BICD 100 Lecture Notes - Lecture 14: Epistasis, Metabolic Pathway, Wild Type
19 Dec 2016
School
Department
Course
Professor
Document Summary
Epistasis: one gene masks or affects the impact of another gene on phenotype: biochemically, both genes may be involved in a single metabolic pathway. If a precursor or early enzyme is needed in the initial steps to get a final product and it is (cid:271)roke(cid:374) the(cid:374) it does(cid:374)(cid:859)t (cid:373)atter if e(cid:374)z(cid:455)(cid:373)es later o(cid:374) i(cid:374) the pro(cid:272)ess still (cid:449)ork. Know cases 1-7 for (cid:862)(cid:373)odifi(cid:272)atio(cid:374)s to (cid:373)e(cid:374)delia(cid:374) ratios (cid:272)aused (cid:271)(cid:455) epistasis(cid:863) table. Squash phenotypic ratio: 9 (disc): 6 (sphere): 1 (long: genotypes. 1: aabb: long: a and b gene could create similar gene product. Sphere is intermediate (going from short and squat to long) Graded change in primary axis of growth. Dosage dependence (one working gene vs. two working genes) Two working copies --> larger effect know gene interactions (slide 34) [see http://www. yourarticlelibrary. com/biology/6-most-important- kinds-of-epistasis-biology/6436/ for examples: dominant epistasis (12:3:1) When dominant allele (cid:858)a(cid:859) (cid:373)asks the e(cid:454)pressio(cid:374) of (cid:858)b(cid:859), (cid:858)a(cid:859) is epistati(cid:272) ge(cid:374)e of (cid:858)b(cid:859).
