皱纹盘鲍的染色体研究

本文报道皱纹盘鲍的染色体制备方法及核型分析结果。皱纹盘鲍的2n=36,可配为18对,中央着丝点(M)的11对,即1,3,6,7,9,11,12,13,14,16,17号染色体。亚中央着丝粒(Sm)的7对,即2,4,5 8,15,18号染色体,NF=72。染色体的长度呈连续递变。其中相对长度最长的1号染色体为7.09,最短的18号染色体4.11,单倍体总长687.05。     

Mammalian INO80 chromatin remodeler cooperates with FANCM to mediate DNA interstrand crosslink-induced checkpoint activation and repair

Chromatin regulators play crucial roles in the DNA damage response. While the chromatin changes needed for double-strand break repair and nucleotide excision repair have been intensely studied, the chromatin requirements of interstrand crosslink (ICL) repair have remained largely unexplored. Here, we studied the effect of silencing the INO80 chromatin remodeler subunits on the cellular response to ICLs. Cells depleted of Ino80 ATPase were more sensitive to mitomycin C (MMC) and defective in FANCD2 chromatin recruitment. Ino80-deficient cells displayed strongly reduced Chk1 phosphorylation after MMC treatment indicating impaired ATR-dependent DNA damage signaling, likely due to the significantly slower RPA foci formation which we observed in these cells. MMC treatment of cells silenced for FANCM - a protein required for ICL-induced checkpoint signaling, Ino80 or both genes simultaneously led to similar decreases in RPA phosphorylation suggesting that the two proteins were involved in the same checkpoint pathway. Co-immunoprecipitation data indicated that Ino80 and FANCM interact physically. Taken together our data demonstrate for the first time that the INO80 chromatin remodeler cooperates with FANCM to mediate ICL-induced checkpoint activation by promoting accumulation of RPA at the lesion sites. This constitutes a novel mechanism by which the INO80 chromatin remodeler participates in the repair of ICLs and genome integrity maintenance.     

皱纹盘鲍的个体能量收支

对皱纹盘鲍的呼吸、摄食、生长及能量收支等实验研究表明, 鲍的耗氧率与壳长、体重、温度及昼夜变化有关, 耗氧率与壳长、体重均呈幂函数关系, 一天中16~4时(夜间)耗氧率高于4~16时(白天)且在18~20时达峰值.同温度下鲍日摄食率与体重呈幂指数关系, 日(相对)摄食率随温度升高而增加, 而日相对摄食率、日相对生长率均随壳长、体重增加呈下降趋势.鲍在14~20℃内对海带的总转化效率为53%.鲍软体部、海带及鲍粪便干品的比能值分别为19.2、8.57和7.23kJ·g^-1.14~20℃皱纹盘鲍摄入能量的34.6~48.6%为粪能, 22.0~38.2%的能量用于自身代谢, 5.6~28.2%用于贝体软体部的生长.     

Chromatin Remodeling Factors Isw2 and Ino80 Regulate Checkpoint Activity and Chromatin Structure in S Phase

When cells undergo replication stress, proper checkpoint activation and deactivation are critical for genomic stability and cell survival and therefore must be highly regulated. Although mechanisms of checkpoint activation are well studied, mechanisms of checkpoint deactivation are far less understood. Previously, we reported that chromatin remodeling factors Isw2 and Ino80 attenuate the S-phase checkpoint activity in Saccharomyces cerevisiae, especially during recovery from hydroxyurea. In this study, we found that Isw2 and Ino80 have a more pronounced role in attenuating checkpoint activity during late S phase in the presence of methyl methanesulfonate (MMS). We therefore screened for checkpoint factors required for Isw2 and Ino80 checkpoint attenuation in the presence of MMS. Here we demonstrate that Isw2 and Ino80 antagonize checkpoint activators and attenuate checkpoint activity in S phase in MMS either through a currently unknown pathway or through RPA. Unexpectedly, we found that Isw2 and Ino80 increase chromatin accessibility around replicating regions in the presence of MMS through a novel mechanism. Furthermore, through growth assays, we provide additional evidence that Isw2 and Ino80 partially counteract checkpoint activators specifically in the presence of MMS. Based on these results, we propose that Isw2 and Ino80 attenuate S-phase checkpoint activity through a novel mechanism.     

皱纹盘鲍肠粘膜上皮的结构和功能

以透射电镜和扫描电镜观察、组织化学及酶活性测定等方法研究了皱纹盘鲍的肠和直肠,肠和直肠粘膜上皮由5种细胞组成。具微绒的柱状细胞呈现吸收细胞的超微结构特征,纤毛柱状细胞参与运输食物颗粒和粪便,Ⅰ型腺细胞具蛋白酶、非特异性酯酶和脂酶活性,以顶浆分泌形式分泌消化酶,Ⅱ型腺细胞分泌物可能与包裹粪便有关,状细胞分泌酸性粘多糖。体外酶活性分析表明肠和直肠粘膜上皮分别具有4种和3种植物多糖酶。     

皱纹盘鲍脓毒败血症的流行病学研究

在１９９２年９月到１９９５年１１月间,我们对辽宁、山东沿海数个皱纹盘鲍Ｈａｌｉｏｔｉｓｄｉｓ－ｃｕｓｈａｎｎａｉＩｎｏ．产区进行了实地调查和样本的细菌学检验,证实了鲍脓毒败血症的发生和流行遍布辽宁、山东沿海,发现：病原菌Ｖｉｂｒｉｏｃａｍｐｌｂｅｌｉ主要是在鲍的消化道内越冬的。海水温度是启动鲍脓毒败血症爆发、流行和结束的首要因子。在浮筏式养殖体系中,Ｖ．ｃａｍｐｂｅｌｉ主要是经由消化道感染鲍的。人工感染实验中,第一周内的死亡数占总死亡数的７０％以上。     

皱纹盘鲍一种球形病毒的感染及其发生

在发病的皱纹盘鲍（HaliotisdiscushannaiIno）幼鲍的足、内脏团、外套膜的血细胞质内,发现一种直径为90～140um的球形病毒粒子,带双层囊膜,无包涵体。负染病毒粒子与超薄切片大小形态相同。用被病毒感染的患病幼鲍感染健康鲍获同样症状,死亡率为50％。并于人工感染死亡鲍鱼体内观察到同样病毒。     

皱纹盘鲍伴侣蛋白CCTζ的分子克隆及其在不同锌含量日粮处理下的表达分析

伴侣蛋白CCT在蛋白折叠、抗胁迫以及调节细胞生长等生理过程中担负重要作用。研究利用同源克隆和RACE技术克隆了皱纹盘鲍伴侣蛋白CCTζ(HdhCCTζ)cDNA全长序列,并对CCTζ基因的序列特征进行了分析。HdhCCTζcDNA序列长1960 bp,开放阅读框为1599 bp,编码532个氨基酸,生物学软件推测其编码蛋白相对分子量为58.46 kD,等电点为6.53。BLAST分析结果表明HdhCCTζ与哺乳动物、鸟和鱼类等物种的CCT具有较高的同源性。生物信息学分析结果显示,HdhCCTζ蛋白序列中包含3个典型的CCT信号基序(35RTNLGPKGTLKML47,56LTKDGNVLLHEMQIQHP72和84QDDITGDGT92)以及1个腺苷三磷酸结合基序(89GDGTTS94)。此外,在HdhCCTζ蛋白序列中还包含3个糖基化位点(23NISA26,128NKSL131and234NVSL237)。实时荧光定量PCR检测结果显示,HdhCCTζ在皱纹盘鲍组织中为组成型表达,但主要集中在性腺、血淋巴和肝胰腺中表达。使用不同锌含量(6.69 mg/kg、33.85 mg/kg、710.63 mg/kg和3462.5 mg/kg)的日粮来饲喂幼鲍20周后,取其肝脏和血细胞总RNA,利用实时荧光定量PCR技术进行HdhCCTζmRNA的表达水平分析。分析结果显示,随着日粮中锌含量的增加,HdhCCTζmRNA在血淋巴和肝胰腺中的表达水平呈现上调的趋势。相比于锌适量组(33.85 mg/kg),过量的锌(3462.5 mg/kg)却能够下调HdhCCTζmRNA的表达水平。上述结果表明,HdhCCTζ的表达受到日粮中锌添加量的影响,而高表达量的HdhCCTζ可能在提高皱纹盘鲍机体抗胁迫过程中发挥重要作用。