《医学遗传学 Medical Genetics》课程PPT教学课件（英文版）the Basis of Genetics

Medica, Genetics the basis of genetics

the Basis of Genetics Medical Genetics

Cellular basis of genetics

Cellular Basis of Genetics

Structure of Eukaryote mIcrofilament Centriole Nucleus Ribosomes endoplasmic reticulum Mitochondrion Rough endoplasmic reticulum Golgi apparatus Lysosome

Structure of Eukaryote

Chromatin chromosome Euchromatin heterochromatin Euchromatin Heterochromatin 1. Strongly condensed 2. Genetic inertia 3. Be late to replicate a. Constitutive heterochromatin b. Facultative heterochromatin

1. Strongly condensed Euchromatin & heterochromatin Euchromatin Heterochromatin Chromotin & Chromosome 2. Genetic inertia 3. Be late to replicate a. Constitutive heterochromatin b. Facultative heterochromatin

Chromatin chromosome Sex chromatin X chromatin X body Barr body

Sex chromotin X chromatin X body Barr body Chromotin & Chromosome

Chromatin chromosome Sex chromatin Lyon hypothesis(1961) 1. Inactivation of all but one x chromosome 2. Happened at an early stage of embryogenesis 3. Happened on a random basis and maintained in all descendant cells Dosage compensation

Sex chromotin Lyon hypothesis (1961) 1. Inactivation of all but one X chromosome 2. Happened at an early stage of embryogenesis 3. Happened on a random basis and maintained in all descendant cells Dosage compensation Chromotin & Chromosome

Chromatin chromosome Sex chromatin Y-chromatin

Sex chromotin Y-chromatin Chromotin & Chromosome

Sex Determining Mechanism Chromosomal mechanisms(XY &o Two sex chromosomes of different sizes, X is larger . Females are XX males are Xr g Males determine the sex of the offspring Y chromosome TDF: testis-determining factor & SRY: sex-determining region of Y chromosome

Sex Determining Mechanism Chromosomal mechanisms (XY) Y chromosome ❖ Two sex chromosomes of different sizes, X is larger ❖ TDF：testis-determining factor ❖ SRY：sex-determining region of Y chromosome ❖ Females are XX, males are XY ❖ Males determine the sex of the offspring

Molecular basis of genetics

Molecular Basis of Genetics

Structure of dna P Deoxyribose bp A T GC

bp P A T G C Structure of DNA Deoxyribose