BIOEE 1780 Lecture Notes - Lecture 24: Body Plan, Chordin

• School: Cornell University
• Department: Ecology & Evolutionary Biology
• Course: BIOEE 1780
• Professor: John I.Lovette, Abby Grace Drake

Document Summary

Temporal and spatial control of gene expression. Ectopic addition of the gene, shh (sonic the hedgehog), causes development of 5th leg. Knockout is when they mutate genes to see how much it takes. Cis-regulatory control of gene expression is how coding region was identical in freshwater and marine fish. Hox genes: genes that control the body plan of an embryo along a head-tail axis. Orthologs: same genes in different lineages of organisms. Paralogs: homologous chromosomes that occur within one species and have diverged after a duplication event; new gene that holds new function. Hox genes are same toolkit genes, expressed at different times in different places, and different amounts during development, can yield very different morphologies. Hox genes encode proteins called transcription factors. : transcription factors bind to dna and control transcription of other genes. Hox genes control what grows where (segment identity) Control the spatial and temporal expression of other genes, are important determinants of body pattern.