Population cytogenetics of rare fragile sites in Japan.
A population cytogenetic study of three groups of rare fragile sites defined in Human Gene Mapping 8 (HGM8, Berger et al. 1985) has been conducted using peripheral blood lymphocytes of healthy Japanese subjects. We have examined 1,022 blood donors for folate-sensitive and bromodeoxyuridine (BrdU)-requiring, and 845 for distamycin A-inducible fragile sites. Out of 17 rare autosomal fragile sites defined in HGM8, the following six were identified in Japan; folate-sensitive fra(2)(q11), fra(11)(q13) and fra(11)(q23), distamycin A-inducible fra(16)(q22) and fra(17)(p12), and BrdU-requiring fra(10)(q25). The incidences of distamycin A-inducible fra(16)(q22) (1.42%) and fra(17)(p12) (3.08%) were considerably higher than those of the other sites in Japan. Furthermore, a folate-sensitive fra(17)(p12) and a distamycin A-inducible fra(8)(q24.1) have been newly found in the present study. Their incidences were 0.10% (1/1,022) and 0.71% (6/845), respectively. Since the expression of this fra(17)(p12) was induced by fluorodeoxyuridine, suppressed by thymidine, but not induced by distamycin A, it can be classified as a folate-sensitive site. The expression of the new distamycin A-inducible fra(8)(q24.1) was also enhanced by treatment with Hoechst 33258, berenil and 4',6-diamidino-2-phenylindole (DAPI). This fragile site fulfils all four classical criteria suggested by Sutherland (1979) and also new criteria for a rare fragile site defined in HGM8 (Berger et al. 1985).
Takahashi
E
E
Division of Genetics, National Institute of Radiological Sciences, Chiba, Japan.
Hori
T
T
Murata
M
M
D001973:Bromodeoxyuridine / Q000494:pharmacology; D002871:Chromosome Banding; D043283:Chromosome Fragile Sites; D002873:Chromosome Fragility; D004214:Distamycins / Q000494:pharmacology; D005260:Female; D005492:Folic Acid / Q000494:pharmacology; D005787:Gene Frequency; D014644:Genetic Variation; D006801:Humans; D007564:Japan; D007621:Karyotyping; D008297:Male
D004214:Distamycins; C030000:stallimycin; D005492:Folic Acid; D001973:Bromodeoxyuridine