Structure fine du rein de l'Epinoche (Gasterosteus aculeatus L.) au cours de sa transformation muqueuse

Résumé Pendant la période de reproduction, les néphrons du rein de l'Epinoche mâle subissent d'importantes modifications de structure sous l'action des hormones sexuelles. Au niveau de chacun d'entre eux, se différencient deux segments distincts par leur fonction et par leur cytologie. Le segment urinaire, très court, est formé de cellules identiques à celles du jeune, qui remplissent leur fonction d'excrétion. Le segment glandulaire, plus volumineux, subit une transformation muqueuse et élabore une sécrétion qui sert à construire le nid. L'évolution de ces deux segments est étudiée au cours de la période de reproduction et les modifications cytologiques correspondantes sont décrites.

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Fine structure of the kidney of the three-spined-stickleback (Gasterosteus aculeate L.) during its mucous transformation

Summary Under the action of sexual hormones the nephrons of the kidney of the male three-spined-stickleback undergo considerable transformations during the breeding period. They differentiate into two segments which differ from one another in function and cytology. The cells of the urinary segment are identical to those of the young fish. They have an excretory function. The glandular segment undergoes a mucous transformation and synthesizes a secretion which is used for the building of the nest. The cytological transformations occuring at the level of these two segments during the breeding period are described with special attention to the mucous cells.

     

Function of the cytoskeleton in cells with microridges from the oral epithelium of the carp Cyprinus carpio

Superficial cells of the oral mucosal epithelium in the carp and the cytoskeleton of the epithelial cells are examined by scanning and transmission electron microscopy. Microridges are formed on the surface of the epithelium. Epithelial cells contain two types of vesicles: mucous secretory vesicles and coated vesicles. Most of the mucous vesicles are situated in the center of the cell near the Golgi apparatus. In freeze-fracture replicas, intramembranous particles are abundant in the membranes of the secretory vesicles but rare in the apical plasma membrane. Coated vesicles are situated in the apical and subapical cytoplasm. A great number of thick filaments, considered to be keratin filaments, run randomly throughout the cell to form a meshwork. Thick filaments, which are sparse in the central cytoplasm, are connected to the membranes of the secretory vesicles and other membranous organelles. A layer of closely packed thin filaments, considered to be actin filaments, is found just beneath the apical plasma membrane. Microtubules also occur in the apical cytoplasm and run almost parallel to the cell surface. Both kinds of vesicles are connected to the thin and thick filaments. Their functional significance in the regulation of membrane at the free surface is discussed.     

Structural organization and epithelial cell types of the intestinal diverticula (protopancreas) of ammocoetes of southern hemisphere lampreys: functional and phylogenetic implications

Larvae of the two southern hemisphere lamprey genera, Mordacia and Geotria, possess one and two intestinal diverticula, respectively, each originating at the oesophageal-intestinal junction. These diverticula comprise an inner layer of simple columnar epithelium composed solely of zymogen and mucous cells, a middle layer consisting mainly of a blood sinus, and an outer serosa layer covered by a simple squamous epithelium (mesothelium). The inner surface is highly folded only in Mordacia. The secretion of mucus probably protects the epithelium from the effects of digestive enzymes secreted by the zymogen cells and/or bile, which enters the diverticulum at its tip. Unlike the situation in southern hemisphere lampreys, the zymogen cells of the larvae of holarctic lampreys are located in the anterior intestine, a condition considered to be primitive. It is thus proposed that intestinal diverticula were developed during the evolution of southern hemisphere lampreys. The relocation of zymogen cells in the diverticula increases the area for these cells, and thus the capacity for the synthesis and secretion of digestive enzymes, particularly in Mordacia where the inner surface is folded.     

Ciliary function of the frog oro-pharyngeal epithelium

Summary The palate epithelium of the frog was examined by scanning electron microscopy, light microscopy and high speed cine micrography. The cilia remain stationary for much of the time in the end-of-effective stroke position. Each beat cycle begins with a forwardly-directed recovery stroke lasting about 60 ms, followed by an effective stroke towards the oesophagus lasting about 12 ms. Activity can often be correlated with the presence of mucus, which is carried as strands on the tips of the ciliary effective strokes whilst the recovery strokes move beneath the mucus. Coordination of ciliary activity was very variable; local antiplectic metachrony of the recovery strokes could almost always be seen, and on very active epithelia effective strokes were associated with approximately diaplectic waves (either to left or right), but any particular pattern of coordinated activity was transient and quickly transformed to another pattern. Beating and coordination of these short cilia were compared with those of cilia propelling water.     

Fine structure of the organ of attachment of the teleost, Garra gotyla gotyla (Ham)

We describe the morphology of the attachment organ (AO) of the teleost, Garra gotyla gotyla (Cyprinidae). It is located ventrally around the mouth opening and used by the species for attachment to submerged rocks in sub-Himalayan streams and rivers where it lives. The AO consists of three crescentic parts and a central callus part. Scanning electron microscopy (SEM) shows the former to possess numerous tubercles, each of which bears about 23–27 curved spines. Light microscopy shows the epidermis of the tuberculated parts to possess one type of cell arranged into 7–8 rows. Transmission electron microscopy (TEM) reveals these cells to contain abundant tonofilaments (hence called the filament cells). The epidermis of the callus part possesses the filament cells and additionally mucous cells, which are absent in the tuberculated parts. The superficial epidermis is apparently keratinized (thickness: 5–8 μm), and a part of the cells of the outer row is modified into spines. These cells show a thick plasma membrane envelope and possess mucous granules (diameter: 0.1–0.3 μm) and bundles of tonofilaments. The cells of the inner two to four rows possess similar organelles and additionally, prominent Golgi bodies and rough endoplasmic reticulum. Immunohistochemically, the cells of the outer row and the spines stain positively for cytokeratin. The cells of the innermost rows (five to eight) possess few tonofilaments and no mucous granules. It is evident that the filament cells of the mid- to upper epidermis are specialized for the production of mucous granules and tonofilaments, which is unique for the teleost epidermis concerned. It appears that the tuberculated parts with spines assist in anchorage and interlocking with the substratum, while the central callus part probably utilizes both suction and frictional mechanisms, and mucous secretion protects the spines from damage during anchorage and abrasion.     

皱纹盘鲍外套膜、鳃和足粘液细胞的类型与分布

以阿新兰和过碘酸雪夫氏反应(AB．PAS)染色法显微观察皱纹盘鲍(1taliotis discus hannai)的外套膜、鳃和足的粘液细胞。根据所显示颜色的不同,可将粘液细胞分为Ⅰ～Ⅳ4种类型：分别呈红色、蓝色、紫红色和蓝紫色。外套触手和外套膜上皮的粘液细胞以Ⅱ型为主,Ⅳ型较少,密度不均,多为近圆形细胞,大型和小型细胞均有分布。鳃轴和鳃叶上皮的粘液细胞密度较大,以Ⅱ型和Ⅰ型为主,Ⅲ型和Ⅳ型较少,形态有杯形、近圆形或棒状等,多为中型及小型细胞。足的上皮粘液细胞较少,均为Ⅱ型,但局部上皮的细胞含有许多棕色颗粒。     

滑鼠蛇的繁殖输出及孵化热环境对孵出幼体表型特征的影响

用15条2002年6月中旬捕自浙江丽水的怀卵滑鼠蛇研究繁殖输出及孵化热环境对孵出幼体表型特征的影响。母体在捕后3周内各产一窝柔性卵。窝卵数、窝卵重和卵大小均随母体体长增加而增大,平均值分别为13．3(枚卵)、332．4g和24．8g。窝卵数和卵大小的变异系数分别为0．18和0．13。窝卵数与产后母体状态呈正相关,卵数量和大小无关。每窝部分可孵卵分别用恒温(24、27、30、33℃)和21．0-39．0℃(平均28．3℃)范围内的波动温度孵化,每隔5d记录恒温孵化卵的重量。孵化热环境对卵与环境之间的水分交换有显著影响,并影响孵化卵重量的时间变化。24、27、30、33℃和波动温度的平均孵化期分别为105．4、78．0、57．8、51．3和58．6d。不同热环境下的孵化成功率和幼体畸形率有一定差别,但统计上不显著。24℃和30℃孵出幼体雄性比例较高,27℃、33℃和波动温度孵出幼体雌性比例较高,但没有证据表明孵化温度能决定滑鼠蛇性别。除孵出幼体灰分含量外,孵化温度对其它幼体特征均有显著影响。33℃孵出幼体SVL较小,但剩余卵黄和其中的灰分含量大于其它温度孵出的幼体。24℃和30℃孵出幼体的总干重、总能量、躯干干重、脂肪体干重总体上小于27℃和波动温度孵出幼体。24℃孵出幼体特征性具有最小的剩余卵黄,33℃孵出幼体则特征性地具有最大的剩余卵黄。24℃和30℃孵出幼体特征较为接近,27℃和波动温度孵出幼体较为接近。对9个幼体特征变量做主成分分析发现,第一和第二主成分共解释81．2％的变异。幼体SVL、湿重、干重、脂肪含量、能量、躯干干重和脂肪体干重在第一主成分有较高的正负载系数(解释56．9％变异),剩余卵黄干重在第二主成分有较高的正负载系数(解释24．3％变异),第一和第二主成分的分值均差异显著。主成分分析进一步显示,24、30和33℃孵出幼体总体上小于27℃和波动温度孵出幼体[动物学报50(4)：541-550,2004]。     

N-乙酰氨基葡萄糖残基在发育鼠胃底腺颈粘液细胞中的表达

目的 通过大鼠在不同发育阶段中胃底腺细胞表达α-N-乙酰氨基葡萄糖（GluNAc)残基的情况,来研究大鼠胃底腺颈粘液细胞的发生。方法 利用单克隆抗体HIK1083能特异性识别α-GluNA残基的特点,进行免疫组化研究。结果 HIK1083阳性细胞从第19.5天胚胎鼠的胃底腺中开始辨认出来,一直存在至成鼠,这些细胞最初出现在胃底腺的底部,然后向上方移动,最后位于腺体的颈部。结论 胚胎晚期开始表达α-GluNAc残基的细胞可能是原始的颈粘液细胞,随着鼠胃底腺的发育。这些细胞逐渐向上方移动,最终成为颈粘液细胞。     

短蛸外套膜和足粘液细胞的类型及分布

采用阿新兰与过碘酸雪夫氏反应(AB-PAS)染色法对短蛸(Octopusocellatus)外套膜和足各部位粘液细胞进行分类及分析。将粘液细胞分为Ⅰ~Ⅳ4种类型:分别呈红色、蓝色、紫红色和蓝紫色。胴体部背面和腹面的外套膜外表皮均有4种粘液细胞,以Ⅲ型和Ⅳ型粘液细胞为主,背面粘液细胞密度较小,腹面的密度较大。腕上皮皱褶处粘液细胞密度较大,其他大部分区域粘液细胞密度较小,以Ⅱ型为主,另有少量Ⅲ型和Ⅳ型粘液细胞;吸盘外上皮含有大量的粘液细胞,也以Ⅱ型为主。漏斗内外上皮粘液细胞密度较大,基部以Ⅱ型为主,其他部位则以Ⅲ型为主。通过对各部位粘液细胞的分类和比较,可以看出粘液细胞的分布和类型与其所在部位执行的功能有密切的联系。     

两种海马鳃组织和消化道的黏液细胞类型及分布

运用阿新兰(AB,pH 2.6)和过碘酸雪夫氏(PAS)反应染色方法,对三斑海马(Hippocampus trimaculatus)和日本海马(H.japonicus)鳃组织与消化道中的黏液细胞类型及分布进行了研究。染色结果显示:两种海马的鳃组织和消化道中均含有黏液细胞,日本海马的鳃组织中含有Ⅰ型和Ⅳ型黏液细胞,三斑海马的鳃组织中含有Ⅰ型、Ⅲ型和Ⅳ型黏液细胞。两种海马消化道各部位的黏液细胞类型和数量有明显差异:日本海马的食道中Ⅰ型细胞最多,而三斑海马的食道中Ⅳ型细胞最多;日本海马的前肠中只含有Ⅰ型细胞,而三斑海马的前肠中含有Ⅰ型、Ⅲ型和Ⅳ型细胞,其中Ⅰ型细胞含量最多;日本海马的中肠中含有Ⅰ型、Ⅲ型和Ⅳ型细胞,其中Ⅲ型细胞含量最多,而三斑海马中肠中只含有Ⅰ型细胞;日本海马与三斑海马的后肠中都分布有Ⅰ型、Ⅱ型、Ⅲ型和Ⅳ型细胞,两者不同的是,日本海马的后肠中Ⅲ型细胞含量最多,三斑海马的后肠中Ⅳ型细胞含量最多。