关于“贝种退化”问题的探讨

据称合浦珠母贝在养殖场“退化了”,“变小了”,是“近亲交配”引起的,这种说法已颇为流行,影响也很大。但是,在理论上还说明不了,也未曾见过有合浦珠母贝退化的研究报告。而且,在养殖场的人工育苗生产中,实际上已极大限度地避免了近亲交配,防止了近亲交配引起退化的可能性。所以,这种所谓“近亲交配”引起“退化”的说法,还缺少严格的科学实验根据。事实证明了,养殖的合浦珠母贝同野生个体的生长一样快,但生活环境不同对生长的影响较大,而在管养条件不良时生长最差。因此建议在生产中加强管养工作,育壮苗、养大贝、出好珠,也要加强基础科学知识的教育,促进合浦珠母贝养殖珍珠生产更好更快地发展。     

Inhibition of Alkaline Phosphatase from Pearl Oyster Pinctada fucata by o-Phthalaldehyde： Involvement of Lysine and Histidine Residues at the Active Site

Alkaline phosphatase from Pinctada fucata was inactivated by o-phthalaldehyde （OPA）. The inactivation followed pseudo first-order kinetics with a second rate constant of 0.167 （mmol/L）^-1·min^-1 at pH 7.5 and 25℃. A Tsou＇s plot analysis showed that inactivation occurred upon formation of one isoindole group. The OPA-modified enzyme lost the ability to bind with the specific affinity column and the presence of substrates or competitive inhibitors protected the enzyme from inactivation. The results revealed that the OPA-reaction site was at the enzyme substrate binding site. Prior modification of the enzyme by lysine or histidine specific reagent abolished formation of the isoindole derivatives, suggesting that lysine and histidine residues were involved in the OPA-induced inactivation. Taken together, OPA inactivated the alkaline phosphatase from Pinctada fucata by cross-linking lysine and histidine residues at the active site and formed an isoindole group at the substrate binding site of the enzyme.     

东亚钳蝎食性的研究

东亚钳蝎(Buthus martensii Karsch)肉食性,尤其嗜食活体小动物。人工养蝎通常以黄扮虫、地鳖为饲料。若以黄粉虫为饲料,分点碟放的投食方式明显优于撒放的投食方式。在蝎的活动期内,昼夜取食活动高峰视季节不同出现在19～21时或20～23时。但幼蝎也常见白天取食。季节旺盛取食期是5～10月,15℃时不取食,20℃少量取食,25～30℃大量取食,35℃取食量最大。蝎的耐饥力较强,但供食不足易引发自相残食。     

傅里叶变换红外光谱法对马氏珠母贝贝壳的研究

本文通过傅里叶变换红外光谱法对不同剖面层次的马氏珠母贝贝壳进行了研究。结果表明,马氏珠母贝贝壳的主要成分均为碳酸钙,并含有少量有机质。     

北海营盘马氏珠母贝养殖海域春秋季水化学环境参数变化特征

于2008年9月21日和2009年4月12日对北海营盘青山头马氏珠母贝(Pinctada martensii Dunker)养殖区进行春、秋两季水化学要素调查与测定。结果显示,营盘青山头南珠养殖区水质良好,各水化学要素符合海水水质二类标准;秋季活性硅酸盐与盐度成显著正相关(r=0.828),无机磷与pH值、活性硅酸盐与溶解氧、无机磷与叶绿素a都有较高的正相关趋势,春季营养盐与各环境因子的相关关系不显著;春季N、P和秋季N、P、Si含量持平或高于浮游植物摄食的最低阈值,其中秋季Si含量丰富;春、秋两季氮磷比平均值分别为7.0和5.5,均以氮为浮游植物摄食的限制因子;营盘马氏珠母贝养殖区的无机氮以氨氮的存在为主要形式,春、秋两季氨氮所占无机氮含量的比例最高,分别为56.6%和74.4%。     

海水珍珠分泌细胞在白云岩表面的沉积序列

采用“平板珍珠”研究方法,将白云岩平板插入和固定在马氏珠母贝Pinctadamartcnsij（Dunkcr）的内表面,获得不同阶段的平板珍珠、采用扫描电子显徽镜观察在平板珍珠形成过程中沉积序列,旨在阐明海水珍珠的形成机理。为开发新型珠核材料提供理论指导。     

腺病毒介导的BmK CT基因抑制神经胶质瘤U251细胞迁移及诱导凋亡的研究

以腺病毒为载体介导东亚钳蝎氯离子通道神经毒素(BmK CT)感染人脑神经胶质瘤细胞株U251,研究其对细胞迁移及凋亡的影响,并探讨可能的作用机制.首先以含BmK CT基因的腺病毒Ad-BmK CT及对应的腺病毒空载体转染U251细胞筛选出最佳感染浓度,随后利用Boyden Chamber实验和划痕实验检测了BmK CT对U251细胞迁移能力的影响,MTT检测了细胞存活能力,用Annexin V-Cy5和PI双标记流式检测分析细胞凋亡情况,并通过Western-blot检测凋亡相关蛋白分析可能的凋亡机制.结果显示,U251细胞感染Ad-BmK CT 48h后,迁移能力受到明显抑制;细胞变圆漂浮,Western-blot检测发现细胞色素c开始释放,caspase-3表达上调.     

Cloning, Characterization, and Expression Analysis of Calreticulin from Pearl Oyster Pinctada fucata

Calreticulin is a unique calcium-binding protein with multiple functions mostly located in the sarcoplasmic/endoplasmic reticulum. A large amount of calcium is absorbed from the medium and transported to mineralization sites during biomineralization in pearl oyster. This paper describes the cloning of the full-length cDNA of calreticulin from Pinctada fucata, namely PCRT. PCRT encodes a deduced 414-amino acid protein, which includes a predicted 17- amino acid signal peptide and an endoplasmic reticulum retrieval sequence HDEL. The protein shows 63%-76% sequence identity and shares some common characteristics with calreticulins from other species. Semi-quantitative RT-PCR indicates that PCRT is ubiquitously expressed in all tissues tested with the highest expression in the hemolymph and the mantle. In situ hybridization analysis of PCRT in the mantle showed strong signals in the inner fold, the inner side of middle fold, and the inner side of outer fold of the mantle epithelium, All these results suggest PCRT might be involved in Ca^2＋ transport and storage during oyster biomineralization.