A Comparative Transcriptome Analysis between Wild and Albino Yellow Catfish (Pelteobagrus fulvidraco)

Abstract

Body colours are important and striking features for individual survival and reproductive success, in particular in vertebrates where mating behaviour and mate preference may be strongly influenced by non-normal phenotypes. Pigmentation disorders may be generated by disruption of one or many independent genes as well as by environmental factors. The first discovery of albino yellow catfish (Pelteobagrus fulvidraco Richardson) with golden skin colour from fish farms in China provides us valuable material to study the molecular mechanism underlying the abnormalities of pigmentation. In this study, transcriptome sequencing of fin tissues corresponding to the distinct body colours, wild type and mutant albino yellow catfish, were performed using Illumina sequencing technology. Based on next-generation sequencing technology and de novo assembly, we generated a transcriptome of P. fulvidraco. A number of genes differentially expressed between the wild types and albinos were identified, suggesting their contribution to the different phenotypes and fitness. However, non-synonymous mutations result from single nucleotide substitutions residing in coding regions may not contribute to such differences. Based on the high-throughput expression data generated for the two different types of P. fulvidraco, we found that alterations of expression pattern may be more common than non-synonymous mutations. The transcriptome of P. fulvidraco will be an invaluable resource for subsequent comparative genomics and evolutionary analyses of this economically important fish.

Molecular cloning and expression analysis of tyr and tyrp1 genes in normal and albino yellow catfish Tachysurus fulvidraco

“…Based on the transcriptome analysis of T. fulvidraco (Zou et al ., ), partial cDNA sequences of tyr and tyrp1 were obtained. Then primer pairs (Tyr‐F and Tyr‐R; Tyrp1‐F and Tyrp1‐R) (Table ) were designed to amplify the Open reading frames (ORF) of both tyr and tyrp1 by the following PCR conditions: initial incubation at 95° C for 3 min, then 35 reaction cycles were run‐each consisting of 30 s at 95° C, 40 s at 57° C and 1 min 12 s at 72° C. The final step was conducted at 72° C for 10 min.…”

“…Previous studies showed that differentially expressed genes and mutations might contribute to this colour variation. Five colour genes, namely tyr , tyrp1 , slc7a11 , mreg and ednrb1a , were identified as differentially expressed genes, but no single‐base substitution mutations were found in colour‐related genes (Zou et al , ). To further investigate the regulation of colour related genes tyr and tyrp1 in wild and albino T. fulvidraco , full‐length complementary (c)DNA of these two genes were cloned, and the messenger (m)RNA expression levels were examined in various adult tissues and at different embryonic and larval development stages.…”

Tracing key genes associated with the Pinctada margaritifera albino phenotype from juvenile to cultured pearl harvest stages using multiple whole transcriptome sequencing

“…For instance, in albino rainbow trout Oncorhynchus mykiss , the associated phenotype is characterised by a white or yellow skin according to the species [ 4 ]. Albino yellow catfish Pelteobagrus fulvidraco have been observed in control breeding in China [ 5 ]. Albino individuals have also been observed among aquacultured Russian sturgeons, one of the most valuable freshwater fish species worldwide [ 6 ].…”

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“…Body colour and colour patterns are important phenotypic characters in most of the vertebrates, which help for mate selection, species recognition, crypsis and warning or threatening of predators in a living environment (Zou, Zhang, Shi, Lin, Ouyang, & Zhang, 2015). Changes in the colour pattern often lead to misidentification of an organism in a closely related species.…”