The key points from this module are:
In many organisms, sex determination depends on unique chromosomes.
Example:
XX- female and XY- male

Germplasm theory is when an embryo where the cleavage is over the two primordial germ cells retain the chromosomes intact, while in others it has be broken down into smaller pieces.

Keith Porter developed a technique to remove the nucleus from the egg.

Briggs and King were able to make a frog egg develop normally with a transplanted nucleus.

An Enhancer Trap is a method to identify enhancers.

Reporter genes help in determining the spatial and temporal specificity of enhancer activity.

Enhancers are modulators, but the final activation depends on the combinatorial action of multiple transcription factors
Transcription factors usually contain three major domains.
DNA- binding domain
Trans-activating domain
Protein- protein interaction domain

Silencers are opposite of the enhancers

Gene expression can be regulated at different levels
Differential gene transcription
Selective nuclear RNA processing
Selective messenger RNA translation
Differential protein modification
The most complex alternative splicing that we know currently is Dscam,
Approximately 30 to 40% of all human mRNA are subject to regulation by small mRNAs called miRNAs, micro interfering RNA molecules, or micro RNA shortly.