Expression and contribution of microphthalmia-associated transcription factor to the melanin deposition in Liancheng white ducks

The present study investigates the expression of microphthalmia-associated transcription factor(MITF) and its contribution to the melanin deposition in Liancheng white ducks.Nested PCR was used to clone the MITF gene sequence from the skin tissue of female Liancheng white ducks.Ultraviolet spectrophotometry was used to detect the melanin deposition.MITF mRNA expression and melanin deposition in different tissues and organs were detected and their correlation was analyzed.The MITF gene(GenBank number: MG516570) was 1 323 bp in length,contains a complete CDS region(34-1 323 bp) and codes 429 amino acids with 100% homology to the MITF of Anas platyrhynchos and over 95% homology to those of Gallus gallus and Coturnix japonica.Genetic evolution analysis reveals a close relationship of Liancheng white ducks with A.platyrhynchos,and also to lesser extents with Anser cygnoides,silky fowl and G.gallus,as well as Sus scrofa,Ovis aries and other mammals.Real-time quantitative PCR(qPCR) analysis demonstrated that MITF was expressed in skin,gizzard,liver,kidney and muscle,and of these tissues,its expression was the highest in the skin tissue(skin>gizzard>liver>kidney>muscle).Ultraviolet spectrophotometry showed that melanin deposition was positively correlated with the MITF expression level in these five tissues and organs(P<0.05).Together,these results demonstrated a tissue-specific pattern of MITF expression and a positive correlation between MITF expression and melanin deposition,indicating that MITF expression may contribute to the melanin deposition in Liancheng white ducks.

Identifying a melanogenesis-related candidate gene by a high-quality genome assembly and population diversity analysis in Hypsizygus marmoreus

Hypsizygus marmoreus is one of the most important edible fungi in Basidiomycete division and includes white and gray strains.However,very limited knowledge is known about the genomic structures and the genetic basis for the white/gray diversity of this mushroom.Here,we report the near-complete high-quality H.marmoreus genome at the chromosomal level.Comparative genomics analysis indicates that chromosome structures were relatively conserved,and variations in collinearity and chromosome number were mainly attributed by chromosome split/fusion events in Aragicales,whereas the fungi genome experienced many genomic chromosome fracture,fusion,and genomic replication events after the split of Aragicales from Basidiomycetes.Resequencing of 57 strains allows us to classify the population into four major groups and associate genetic variations with morphological features,indicating that white strains were not originated independently.We further generated genetic populations and identified a cytochrome P450 as the candidate causal gene for the melanogenesis in H.marmoreus based on bulked segregant analysis (BSA)and comparative transcriptome analysis.The high-quality H.marmoreus genome and diversity data compiled in this study provide new knowledge and resources for the molecular breeding of H.marmoreus as well as the evolution of Basidiomycete.