Lecture 37 – Sex determination and dosage compensation I. Introduction A. What is it? In early development, animal embryo must specify gender B. How is it studied? Mutations that transform individuals into inappropriate gender. II. Sex determination - mechanism varies between species A. C. elegans - acts at level of individual cell ratio chromo. gender 1.0 2X:2A hermaphrodite 0.5 1X:2A male 0.67 2X:3A male 0.75 3X:4A hermaphrodite 1. genetic pathway regulating sex in C. elegans 2. what about mutations? - eg. her-1, tra-1 B. Interactions between genes in the same pathway 1. either mutation causes same phenotype - what does this do to the dihybrid ratio? c+/c–; p+/p– X c+/c–; c+/–; p+/–
Lecture 37 – Sex determination and dosage compensation I. Introduction A. What is it? In early development, animal embryo must specify gender B. How is it studied? Mutations that transform individuals into inappropriate gender. II. Sex determination - mechanism varies between species A. C. elegans - acts at level of individual cell ratio chromo. gender 1.0 2X:2A hermaphrodite 0.5 1X:2A male 0.67 2X:3A male 0.75 3X:4A hermaphrodite 1. genetic pathway regulating sex in C. elegans 2. what about mutations? - eg. her-1, tra-1 B. Interactions between genes in the same pathway 1. either mutation causes same phenotype - what does this do to the dihybrid ratio? c+/c–; p+/p– X c+/c–; c+/–; p+/–