The second phase of T-cell development

1.Positive selection: Selection for those cells whose T-cell receptors engage self-MHC.

2.Negative selection: Selection against those cells whose T-cell receptors bind too strongly to self-peptide/MHC combinations.

3.Lineage commitment: Commitment of thymocytes to effector cell lineages, including CD4 helper or CD8 cytotoxic populations

TLS Online TPP Program

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#Unit 2. Cellular Organization

The homology between two genes can be plotted in the form of a dot matrix comparison

TLS Online TPP Program

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#Unit 2. Cellular Organization

Sequences that presumably diverged as a result of gene duplication are paralogous.

TLS Online TPP Program

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#Unit 2. Cellular Organization

A gene family is defined as a group of genes that encode related or identical products as a result of gene-duplication events.

TLS Online TPP Program

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#Unit 2. Cellular Organization

Sequences that arose because of speciation are described as orthologous

TLS Online TPP Program

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#Unit 2. Cellular Organization

A mutation that confers a more advantageous phenotype to an organism, relative to individuals in the same population without the mutation, called as positive selection.

TLS Online TPP Program

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#Unit 2. Cellular Organization

Fold potential (measured in negative units) is high (more negative) in introns, and low (more positive) in exons.