Mu Changkao

Expression screening and annotation of Sepiella maindroni ink sac cDNA library

Sepiella maindroni is a high-valued cuttlefish, which is one of the most favorite Chinese seafoods. When stimulated, the cuttlefish squirts out ink which is of interest as it offers an excellent model for understanding melanin formation. The peculiar ink defence system of the cuttlefish S. maindroni is based on the activity of the highly specialized ink gland which continuously produces insoluble black melanin pigment that is stored in the ink sac (Palumbo et al. 1994; Palumbo 2003; Fiore et al. 2004). Construction of cDNA library provides basic information for finding relevant genes and identifying their functions. A cDNA library can be used not only to screen the target genes required, but also to express the genes (Clifton and Mitreva 2009; Frentiu et al. 2009; Luo et al. 2010). Expressed sequence tags (ESTs) are necessary resources for gene discovery and for the development of polymorphic DNA markers, such as microsatellites and single nucleotide polymorphisms (SNP). (D’Agostino et al. 2007; Malde and Jonassen 2008). Significant EST resources have been developed for many aquaculture species including mollusks such as Crassostrea gigas, C. virginica, Argopecten irradians, Tegillarca granosa and Pinctada martensii. However, there is no information available for cephalopods in ESTs database. For organisms with poor genetic background, the ease and relative economy of partial sequencing of cDNA library can be a highly productive way to generate a great deal of information about genetic and functional genes (Rudd 2003; Bao and Lin 2010). The aim of this study was to create a cDNA library for the analysis of ESTs and to indentify genes related to melanogenesis.

CO 2 驱动海洋酸化对三疣梭子蟹( Portunus trituberculatus )幼蟹甲壳结构和组成成分的影响

大气中过量的CO2溶解到海水中造成海洋酸化，破坏了海水原有的酸碱平衡和碳酸盐溶解平衡。甲壳类动物甲壳的形成过程依赖于海水正常的酸碱平衡和碳酸钙溶解平衡。本研究以三疣梭子蟹幼蟹为研究对象，采用CO2与空气的混合气体对自然海水进行曝气，模拟在现有CO2排放速度下，本世纪末和下世纪末海洋酸化的程度（表层海水pCO2分别为750μatm，1500μatm），研究不同海洋酸化程度对三疣梭子蟹幼蟹甲壳结构和组成成分的影响。结果发现，海洋酸化导致：（1）三疣梭子蟹幼蟹甲壳上表皮的外表面微刺排列趋于简单化，由2-3个微刺为主要排列形式逐渐变为单个微刺排列的形式；（2）甲壳厚度变薄，甲壳厚度从正常海水对照组（pH 8.13±0.02）90.20±4.85μm，变薄到OA1组（pH 7.98±0.02）84.53±13.71μm，再到OA2组（pH 7.75±0.03）61.94±13.43μm，并且有随海洋酸化程度加重厚度变得更薄的趋势；（3）随着酸化程度的加深，甲壳中甲壳素含量显著上升，从对照组（13.10±0.07）%上升到OA1组（14.22±0.04）%，再到OA2组（14.30±0.06）%（P=0.000**）；（4）甲壳中钙、镁元素含量及钙镁比没有明显变化。结果表明海洋酸化对三疣梭子蟹幼蟹甲壳的结构和甲壳素含量产生了较大影响。