Article

Genetic mapping of the dominant albino locus in rainbow trout (Oncorhynchus mykiss).

Department of Aquatic Biosciences, Tokyo University of Fisheries, Japan.
Molecular and General Genetics (impact factor: 2.63). 07/2001; 265(4):687-93. pp.687-93
Source: PubMed

ABSTRACT Albinism in animals is generally a recessive trait, but in Japan a dominant oculocutaneous albino (OCA) mutant strain has been isolated in rainbow trout (Oncorhyncus mykiss). After confirming that this trait is not due to a tyrosinase gene mutation that causes OCA1 (tyrosinase-negative OCA), we combined the amplified fragment length polymorphism (AFLP) technique with bulked segregant analysis (BSA) to map the gene involved in dominant oculocutaneous albinism. Four AFLP markers tightly linked to the dominant albino locus were identified. One of these markers was codominant and we have it converted into a GGAGT-repeat microsatellite marker, OmyD-AlbnTUF. Using this pentanucleotide-repeat DNA marker, the dominant albino locus has been mapped on linkage group G of a reference linkage map of rainbow trout. The markers identified here will facilitate cloning of the dominant albino gene in rainbow trout and contribute to a better understanding of tyrosinase-negative OCA in animals.

0 0
 · 
0 Bookmarks
 · 
19 Views
  • Source
    Article: Molecular cloning, gene expression in albino mutants and gene knockdown studies of tyrosinase mRNA in rainbow trout.
    Surintorn Boonanuntanasarn, Goro Yoshizaki, Kenichi Iwai, Toshio Takeuchi
    [show abstract] [hide abstract]
    ABSTRACT: Tyrosinase has a role in melanin synthesis and several defects of the tyrosinase gene lead to albinism. Here, we cloned and characterized rainbow trout tyrosinase cDNAs and carried out the molecular and biochemical characterization of albino mutants. Two types of cDNA were cloned: tyrosinase-1 (Tyr-1) and tyrosinase-2 (Tyr-2). Both contained regions predicted to encode structural features of tyrosinase, and phylogenetic analysis confirmed that Tyr-1 and Tyr-2 were members of the tyrosinase family. Tyr-1 transcripts were first detected in embryos at 5 d post-fertilization (dpf) and Tyr-2 transcripts at 15 dpf. 3,4-dihydroxyphenylalanine assays revealed significantly reduced tyrosinase activities in dominant and recessive albino mutants compared with wild-type embryos. However, reverse-transcription PCR showed no differences in the amounts or lengths of the coding regions of Tyr-1 and Tyr-2 transcripts between wild-type embryos and albino mutants. Antisense morpholino oligonucleotides (AMOs) designed to knockdown tyrosinase gene expression in wild-type embryos led to reduced pigmentation in the retina and skin of embryos at 25 and 35 dpf, respectively. Furthermore, the tyrosinase activities of AMO-treated embryos were significantly reduced. We conclude that both Tyr-1 and Tyr-2 are crucial for melanin synthesis in rainbow trout embryos. Furthermore, we describe a potential application of AMOs in the treatment of hyperpigmentation.
    Pigment Cell Research 09/2004; 17(4):413-21. · 4.29 Impact Factor
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.

Keywords

amplified fragment length polymorphism
 
BSA
 
bulked segregant analysis
 
cloning
 
dominant albino gene
 
dominant albino locus
 
dominant oculocutaneous albinism
 
dominant oculocutaneous albino
 
GGAGT-repeat microsatellite marker
 
linkage group G
 
OmyD-AlbnTUF
 
Oncorhyncus mykiss
 
rainbow trout
 
reference linkage map
 
tyrosinase gene mutation
 
tyrosinase-negative OCA
 

K Nakamura