Essential Knowledge 3.B.2

A variety of intercellular and intracellular signal transmissions mediate gene expression.

Signal transmission within and between cells mediates gene expression. Examples include:

• Cytokines regulate gene expression to allow for cell replication and division.
• Mating pheromones in yeast trigger mating gene expression.
• Levels of cAMP regulate metabolic gene expression in bacteria.
• Expression of the SRY gene triggers the male sexual development pathway in animals.
• Ethylene levels cause changes in the production of different enzymes, allowing fruits to ripen.
• Seed germination and gibberellin.

Signal transmission within and between cells mediates cell function. Examples include:

• Mating pheromones in yeast trigger mating genes expression and sexual reproduction.
• Morphogens stimulate cell differentiation and development.
• Changes in p53 activity can result in cancer.
• HOX genes and their role in development.

Students should be able to:

LO 3.22 Explain how signal pathways mediate gene expression, including how this process can affect protein production.

LO 3.23 Use representations to describe mechanisms of the regulation of gene expression.