复旦大学上海医学院：《医学遗传学 Medical Genetics》课程PPT教学课件（英文）09人类染色体 human chromosome

Medical Genetics There are two types of heterochromatin Facultative heterochromatin and constitutive heterochromatin

Medical Genetics There are two types of heterochromatin: Facultative heterochromatin and Constitutive heterochromatin

Medical Genetics Facultative heterochromatin is condensed chromatin that unfolds and becomes transcriptionally active during some portion of the cell cycle (Barr body)

Medical Genetics Facultative heterochromatin is condensed chromatin that unfolds and becomes transcriptionally active during some portion of the cell cycle (Barr body)

Medical Genetics Constitutive heterochromatin refers to the chromatin that remains transcriptionally inert during the entire cell cycle

Medical Genetics Constitutive heterochromatin refers to the chromatin that remains transcriptionally inert during the entire cell cycle

Medical Genetics The bulk of constitutive heterochromatin is composed of non coding dNa sequences that are repeated hundreds of thousands or even millions of times

Medical Genetics The bulk of constitutive heterochromatin is composed of non￾coding DNA sequences that are repeated hundreds of thousands or even millions of times

Medical Genetics

Medical Genetics