Molecular basis of morphological evolution

Question 1

how common are changes to morphological evolution

Answer 1

• cis elements - common
• Protein sequence changes - common
• • one or more amino acid sequence changes, change in function, LOF, premature stop, change in splicing to -create non functional protein
• Transposable element insertion- occasional
• • can cause cis element change or disrupted protein
• miRNA regulation- occasional
• Methylation changes- rare

Question 2

describe 2 examples of the molecular basis of morphological evolution

Answer 2

1. size of domesticated tomatoes
   - fw2.2 gene codes for negative regulator of cell division that controls cell number
   - - less fw2.2= larger fruit
   - changes in nucleotide sequence in cis regulatory elements of domesticated tomatoes lower RNA expression levels
   - - example of a quantitative trait
2. Mcr1 gene and coat colour of mice
   - single amino acid difference ( arginine to cysteine)
   - - reduces receptor function in light coloured mice
   - mainland mice= high receptor function= brown
   - beach mice= low receptor function = light mice
   - able to blend into environment better