Impact of Editing on Coat Pigmentation and Fresh Meat Color in Yorkshire Pigs.

The white coat color of Yorkshire pigs is caused by the dominant white allele, which has been associated with at least one copy of the 450-kb duplication encompassing the entire gene and a splice mutation (G > A) at the first base of intron 17. The splice mutation in has an adverse effect on pigmentation in mice. Therefore, removing the 450 kb duplications harboring the copy with splice mutations is expected to affect Yorkshire pig pigmentation.

Functional characterization of cAMP signaling of variant porcine MC1R alleles in PK15 cells.

The melanocortin 1 receptor (MC1R), encoded by the classical extension (E) coat color locus, is expressed on the surface of melanocytes and plays a critical role in switching melanin synthesis from pheomelanin (red/yellow) to eumelanin (black/brown). Different MC1R alleles associated with various coat color patterns in pigs have been identified over the past decades. However, functional analysis of variant porcine MC1R alleles has not yet been performed.

Functional Analysis of Gene Structural Mutations Causing the Porcine Dominant White Phenotype Using Genome Edited Mouse Models.

The dominant white phenotype in pigs is thought to be mainly due to a structural mutation in the gene, a splice mutation (G > A) at the first base in intron 17 which leads to the deletion of exon 17 in the mature mRNA. However, this hypothesis has not yet been validated by functional studies. Here, we created two mouse models, to mimic the splice mutation, and to partially mimic the duplication mutation of gene in dominant white pigs using CRISPR/Cas9 technology.

Bone Morphogenetic Protein 15 Knockdown Inhibits Porcine Ovarian Follicular Development and Ovulation.

Bone morphogenetic protein 15 () is strongly associated with animal reproduction and woman reproductive disease. As a multifunctional oocyte-specific secret factor, BMP15 controls female fertility and follicular development in both species-specific and dosage-sensitive manners. Previous studies found that BMP15 played a critical role in follicular development and ovulation rate in mono-ovulatory mammalian species, especially in sheep and human, but study on knockout mouse model implied that BMP15 possibly has minimal impact on female fertility of poly-ovulatory species.

Highly efficient correction of structural mutations of 450 kb KIT locus in kidney cells of Yorkshire pig by CRISPR/Cas9.

The white coat colour of Yorkshire and Landrace pig breeds is caused by the dominant white I allele of KIT, associated with 450-kb duplications and a splice mutation (G > A) at the first base in intron 17. To test whether genome editing can be employed to correct this structural mutation, and to investigate the role of KIT in the control of porcine coat colour, we designed sgRNAs targeting either intron 16 or intron 17 of KIT, and transfected Cas9/sgRNA co-expression plasmids into the kidney cells of Yorkshire pigs. The copy number of KIT was reduced by about 13%, suggesting the possibility of obtaining cells with corrected structural mutations of the KIT locus.