以次世代定序技術解析台灣常見三種養殖鰻魚 (日本鰻、鱸鰻、太平洋雙色鰻) 之轉錄體及探討其基因表現概況

Abstract

The Japanese eel (Anguilla japonica) is a commercially important aquaculture species in Taiwan. Because the full dependence of the glass eel supply caught from the wild for aquaculture, the available glass eel resource thus determines the sustainability of the eel aquaculture industry. In the past decades, glass eel abundances have been declining significantly, especially in the recent years. One piece of glass eel even costs as high as 200 NT dollars. This makes eel aquaculture industry suffer difficult condition. Therefore, the culture of other eel species becomes more and more popular during recent years. Abundant glass eels are imported from other countries, especially for the A. marmorata and A. bicolor pacifica. There are a total of 4 endemic eel species found in Taiwan, with Japanese eel and A. marmorata being the most common ones. The other 2 tropical eel species, namely A. bicolor pacifica and A. luzonensis, are rare in Taiwan. In present, the basic biological information of these aquaculture eel species, however, are still poor. In this study, we obtained transcriptome of A. japonica, A. marmorata and A. bicolor pacifica by Illunina HiSeq 2000. In each species, over 100 million reads were assembled into more than 200 thousand contigs (ave. length>800 bps). Over 40 % of contigs contain protein coding region. By KEGG pathway analysis, over 37% of contigs were annotated and involved in most KEGG metabolism pathway. A. marmorata and A. bicolor pacifica have similar gene expression patterns of digestive enzymes and may have similar dietary requirment, especially; the expression level of enzymes of protein is higher than A. japonica. It indicated that the requirement of protein for A. marmorata and A. bicolor pacifica is more than for A. japonica. In skeletal muscle analysis, slow muscle paly a major role in glass eel stage, and the expression level of gene of slow muscle is higher in A. marmorata and A. bicolor pacifica than in A. japonica. It suggested that the different expression level among three eel species may result in the difference of habitat usage. Thus A. japonica major lives in downstream and both of A. marmorata and A. bicolor pacifica are live in upstream. Finally, we constructed ANGEL database website, it may offer valuable information on biological research for scientists. The website opens to the world for free access. This can greatly increase the visibility of our science power on aquatic research.