Transcript Regulation of gene expression powerpoint

Bellwork
 What do you think makes cells in the body different
from one another; why do lung cells look different
than skin cells under a microscope? How do you
think this arises?
Regulation of gene expression
How to get from an egg to a tadpole
 Cell division – making
more cells
 Cell differentiation –
cells become specialized
in structure and function
 Morphogenesis – the
process that gives an
organism its shape
How it all starts
 Cytoplasmic
determinants – mother’s
nurse cells, around the
egg, sends signals telling
it where the head, tail,
dorsal and ventral sides
will be.
Look at pg 372
Inductive signals
 Induction – changes in
the target cells from cells
around them
What do these signals do?
Regulate gene expression!!!
Example of a muscle cell
 Master regulatory genes
turn on or off other genes
(control transcription)
Now, more specifically, how is
gene expression controlled?
First, think about the differences between
eukaryotic and prokaryotic protein synthesis
A lot of mechanisms for gene regulation
 Prokaryotes (ex. Bacteria)
 Negative regulation
Inducible operons
 Repressible operons


Positive regulation

Activator proteins
 Eukaryotes
 Regulation at all stages of protein synthesis
Chromosome structure
Histone acetylation