| 释义 |
DictionarySeeheterochromatinconstitutive heterochromatin
constitutive heterochromatin[′kän·stə‚tüd·iv ¦hed·ə·rō′krō·məd·ən] (genetics) A type of heterochromatin that is always condensed and is often centered on either side of the centromere, and that stains to give a C band. constitutive heterochromatin
heterochromatin [het″er-o-kro´mah-tin] that state of chromatin in which it is dark-staining, genetically inactive, and tightly coiled.constitutive heterochromatin the chromatin in regions of the chromosomes that are invariably heterochromatic; it contains highly repetitive sequences of DNA that are genetically inactive and serves as a structural element of the chromosome.facultative heterochromatin the chromatin in regions of the chromosomes that become heterochromatic in certain cells and tissues; for example, it makes up the inactive X chromosome in female somatic cells.con·sti·tu·tive het·er·o·chro·ma·tinrepetitive heterochromatin that lies in secondary constrictions in the nucleolar organizers. |