释义 |
DictionarySeesex chromatinEncyclopediaSeeSex Chromatinparanucleolus
sex chro·ma·tina small condensed mass of the inactivated X-chromosome usually located just inside the nuclear membrane of the interphase nucleus; the number of sex chromatin bodies per nucleus is one less than the number of X-chromosomes; normal males and females with Turner syndrome (XO) have none (sex chromatin negative), normal females and males with Klinefelter syndrome (XXY) have one, and XXX-females have two. For technical reasons only about half the cells in a preparation show typical masses. See also: Lyon hypothesis. Synonym(s): Barr chromatin bodyparanucleolus (păr″ă-nū-klē′ō-lŭs) A darkly staining structure within a cell nucleus. |