TERMIUM Plus^®

Record 1,  Textual support,  English

Record number: 1, Textual support number: 1 DEF

The theory that all X chromosomes in a cell in excess of one are inactivated (in the form of sex chromatin) on a random basis in all mammalian cells at an early stage of embryogenesis. In the normal human female the paternal X chromosome is inactivated in some cells and the maternal one in the remainder. During oogenesis, the inactive X is reactivated so that products of both Xs are represented in the mammalian egg.  4, record 1, English, - Lyon%20hypothesis

Record number: 1, Textual support number: 1 OBS

also found in the adjectival form. Lyonized (ex.: a Lyonized haircell precursor).  5, record 1, English, - Lyon%20hypothesis

Record 1,  Textual support,  French

Record number: 1, Textual support number: 1 DEF

Hypothèse selon laquelle, lorsque le nombre des chromosomes X est supérieur à 1 (chez la femme normale, par exemple), un de ces chromosomes est inactivé, c'est-à-dire ne s'exprime pas génétiquement. Cette inactivation, qui se produirait à un stade précoce de l'embryogenèse, serait due au hasard et porterait donc dans 50 p. cent des cas sur le chromosome X paternel et dans 50 p. cent des cas sur le chromosome X maternel.  1, record 1, French, - hypoth%C3%A8se%20de%20Lyon

Record 1,  Textual support,  Spanish