铅在日本沼虾体内的分布和积累

应用组织化学、透射电镜和原子吸收光谱分析等方法,研究了Pb在日本沼虾各主要器官和组织中的分布和积累情况.结果表明,在浓度为0.625mg·L^-1Pb溶液暴露10d后的日本沼虾触角腺内,具有大量的电子密度较高的Pb颗粒.在电镜下细胞内的溶酶体中沉积有大量的Pb颗粒,这些Pb通过积聚,在细胞顶端部位逐渐增多,从而出现外排现象.中肠细胞内含有Pb颗粒,细胞质出现空泡化,核膜和线粒体内嵴部分解体.肝胰脏细胞内除分布有少量Pb颗粒外,细胞结构基本完整.在沼虾鳃细胞内未发现Pb颗粒,但在鳃丝之间发现少量Pb颗粒吸附在鳃丝的表面.原子吸收光谱分析结果表明,触角腺中Pb含量最高,达637.6mg·kg^-1;触角腺在Pb的解毒方面起着重要作用.     

金属铜在日本沼虾体内的分布和积累

应用组织化学、透射电镜和原子吸收光谱分析等方法,研究了铜在日本沼虾各主要器官和组织中的分布和积累情况。结果表明,在铜离子浓度为0.08 mg.L-1的溶液中暴露10 d后的日本沼虾肝胰脏内,具有大量的电子密度较高的铜颗粒,主要分布在肝胰脏的肝小管和R细胞中,在血腔中有从R细胞排出的铜颗粒;电镜观察发现铜主要分布在细胞内的溶酶体中,少量颗粒吸附在滑面内质网上;这些铜颗粒通过积聚,在细胞顶端逐渐增多,从而出现外排现象。中肠细胞内也分布有铜颗粒,细胞质出现空泡化,线粒体内嵴部分解体,并有铜颗粒附着在线粒体上。在触角腺中分布有少量的铜颗粒,触角腺细胞内的铜颗粒主要分布于溶酶体中,内质网出现弯曲。原子吸收光谱分析结果表明,肝胰脏中铜的含量最高,达到546.39 mg.kg-1,肝胰脏有储藏铜元素的功能。     

日本沼虾触角腺组织学的初步研究

利用石蜡切片技术对日本沼虾触角腺进行了组织学的初步研究。结果表明，日本沼虾触角腺可分为端囊、迷路和肾管三部分。端囊部分的细胞呈柱状，细胞核位于基部或中部；迷路部分的细胞也呈柱状，其顶端具刷状缘，核位于细胞的基部或中部，迷路部分可分为二个亚区；肾管部分的细胞柱状或较为扁平，核位于细胞顶端，肾管部分可分成三个不同的亚区。     

日本沼虾高尔基体在精子发生过程中的变化

用岸民镜技术研究了日本沼虾精子发生过程中生精细胞内高尔基体变化。结果表明：精原细胞内,高尔基体结构典型,分布在核膜附近,许多膜囊通过过连接小管相互连接。初级精母细胞内,高尔基体结构紧凑且更典型,更造近核膜,在反面的分泌活动旺盛,产生大量初级溶酶体;     

罗氏沼虾小触角表面结构的观察

罗氏沼虾的小触角是一类具附鞭的小触角。作者应用解剖镜和扫描电子显微镜观察了它的表面形态结构。发现它具有如下特征 :1)内、外鞭极长 ,外鞭另具一条附鞭 ,而附鞭很短 ,位于内外鞭之间 ;2 )柄节具 2 5 0根以上的羽状刚毛、少量的笋状刚毛与硬刺刚毛 ;3)内鞭、主鞭分节 ,各节前缘环行分布着 4— 4 0根不等的软刺刚毛 ;4 )附鞭系一凹槽结构 ,槽内约着生着 2 0 0多根化感刚毛 ;5 )附鞭能纵向卷曲成圆筒状 ,以包裹槽内的化感刚毛 ;6 )化感刚毛分两段 ,下为硬管段 ,上为膜管段 ,其中膜管壁极薄 ;7)凹槽近侧端的节段内还具有许多芽状的初生化感刚毛 ,它们可发育成化感刚毛。因此 ,罗氏沼虾小触角的表面形态迥异于以往报道的十足目甲壳动物小触角 ,其附鞭构成嗅觉器官的主体结构 ,且其本身具有独特的保护化感刚毛之方式。此外 ,作者按形态学特征将已报道的十足目甲壳动物小触角分为蟹型、龙虾型、小龙虾型和对虾型四种类型 ,而罗氏沼虾小触角则属于另一种类型———罗氏沼虾型。     

日本沼虾ITS1序列分析及SNPs位点的筛选

研究采用直接测序法,分析日本沼虾(Macrobrachium nipponense)rDNA基因内转录间隔区ITS1的DNA序列,以筛选日本沼虾SNPs位点。共分析了32个太湖水域野生日本沼虾样本,结果表明,日本沼虾ITS1序列平均长度为1749.8bp,是迄今已报道的最长的ITS1序列,A、G、T和C的平均含量分别为29.9%、28.3%、27.7%、14.0%,G+C的含量平均为42.3%。通过序列比对,共筛选出22个SNPs位点,SNPs位点出现频率为0.0126,其中9个为C/T转换(占40.91%),4个为A/G转换(占18.18%),2个为A/T颠换(占9.09%),5个为T/G颠换(占22.73%),1个为A/C颠换(占4.55%),1个A/T或C颠换(占4.55%)。日本沼虾ITS1序列的22个SNP位点中,21个位点为2个等位基因,1个位点出现了3个等位基因,为复等位基因位点。日本沼虾ITS1序列中还发现3个具有多态性的微卫星位点、1个高度变异区以及大量的缺失、插入。研究首次对日本沼虾ITS1序列进行了分析,并发现了大量的SNP位点,为日本沼虾遗传育种研究提供了新的分子标记。       

环境因子对日本沼虾消化酶和碱性磷酸酶的影响

研究了水环境中不同Ca2 + 浓度 (2 0、35、6 0、80和 15 0mg·L-1)、盐度 (7、14和 2 0‰ )和 pH(7 6、8 8和 9 8)对日本沼虾 (Macrobrachiumnipponense)肝胰腺中消化酶 (胃蛋白酶和类胰蛋白酶 )和碱性磷酸酶的影响 .结果表明 ,Ca2 + 对日本沼虾的胃蛋白酶有促进作用 ,Ca2 + 浓度为 15 0mg·L-1时酶活力最高 ;高浓度的Ca2 + 对类胰蛋白酶有抑制作用 ,而在一定范围内 ,碱性磷酸酶活力随Ca2 + 浓度的增高而增高 .盐度为 14‰时 ,日本沼虾的胃蛋白酶、类胰蛋白酶和碱性磷酸酶活力均高于 7‰和 2 0‰组 .随着 pH值升高 ,蜕皮率和 3种酶活力也随之增高 ,pH9 8时均达到最高值 ,但增长率和增重率则降低 .     

马氏沼虾蚤状幼体发育特征及其与罗氏沼虾幼体的形态差异

马氏沼虾(Macrobrachium malcolmsonii)的幼体从孵化到变态为幼虾要经过多次蜕皮,每次蜕皮均伴随形态及附肢特征的改变。采用显微观测摄像法对马氏沼虾Z1-Z12各期幼体样本30尾进行了观察,测量结果表明Z2与Z1在复眼上存在较大差异,Z3与Z2、Z4与Z5的主要分期特征均位于尾节上,Z6的腹部出现腹足萌芽,Z7与Z8的形态差异在于第一触角内鞭和外鞭的附肢变化,判别Z9-Z12的主要分期依据为步足、腹足和额角形态。因此通过观察Z1-Z12幼体第1触角上的内鞭和外鞭,第2触角上的触角鞭和触角片,头胸甲上的额角、背刺、复眼和第1、2对步足,腹部的附肢、尾节和尾扇等形态变化,及测定各期幼体附肢的分节数和刚毛数等可量性状上的差异,可为马氏沼虾蚤状幼体分期提供生物学依据;此外还对马氏沼虾与罗氏沼虾幼体的形态差异进行了比较,通过测定幼体触角鞭的分节数量,为两种沼虾幼体之间的鉴别提供参考数据。       

光Hongg毒腺的显微和超微结构

为探讨Hong类螯伤机理,用光镜和电镜观察了光Hong的毒棘腹外侧纵沟内的毒腺的组织结构,结果表明：光Hong的毒腺为鱼层上皮,从基底面到游离而依次为基底层,棘细胞层和嗜酸性细胞层,基底层细胞和棘层的细胞嗜碱性,棘细胞间有少量,散在分布的嗜酸性细胞;棘细胞的外层至腺上皮的游离面的嗜酸性细胞密集排列。电镜下可见基底细胞有丰富的核糖体,棘细胞内粗面内质网,高尔基复合体等较丰富,嗜酸性细胞内有电子密度低的膜包分泌颗粒;接近表面的细胞内颗粒部分融合;表层细胞核消失,胞质充满融合的颗粒,游离面侧的胞膜呈角质样增厚,腺上皮内还可见到黑色素细胞,郎格罕细胞和梅克尔细胞,提示毒腺组织内有两种类型的细胞,一类为毒液形成细胞,另一类为非毒液形成细胞,嗜酸性细胞内的电子密度低的膜包分泌颗粒成分可能是赞成螯伤剧痛及全身症状的关键因素。     

光魟毒腺的显微和超微结构

为探讨魟类螫伤机理,用光镜和电镜观察了光魟的毒棘腹外侧纵沟内的毒腺的组织结构。结果表明：光魟的毒腺为复层上皮。从基底面到游离面依次为基底层、棘细胞层和嗜酸性细胞层。基底层细胞和棘层的细胞嗜碱性,棘细胞间有少量、散在分布的嗜酸性细胞;棘细胞的外层至腺上皮的游离面的嗜酸性细胞密集排列。电镜下可见基底细胞有丰富的核糖体。棘细胞内粗面内质网、高尔基复合体等较丰富。嗜酸性细胞内有电子密度低的膜包分泌颗粒;接近表面的细胞内颗粒部分融合;表层细胞核消失,胞质充满融合的颗粒,游离面侧的胞膜呈角质样增厚。腺上皮内还可见到黑色素细胞、郎格罕细胞和梅克尔细胞。提示毒腺组织内有两种类型的细胞,一类为毒液形成细胞,另一类为非毒液形成细胞。嗜酸性细胞内的电子密度低的膜包分泌颗粒成分可能是造成螫伤剧痛及全身症状的关键因素。     

Autometallographical localisation of Cu and Zn within target cell compartments of winkles following exposure to Cu&Zn mixtures

This investigation attempts to determine the usefulness of autometallography to localise particular metals in certain key tissues of molluscs exposed to metal mixtures. For this purpose, winkles (Littorina littorea) removed from shell were exposed to very high concentrations of either copper (Cu), zinc (Zn) or a mixture of both metals (Cu&Zn) dissolved in sea-water for short periods of time. Protein-bound metals were detected by autometallography as black silver deposits (BSD) on histological sections of gills, foot, mantle, digestive gland/gonad complex, stomach and kidney. Copper was localised within cytoplasmic granules of gill ciliated cells, nephrocytes and stomach epithelial cells as well as within digestive cell lysosomes. Zinc was essentially found in the basal lamina (histological sense) of gill, stomach, kidney and digestive gland epithelia. BSD were also evidenced in cytoplasmic granules of pore cells present in parenchymal connective tissue of mantle, foot, gill, digestive gland and stomach. Copper and zinc concentrations were additionally calculated for the whole soft body as well as for certain organs by atomic absorption spectrophotometry (AAS). According to AAS, a synergistic phenomenon would contribute to increase the rate of Cu and Zn accumulation in presence of each other. However, after exposure to Cu&Zn autometallography did not evidence any synergistic phenomenon, and Cu and Zn were localised in their respective accumulation sites. In conclusion, autometallography might indicate the presence of certain metals in the environment irrespective of factors, such as "metal-metal interaction-like" phenomena, affecting metal concentrations in soft tissues.     

The uptake and storage of iron and lead in cells of the crayfish (Orconectes propinquus) hepatopancreas and antennal gland

The heavy metals iron and lead are taken up and metabolized in a similar manner by the crayfish hepatopancreas, but only lead appears to enter cells of the antennal gland (green gland). Iron, on the other hand, which apparently is not taken up by the antennal gland cells following systemic injections of low doses (0.05 mg), exerts striking alterations in cell ultrastructure after pericardial injections of massive doses (0.5 mg). Electron microscopic examination and atomic absorption spectrophotometric analyses of the hepatopancreas and antennal glands of iron-injected crayfish revealed that iron was selectively stored in metal-containing vacuoles of R- and F-cells in the hepatopancreatic cells, where it accumulated in concentrations that were toxic to these cells. High doses of iron caused alterations in the ultrastructural morphology of the cells of the antennal glands, although no accumulation of iron was apparent. Lead was similarly stored in metal-containing vacuoles of the cells of the hepatopancreas of lead-injected crayfish, but also accumulated in high concentrations (prior to being excreted) in vacuoles, cytoplasmic bodies and vesicles in the cells of the antennal gland. In contrast, lead in high concentrations was relatively non-toxic to any of these cells, suggesting that crayfish were more efficient in detoxifying and eliminating lead than iron.     

黄斑篮子鱼和金钱鱼鳃的扫描电镜观察

对两种鲈形目鱼类黄斑篮子鱼(Siganus oramin)和金钱鱼(Scatophagus argus)的鳃结构进行扫描电镜观察。结果表明,黄斑篮子鱼和金钱鱼鳃的表面结构及微细结构与其他硬骨鱼类基本相似,鳃丝表面都具有规则或不规则分布的环形微嵴、沟、坑、孔等结构。黄斑篮子鱼的鳃片中部鳃丝表皮有大量凸起,而端部鳃丝表皮的凹凸程度明显较低,黄斑篮子鱼的鳃小片高度较金钱鱼鳃小片高。黄斑篮子鱼和金钱鱼鳃上皮的扁平上皮细胞、氯细胞和黏液细胞的形态结构及数量分布存在细微的差异。黄斑篮子鱼鳃片鳃丝的端部和中部表面有黏液细胞,金钱鱼鳃丝表面的黏液细胞很难观察到,与大多数淡水鱼类相似。黄斑篮子鱼鳃丝表面分布的氯细胞数量多于金钱鱼,这可能与两种鱼生活环境、生活习性的长期演变相关。     

Gill‐derived glands in species of Astyanax (Teleostei: Characidae)

The presence of a gill‐derived gland is herein reported for the first time in males of species of Astyanax and related genera; they are described through histological cuts and SEM. The gill‐derived glands described for the Characidae, when fully developed, present a similar structure in different species. The main external feature of gill‐derived glands is the fusion of anteriormost gill filaments on the ventral branch of first gill arch. This fusion is caused by squamous stratified epithelial tissue that covers adjacent filaments, forming a series of chambers. In the region where the gill‐derived gland develops, the secondary lamellae of the gill filaments are much reduced or completely atrophied being characterized by the presence of glandular cells forming nests.     

Antennal ampullary glands of<Emphasis Type="Italic"> Helicoverpa zea</Emphasis> (Lepidoptera: Noctuidae)

In adult moths, the cephalic aorta terminates in an apical sack from which extends a pair of optic and antennal vessels that lie on either side of the esophagus, at the dorsoanterior surface of the brain. The base of each antennal vessel is dilated to form an ampulla that contains an oval mass of tissue, the antennal ampullary gland (AAG). An ultrastructural study revealed that the AAG of the corn earworm moth, Helicoverpa zea (Lepidoptera, Noctuidae), is composed of a single type of 40-50 parenchymal cells that produce secretory granules. The secretory material is released into the lymph channel of the ampullary vessel, suggesting that the AAG is an endocrine gland. Unlike the prothoracic gland and the corpus allatum, the AAG does not receive direct neural innervation; however, portions of the aortal muscle, associated with the ampullary wall, contain neurosecretory terminals and some of their products may also affect the AAG. No morphological differences were found between the AAG of males and females, with the exception that the glands in males were slightly larger. The function of the AAG remains unknown at this time. Because the AAG is located within the ampulla of the antennal vessel, one could assume that the product(s) of this gland may influence the response of the antennal sensory neurons to external stimuli.     

Characterization of mussel gill cells in vivo and in vitro

Mussel gill cells are attractive models in ecotoxicological studies because gills are the first uptake site for many toxicants in the aquatic environment; gill cells are thus often affected by exposure to pollutants. Our aim was to characterize mussel gill cells in vivo and in vitro by using morphological, histochemical and functional end-points. In paraffin sections stained with haematoxylin–eosin, three zones were distinguished in the long central gill filaments: frontal, intermediate and abfrontal. Various types of ciliated cells were present in the frontal zone, and both ciliated and non-ciliated cells were found in the abfrontal zone. The intermediate zone was comprised of flattened endothelial cells. Lipofuscin granules occurred in the three zones in variable amounts, depending on the specimen. Haemocytes were found in the haemolymph sinus of gill filaments. Mucocytes were identified in both frontal and abfrontal zones by means of periodic acid Schiff-alcian blue (PAS-AB) staining. In cryostat sections, succinate dehydrogenase (SDH) activity was mainly found in ciliated cells, whereas neutral lipids and acid-phosphatase-reactive lysosomes were present in all portions of the gill filament, mostly being related to lipofuscin granules. In mussels exposed to 5-bromo-2-deoxyuridine in vivo, proliferating cells were scattered throughout the gill filament. Gill cells (typically 2×10⁷ cells/ml per mussel; 95% viability) were isolated by dissociation with dispase. Gill cell suspensions were heterogeneous: 58% were ciliated epithelial cells (positive for SDH), 42% were non-ciliated cells (including epithelial cells and haemocytes), 2.3% were mucocytes (positive for PAS-AB) and 4.25% were haemocytes (able to phagocytose neutral red-stained zymosan). Gill cell cultures were maintained up to 18 days without changing the culture medium, viability decreasing below 50% at day 18. Primary cultures of mussel gill cells might therefore be useful models for the in vitro assessment of xenobiotic impacts on coastal and estuarine ecosystems.This work was funded by the Spanish Ministry of Science and Technology (project AMB99-0324), by the Basque Government through the Cooperation Fund Aquitaine/Euskadi 2001, by the University of the Basque Country through a grant to Consolidated Research Groups and by the European Commission (BEEP project, contract no. EVK3-CT2000-00025). Amagoia Gómez-Mendikute is the recipient of a predoctoral fellowship from the Spanish Ministry of Education and Culture.     

Blood and other possible inflammatory cells in the sparid Acanthopagrus australis (Günther)

The peripheral blood cells of Acanthopagrus australis include erythrocytes, elongated and rounded thrombocytes, lymphocytes, neutrophils and monocytes. The ultrastructure of lymphocytes, neutrophils and monocytes is described. Type 1 cells with characteristic elongated, eosinophilic granules and type 2 cells with rounded, apparently labile granules are common in the gill filaments and do not increase or decrease significantly in abundance in ectoparasite-infested gill filaments. Extravascular neutrophils tend to be more evident in pathologic tissue. Lymphocytes and the macrophage-like type 3 cells are the most abundant infiltrating cells in pathologic gill tissue. Apart from ultrastructural and histochemical data, granule length and width are sufficient criteria to distinguish between the neutrophil, type 1, type 2 and type 3 cells.     

Virus-like particles in venom of Meteorus pulchricornis induce host hemocyte apoptosis

Ultrastructural studies on the reproductive tract and venom apparatus of a female braconid, Meteorus pulchricornis, revealed that the parasitoid lacks the calyx region in its oviduct, but possesses a venom gland with two venom gland filaments and a venom reservoir filled with white and cloudy fluid. Its venom gland cell is concaved and has a lumen filled with numerous granules. Transmisson electron microscopic (TEM) observation revealed that virus-like particles (VLPs) were produced in venom gland cells. The virus-like particle observed in M. pulchricornis (MpVLP) is composed of membranous envelopes with two different parts: a high-density core and a whitish low-density part. The VLPs of M. pulchricornis is also found assembling ultimately in the lumen of venom gland cell. Microvilli were found thrusting into the lumen of the venom gland cell and seem to aid in driving the matured MpVLPs to the common duct of the venom gland filament. Injection of MpVLPs into non-parasitized Pseudaletia separata hosts induced apoptosis in hemocytes, particularly granulocytes (GRs). Rate of apoptosis induced in GRs peaked 48h after VLP injection. While a large part of the GR population collapsed due to apoptosis caused by MpVLPs, the plasmatocyte population was minimally affected. The capacity of MpVLPs to cause apoptosis in host's hemocytes was further demonstrated by a decrease ( approximately 10-fold) in ability of host hemocytes to encapsulate fluorescent latex beads when MpVLPs were present. Apparently, the reduced encapsulation ability was due to a decrease in the GR population resulting from MpVLP-induced apoptosis.     

Structures and immunolocalization of Na+, K+ -ATPase, Na+ /H+ exchanger 3 and vacuolar-type H+ -ATPase in the gills of blennies (Teleostei: Blenniidae) inhabiting rocky intertidal areas

The structure and immunolocalization of the ion transporters Na(+) ,K(+) -ATPase (NKA), Na(+) /H(+) exchanger (NHE3) and vacuolar-type H(+) -ATPase (VHA) were examined in the gills of teleosts of the family Blenniidae, which inhabit rocky shores with vertical zonation in subtropical seas. These features were compared among the following species with different ecologies: the amphibious rockskipper blenny Andamia tetradactylus, the intertidal white-finned blenny Praealticus tanegasimae and the purely marine yaeyama blenny Ecsenius yaeyamaensis. Light and electron microscopic observations indicated that thick gill filaments were arranged close to each other and alternately on two hemibranches of a gill arch in the opercular space of A. tetradactylus. Many mucous cells (MC) and mitochondrion-rich cells (MRC) were present in the interlamellar regions of the gill filament. An immunohistochemical study demonstrated that numerous NKA, NHE3 and some VHA were located predominantly on presumed MRCs of gill filaments and at the base of the lamellae. Analyses using serial (mirror image) sections of the gills indicated that only a few NKA immunoreactive cells (IRC) were colocalized with VHA on some MRCs in the filaments. In the gills of P. tanegasimae, NKA- and NHE3-IRCs were observed in the interlamellar region of the filaments and at the base of the lamellae. VHA-IRCs were located sparsely on the lamellae and filaments. In the gills of E. yaeyamaensis, the lamellae and filaments were thin and straight, respectively. MCs were located at the tip as well as found scattered in the interlamellar region of gill filaments. NKA-, NHE3- and VHA-IRCs were moderately frequently observed in the filaments and rarely on the lamellae. This study shows that the structure and distribution of ion transporters in the gills differ among the three blennid species, presumably reflecting their different ecologies.     

Gill-derived glands in glandulocaudine fishes (teleostei: Characidae: Glandulocaudinae)

The Glandulocaudinae is a subfamily of neotropical characid fishes from Central and South America. A unifying feature of the subfamily is the caudal gland, found almost exclusively in males. The gland consists of tissue on the base of the caudal fin covered in part by hypertrophied scales. Scale movement as the caudal fin is flexed appears to facilitate the release of chemical compounds from the glandular tissue. We describe here a different structure, found in the gill cavity of mature males in 12 of 17 glandulocaudine genera examined. Termed a gill gland, it develops as a male secondary sex character and appears morphologically suited to release chemical signals. The gland forms by the growth of tissue over and around 4-13 anterior gill filaments on the first gill arch, forming chambers with ventral openings. Within the gland chambers, gill secondary lamellae usually shorten and may disappear. When secondary lamellae persist, simple columnar epithelial cells develop between them. In the absence of secondary lamellae, the gland chambers are lined with a simple cuboidal or columnar epithelium. Gland size and the degree of gill modification vary among species. Gill glands appear absent in five glandulocaudine genera, suggesting character reversals based on current phylogenetic hypotheses and systematic classification. Gill gland morphology suggests that this structure releases chemical compounds into the gill current. The presence of gill glands only in mature males suggests a function in reproduction and/or male aggression. Together with studies of the caudal gland, this research suggests that chemical signals may play important roles in glandulocaudine reproduction.