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Absence of Genomic Imprinting at the DiGeorge Locus

Published online by Cambridge University Press:  01 August 2014

D. Theophile
Affiliation:
Laboratoire d'Histologie-Embryologie et de Cytogénétique, Hopital Necker-Enfants-Malades, Paris, France
D. Bérubé
Affiliation:
Laboratoire d'Histologie-Embryologie et de Cytogénétique, Hopital Necker-Enfants-Malades, Paris, France
J. Augé
Affiliation:
Laboratoire d'Histologie-Embryologie et de Cytogénétique, Hopital Necker-Enfants-Malades, Paris, France
M. Vekemans*
Affiliation:
Laboratoire d'Histologie-Embryologie et de Cytogénétique, Hopital Necker-Enfants-Malades, Paris, France
*
Laboratoire Histologie-Embryologie Cytogenetique, Hopital Necker, 149, rue de Sevres F-75015 Paris, France

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Fluorescence in situ hybridization (FISH) has been used to visualize specific genomic DNA sequences in interphase nuclei. Timing of replication can be measured by FISH to interphase nuclei: nuclei with a sequence that has not replicated reveal two single signals (G1), whereas those in which the sequence has replicated show two signal doublets (G2). Asynchronous nuclei show a single signal on one allele and a double hybridization dot on the other homologue. In general, most sequences replicate synchronously on the two homologues, with only 10% of nuclei showing an asynchronous hybridization pattern. However, for the sequences known about to be imprinted, approximately 30% of nuclei reveal asynchronous replication. Little is known whether or not the proximal region of chromosome 22, involved in the DiGeorge syndrome [1], is imprinted. We have, therefore, examined the replication timing pattern of the DiGeorge critical region (DGCR).

Type
Research Article
Copyright
Copyright © The International Society for Twin Studies 1996

References

REFERENCES

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