The role of gene fusion and gene fission in the evolution of genetic complexity

Question 1

example- gene fusion in light perception

Answer 1

rhodopsin-guanylyl cyclase fusion event in B. blastocladiella, different type of light sensing mechanism enabled by gene fusion

Question 2

example- amino acid synthesis

Answer 2

shikimate pathway- pathway involved in amino acid biosynthesis, various levels of gene fusion across the tree of life
-e.g. 5 gene fusions in fungi, toxoplasma
-one fusion in plants (generally less fusion when genes are in plastids)

Question 3

what can drive gene fusions

Answer 3

-high linkage- co-inheritance
-co-transcription
-co-localisation and lack of intermediates

Question 4

benefits of gene fusion

Answer 4

-better pathway efficiency, e.g. substrate channelling (‘substrate flux’)
-can protect metabolic intermediates

Question 5

issues with inferring phylogeny from gene fusions

Answer 5

gene loss etc can obscure relationships
pathways can end up getting lost or replaced