Polymorphism in the coding sequence of the horse transferrin gene.
Transferrin, the iron transport protein of the blood, is highly polymorphic in many species, including the horse. A number of sequence polymorphisms that distinguish several of the variants of horse transferrin are reported here. Previous studies indicated that exons 12 and 15 were likely to be polymorphic. Sequencing regions of exons 12 and 15 from D and R variants revealed 10 nucleotide substitutions that encoded six amino acid replacements. The F1, F2, H2, and * variants were identical to D, and the O variant was almost identical to R, in the regions studied. The data indicated that the horse transferrin variants make up two distinct groups. The positions of differences between the D and F1 alleles were determined by analyzing single-stranded conformation polymorphisms. Sequencing then revealed three nucleotide substitutions, two of which encoded amino acid substitutions. Location of the eight polymorphic residues on the three-dimensional structure of human lactoferrin revealed that all were clustered at one end of the C-lobe.
Carpenter
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AgResearch Grasslands Research Centre, Palmerston North New Zealand.
Broad
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D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D004277:DNA, Single-Stranded / Q000737:chemistry / Q000235:genetics; D005091:Exons; D014644:Genetic Variation; D006736:Horses / Q000235:genetics*; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D011110:Polymorphism, Genetic; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid; D014168:Transferrin / Q000737:chemistry / Q000235:genetics*
D017931:DNA Primers; D018076:DNA, Complementary; D004277:DNA, Single-Stranded; D014168:Transferrin