Summary
A protocol is reported which allows the efficient induction of bromodeoxyridine (BrdU)-induced R-type replication patterns in fibroblast cultures prepared to demonstrate the fragile site fra(X)(q27). The technique includes partial synchronization of the culture by fluorodeoxyuridine (FdU) blocking at the G1/S transition. This block does not impair the induction of the fragile site in medium 199 containing methotrexate. The marked increase of the mitotic index in the synchronized culture may be an advantage in the study of folic acid sensitive fragile sites in fibroblasts. Adding BrdU after block removal leads to an efficient labeling of replicating chromosomes without severely impairing the manifestation of fra(X)(q27).
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References
Albertini RJ, DeMars (1974) Mosaicism of peripheral blood lymphocyte populations in females heterozygous for the Lesch-Nyhan mutation. Biochem Genet 11:397–411
Barbi G, Steinbach P (1982) Increase in the incidence of the fragile site Xq27 in prometaphases. Hum Genet 61:82
Chudley AE, Knoll J, Gerrard JW, Shepel L, McGahey E, Anderson J (1983) Fragile (X) X-linked mental retation. I: Relationship between age and intelligence and the frequency of expression of fragile(X)(q28). Am J Med Genet 14:699–712
Epplen JT, Siebers JW, Vogel W (1975) DNA replication patterns of human chromosomes from fibroblasts and amniotic fluid cells revealed by a Giemsa staining method. Cytogenet Cell Genet 15: 177–185
Froster-Iskenius U, Schwinger E, Weigert M, Fonatsch C (1982) Replication pattern in XXY cells with fra(X). Hum Genet 60: 278–280
Howell RT, McDermott A (1982) Replication status of the fragile X chromosome, fra(X)(q27), in three heterozygous females. Hum Genet 62:282–284
Lubs HA (1969) A marker X chromosome. Am J Hum Genet 21: 231–244
McDonald JA, Kelley WN (1972) Lesch-Nyhan syndrome: Absence of the mutant enzyme in erythrocytes of a heterozygote for both normal and mutant hypoxanthine-guanine phosphoribosyl transferase. Biochem Genet 6:21–26
Steinbach P, Barbi G, Baur S, Wiedenmann A (1983a) Expression of the fragile site Xq27 in fibroblasts. I. Detection of fra(X)(q27) in fibroblast clones from males with X-linked mental retardation. Hum Genet 63:404–405
Steinbach P, Barbi G, Baur S, Vogel W (1983b) Expression of the fragile site Xq27 in fibroblasts. II. Detection of fra(X)-negative and fra(X)-positive clones from female carriers for the Martin-Bell syndrome. Hum Genet 64:279–282
Sutherland GR (1979) Heritable fragile sites on human chromosomes. I. Factors affecting expression in lymphocyte culture. Am J Hum Genet 31:125–135
Uchida IA, Joyce EM (1982) Activity of the fragile X in heterozygous carriers. Am J Hum Genet 34:286–293
Vogel W, Schempp W, Sigwarth I (1978) Comparison of thymidine, fluorodeoxyridine, hydroxyurea, and methotrexate blocking at the G1/S phase transition of the cell cycle, studied by replication patterns. Hum Genet 45:183–198
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Barbi, G., Steinbach, P., Wiedenmann, A. et al. Manifestation of the fragile site Xq27 in fibroblasts. Hum Genet 65, 76–78 (1983). https://doi.org/10.1007/BF00285034
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DOI: https://doi.org/10.1007/BF00285034