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Lack of evidence that inactivation of the mouse X-chromosome is incomplete

Published online by Cambridge University Press:  14 April 2009

Mary F. Lyon
Mary F. Lyon
Affiliation:
Medical Research Council Radiobiological Research Unit, Harwell, Berkshire, England
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The fact that the X-linked genes scurfy (sf) and sparse-fur (spf) of the mouse do not produce a mosaic effect in heterozygotes had been taken, by other workers, together with results from X-Autosome translocations, as evidence that inactivation of the mouse X was incomplete. In this paper it is argued that absence of a mosaic effect is not adequate evidence that a gene is not inactivated. The argument was backed by an experiment in which the spf gene was introduced heterozygously into females carrying an X-linked translocation resulting in non-random X-inactivation with the same X active in all cells. When the mutant (spf) allele was on the active X its effect was fully expressed, indicating that the normal allele on the structurally normal inactive X was undergoing inactivation. Argument is further presented that results from X-Autosome translocations do not indicate the degree of completeness of inactivation in a structurally normal X. Hence, there is no evidence that inactivation of the mouse X is incomplete, although evidence from XO females does suggest that it may be incomplete in man.

Type
Research Article
Information
Genetics Research , Volume 8 , Issue 2 , September 1966 , pp. 197 - 204
Copyright
Copyright © Cambridge University Press 1966

References

REFERENCES

Carr, D. H. (1965). Chromosome studies in spontaneous abortions. Obstet. Gynec., N.Y., 26, 308–326.Google ScholarPubMed
Cattanach, B. M. (1962). XO mice. Genet. Res. 3, 487–490.CrossRefGoogle Scholar
Cattanach, B. M. & Isaacson, J. H. (1965). Genetic control over the inactivation of autosomal genes attached to the X-chromosome. Z. VererbLehre, 96, 313–323.Google ScholarPubMed
Ferguson-Smith, M. A. (1965). Karyotype–phenotype correlations in gonadal dysgenesis and their bearing on the pathogenesis of malformations. J. med. Genet. 2, 93–156.CrossRefGoogle ScholarPubMed
Ford, C. E., Jones, K. W., Polani, P. E., De Almeida, J. C. & Briggs, J. H. (1959). A sex-chromosome anomaly in a case of gonadal dysgenesis (Turner's syndrome). Lancet, 1, 711–713.CrossRefGoogle Scholar
Grumbach, M. M. (1964). Session I. Discussion. In Second International Conference on Congenital Malformations, pp. 62–67. New York: International Medical Congress Ltd.Google Scholar
Grüneberg, H. (1966). The molars of the tabby mouse, and a test of the ‘single-active X-chromosome’ hypothesis. J. Embryol. exp. Morph. 15, 223–244.Google Scholar
Hayman, D. L. & Martin, P. G. (1965 a). Sex chromosome mosaicism in the marsupial genera Isodon and Perameles. Genetics, 52, 1201–1206.CrossRefGoogle Scholar
Hayman, D. L. & Martin, P. G. (1965 b). An autoradiographic study of DNA synthesis in the sex chromosomes of two marsupials with an XX/XY1Y2 sex chromosome mechanism. Cytogenetics, 4, 209–218.CrossRefGoogle Scholar
Lindsten, J. (1963). The Nature and Origin of X-chromosome Aberrations in Turner's Syndrome. Stockholm: Almqvist and Wiksell.Google Scholar
Lyon, M. F. (1962). Sex chromatin and gene action in the mammalian X-chromosome. Am. J. hum. Genet. 14, 135–148.Google ScholarPubMed
Lyon, M. F. (1964). Session I. Discussion. In Second International Conference on Congenital Malformations, pp. 67–68. New York: International Medical Congress Ltd.Google Scholar
Lyon, M. F. (1966 a). X-chromosome inactivation in mammals. In Advances in Teratology (Woollam, D. H. M., ed.). London: Logos Press.Google Scholar
Lyon, M. F. (1966 b). Order of loci on the X-chromosome of the mouse. Genet. Res. 7, 130–133.CrossRefGoogle ScholarPubMed
Lyon, M. F., Searle, A. G., Ford, C. E. & Ohno, S. (1964). A mouse translocation suppressing sex-linked variegation. Cytogenetics, 3, 306–323.CrossRefGoogle ScholarPubMed
Ohno, S. (1963). Restoration of XX-öogonia in XO females of Microtus oregoni. In Second International Conference on Congenital Malformations, pp. 40–42. New York: International Medical Congress Ltd.Google Scholar
Russell, L. B. (1963). Mammalian X-chromosome action: inactivation limited in spread and in region of origin. Science, N.Y., 140, 976–978.CrossRefGoogle ScholarPubMed
Russell, L. B. (1964). Another look at the single-active-X-hypothesis. Trans. N.Y. Acad. Sci. 26, 726–736.CrossRefGoogle Scholar
Welshons, W. J. & Russell, L. B. (1959). The Y-chromosome as the bearer of male-determining factors in the mouse. Proc. natn. Acad. Sci. U.S.A. 45, 560–566.CrossRefGoogle ScholarPubMed