Differential Gene Expression Overview

Differential Gene Expression

• All somatic cells have the same DNA, but different functions due to cellular differentiation.
• Cellular differentiation is driven by differential gene expression, where different genes are activated in a cell to give it a unique function.
• Stem cells are undifferentiated, and their final form depends on which genes are activated.
• Stem cells differentiate into somatic cells, maintaining the same genotype but expressing different phenotypes (characteristics).
• Differential gene expression occurs during fetal development to create different cells and tissues.
• This process is crucial for the development of multicellular organisms.

What Differential Gene Expression Means

• Differential gene expression is the process of activating different genes in different cells to give them distinct functions.
• Involves stem cells differentiating into specialized somatic cells.
• Genes determining a cell's function are expressed (active), while the others are silenced (inactive).
• This control over gene expression is essential; if a skin cell expressed liver protein production, it would be problematic, for example.

How Differential Gene Expression Works

• DNA contains instructions for producing all proteins, including structural components of cells, tissues, organs, etc.
• Gene expression involves copying (transcribing) the DNA code into mRNA.
• mRNA carries the code to ribosomes, the protein-producing factories.
• This process of copying and using instructions is called transcription and translation, respectively.
• Cells can only express genes relevant to their phenotype and function.

Genome and Differential Gene Expression

• Cells' nuclei store DNA as chromosomes.
• The genome contains the complete DNA sequence.
• Only specific genes relevant to the cell's function are expressed.
• This selective gene expression is critical for the development of cellular diversity and structure.

Differential Gene Expression Analysis (DGE)

• DGE is a technology to analyze which genes are active and their expression levels in cells.
• RNA sequencing (RNA-seq) is used to determine active genes.
• This technology helps understand the causes of diseases and impacts of environmental factors on cells.
• Three key standards of DGE: identical genomes, unneeded genes are silenced, and only needed genes are expressed.
• DGE analysis compares gene expression in different cell types or conditions.
• DGE analysis involves sample collection, replication, sequencing, quantification, and statistical analysis using tools like DESeq2.

Explore the concept of differential gene expression and its role in cellular differentiation. Understand how stem cells develop into specialized somatic cells and the significance of gene activation during fetal development for multicellular organisms. Dive into the mechanisms that allow all somatic cells to share the same DNA yet perform distinct functions.