Developmental mechanisms of morphological change

Question 1

example of transcription factors changing developmental mechanisms

Answer 1

differential hox gene expression- e.g. Hoxc-6- altering body structure, e.g. sliding ribs around

Question 2

example of TF changes in crustaceans

Answer 2

Ubx changing which limbs it is expressed in, not expressed in feeding limbs but is expressed in swimming limbs

Question 3

example of signalling molecules altering morphology

Answer 3

hedgehog signalling- manipulation of Shh changes digit number, e.g. mice have 5 cows have 2
possibly related to patched- lower expression in cows and transgenic mice, suggests that wider influence of hh can change the number of digits

Question 4

example of changes in structural genes contributing to developmental changes

Answer 4

tunicate larva- found increased expression of notochord genes in larvae with a tailbud- gene regulatory changes

Question 5

example of a hypothesis-free approach to looking at developmental changes

Answer 5

the tunicate thing, differential gene expression at different stages

finch beaks- RNAseq or microarrays to track differences in beaks- shockingly, genes for long beaks are upregulated in finches with long beaks- 100 genes with this correlation

Question 6

example of a pathway being uncovered by hypothesis-free approaches

Answer 6

bird beak length- CaM gene associated w beak size in chickens, can activate a downstream effector and found changes in beak length