PPT-Gene Interaction and Epistasis

We know that many characteristics are passed on through genes Most of these characteristics are not passed on through one gene with only two alleles Most are polygenic where their traits are caused by a number of different genes. Instructor: Van Savage. Spring 2010 Quarter. 4. /6/. 2010. Crash Course in Evolutionary Theory. What. is fitness and what does it describe?. Ability of an entity to survive and propagate forward. in time. It is inherently a dynamic (time evolving property). Can assign fitness to. and. Gene-environment correlation. Charlotte Huppertz. VU University . Medical Center Amsterdam. Netherlands Twin Register. Book recommendation. Chapter: “The interplay between genes and environment” . . GENE GENE INTERACTION. DOMINANCE. :-When one member of allellic pair marks the expression of the other member then it is known as dominance.. EPISTASIS. :-When there is suppression of action of a gene then it is known as epistasis.. . Dorret Boomsma. . Vrije Universiteit Amsterdam. Dept. Biological Psychology. No aspect of human behavior genetics has caused more confusion and generated more obscurantism than the analysis and interpretation of the various types of non-additivity and non-independence of gene and environmental action and interaction . The genotype/phenotype relationships explored by Mendel are valid but atypical. Most phenotypes are not derived from a single gene/single phenotype model.. Why?. More than two alleles often exist. Dominance of one allele over another may not be complete. Gene regulation Genetically related genotypes with striking phenotypic differences, but similar allelic architecture. Within a genotype – striking phenotypic differences between growth stages and/or between tissues. aa black. cc – – white. C– A – agouti. C– aa black. Inheritance of blood groups. (A-). (B-). (A-). (B-). (A-). (B-). (A-). (B-). Possible child’s blood type. Possible father’s blood type. Related organisms . Striking phenotypic differences but similar genetic structures . Within an organism . Phenotypic differences between growth stages and between tissues . The gene is there but not the expected . . Inter-locus Interactions. PBG 430. Locus. A. Allele A. Allele a. Locus. B. Allele B. Allele b. Phenotype. Inter-locus interactions . (Epistasis). Interaction(s) between alleles at different loci (i.e. interaction between genes). What do these two famous people have in common?. Title: . Using genetics. . . Thursday 23. rd. . January 2014. Homework: . Learning package 6 (apart from 1(c) ) for . Monday 27. th. January. Learning Outcomes. and . Non-allelic Genes. Jason S. . Martinez. NIS Almaty. Review Vocabulary. Heterozygous (hybrid). Homozygous (purebred). Codominance. Incomplete Dominance. Multiple alleles. Polygenic trait. Ratio. lec3. The gene is a chemical determiner. Whereas a phenotypic trait results from the combined action of many genes and their products constantly interacting with the environment. The environment includes not only ecological factors such as temperature and the amount or quality of light but also internal factors such as hormones and enzymes. The enzymes are proteins and the specific molecular organization of protein is determined by genes. The enzymatic proteins perform a catalytic function in various cellular chemical (metabolic) reactions and causing the splitting or union of various molecules.. GENETIC INTERACTION. With the help of different experiments, it was found that most of the characters of living organisms are controlled / influenced / governed by a collaboration of several different genes.. In . epistasis less than four phenotypes appear in F2. .. (і) . Dominant Epistasis. (12:3:1). (ii) Recessive epistasis.(9:3:4)(Supplementary interaction). (iii) Duplicate Recessive Genes (9:7) (. Complementary Genes.