现代生物技术在紫菜属中的应用

本文综述了近十年来国内外紫菜生物技术的发展与研究。在细胞生物学方面，介绍了紫菜原生质体制备、组织培养和细胞融合等技术，及其在新种质创建，工业苗种生产、单细胞活饵料开发和基因组操作等研究中的广泛应用，而细胞分光光度技术（MSP）和流式细胞技术（FCM）的加盟使得对紫菜细胞DNA的了解达到量化，快速分选细胞并实现对其生理代谢动态 观测，在生物化学方法中，讨论了用同工酶电泳技术来评价紫菜群体遗传结构、鉴别种质和描述系统发育等研究，以及利用生化方法对糖类等其它化合物进行提纯与测定等工作，在分子生物学方面；总结了如何获得高纯度DNA，并将其应用于DNA分析研究，RFLP、RAPD和DNA-序列测定等分子标记技术所揭示的紫菜的多态性，以及利用DNA-指纹和消减DNA文库的技术来构建紫菜的质体基因图谱和cDNA文库，并进行紫菜比较基因组学的研究，此外还介绍了紫菜基因转移方面的工作。     

BIOCHEMICAL GENETIC STUDIES ON CUTYLEFISH SEPIELLA MAINDRONI （CEPHALOPODA： SEPIIDAE）——ACTIVE LOCI SCREENING OF ISOZYME

Screening of 46 putative enzyme-coding loci and 4 different kinds of tissues of Sepiella maindroni de Rochebrone, 1884 for enzymatic activities using starch gel electrophoretic technique proved that the 21 enzymes such as AAT, AK, ALP, AP, CK, DIA, ES, FBP, G3PDH, GPI, GRS,IDH, LDH, MDH, MEP, MPI, NP, PGDH, PGM, SOD and XO* , were active to Sepiella maindroni after being stained. The tissue exhibiting stable and clear bands was also determined. Among tissues tested, mantle muscle tissue was the best for electrophoretic survey of isozymes. Buccal bulb muscle, eye and liver were fairly good for some special enzymes, such as DIA, ES, MPI, NT, etc.     

Biochemical, chromatographic and spectroscopic analyses of Suwannee River fulvic acid-Evidence for the presence of a DNA-like material

Naturally occurring organic compounds are complicated materials that are hard to fractionate into individual components. Organic materials from lakes, rivers and oceans often contain biological molecules related to proteins and DNA, and have global environmental and ecological importance. In this study, we used a combination of biochemical, chromatographic and spectroscopic methods to fractionate and characterize Suwannee River fulvic acid （SRFA） to determine if it contains proteins and DNA or DNA-like materials. A stock solution of SRFA （50 mg/mL） was prepared in double distilled deionized water. An initial biochemical analysis indicated that SRFA contained approximately 2% protein by weight, as determined by Bradford method using bovine serum albumin as standard. In order to determine the presence of DNA-like materials, a portion of the SRFA sample was extracted for DNA using chloroform/phenol extraction and ethanol precipitation method. When ethanol precipitated fraction was separated by agarose gel electrophoresis along with known DNA markers, a diffused ehthidium bromide staining was observed throughout the lane containing SRFA sample with a strong staining observed at the dye front, suggesting the presence of DNA or ＂DNA-like＂ molecules of various sizes in SRFA. To further fractionate, the DNA-like material on the gel was cut into seven fractions, each of which was extracted into aqueous phase. These fractions, along with the fractions obtained similarly from the original SRFA and an interface material during chloroform/ phenol extraction, were analyzed using UV-vis and fluorescence spectrometers, and LC/UV/MS. Comparisons of the absorption, fluorescence and mass spectra of various fractions revealed significant differences in their spectral properties. The DNA extracted materials showed stronger absorption in the DNA range of -260 nm than the original SRFA and interface material.     

湘黔地区下寒武统黑色岩系型镍钼矿床中磷结核的成分特征初步研究

对湘黔地区下寒武统黑色岩系底部镍钼矿床中磷结核的成分进行了电子探针分析。根据20个磷灰石成分的测定结果,得出Ca/P变化范围为1.36~1.710,平均值为1.605,认为磷结核中磷灰石类型为羟磷灰石,成因类型为生物化学沉积型。磷结核中Na+,Fe2+,Al3+,La3+,Sm3+,Ce+,Cr3+,Ti4+的含量较高,并且均显示了异常丰富的组合类型,如Na+和LREE。在1/4大小的磷结核横剖面上,存在着单核或双核沉积中心,结核的内部构造类型为不规则纹层状。磷结核从边部到中心的贵金属元素,其活性元素相对惰性元素的参数(Pd/Pt,Ag/Au,TD/SUHR)呈现同样的变化趋势。磷结核的外层是相对活性的元素,核部则为相对惰性的元素,部分相对活性的元素(如Pt,Pd,Ag)向外层发生初步迁移。铂族元素的超常富集归因于携带海底岩石物质的热水作用。     

Geochemical records of phosphorus in Jiaozhou Bay sediments-Implications for environmental changes in recent hundred years

Phosphorus is a key element and plays an important role in global biogeochemical cycles. The evolution of sedimentary environment is also influenced by phosphorus concentrations and fractions as well as phosphate sorption characteristics of the marine sediments. The geochemical characteristics of phosphorus and their environmental records were presented in Jiaozhou Bay sediments. Profiles of different forms of phosphorus were measured as well as the roles and vertical distributions of phosphorus forms in response to sedimentary environment changes were investigated. The results showed that inorganic phosphorus (IP) was the major fraction of total phosphorus (TP); phosphorus which is bound to calcium, iron and occluded phosphorus, as well as the exchangeable phosphorus were the main forms of IP, especially calcium-phosphorus, including detrital carbonate-bound phosphorus (Det-P) and authigenic apatite-bound phosphorus (ACa-P), are the uppermost constituent of IP in Jiaozhou Bay sediments. Moreover, the lead-210 chronology technology was employed to estimate how much phosphorus was buried ultimately in sediments. And the research showed that the impacts of human activities have increased remarkably in recent years especially between the 1980s and 2000. According to research, the development of Jiaozhou Bay environment in the past hundred years can be divided into three stages: (1) before the 1980s characterized by the relatively low sedimentation rate, weak land-derived phosphorus inputs and low anthropogenic impacts; (2) from the 1980s to around 2000, accelerating in the 1990s, during which high sedimentation rates, high phosphorus abundance and burial fluxes due to the severe human activities impacted on the whole environmental system; (3) after 2000, the period of the improvement of environment, the whole system has been improved including the decreasing sedimentation rates, concentration and the burial fluxes of phosphorus.