Coat colour largely determines the market demand for several cat breeds. The KIT proto-oncogene (KIT) gene is a key gene controlling melanoblast differentiation and melanogenesis. KIT mutations usually cause varied changes in coat colour in mammalian species. In this study, we used a pair of single-guide RNAs (sgRNAs) to delete exon 17 of KIT in somatic cells isolated from two different Chinese Li Hua feline foetuses. Edited cells were used as donor nuclei for somatic cell nuclear transfer (SCNT) to generate cloned embryos presenting an average cleavage rate exceeding 85%, and an average blastocyst formation rate exceeding 9.5%. 131 cloned embryos were transplanted into four surrogates, and all surrogates carried their pregnancies to term, and delivered 4.58% (6/131) alive cloned kittens, with 1.53% (2/131) being KIT-edited heterozygotes (KITD17/+). The KITD17/+ cats presented an obvious darkness reduction in the mackerel tabby coat. Immunohistochemical analysis (IHC) of skin tissues indicated impaired proliferation and differentiation of melanoblasts caused by the lack of exon17 in feline KIT. To our knowledge, this is the first report on coat colour modification of cats through gene editing. The findings could facilitate further understanding of the regulatory role of KIT on feline coat colour and provide a basis for the breeding of cats with commercially desired coat colour.

White coat pigmentation is a striking phenotype of many domesticated species and has various genetic controls. The Tianzhu White yak, an indigenous breed with a complete white coat, has fascinated Tibetans for centuries. However, the genetic basis of this trait remains unknown. Here, we conducted population genomics analysis and genome-wide association study based on the whole-genome sequencing data of 38 white and 59 non-white-coated yak. The results revealed the presence of KIT-linked Cs alleles characterized by the translocations between chromosomes 6 and 29 in all-white yak. Furthermore, structural variations showed additional duplications of the Cs alleles in white yak compared with colour-sidedness cattle. Interestingly, the Cs alleles associated with the white coat phenotype in yak were found to have introgressed from taurine cattle. Our findings unveil the shared genetic control of the white coat phenotype and its evolution in closely related bovine species.

The natural coat color is an important trait of vertebrate animals. For example, the coat color can help avoid harm to human beings caused by chemical dyeing, and it has economic significance for domestic animals. The bone morphogenetic protein 4 (BMP4) and its antagonist Noggin can regulate pigmentation and the generation of coat color in mice; thus, they may also regulate the coat color of Kazakh sheep. To gain mechanistic insight into this possibility, we determined the relative expression levels of BMP4 and Noggin in the skin of white and brown Kazakh sheep by quantitative real-time polymerase chain reaction (qPCR) and western blotting analysis. The localization of BMP4 and Noggin were detected by immunohistochemistry (IHC). The results of qPCR and western blot analysis demonstrated that the relative expression levels of BMP4 and Noggin in the skin of brown Kazakh sheep were significantly higher than those in white Kazakh sheep. Our IHC results showed that the BMP4 protein was expressed in the epidermis and root sheath of the Kazakh sheep skin. The Noggin protein was expressed in the epidermis, root sheath, hair shaft, and dermal papilla of the Kazakh sheep skin. These results provide a theoretical basis for additional studies regarding the association and mechanism of BMP4 and Noggin in coat-color formation in Kazakh sheep. These results may provide new methods for developing treatment strategies for pigmentation disorders and diseases.

The effects of storage duration on the seed germination and metabolite profiling of soybean seeds with five different coloured coats were studied. Their germination, constituents and transcript expressions of isoflavones and free fatty acids (FFAs) were compared using chromatographic metabolomic profiling and transcriptome sequencing. The seed water content was characterized using nuclear magnetic resonance (NMR) relaxometry. Results showed that dark-coloured seeds were less inactivated than light-coloured seeds. The aglycone and β-glucoside concentrations of upstream constituents increased significantly, whereas the acetylglucosides and malonylglucosides of downstream constituents decreased with an increase in the storage period. FFAs increased considerably in the soybean seeds as a result of storage. These results indicate that dark-coloured soybean seeds have better storability than light-coloured seeds, and seed water content plays a role in seed inactivation. It was concluded that there are certain metabolic regularities that are associated with different coloured seed coats of soybeans under storage conditions.

OBJECTIVE: Qingyu pig, a Chinese indigenous pig breed, exhibits two types of coat colour phenotypes, including pure black and white with black spotting respectively. Melanocortin receptor 1 (MC1R) and agouti signaling protein (ASIP) are two widely reported pivotal genes that significantly affect the regulation of coat colour. The objectives of this study were to investigate whether the polymorphisms of these two genes are associated with coat colour and analyze the molecular mechanism of the coat colour separation in Qingyu pig.
METHODS: We studied the phenotype segregation and used polymerase chain reaction amplification and Sanger sequencing to investigate the polymorphism of MC1R and ASIP in 121 Qingyu pigs, consisting of 115 black and 6 white with black spotted pigs.
RESULTS: Coat colour of Qingyu pig is associated with the polymorphisms of MC1R but not ASIP. We only found 2 haplotypes, EQY and Eqy , based on the 13 observed mutations from MC1R gene. Among which, Eqy presented a recessive inheritance mode in black spotted Qingyu pigs. Further analysis revealed a g.462-463CC insertion that caused a frameshift mutation and a premature stop codon, thus changed the first transmembrane domain completely and lost the remaining six transmembrane domains. Altogether, our results strongly support that the variety of Qingyu pig\'s coat colour is related to MC1R.
CONCLUSIONS: Our findings indicated that black coat colour in Qingyu pig was dominant to white with black spotted phenotype and MC1R gene polymorphism was associated with coat colour separation in Qingyu pig.

With the Illumina BovineSNP50K BeadChip, we performed a genome-wide association study (GWAS) for two pigmentation traits in a Chinese Holstein population: proportion of black (PB) and teat colour (TC). A case-control design was used. Cases were the cows with PB <0.30 (n = 129) and TC <2 points (n = 140); controls were those with PB >0.90 (n = 58) and TC >4 points (n = 281). The RM test of roadtrips (version 1.2) was applied to detect SNPs for the two traits with 42 883 and 42 741 SNPs respectively. A total of nine and 12 genome-wide significant (P < 0.05) SNPs associated with PB and TC respectively were identified. Of these, two SNPs for PB were located within the KIT and IGFBP7 genes, and the other four SNPs were 23~212 kb away from the PDGFRA gene on BTA6; nine SNPs associated with TC were located within or 21~78.8 kb away from known genes on chromosomes 4, 11, 22, 23 and 24. By combing through our GWAS results and the biological functions of the genes, we suggest that the KIT, IGFBP7, PDGFRA, MITF, ING3 and WNT16 genes are promising candidates for PB and TC in Holstein cattle, providing a basis for further investigation on the genetic mechanism of pigmentation formation.