《医学遗传学 Medical Genetics》课程授课教案（PPT课件讲稿）第十二讲 人类染色体畸变 chromosome aberration

Medical Genetics 10人类染色体畸变 chromosome aberration

Medical Genetics 10 人类染色体畸变 chromosome aberration

Medical Genetics Any type of change in the chromosome structure or number (deficiencies, duplications translocations, inversions, etc.)

Medical Genetics Any type of change in the chromosome structure or number (deficiencies, duplications, translocations, inversions, etc.)

Medical Genetics Although it can be a mechanism for enhancing genetic diversity, such alterations are usually fatal or ill adaptive especially in animals

Medical Genetics Although it can be a mechanism for enhancing genetic diversity, such alterations are usually fatal or ill￾adaptive, especially in animals

Medical Genetics 1. factors inducing chromosome aberration A, Ionizing radiation Ionizing radiation produces rearrangements of the genome

Medical Genetics 1. factors inducing chromosome aberration A. Ionizing radiation Ionizing radiation produces rearrangements of the genome

Medical Genetics Radiosensitivity of Various Cell Types Radiosensitivity Cell Type L。w Nerve cells Muscle cells Intermediate Osteoblast Endothelial cells Fibroblast Spermatids High Spermatogonia Lymphocytes Stem Cells Intestinal mucosa cells Erythroblast

Medical Genetics

Medical Genetics When irradiation occurs during the Go/G1 phase of the cell cycle large-scale rearrangements appear as exchange-type chromosome a berrations at the next mitosis, such aberrations can alter cellular phenotypes, and are important in various areas of biology

Medical Genetics When irradiation occurs during the G0/G1 phase of the cell cycle, large-scale rearrangements appear as exchange-type chromosome aberrations at the next mitosis. Such aberrations can alter cellular phenotypes, and are important in various areas of biology:

Medical Genetics Medical and public-health applications include perinatal diagnostics characterization of specific cancer types, carcinogenesis risk estimation, radiation biodosimetry and adiotherapeutic treatment planning

Medical Genetics Medical and public-health applications include perinatal diagnostics characterization of specific cancer types, carcinogenesis risk estimation, radiation biodosimetry and radiotherapeutic treatment planning

Medical Genetics Analyzing chromosome aberrations helps characterize repair/misrepair pathways involved in the processing of DNA damage. Ionizing radiation has some unique features as a probe of such pathways. Compared to other genotoxic agents, it produces copious quantities of DNA double strand breaks(DSBs),and its timing can be controlled more accurately

Medical Genetics Analyzing chromosome aberrations helps characterize repair/misrepair pathways involved in the processing of DNA damage. Ionizing radiation has some unique features as a probe of such pathways. Compared to other genotoxic agents, it produces copious quantities of DNA double strand breaks (DSBs), and its timing can be controlled more accurately

Medical Genetics Moreover initial radiation damage has a discrete, stochastic character that can be modulated by using different kinds of radiation(e. g a-particles versus x-rays) having different ionization densities

Medical Genetics Moreover, initial radiation damage has a discrete, stochastic character that can be modulated by using different kinds of radiation (e.g. a -particles versus x-rays) having different ionization densities

Medical Genetics The spectrum of different radiation-induced chromosome aberrations is informative about the geometry of chromosomes during interphase, and vice versa

Medical Genetics The spectrum of different radiation-induced chromosome aberrations is informative about the geometry of chromosomes during interphase, and vice versa