Lecture 13 - Evolution and conservation of Hox gene function Flashcards
How does Gene duplication effect Pleitropy and event frequency?
- Minimises Pleitropy
- Infrequent events
How does Protein Sequence Evolution effect Pleitropy and even frequency?
- Pleitropic
- Frequent events
How does Cis-regulatory Sequence Evolution effect Pleitropy and even frequency?
- Minimises Pleitropy
- Frequent events
Give two examples of cic-regulatory evolution of a Hox gene. [2]
- Differences in trichomes on the T2 leg in Drosophila
- Changes in Ubx/Abda regulatory elements explains transitions in limbs number for butterfly prolegs
Give one example of cis-regulatory evolution of a Hox target gene. [1]
The formation of pigmented patterns
What controls the yellow expression in the developing wing and body
Separate cis-regulatory elements
What causes the dark posterior pigmentation in some Drosophila species?
ABD-B regulation of the yellow body CRE in D.melanogaster
Which species of Drosophila shows a loss of ABD-B regulation?
- D.kikkawai
- Has lost posterior pigmentation
[A] within groups has evolved around a common set of [B].
A - Diversity
B - Hox genes
What did Hexapods arthropods evolve from?
They evolved from
ancestral arthropods with many limbs
What promotes and represses the formation of limbs in Drosophila?
- Promotes: Distalless
- Repress: Ubx & AbdA
What effect does changing the Hox orthologs have?
Activates/Represses domains and morphological evolution
What effects do Antp, Ubx, and AbdA have on an organism?
They act to regulate the abdomen length
What is different between the expression of Ubx in Drosophila and Artemia?
Ubx represses larval limb in Drosophila but does not in Artemia
What can explain the reduction in limb number in the insect lineage?
Changes in the Ubx and AbdA proteins
