Question

The classic experiment that examined DNAse I sensitivity of chicken embryonic DNA from different tissues and at different developmental stages shows that: (Select all that apply.)

A. the gene expression pattern changes during development.

B. DNAse I sensitivity comes from sporadic mutations occurred during development.

C. the chromatin structure changes in the course of development.

D. DNAse I sensitivity only occurs in chicken but in no other organisms.

Answer 1

A. the gene expression pattern changes during development - the DNA methylation patterns of the chicken embryo showed a gradually increasing tendency.gene expression may be simultaneously regulated by promoter hypomethylation and gene body hypermethylation.

C. the chromatin structure changes in the course of the development - DNase I hypersensitive sites (DHSs) are regions of chromatin that are sensitive to cleavage by the DNase I enzyme. In these specific regions of the genome, chromatin has lost its condensed structure, exposing the DNA and making it accessible.