Flashcards in Evodevo Deck (16)
What factors produce an adults phenotype?
An interaction of genes, gene products, and the environment
What are anemone fish know for?
May change sex midway through life, showing development isn't purely genetic
What can be understood from the fact that there are similarities among organisms?
They had a common ancestor and some genes are highly conserved , and differences are down to natural selection when adapting to different lifestyles
What is evo-devo the study of?
Genetics + Embryology - How changes in the genes that regulate development affect the adult forms, how these genes have changed over the course of evolution and how the changes have influenced evolution
What provides anterior and posterior information in mammals and insect embryos?
Same set of hox genes
There is a huge variety of organisms produced form a common set of instructions. This means morphology isn't just down to genetics, what else has an influence?
Mutations in genes that regulate
Changes in the spatial expression of developmental genes
Changes in the temporal expression of developmental genes
There is a mutation in the Ultrabithorax (Ubx) gene expressed the abdomen of the insect , how does it affect developement?
Represses the distal-less (dll) gene, which is essential for leg formation in arthropods, so the insects don't form legs on their abdomens
What does the gene encoding bone morphogenetic protein - BMP4 - control in birds?
Expressed between developing toes, instructs for the cells to undergo apoptosis, which destroys the webs
How come ducks have webbed feet?
Have an BMP inhibitor protein called gremlin in their webs which stops BMP4 from signalling cell death
How do changes in temporal expression affect developement in salamanders?
Webs of most salamanders disappear as the animal matures, if expression of the genes is delayed, then webs don't dissolve and digits don't grow, resulting in 'juvenile' feet
How does environment affect developmental patterns?
A single genotype may encode a range of phenotypes under different environmental conditions
What is an example of an environmental cue required for normal development?
In Aedes aegypti a blood meal stimulates production of vitellogenin, a necessary component of eggs.
In Euscelis leafhoppers gut bacteria
are necessary for normal abdomen development
What is an example of an environmental cue that predicts future conditions in butterflies and caterpillars?
The West African butterfly Bicyclus anynana has a dry-season and a wet-season form with different wing colouration. Temperature during pupation determines adult form.
The spring larvae of Nemoria arizonaria feed on and resemble oak flowers, the summer larvae feed on oak leaves and resemble oak leaf stems.
What is the developmental response to predator in daphnia?
Increase the sizeof their helmets when they encounter chaoborus, occurs if swim in water larvae have been in, offspring in mothers with large helmets will also have large helmets
What is the developmental response to the environment in Spadefoot toads?
If pond begins to dry up they develop a wider mouth, a more powerful jaw and a modified intestine, eating other tadpoles to speed up their development