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Biomedical subjects

C J Epstein

Publications and source records attributed to C J Epstein.

At least 271 records · Page 15Linked to original sources

Expression of the mammalian X chromosome before and after fertilization.

The activity of hypoxanthine-guanine phosphoribosyltransferase in unfertilized mouse ova and in mouse embryos at the two-cell stage is proportional to the number of X chromosomes present during oogenesis. This indicates that the enzyme is X-linked in the mouse and that inactivation of the X chromosome does not occur during oogenesis. However, the genetic dosage effect of the X chromosomes is not present after the increase in hypoxanthine-guanine phosphoribosyltransferase activity in the late morula and the blastocyst stages. These results indicate that the X-linked enzyme lacuts is expressed sometimne after fertilization but before the morula stage.

Aminohydrolases↗