title: Human fetal globin DNA sequences suggest novel conversion event.
abstract: DNA sequencing studies of two recently cloned human A gamma globin alleles has revealed a number of base differences which are clustered in the large intron (IVS-2). One allele has a previously undescribed IVS-2 sequence. Most of the allelic differences can be explained as resulting from a gene conversion event involving G gamma as a donor. A novel feature of this event is that three G gamma-like regions occur interspersed among unconverted areas of the A gamma gene. We propose that an alternating purine-pyrimidine run which is located between two of the converted sites is the initiation site of the conversion event. Consistent with models of gene conversion, this poly (purine-pyrimidine) tract has single-stranded characteristics in supercoiled plasmids as assayed by S1-nuclease.
mesh_terms: D000483:Alleles; D001483:Base Sequence; D003001:Cloning, Molecular; D004720:Endonucleases; D005260:Female; D005326:Fetal Proteins / Q000235:genetics*; D005333:Fetus; D005796:Genes; D005914:Globins / Q000235:genetics*; D006801:Humans; D007962:Leukocytes / Q000032:analysis; D010957:Plasmids; D011247:Pregnancy; D015719:Single-Strand Specific DNA and RNA Endonucleases
chemical_list: D005326:Fetal Proteins; D005914:Globins; D004720:Endonucleases; D015719:Single-Strand Specific DNA and RNA Endonucleases