【摘要】 cDNA基因芯片技术已广泛应用于生物物种间功能基因组和表达谱学研究。然而,鱼类基因芯片开发和应用相对落后。为了筛选与肉质性状相关功能基因,本研究首次试用异源斑马鱼基因cDNA芯片,对两种肉质性状明显差异的鳜鱼和鲢鱼肌肉组织中基因表达进行了比较分析。从两种鱼肌肉组织中提取总RNA,经Biotin荧光标记与拥有15617个cDNA片段的斑马鱼基因芯片(Affymetrix)杂交后,检测出375个表达基因。与鲢鱼比较,鳜鱼肌肉组织锁定的基因中有180个上调表达基因和195个下调表达基因。在鳜鱼肌肉组织180个上调基因中,49个为已知功能基因,131个为未知功能基因。根据基因文库同源功能基因分析,我们将49个已知上调基因按功能大约分为七大类,其中与肌肉结构相关基因包括肌球蛋白重链基因(MYH)、肌纤维间连接基因和细胞骨架结构基因等。同时,我们对与肉质结构性状密切相关的功能基因进行了分析,并结合与鳜鱼优良肉质结构和功能基因表达关系进行了讨论。更多还原

【Abstract】 The mandarin fish has been recently becoming one of the most important aquaculture fish species in China because of its good meat quality and protein composition.Improving the production of these fish is a continuing goal of the aquaculture industry,and a better understanding of the molecular control of the muscle structure and development in this commercially important species could prove beneficial for more economic rearing and quality of production.Therefore,we intended to investigate what genes control the development of large amount of high-quality white muscle in this species,which may provide foundation for the understanding of its myogensis and information to refine musculature for aquaculture. cDNA microarray is a powerful tool for the assaying of an organism’s gemone and expression profiles.However,it is relatively behind in fish because limited arrays available.In order to obtain the gene expression profile and screen differentially expressed genes in muscle tissues in the mandarin fish,we applied the Affymetrix zebrafish cDNA microarray heterolously hybridized to both the madarin fish,Siniperca chuatsi and the silver carp,H.molitrix.Total RNAs were isolated from the muscle tissues of the two species of fish and labeled with biotin,and hybridized to Zebrafish cDNA gene chips.Hybridized microarray chips were scanned with Affymetrix 418 Array Scanner.All expression signals from the hybridization to 15617 genes in zebrafish cDNA array were analyzed by R/Bioconductor software(http://www.bioconductor.org).Background correction and normalization were done by the methods of Robust multi-Array Average known as gcRMA in R/Bioconductor.Out of 15617 genes in Zebrafish cDNA chips,total of 375 genes were identified to be significantly expressed in the muscle tissues of the two fishes.Compared to the silver carp,180 genes are up-regulated and 195 are down-regulated in the madarine fish’s muscle tissues.Among the 180 up-regulated genes,49 genes are functionally known and 131 are unknown.The 49 known genes could be categorized into seven functional groups and several of them are considered as potential candidates related to the fish’s muscle structure and development.Several genes related to the muscle structure and meat textures were identified,including myosin heavy chain gene(MYH),myofiber linker gene(plectin) and cytoskeletal structure genes(tubulin and actin).In the mandarin fish,myosin heavy chain gene is expressed extremely higher at 32% than that in the silver carp(Tab.2) and this large amount of myosin heavy chain protein expression may reflect to the large abundance of high-quality white muscle in this fish.Plactin identified from mammalian muscle tissue is another gene directly related to muscle structure and it functions as a cytolinker to cytoskeletal proteins and signal transductor.Plactin was expressed 16.5% higher in the mandarin fish than that in silver carp(log2 ratio at 3.95/3.30).Titin gene was also highly expressed in both of the two fish.These results indicated that the muscle tissue of the mandarin fish was highly endurant and elastic.A cluster of genes functioning in cytoskeleton and dynamics including tubulin isoforms,actin and microtubule-associated protein genes were quite abundantly expressed in the muscle of the mandarin fish.This group of genes played important roles in muscle cell structure,cell division and material transportation.In comparison to the silver carp,both alpha-and beta-tubulin were expressed at 21% and 17% higher in the mandarin fish,which suggested that high amount of tubulin protein in muscle cells of the mandarin fish may be directly related to its muscle elastic feature.This is the first study using zebrafish cDNA microarray to heterogonous hybridization of other evolutionally far from fish species,and this information can be used to help select strains of high quality of muscular species for aquaculture industry and to provide a better understanding of gene expression profiles in relation to their biological functions in muscle tissue of different fish species.更多还原