花背蟾蜍蝌蚪胃的发育形态学观察

应用大体解剖、组织切片和扫描电镜3种形态学方法对花背蟾蜍(Bufo raddei)蝌蚪在生长发育和变态过程中胃的形态结构变化进行了观察。结果显示,在蝌蚪发育24期(即G24)消化道呈简单的管状结构,胃与小肠等区分不明显,胃壁由内层矮柱状黏膜上皮细胞和其外的扁平上皮细胞层构成;直到26期胃略膨大,呈短粗管状,与小肠和食道可明显区分,胃壁内层的黏膜上皮细胞呈高柱状,上皮细胞间出现少量杯状细胞;36期的胃管明显膨大,其壁已具有胃的4层基本组织结构,杯状细胞数量增加,黏膜上皮细胞游离面有细长的微绒毛交织成网状覆盖;42期胃发育呈"C"字形,胃壁具备了消化道典型的4层结构,有胃腺芽出现,黏膜细胞的微绒毛短而直立,仅极少数细胞有长的微绒毛;蝌蚪发育到46期,肠道缩短,胃呈"J"字状,占消化道大部分,胃体中胃腺发达。在临近肝一侧,黏膜上皮细胞的微绒毛较短,胃腺少而小;而在相反一侧,微绒毛较长,胃腺多而大。基于上述结果说明,花背蟾蜍蝌蚪胃在36期已经基本完成了组织结构的分化,在变态发育期间结构和功能得到进一步完善,以适应变态后陆地生活的食性变化。     

复合肥对花背蟾蜍蝌蚪红细胞微核及核异常的影响

以花背蟾蜍蝌蚪外周血红细胞微核及核异常作为毒理监测指标,对Gosner 31、42和46期蝌蚪进行观察,研究了复合肥对水生生物的毒性效应.结果表明:用复合肥溶液浓度为1、1.5、2、2.5和3g·L-1进行染毒时,红细胞出现了大、小2种类型的微核,在核异常类型中出现了严重的核分叶和双核类型;在3个被观察的蝌蚪发育期中,42期蝌蚪红细胞微核细胞率和核异常细胞率数值明显低于其他两个发育期;在5个浓度的染毒中,2.5g·L-1浓度组在微核、双核和核分叶与对照组间无显著性差异;花背蟾蜍不同发育时期的蝌蚪,对生境中不良因素的抵抗能力存在着明显的差别,且微核和核异常与复合肥浓度之间没有明显的剂量-效应关系.     

大凉疣螈皮肤的组织学观察

对大凉疣螈Tylototriton taliangensis的皮肤进行了显微观察,结果表明,其体表不同部位皮肤的厚度存在一定差异,但基本结构相同.皮肤表面粗糙,表皮角质化程度较高.表皮与真皮相接处毛细血管丰富,毛细血管常向表皮突起,突起处表皮细胞层数减少,背部毛细血管密度大于腹部.皮肤中含有丰富的色素细胞,主要分布在真皮疏松层浅表.真皮中有丰富的皮肤腺:粘液腺体积较小,分布遍及全身,腹侧密度较大;颗粒腺体积较粘液腺大,主要分布在耳区、体背两侧及尾背侧,形成耳后腺、背嵴、尾部颗粒腺区等特殊结构.     

版纳鱼螈幼体和成体皮肤的结构

采用光镜和扫描电镜,对我国特有的珍稀濒危两栖动物版纳鱼螈Ichthyophis bannanicus幼体和成体的皮肤进行形态学和组织学观察.版纳鱼螈幼体和成体的皮肤均可分为表皮、真皮疏松层和真皮致密层;皮肤中含有粘液腺和颗粒腺;在不同发育阶段或同一个体的不同部位,其皮肤的各种组成成分在结构和厚度上存在着差异:成体和幼体都是头部的表皮最厚,尾部的最薄;幼体表皮各层细胞分化不明显,几无角化现象,成体表皮的各层细胞分化明显,表层细胞明显角化;成体躯干部皮肤最厚,头部最薄,幼体则是头部皮肤最厚,尾部最薄;幼体和成体的头部皮肤都分布有大量的粘液腺,颗粒腺分布较少;幼体的躯干部皮肤则主要分布着大量颗粒腺,尾部只有颗粒腺,未见粘液腺;成体躯干部和尾部皮肤均分布有大量的颗粒腺和粘液腺.     

西藏蟾蜍皮肤的组织学观察

为了解西藏蟾蜍Bufo tibetanus与其高海拔生活环境的适应性,采用常规石蜡切片和苏木精-伊红染色方法,对西藏蟾蜍雌雄性头部、躯干和四肢的背、腹侧皮肤显微结构进行了观察、测量和比较。结果显示皮肤的基本结构与已报道的无尾两栖类相似,由表皮和真皮组成。表皮较薄,由5~8层细胞构成,由外到内分为角质层、中间层和基底层。真皮较厚,分为疏松层和致密层。各部位大多表现为背侧皮肤厚度大于腹侧,相应部位大多为雌性大于雄性。皮肤厚度的变化在一定程度上与西藏蟾蜍运动方式和繁殖期间抱对行为相适应。皮肤腺体分粘液腺和颗粒腺2种。色素细胞主要分布在疏松层近表皮处,但在表皮和腺体周围也可见色素细胞的不连续分布。皮肤中毛细血管极其丰富,不仅在表皮下几乎成连续分布,而且在腺体周围也有密集分布。西藏蟾蜍皮肤结构明显表现出与生活环境中强紫外辐射和缺氧环境相适应的特点。     

爪鲵呼吸器官的胚后发育

应用石蜡切片和扫描电镜技术,对爪鲵(Onychodactylus fischeri)幼体、亚成体和成体3个不同发育阶段的皮肤、外鳃、咽等呼吸器官进行了显微观察与比较分析,旨在揭示爪鲵不同发育阶段各呼吸器官的演化规律.结果表明,爪鲵的皮肤随年龄的增长而逐渐增厚,幼体阶段其背腹皮肤厚度相差不大,亚成体及成体背部皮肤明显厚于腹部;外鳃是幼体和亚成体爪鲵呼吸器官的重要组成部分,随着发育外鳃逐渐完善,到亚成体阶段达到顶峰,随后逐步退化;咽部是爪鲵的重要呼吸器官,幼体期口腔和咽发育不完善,亚成体咽部逐渐发育,至成体时发育完善.     

中国林蛙消化管胚后发育的组织学观察

用解剖和组织切片技术对中国林蛙Rana chensinensis蝌蚪(23～46期)消化管的形态和显微结构变化进行观察比较.结果 表明,在中国林蛙幼体的胚后发育过程中,消化管长度从28期的37.0 mm逐渐增加至39期的95.3 mm,在变态过程中又缩短至22.0 mm.胃从42期开始膨大, 46期在位置和形态上与成蛙相似.消化管粘膜上皮逐渐完善,粘膜下层和肌层逐渐出现并加厚.胃腺、小肠腺以及杯形细胞在42～43期出现.说明林蛙消化管的组织结构特征与变态发育过程中食性的变化相适应.     

林蛙属3物种皮肤的组织结构比较

利用石蜡切片和H.E染色技术,对蛙科(Ranidae)林蛙属(Rana)高原林蛙(R.kukunoris)、昭觉林蛙(R.chaochiaoensis)和峨眉林蛙(R.omeimontis)的皮肤组织结构进行了观察。应用SPSS 13.0统计软件,对皮肤的厚度、皮肤腺的相对数量和面积作了比较分析。3物种皮肤的基本结构相似,都由表皮和真皮组成。表皮是角质化的复层扁平上皮,由角质层、颗粒层、棘细胞层和生发层构成。真皮又分为疏松层和致密层,疏松层内分布有黏液腺、颗粒腺和脂腺3种类型的皮肤腺,黏液腺在体背和体腹皮肤内基本均匀分布,而颗粒腺主要以团块聚集形式散布在体背皮肤中。在高原林蛙皮肤中还发现了1种与以往描述不同的特殊嗜酸性腺体。皮肤厚度存在种间差异和部位差异。高原林蛙的表皮里有少量毛细血管和发达的色素细胞分布,真皮疏松层里有发达的腺体,这些可能是其对高海拔、低氧、低温和强紫外线辐射生活环境的适应策略。在峨眉林蛙和昭觉林蛙皮肤真皮的疏松层和致密层相邻处,发现有呈波浪条带状的、H.E染色呈蓝色的钙化层结构,体背部的钙化层比体腹部的发达。钙化层的功能可能包括防止体内水分散失、贮存钙离子、构成与体外环境进行物质交换的屏障等方面。     

隆肛蛙皮肤及其腺体的显微结构特征

观察了隆肛蛙(Paa quadranus)皮肤及其腺体的显微结构特点,主要对成体、幼蛙和蝌蚪泄殖腔上方皮肤腺进行了描述和比较。结果表明,隆肛蛙的表皮和真皮内均分布有微血管及黑色素细胞;皮肤腺为泡状腺,腺泡位于真皮浅层的疏松层内,属顶质分泌的粘液腺;雄性成体泄殖腔上方皮肤腺是隆肛蛙的特有结构,属于雄性的第二性征,本文建议称其为肛上腺(supra-anal gland)。文中对肛上腺及其机能、表皮中微血管与皮肤呼吸、黑色素细胞与体温调节等之间的关系进行了讨论。     

花背蟾蜍蝌蚪皮肤在类坏死条件下超微结构的变化~*

已知发生类坏死的无尾两栖类蝌蚪皮肤,可加速被眼诱导为角膜的进程。采用弱酸(0.01N醋酸)和弱碱(0.001N氨水)处理花背蟾蜍蝌蚪皮肤使之发生类坏死,对比观察了正常和发生类坏死皮肤的超微结构,结果发现皮肤在类坏死条件下发生下列变化:(1)表皮细胞内的张力原纤维显得疏松,有变粗及聚集的现象,弱酸处理者更明显;(2)表皮细胞中细胞器减少,细胞质内出现大量液泡;相邻细胞的细胞间隙变狭窄;(3)表皮细胞核内的染色质分布不均匀,浓缩为较大的团块,使核内出现不规则的空隙;(4)基膜中胶原纤维明暗相间的条纹结构较模糊。文中对类坏死条件下皮肤超微结构的变化和加速角膜诱导进程间的可能关系进行了讨论。     

SD大鼠皮肤组织病理学观察

目的观察不同日龄SD大鼠皮肤组织学结构。方法10％甲醛固定,行石蜡切片,HE染色。结果新生大鼠皮肤较薄,透明层缺乏,皮脂腺发育良好。6月龄时表皮、真皮和皮下组织明显增厚,毛囊增粗,生长旺盛,毛囊深入皮下脂肪层。24月龄时,大鼠皮脂腺及汗腺萎缩,表皮变薄,真皮成纤维细胞、血管数量减少,弹力纤维变细。结论不同日龄SD大鼠皮肤组织学结构有差异。     

Development of integument and cutaneous glands in larval,juvenile and adult toads (Rhinella granulosa): a morphological and morphometric study

In this study, the development of integument and cutaneous glands in the toad Rhinella granulosa (Bufonidae) at different larval stages and in postmetamorphic and adult forms was examined. The analyses were conducted using histological, ultrastructural and morphometric methods. The results showed that cellular aggregations of precursor epidermal glands start to appear in stage 31 of (Herpetologica, 16, 1960 and 183) and then proliferate and invade the dermis. After stage 41, granular and mucous glands are very similar to those found in adults. The granular glands are syncytial and are surrounded by a distinct layer of myoepithelial cells. In the region of parotoid macroglands, the granular glands accumulate and their alveoli progressively increase until they reach adult size. An analysis by scanning electron microscopy showed the inner distribution of the syncytial nuclei and the myoepithelial cells. The morphological changes observed in the integument of tadpoles are associated with the gradual adaptation to terrestrial environments by preparing the individual for future chemical defence against predators and micro‐organisms.     

角蟾亚科3物种皮肤的组织学观察

应用石蜡切片和H.E染色技术,对角蟾亚科3个属的代表物种:短肢异角蟾(Xenophrys brachykolos)、宽头短腿蟾(Brachytarsophrys carinense)和小口拟角蟾(Ophryophryne microstoma)的皮肤进行了组织学观察及参数测量比较。分别取头背、体背和体腹3个部位的皮肤进行观察。结果表明,3物种的皮肤基本结构相似,均由表皮和真皮组成,真皮包括疏松层和致密层,疏松层中有大量腺体分布,包括黏液腺和颗粒腺2种。皮肤厚度、各组织层相对厚度以及腺体密度之间存在种间差异和部位差异。在宽头短腿蟾背部皮肤中,发现了与尖吻山角蟾(Megophrys nasuta)皮肤中一种片层状、H.E染色呈蓝色的皮肤真皮骨化结构(osteoderms)很相似的结构;短肢异角蟾皮肤中有明显的钙化层结构,小口拟角蟾皮肤钙化程度较弱。皮肤的骨化和钙化可能具有防止水分流失,抵御干燥的功能。2种内骨骼在角蟾亚科中同时存在,为探讨两栖动物皮肤内骨骼的进化提供了重要的研究基础。     

Histology and lectin-binding patterns in the skin of the terrestrial horned frog Ceratophrys ornata

The terrestrial horned frog, Ceratophrys ornata, lives on a wet substratum and absorbs water through the ventral epidermis; water is lost by evaporation from the dorsal skin. Thus, this species may be useful as a model for determining whether or not skin histology and lectin-binding patterns, indicative of glycoconjugates, are related to skin functions such as osmoregulation and water balance. With this in mind, a histological and lectin-histochemical study was carried out on dorsal and ventral skin of aquatic tadpoles and of a young terrestrial frog of C. ornata. Sections of skin were stained with various dyes to demonstrate general histological features and with two horseradish peroxidase (HRP)-conjugated lectins, Ulex europaeus agglutinin (UEA 1) and soybean agglutinin (SBA) which bind to specific terminal sugar residues of glycoconjugates, namely L-fucose and N-acetyl-D-galactosamine or D-galactose, respectively. In early stage tadpoles both lectin-binding patterns were similar in the bilaminar epidermis of dorsal and ventral skin (i.e., each lectin stained the apical cell layer). However, metamorphic changes resulted in a young frog with typical adult-type skin composed of a stratified squamous epidermis and three distinct types of glands containing glycoconjugates in their secretions. Strikingly different lectin-binding patterns were evident in the epidermis from dorsal and ventral regions of the body. The epidermis from the dorsal region was stained by both lectins; in contrast, that from the ventral region although stained strongly by HRP-SBA, did not react with HRP-UEA 1 indicating that few, if any, fucose residues were present in the ventral epidermis. These findings, as suggested in the discussion, indicate that different glycoconjugate patterns in dorsal and ventral skin may be associated with the regulation of water balance in the frog.     

似鲇高原鳅皮肤与鳍的组织学观察

采用石蜡切片技术及H.E和AB-PAS染色方法,对似鲇高原鳅(Triplophysa siluroides)头部、腹部、背部、侧线部和尾部皮肤结构及胸鳍、腹鳍、背鳍、臀鳍和尾鳍的组织结构进行观察。各部位皮肤均由表皮和真皮构成,真皮包括疏松层和致密层,不同部位皮肤厚度不同。表皮层腹部最厚,为(84.62±10.82)μm,侧线部最薄,为(14.97±3.95)μm,各部位表皮厚度差异显著。表皮层分布着黏液细胞、棒状细胞及味蕾。疏松层头部最厚,为(282.71±70.56)μm,尾部最薄,为(29.07±4.88)μm,该层分布有黑色素细胞、空泡状细胞和颗粒腺,而黏液腺分布于致密层。各部位的鳍均由表皮层、胶原纤维层、胶原下层及鳍条构成,表皮层与皮肤表皮层组成相似,鳍条是矿化的结缔组织。     

Presumptive Primordial Germ Cells (pPGCs) and PGCs in Tadpoles from UV-irradiated embryos of Xenopus

In order to determine whether or not tadpoles that once lacked primordial germ cells (PGCs) in the genital ridges and dorsal mesentery as a result of ultraviolet (UV) irradiation subsequently contained germ cells at more advanced stages of larval development, the numbers of presumptive PGCs or PGCs were carefully examined in Xenopus tadpoles at Nieuwkoop and Faber's stage 35/36–52 that developed normally from UV-irradiated eggs.
No late-appearing germ cells were observed in almost all the UV-irradiated tadpoles examined at stages 49–52. This same population had completely lacked PGCs at about stage 46. Moreover, presumptive PGCs (pPGCs) or cells with granular cytoplasm that reacted with a monoclonal antibody specific for the germ plasm of cleaving Xenopus eggs stayed in the central part of the endoderm cell mass in the irradiated tadpoles at stage 35/36, when the majority of those cells were located in the dorsal part of the endoderm in unirradiated controls. Furthermore, in the irradiated embryos pPGCs were demonstrated to decrease in number with development and eventually to disappear in tadpoles at about stage 40. The results strongly suggest that UV irradiation under the conditions used here totally eliminated germline cells from the irradiated animals.     

Localization of prolactin receptor in the dorsal and ventral skin of the frog (Rana ridibunda)

The dorsal and ventral skin in amphibians plays an important role in osmoregulation. Prolactin hormone is involved in regulation of amphibian skin functions, such as water and electrolyte balance. Therefore, amphibians may be useful as a model for determining the sites of the prolactin receptor. In this study, prolactin receptor was detected in frog dorsal and ventral skin using immunohistochemical staining method. Prolactin receptor immunoreactivity was localized in all epidermal layers except stratum corneum of dorsal skin epidermis, stratum germinativum layer of ventral skin epidermis, myoepithelial cells, secretory epithelium and secretory channel cells of granular glands in both skin regions. The mucous glands and secretory granules of granular glands did not show immunoreactivity for the prolactin receptor. According to our immunohistochemical results, the more widespread detection of prolactin receptor in dorsal skin epidermis indicates that prolactin is more effective in dorsal skin. Presence of prolactin receptors in epidermis points out its possible osmoregulatory effect. Moreover, detection of receptor immunoreactivity in various elements of poison glands in the dermis of both dorsal and ventral skin regions suggests that prolactin has a regulatory effect in gland functions.     

The morphology of the dorsal and ventral skin of Triturus karelinii (Caudata: Salamandridae)

In this study, for the first time, the morphology of the dorsal and ventral skin of Triturus karelinii using light microscopy through histochemical methods was described. The skin exhibited basic morphological characteristics of the other urodeles: the epidermis composed of keratinized stratified epithelium with numerous conical protrusions and the dermis subdivided into spongy and compact layers. In the spongious dermis, three distinct types of glands were observed, namely serous, mucous and mixed glands. These glands were alveolar and occurred in both males and females. The morphologies of all three skin glands differed from anurans and other urodeles, having peculiar characteristics. Serous glands exhibited three different appearances. An unusual finding in mucous glands was the different appearance of their granules, showing diverse density after staining with PAS and AB. The histochemical analysis clearly demonstrated the presence of neutral, acid and sulfated mucins in the adenocytes of mucous glands. Mixed glands formed by mucous and serous glands exhibited the same morphological traits of both types of glands. Light microscopic observations revealed that the dorsal and ventral skin showed structural similarities with some minor differences, possibly resulting from their functions.     

多疣狭口蛙不同繁殖时期皮肤显微结构观察

采用常规石蜡切片及HE染色,对多疣狭口蛙不同繁殖时期背腹皮肤结构进行显微观察.结果发现:多疣狭口蛙3个不同繁殖时期皮肤结构无明显变化,其背部腺体要比腹部发达.尤其是颗粒腺,比腹部丰富.背部皮肤的色素层也比腹部发达.繁殖前期、繁殖中期粘液腺含量比繁殖后期略微多.     

Glycoconjugate localization in larval and adult skin of the bullfrog, Rana catesbeiana: a lectin histochemical study

This study investigates whether or not the distribution of specific glycoconjugates within the skin is related to the regulation of water balance in the aquatic larvae and semiaquatic adults of the bullfrog, Rana catesbeiana. A lectin histochemical study was carried out on paraffin sections of dorsal and ventral skin from tadpoles in representative stages as well as from adult frogs. Sections were stained with the following horseradish peroxidase (HRP)-conjugated lectins, which bind to specific terminal sugar residues of glycoconjugates: UEA 1 for alpha-L-fucose, SBA for N-acetyl-D-galactosamine, WGA for N-acetyl-B-D-glucosamine, and PNA for beta-galactose. Results indicate that lectins serve as markers for specific skin components (e.g., a second ground substance layer within the dermis was revealed by positive UEA 1 staining). Moreover, each lectin has a specific binding pattern that is similar in dorsal and ventral skin; the larval patterns change as the skin undergoes extensive histological and physiological remodeling during metamorphic climax. These findings enhance our understanding of glycoconjugates and their relationship to skin structure and function-in particular, to the regulation of water balance in R. catesbeiana.