Associations of MC1R Substitutions With Body Color Variation in a Desert Lizard

Area of Science:

• Genetics and evolutionary biology
• Molecular biology
• Animal coloration

Background:

• Body color variation is common in animals.
• The melanocortin 1 receptor (MC1R) gene regulates pigmentation.
• Amino acid substitutions in MC1R can alter animal coloration.

Purpose of the Study:

• To investigate the association between MC1R gene variants and body color variation in toad-headed lizards (P. versicolor).
• To understand the molecular mechanisms underlying color differences between melanistic and non-melanistic lizard populations.

Main Methods:

• Obtained complete coding sequences of the MC1R gene in P. versicolor.
• Performed sequence analysis to identify amino acid substitutions.
• Conducted in silico structural analysis to assess the impact of substitutions on receptor-ligand binding.

Main Results:

• Identified two significant amino acid substitutions (V165I and V237I) in MC1R associated with color variation.
• Melanistic MC1R variants showed stronger binding affinity to α-MSH.
• Structural analysis indicated altered pocket size and improved binding characteristics in melanistic MC1R.

Conclusions:

• Amino acid substitutions in MC1R play a crucial role in regulating body color variation in P. versicolor.
• Enhanced MC1R binding to α-MSH likely promotes increased melanin synthesis in melanistic lizards.
• These findings offer insights into genotype-phenotype correlations in pigmentation.