Albinism-associated genes in Wels catfish (Silurus glanis), RNA-seq data

Albinism is a widespread departure from a typical body coloration due to altered melanin production. The Wels catfish (Silurus glanis) is among the largest freshwater fish species in the world, and albino individuals occur both in wild and in aquaculture. Here, we performed transcriptome-wide analysis of albino and normally pigmented S. glanis using four tissues (skin, dorsal fin, whole eye and liver) to identify genes associated with albinism by exploring patterns of differential expression (DE) and differential alternative splicing (DAS). Multi-tissue analyses revealed a large number of genes associated with albino phenotype in S. glanis. Several DE genes across multiple tissues were detected as most promising candidates (e.g. HPS4, HSP90B1, RAPH1, UQCRFS1, ADCY- and WTN-family) potentially causally linked to albino phenotype in Wels catfish. Moreover, our findings supported earlier observations of physiological differences between albino and normally pigmented individuals, particularly in energy metabolism and immune response. In contrast to regulation of gene expression, only very few genes showed DAS suggesting that alternative splicing is not linked with albinism in S. glanis. This work provides first transcriptome-wide insights into albinism of S. glanis and serves as a basis helping to understand the genetic mechanisms of pigmentation in fish.