Epistasis_Presentation_Mevis_Sultana_with_Diagrams.pptx

Epistasis

1. Epistasis and Its Different Types Presented by: Me h vis Sultana B.Sc 3rd Sem Pub Kamrup College, Baihata Date : 1 2 : 8 : 2 2 4

2. Introduction to Epistasis Definition: Epistasis refers to the interaction between genes, where the effect of one gene is modified by another gene. Basic Concept: Some genes mask or modify the effects of others in determining an organism’s phenotype. Examples: Coat color in mice, flower color in peas.

3. Why Epistasis is Important Role in Genetics: Explains phenotypic variations beyond simple Mendelian inheritance. Relevance in Evolution: Influences natural selection and population genetics. Impact on Disease: Epistasis can affect the severity or onset of genetic disorders.

4. Types of Epistasis Main Types: - Dominant Epistasis - Recessive Epistasis - Duplicate Gene Epistasis - Complementary Gene Epistasis - Suppressive Epistasis

5. Dominant Epistasis Definition: A dominant allele at one locus masks the effect of alleles at a second locus. Example: Fruit color in summer squash, where a dominant allele masks pigment production. Diagram: Include a Punnett square showing dominant epistasis (e.g., Fruit color in summer squash).

6. Recessive Epistasis Definition: A recessive allele at one locus masks the effect of alleles at another locus. Example: Coat color in Labrador retrievers, where the presence of two recessive alleles blocks pigment expression. Diagram: Punnett square showing recessive epistasis (e.g., Labrador retriever coat color).

7. Duplicate Gene Epistasis Definition: Two genes can compensate for each other, so only one functional allele is needed for a particular trait. Example: Flower color in peas, where two different genes can produce the same phenotype. Diagram: Punnett square showing duplicate gene epistasis.

8. Complementary Gene Epistasis Definition: Two or more genes work together, and both are necessary for the phenotype to be expressed. Example: Purple flower color in sweet peas requires two different genes to produce the pigment. Diagram: Punnett square showing complementary gene epistasis.

9. Suppressive Epistasis Definition: One gene suppresses the expression of another gene, regardless of its own phenotype. Example: Eye color in Drosophila, where one gene suppresses pigmentation. Diagram: Genetic interaction map showing suppressive epistasis.

10. Applications of Epistasis Genetic Research: Understanding epistatic interactions is crucial for identifying gene functions. Medical Implications: Epistasis helps explain variations in complex diseases like cancer, diabetes, etc. Evolution: Epistatic interactions can influence evolutionary pathways.

11. Conclusion Recap of Key Points: Types of epistasis and their impact on phenotypes. Final Thought: Understanding epistasis enriches our understanding of genetics and evolution.