Pig Coat Color Manipulation by MC1R Gene Editing

Area of Science:

• Genetics and Genomics
• Animal Breeding
• Molecular Biology

Background:

• Black coat color in pigs is controlled by the dominant MC1R (E) allele.
• Recessive MC1R (e) alleles result in non-black coat colors.
• Understanding MC1R gene mutations is key to coat color manipulation.

Purpose of the Study:

• To develop a gene editing method for manipulating pig coat color.
• To convert the recessive MC1R (e) allele to the dominant MC1R (E) allele in Duroc pigs.
• To investigate the effects of MC1R mutations on eumelanin synthesis.

Main Methods:

• Comparative sequencing of MC1R gene alleles (E vs. e) identified four missense mutations.
• CRISPR-mediated homologous recombination was employed to replace the 'e' allele with the 'E' allele at the MC1R locus.
• Genotyping was performed to confirm allele status and genetic background.

Main Results:

• MC1R-modified Duroc pigs exhibited a uniform black coat color.
• Genotyping confirmed a heterozygous E/e allele status at the MC1R locus in the modified pigs.
• The pigs retained their original Duroc genetic background post-modification.

Conclusions:

• CRISPR-mediated allele replacement is an effective method for pig coat color modification.
• This gene editing technique enables the creation of new pig varieties with desired traits.
• The study provides a valuable tool for the swine industry to meet diverse market demands.