Week 1: Model Organisms Flashcards
Do good on quiz!
model organisms
studied to give insight into particular biological phenomenon, systems of other organisms, explore causes and treatments for human diseases, and evolution
fundamental mechanism of life; what organism did we learn this from?
DNA replication, transcription; E-coli
properties of budding yeast (S cerevesiae)
rapid growth, easy mutant isolation, DNA transformation, complete genome sequencing
cell division cycle genes (CDC)
identified in yeast and yeast cdc genes are interchangeable with humans because of conservation
limitation of yeast
we cannot learn multicellular information
C. elegans properties
small, harmless, genome sequenced, mutants, simply body with 959 somatic cells
how do we use single cell lineage?
experts can determine which cells express and determine mutations => mutations where programmed cell death should happen
drosophila melanogaster properties
broad knowledge, easy/cheap, large mutant numbrs, genetic tools (transgenics, conditional expression systems, clonal analysis), entire genome sequenced, cell/organ culture, developed informatics, evolutionarily conserved mechanisms
homeotic mutations
transform parts of the body structures appropriate for other positions
Hox genes
homeotic genes that encode regulatory proteins in almost every animal species to establish the identity of body parts
eyeless gene
pax 6 is mice/human homolog => master control gene for eye developement
what happens if you lose the eyeless gene or move it transgenically?
you cannot produce an eye because it is required and sufficient or you may initiate ectopic eye structures in other body segments
required definition
you need it for something to occur and if you remove it you lose it
sufficient definition
adding the gene means you get the whole thing and allows for a structure to be created
master control gene
when turned on you can achieve eye morphogenesis
- all genes may be required but only the master control initiated eye development by coding a TF regulating all genes
Xenopus laevis
African clawed frog => high tolerance for physical and pharmacological manipulation, microsurgery, and experimental embryology
organizer is a small piece of tissue that?
can reorganize the structure of a developing body by secreting molecules when transplanted in a host cell
is an organizer or a host responsible providing cells for a second embryonic primordia
the organizer secretes molecules that have activities to organize host cells to develop body structures
which model organism is good for cell division studies or microsurgery for nervous system development
Xenopus laevis because of its large egg size
genetic redundancy
2 genes serve the same function so one can be knocked out and the genetic product will remain the same
advantages and disadvantages of whole genome duplication
ADV: development of more complex life forms
DIS: separate gene copies can mutate and serve divergent purposes => also makes it more difficult to figure out if a gene code performs certain functions
mus musculus
close genetic/physiological similarities to humans, genetic manipulation, low cost, multiply fast, human-mouse gene counterparts, same complex physiological systems, naturally develop diseases
what physiological systems and diseases do mice share with humans
immune, endo, nervous, cardiovascular, skeletal; cancer, atherosclerosis, hypertension, diabetes, down syndrome, epilepsy, heart disease, and muscular dystrophy
how do we alter mouse embryos?
we use a blastocyst and a clump of ES cells are injected into the blastocyst with a micropipette. Then they are incorporated in the mass of the host blastocyst which develops in a foster mother so the ES can contribute to any tissue
