Sec1-FUT2-Sec1 hybrid allele generated by interlocus gene conversion.
BACKGROUND
Many single-nucleotide polymorphisms have been identified in the coding region of the FUT2 locus, which encodes secretor type alpha(1,2)fucosyltransferase. In addition, three recombination alleles have been reported. Of these recombination alleles, a fusion gene generated by an unequal crossing over between Sec1, a pseudogene that locates 23 kb upstream to and has high sequence homology with FUT2 and FUT2, was identified as a Japanese-specific nonsecretor allele (se(fus)).


METHODS
During the screening of the se(fus) in Mongolians (n = 118), a hybrid allele of Sec1-FUT2-Sec1 was found.


RESULTS
The DNA sequence suggested that the Sec1-FUT2-Sec1 allele contains a 275-bp sequence (between positions 259 and 533) that is identical to the FUT2 sequence including a 54-bp FUT2-specific region (between positions 417 and 470) and that might have been generated by an interlocus gene conversion.


CONCLUSIONS
Because the recombination region of se(fus) and the upstream recombination region of Sec1-FUT2-Sec1 are almost identical, this sequence stretch is likely to be the breakpoint for different kinds of recombinations that occur in this family of genes.
Soejima
Mikiko
M
Department of Forensic Medicine and Human Genetics, Kurume University School of Medicine, Kurume, Japan.
Fujihara
Junko
J
Takeshita
Haruo
H
Koda
Yoshiro
Y
D000483:Alleles; D001483:Base Sequence; D005647:Fucosyltransferases / Q000235:genetics*; D005785:Gene Conversion; D050939:Gene Fusion; D006801:Humans; D008957:Models, Genetic; D051938:Munc18 Proteins / Q000235:genetics*; D016133:Polymerase Chain Reaction; D000097631:Galactoside 2-alpha-L-fucosyltransferase
D005647:Fucosyltransferases; D051938:Munc18 Proteins; D000097631:Galactoside 2-alpha-L-fucosyltransferase; C497937:STXBP1 protein, human