotidyl transferase, carbonic anhydrase, ABO and Rh blood groups, and adult hemoglobins. The K562 cell line therefore exhibits phenotypic properties of embryonic erythroid progenitor cells and a quantitative increase in the expression of some of these properties can be achieved by exposure of the cells to hemin.

Antigens, Surface↗
PubMed1980

Cotransfer of circular and linear prokaryotic and eukaryotic DNA sequences into mouse cells.

We have attempted to introduce some eukaryotic and prokaryotic DNA sequences into mouse fibroblasts. Purified herpes thymidine kinase gene (tk) was introduced into mouse cells. The presence of the herpes tk gene was established by gel electrophoresis, sensitivity to the purine analog acyloguanosine, and Southern blot hybridization. We utilized two different methods to introduce nonselectable markers into mouse cells. Bacterial plasmid pBR322 was ligated to herpes tk and used for transfection. All cells that were TK+ also contained the plasmid sequences. In the second method, pBR322 DNA was mixed with herpes tk DNA and presented to mouse cells. TK+ cells were tested for pBR322 sequences by blot hydridization. The frequency of unlinked cotransfer was greater than 40%. When the circular plasmid containing pBR322 and tk was used for transfection, each of the resulting transfectants acquired several copies of the plasmid. Most of the copies were associated with high molecular weight DNA in the cell. In addition, we found that some of the plasmid molecules may exist as free circular molecules. Using the nonligated cotransfer method, we introduced purified human beta-globin sequences into the recipient cells. We were unable to detect any transcripts of the human beta-globin gene at a level greater than or equal to 10 molecules per cell.

DNA, Circular↗
PubMed1980

Hemolytic anemias: congenital and acquired.

Hemolytic anemia may result from a wide variety of causes, both intrinsic and extrinsic. Diagnosis and appropriate therapy mandate identification of the specific etiology--be it membrane, enzyme, or immunologic defect, toxin, or trauma.

Adrenal Cortex Hormones↗
PubMed1979

Restriction endonuclease mapping of the human gamma globin gene loci.

The restriction endonuclease sites in and around the human gamma globin gene loci have been mapped using the gel blotting technique of Southern, in both normal DNA and DNA from an individual with hereditary persistence of fetal hemoglobin (HPFH). In normal DNA, the gamma genes are linked to the delta (and beta) globin genes, and the orientation of these genes with respect to transcription is (5') G gamma leads to A gamma leads to delta leads to beta (3'). The distance between the G gamma and A gamma genes is 3.5 kb and that between the A gamma and delta genes is 16 kb. In both normal DNA and HPFH DNA, the gamma genes are interrupted by an intervening sequence, approximately 1 kb in length that is situated between codon positions 99 and 121 of the coding sequence. In different DNA samples, there is polymorphism for the presence or absence of a Hind III site in the intervening sequence of either gamma golbin gene. In HPFH DNA, a deletion of at least 16 kb of DNA has been detected. This deletion starts at a point approximately 12.5 kb from the 3'-end of A gamma gene and extends through the delta and beta globin genes to a point at least 3 kb beyond the 3'-end of beta globin gene.

Base Sequence↗
PubMed1979

Prenatal diagnosis of classic hemophilia.

Prenatal diagnosis of classic hemophilia (hemophilia A) in mid-trimester was achieved by means of immunoradiometric assays for factor VIII on fetal plasma and amniotic-fluid mixtures obtained by fetoscopy. Samples were analyzed from six male fetuses at risk for severe hemophilia and from nine control fetuses for which fetoscopy was carried out to attempt prenatal diagnosis of other genetic disorders. The factor VIII coagulant-antigen values for the control (non-hemophilic) samples were 17 to 94, and the factor VIII related-antigen concentrations were 50 to 155 U per deciliter. Three of the fetuses at risk for hemophilia had factor VIII values in the control range, and these infants were normal at birth. The other three fetuses had low concentrations of factor VIII coagulant antigen but normal concentrations of factor VIII related antigen. These values and the diagnoses of severe hemophilia were confirmed with blood from the abortuses.

Amniotic Fluid↗