Cloning and characterization of a novel albinism-related zinc finger protein gene in Japanese flounder

Abstract

A novel zinc finger protein (ZFP) gene of the Japanese flounder, Paralichthys olicaceus, has been isolated by differential mRNA display (DD). This technique was utilized to simultaneously compare the mRNA transcript populations from pigmented skins of the ocular side of normal Japanese flounder (termed N1 skin) and non-pigmented skins of the ocular side of albino Japanese flounder (termed A1 skin). A reproducibly differentially expressed band was isolated and cloned from N1 skin tissue. The isolated 917-bp DD fragment (termed EST917) was screened and sequenced. Sequence analysis of EST917 revealed that it contains a complete open reading frame and encodes a polypeptide of 123 amino acids (named ZFP123), with a predicted molecular weight of 13.293 kDa. Expression profile analysis by a reverse transcription-PCR (RT-PCR) technique revealed the expression of the ZFP123 gene in N1 skin and its lack of expression in A1 skin; it was expressed, however, in both blind sides of normal Japanese flounder (termed N2 skin) and the blind side of albino Japanese flounder (termed A2 skin) in a very similar manner. ZFP123 mRNA was found to be highly expressed in muscle, eye, brain and liver, but weakly expressed or undetectable in the gill and fat in both normal and albino Japanese flounders. The ZFP123 of the Japanese flounder shows a high homology to those ZFPs of other species, and the phylogenetic relationship among 14 sequences isolated from other species are illustrated.

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

“…Colour mutations are also a common phenomenon in fish, especially in tropical ornamental fish, such as in group of Cichlid fish [ 7 ], paradise fish ( Macropodus percularis ), swordtail ( Xiphophorus helleri ) and goldfish ( Carassius auratus ) [ 14 ]. Albinism has also been observed in medaka ( Oryzias zatipes ), as well as in grass carp ( Ctenopharyngodon idella ) [ 15 ], rainbow trout (Oncorhynchus mykiss ) [ 16 ], Japanese flounder ( Paralichthys olicaceus ) [ 17 ], black scabbard-fish ( Aphanopus carbo ) [ 9 ] and the channel catfish [ 18 ]. In most of these fishes, albinism is inherited either in an autosomal recessive manner or in an incomplete dominance manner [ 15 , 19 , 20 ].…”