鱼类甲状腺轴对胚胎发育、仔鱼变态及性别分化的调控作用研究进展

鱼类甲状腺轴由下丘脑、垂体、甲状腺组成,下丘脑通过分泌促甲状腺激素释放激素、促肾上腺皮质激素释放激素调节垂体促甲状腺激素的合成和分泌,促甲状腺激素促进甲状腺滤泡合成并释放甲状腺激素(主要为甲状腺素—T4),T4运输至肝脏等外周组织中,经过脱碘转化形成生物活性更强的三碘甲腺原氨酸(T3),T3主要通过同核受体结合发挥生物学功能。甲状腺激素对鱼类胚胎发育、仔鱼变态及性别分化等早期生长发育过程具有重要调控作用:甲状腺激素为鱼类胚胎发育期所必须,外加适量甲状腺激素能够提高胚胎或仔鱼存活率;仔鱼变态过程中,某些外部形态变化及相关组织分化依赖甲状腺激素的调控,牙鲆等仔鱼变态期体内甲状腺激素水平及其受体表达量会显著升高;性腺发育期,甲状腺激素对调控鱼类性别分化方向可能具有一定作用。     

甲状腺激素在鱼类繁殖中的作用

<正>甲状腺激素(Thyroid hormone,TH),包括三碘甲状腺原氨酸(T3)和四碘甲状腺原氨酸(T4),存在于所有的脊椎动物中。研究表明,TH对哺乳类和两栖类的早期发育和变态过程发挥着至关重要的作用,而在鱼类(尤其是鲆鲽类)的变态过程中,TH的调控作用更加明显[1,2]。近期研究发现,TH在鱼类发育的各阶段都起着重要的调节作用,其中对鱼类繁殖过程的调控作用尤为显著[3]。作者旨在阐述鱼类甲状腺的结构特征,及TH在鱼类繁殖过程中的作用。     

“中华碘泉”矿泉水的特征与开发

在山东省德州市首次探明国内稀有含碘饮用天然矿泉水──“中华碘泉”。研究表明,矿泉水是在新生代断陷盆地发育的构造背景和弱碱氧化的水文地球化学环境条件下,地下水与陆相沉积含水介质长期水岩反应中经溶滤形成的,属古老埋藏型封存水;矿泉水水量丰富、水质优良,为含碘小苏打型矿泉水,但氟含量偏高;为合理开发这一宝贵资源,可采用规模化含碘矿泉水的技术工艺来开发。     

羊栖菜假根培育再生苗技术

羊栖菜,系暖温带性海藻,营养丰富,经济价值高。它富含钙、碘,可滋补大脑,降低甲状腺激素的消耗,常食能健康、长寿。我国药典中记载:羊栖菜主治“痿瘤结气,利小便”;对“奔豚气、水气浮肿、宿食不化”等有治疗功效。羊栖菜的褐藻酸含量为20.48％(超过海带的褐藻酸含量),可作为工业原料应用于纺织、印染、食品、医药等工业。     

对矿泉水国家标准中碘指标界定的商榷——以“中华碘泉”为例

从理论分析入手，以“中华碘泉”含碘矿泉水为例，就国家饮用天然矿泉水标准中对碘指标的界定提出了初步商榷意见。指出，国标中的碘指标应标定“总碘（以Ｉ计）”较为适宜；而与国家匹配的检验方法中也应增补“关于碘酸盐的测定方法”     

“碘”——灵丹妙药

一提起碘,人们就会联想到海洋。的确,全球浩瀚的海水中,蕴藏着800亿吨碘,大海真是一座储量相当可观的碘库。对碘,人们并不陌生,但碘的神奇作用,并非路人皆知。不妨说开去,也许你会对它刮目相看。一个沉重的话题人称碘为生命元素、智慧元素、智能之花、聪明之泉。研究证明,碘是人类生长发育、智力发育、新陈代谢的重要微量元素,据称,缺碘是世界上已知导致人类智力损害的最主要原因。     

甲状腺激素受体在大菱鲆组织细胞中的表达及其与甲状腺激素的关系

为了探讨甲状腺激素受体在大菱鲆(Scophthalmus maximus)体内的表达情况及在细胞水平三碘甲状腺原氨酸(T3)对甲状腺激素受体(TR)表达量的影响,利用荧光定量PCR法检测了大菱鲆8个组织中甲状腺激素受体TRαA、TRβ的表达量,并设计了0,50,75,100和200 nmol/L 5个不同浓度的T3处理大菱鲆肾细胞(SMKC),采用实时荧光定量PCR法测定T3处理后甲状腺激素受体TRαA、TRβ的表达量。结果表明,甲状腺激素受体TRαA、TRβ在大菱鲆不同组织中的表达量各不相同,但两者均在肾脏组织中表达量最高。在不同浓度T3处理后甲状腺激素受体的表达量存在明显的差异,在低浓度条件下,TRαA、TRβmRNA的表达量增加,当T3浓度达到100 nmol/L时,TRαA、TRβmRNA表达量明显降低,说明50,75 nmol/L的T3能够引起细胞中甲状腺激素受体TRαA、TRβ表达量的增加,而100,200 nmol/L的T3会相对抑制细胞中甲状腺激素受体TRαA、TRβ的表达量。     

几种消毒剂对不同发育时期卤虫的影响

研究了几种常用的消毒剂（高锰酸钾、鲁歌氏碘液、新洁尔灭溶液、孔雀石绿）对山西两性卤虫不同发育时期的影响。结果表明：不同发育时期的卤虫对同一试剂有敏感性有明显的不同,其中后无节幼虫是最敏感时期;卡方检验结果表明,卤虫对所用试剂的安全剂量分别是：高锰酸钾≤１ｐｐｍ,鲁歌氏碘液≤１ｐｐｍ,新洁尔灭溶液≤２０ｐｐｍ,孔雀石绿≤０．２ｐｐｍ;由于不同试剂的药理作用不同,因此卤虫对不同试剂的耐受力,并不遵循一     

有机质和营养盐对海洋的污染

进入海洋的有机质,除一部分被动物摄取外,相当大一部分被分解为二氧化碳、水和营养盐等。由于营养盐是生物生长和发育各个阶段所必需的,因此在正常的海水中,加入适量营养盐可以促进生物的繁殖和生长。但是过量的营养盐进入海洋以后,反而会对海洋产生污染,造成严重的后果。所以现在有人把有机质和营养盐对海洋的污染称之为“富营养化”。 调查表明,有机质和营养盐对海洋的危害     

海藻中的碘

碘是自然界中的稀有元素，除动植体内含有一部分有机碘外，基本是以无机盐的形态存在。已有的研究表明，生物体的组成与生存的环境及营养条件有非常密切的关系。众所周知，海洋是“无机盐之宝库”，这直接影响了海洋动植体的化学组成。特别值得研究的是，海洋生物体内碘的分布最为典型地反映了生物体与生活环境的关系。基于国内外已有的研究成果，本文论及了海藻这一特定海洋植物中碘的化学形态及其分布特征。以此为借鉴，研究中国海藻中碘的化学特性，为更有效地利用海藻中的碘提供理论基础。１海藻中碘的分布特征由于海藻生长在海水这一特…     

Iodine in the surface water of the ocean

Iodine in sea water of the Pacific was determined with special interest in the relation between iodide and iodate in the surface water of the ocean. The result was discussed with reference to the mechanism of iodide formation proposed byTsunogai andSase. The concentration of iodide varies widely from the lower value than the detection limit to 0.21g at./l, while the concentration of total iodine is nearly constant and the mean value is 0.41g at./l. The vertical profile of iodide often shows the maximum in the surface layer. In the surface layer, the concentration of iodide is higher in warm water (0,10g at./l on the average) than that in cold water of lower temperature than 20° C (0.03g at/l). The highest concentration of iodide among the warm waters is found in the surface water of the equatorial area (0.13g at./l) where the biological productivity is also high. Iodide is generally more enriched in the water having higher biological activity even in the cold water. These results are considered to be compatible with the mechanism of iodide formation proposed.     

碘甲烷的海洋化学研究进展

评述了海洋环境中碘甲烷的来源、分布、迁移和转化等过程的研究进展,并探讨了该领域有待进一歩研究的问题.开展碘甲烷的海洋化学研究,有助于了解海洋中碘元素的生物地球化学循环及其对大气臭氧层的重要保护作用.     

Iodine in inshore and off-shore marine waters

The temporal variation of iodate and total iodine in the Menai Straits and Irish Sea is discussed together with station data for the Atlantic Ocean. Surprisingly little temporal variation was found in either iodate or total iodine even though seasonal nutrient cycling occurred within these water bodies. The iodate concentrations of the temperate Atlantic Ocean, Irish Sea and Menai Straits surface waters were significantly different. These results, together with the known hydrology of the Menai Straits, make it likely that iodate-reducing substances present in terrestrial run-off will be responsible for relatively low iodate concentrations in shallow-seawaters, such as the Irish Sea. However, it is suggested that the low iodate concentrations of tropical surface waters are more likely to have a biological origin. The possibility that the marine iodine system is open to a thermo-dynamical interpretation, as some workers have suggested, is refuted in the case of temperate surface waters as well as deep ocean waters (>200 m). It is shown that existing analyses indicate that below 200 m at oceanic stations, iodate does not vary significantly with depth.     

Iodine chemistry in deep anoxic basins and overlying waters of the Mediterranean Sea

Iodate (IO₃⁻) is the predominant dissolved species of iodine in the oxygenated waters of the Mediterranean Sea. Iodide (I⁻) is present in significant quantities (up to 65 nM) in oxygenated waters in the photic zone and near the interface above the anoxic and saline Bannock Basin. Lesser quantities of I⁻ (< 10 nM) are found throughout the rest of the oxic water column. An additional unidentified dissolved iodine species is present immediately above the anoxic interface.Total dissolved iodine (ΣI) increases dramatically across the seawater/brine interface. Part of this increase is undoubtedly the result of the dissolution of iodine-rich evaporites during formation of the brine bodies at the Tyro and Bannock Basins. The vertical distribution of ΣI and other dissolved chemical species (particularly PO₄³⁻) in the Bannock Basin brine, however, suggests an additional, present-day, diagenetic source of dissolved iodine to the brine. Based on the increase in the concentration of the most soluble major ions across the seawater/brine interface, 5–7 μM of the 11.5-μM increase in ΣI concentration must be attributed to diagenesis.     

3种海带新品系含碘量的分析

从５０年代起 ,我国海带养殖业迅速发展 ,从北到南广泛开展了人工养殖。７０年代 ,中国科学院海洋研究所和水科院黄海水产研究所曾做过高碘海带新品系的培育工作 ,培育出两个既高产、含碘量又高的新品种８６０和１１７。但在长期推广过程中 ,这些品系的优良性状都不同程度地有所退化。因此 ,重新筛选、培育具有优良形态性状和高碘含量的海带品系 ,已成为一个较为迫切的问题。１材料和方法１．１实验材料作者对生长于青岛太平角海区的３个品系的海带进行了筛选 ,它们是ＳＤ２ ８，８２Ｊ Ｌ．ｇ．，ＡＤ ２ ８ ２，其中前两种是较纯的品系 ,…     

Dissolved Iodate and Total Iodine During an Extreme Hypoxic Event in the Southern Benguela System

Dissolved iodate and total iodine were studied in St Helena Bay, South Africa, during a period of acute hypoxia, following upwelling off Cape Columbine. Despite the generally high concentrations of chlorophyll α (10–30 mg m⁻³) total iodine concentration was essentially constant in the main part of the Bay, and similar to that found elsewhere in the oceans. Occasional, lower concentrations of total iodine (0·28 to 0·42 μM) were found with exceptionally high chlorophyll α concentrations (500 mg m⁻³) in shallow waters. In contrast, iodate was found to be reduced to iodide at both the surface and the bottom of the Bay. The implications of these changes are discussed, given that the surface waters reflect sustained eutrophication while the bottom waters are hypoxic as a result of the organic-rich sediment from the waters above.     

高光谱碘分子和双边缘多普勒测风激光雷达技术比较

对采用原子滤波器的激光雷达技术和双边缘技术的灵敏度和误差进行了详细的讨论。对于纯 Rayleigh散射 ,双边缘系统的灵敏度高于基于碘分子的激光雷达系统 ,而对于 Rayeigh- Mie混合信号 ,双边缘系统通过采用特殊工作点的办法 ,有效解决 2种信号响应不同的问题 ;但同时该工作点的选取使得系统灵敏度降低 ,误差增加。对于后向散射比不是很大 (<10 )的情况下 ,误差可以控制在1m/s以内 ,完全可以满足测量要求 ,因此对于对流层顶部和平流层测风很适合。基于碘分子的激光雷达系统利用碘分子的高吸收性对 Rayleigh- Mie信号有效的进行分离 ,并且灵敏度随着后向散射比的增加而增加 ,从而对底层大气的探测特别有利。