狭胸天牛成虫和幼虫的消化道研究

研究了狭胸天牛成虫和幼虫消化道形态。成虫消化道细长,嗉囊长囊状,中肠前段具极少的稀疏瘤状小突起。幼虫消化道相当长,前肠细短,中肠很长,前中肠粗短而膨大,中肠表面无小盲囊。     

蝗虫消化道结构的比较研究

采用扫描仪分析方法对10种蝗虫消化道形态结构进行了观察比较,发现蝗虫不同类群个体其中肠占消化道总长的比例依进化地位呈现递增趋势,胃盲囊和后肠则呈递减趋势.这种趋势可能是随着蝗虫类群的进化,中肠在消化道所占的比例逐渐增大,对食物的消化吸收能力逐渐增强,与之相应的是胃盲囊呈退化趋势,同时后肠所排泄的残渣逐渐减少,导致蝗虫消化道形态发生适应性变化的结果.     

光滑足距小蠹消化道的解剖结构

采用体视显微和扫描电镜技术研究光滑足距小蠹Xylosandrus germanus(Blandford)消化道的解剖结构。结果表明,光滑足距小蠹消化道由前肠、中肠和后肠三部分组成。成虫前胃由8个骨化的前胃板组成,呈灯笼状结构。前胃板由板状部和片状部组成,板状部短而简单,片状部甚长,由斜面、咀嚼刷和关闭刚毛组成。胃盲囊着生在中肠近后端,有细管状和囊状2种,成虫分别有1对,幼虫有1对细管状和3~5对囊状。6根马氏管分成2组,1组4根,另一组2根。6根马氏管与后肠肠壁形成隐肾系统。消化道具有1对囊状和1对细管状的胃盲囊可作为光滑足距小蠹成虫的识别特征。     

臭腹腺蝗（直翅目：锥头蝗科）胃盲囊的异速生长和功能特性

通过对臭腹腺蝗Zonocerus variegatus（直翅目：锥头蝗科）6个若虫期及成虫期主消化道和胃盲囊分段进行解剖和测量,对其胃盲囊的异速生长和功能特性进行了研究。结果表明,胃盲囊和主消化道的生长是不同速的。胃盲囊前段较后段生长速率更高,但两者生长速率显著相关。消化道和胃盲囊的平均长度亦显著相关。随年龄增长,消化道的生长速率降低,而胃盲囊的生长速率上升。与胃盲囊前段功能相同,胃盲囊后段亦具有消化和吸收功能,被认为能在营养缺乏的旱季起到增加肠胃吸收面的功能。     

桃小食心虫幼虫的消化道和马氏管的显微结构观察

利用光学显微镜和扫描电子显微镜,在形态学和组织学水平上研究_『桃小食心虫 Carposina sasakii 幼虫消化道和屿氏管的结构.桃小食心虫幼虫消化道由前肠、中肠和后肠组成.前肠细短,肌肉层薄.前肠与中肠交界处有突出的胃盲囊.中肠长且粗大,内有围食膜,肠壁细胞较大,外层为发达的环肌和纵肌.后肠上皮细胞内陷很深.6根念珠状的马氏管位于中、后肠分界处.     

臭椿沟眶象幼虫消化道解剖方法

臭椿沟眶象幼虫消化道柔软脆弱,尤其是1龄与2龄幼虫的消化道纤细易断,解剖难度较大。本文介绍了臭椿沟眶象幼虫消化道的具体解剖方法,根据不同龄期幼虫脂肪含量与消化道韧性差异,对1-2龄和3-7龄幼虫,分别使用纵切法和剥离法解剖。结果表明:臭椿沟眶象幼虫消化道分为前肠、中肠和后肠。前肠为窄而细的管状,没有明显的嗉囊和前胃。中肠分为2部分,前部膨大,后部为光滑的管状。后肠由回肠和直肠组成。马氏管6根。这两个方法提高了此幼虫消化道解剖的效率与成功率,希望能为具有体壁柔软、消化道脆弱易损等特点昆虫幼虫的消化道解剖提供借鉴与参考。     

鳜鱼消化道黏液细胞和6种酶的组织化学定位

采用阿利新蓝-过碘酸雪夫氏(AB-PAS)染色和酶组织化学方法对鳜鱼消化道各部位黏液细胞和6种酶的分布与定位进行了研究。结果显示,黏液细胞可为分为4种类型,食道黏液细胞多数为Ⅲ型和Ⅳ型,未见Ⅰ型和Ⅱ型;胃贲门和胃幽门黏膜上皮仅有Ⅰ型黏液细胞;胃体黏膜上皮则以Ⅲ型细胞为主;幽门盲囊中主要为Ⅱ型细胞;前肠和中肠中Ⅳ型黏液细胞最多,Ⅰ型最少;后肠黏液细胞则以Ⅳ型和Ⅱ型为主。酸性磷酸酶(ACP)主要分布于幽门盲囊和前肠的黏膜上皮;碱性磷酸酶(ALP)主要分布于食道、幽门盲囊和整个肠道黏膜上皮;非特异性酯酶(NSE)主要分布于胃幽门、中肠和后肠黏膜上皮;过氧化物酶(POX)在胃幽门黏膜上皮中活性较高;琥珀酸脱氢酶(SDH)主要分布于胃腺中;腺苷三磷酸酶(ATPase)在消化道各部位均有较多分布。鳜鱼消化道黏液细胞和酶的分布型与其它动物有相似之处,也有其一定的特异性,与消化道不同部位的消化吸收机能相适应。     

大豆低聚糖对牙鲆营养效应的研究：II消化率和消化生理

本试验比较研究了不同蛋白源（鱼粉,FM;大豆分离蛋白,SPI）基础饲料中添加大豆低聚糖（SBOS）对牙鲆（Paralichthys olivaceus）消化道（胃、幽门盲囊、前肠、中肠和后肠）和肝脏消化酶活性、饲料表观消化率和消化道（胃、小肠）组织结构的影响。分别以FM、SPI作为主要蛋白源,配制了4种等氮等能饲料。其中,饲料FM、SP1分别以FM、SPI作为主要蛋白源;饲料FMO、SPIO分别在饲料FM、SPI基础上添加10％SBOS（水苏糖：2．61％;棉籽糖：0．61％）。试验表明：①饲料中添加SBOS普遍降低了牙鲆消化道和肝脏蛋白酶活性,但差异均不显著（P〉O．05）。FM基础饲料中添加SBOS显著降低了肝脏脂肪酶活性（P〈0．05）,而对消化道脂肪酶活性无显著影响;SPI基础饲料中添加SBOS显著提高了前肠脂肪酶活性,降低了胃和中肠脂肪酶的活性,而对幽门盲囊、后肠和肝脏脂肪酶活性均无显著影响。FM基础饲料中添加SBOS显著降低了中肠淀粉酶活性,提高了胃淀粉酶活性（P〈0．05）,而对幽门盲囊、前肠、后肠和肝脏淀粉酶活性无显著影响;SPI基础饲料中添加SBOS显著提高了胃和前肠淀粉酶活性,降低了中肠脂肪酶活性（P〈0．05）,而对幽门盲囊、后肠和肝脏淀粉酶活性无显著影响;②FM基础饲料中添加SBOS显著降低了饲料干物质表观消化率（P〈0．05）,而对粗蛋白、粗脂肪和能量表观消化率均无显著影响（P〉0．05）。SPI基础饲料中添加SBOS对干物质、粗蛋白、粗脂肪和能量表观消化率均无显著影响;③饲料中添加SBOS对牙鲆胃和小肠组织结构均无明显负面影响。试验结果表明,饲料中添加SBOS对牙鲆消化道和肝脏消化酶活性、饲料表观消化率和消化道组织结构均没有表现出明显的负面效应;大豆蛋白源中含有的SBOS不是影响牙鲆对其利用率差的主要因素。     

大豆低聚糖对牙鲆营养效应的研究：Ⅱ 消化率和消化生理

本试验比较研究了不同蛋白源(鱼粉,FM;大豆分离蛋白,SPI)基础饲料中添加大豆低聚糖(SBOS)对牙鲆(Paralichthys olivaceus)消化道(胃、幽门盲囊、前肠、中肠和后肠)和肝脏消化酶活性、饲料表观消化率和消化道(胃、小肠)组织结构的影响。分别以FM、SPI作为主要蛋白源,配制了4种等氮等能饲料。其中,饲料FM、SPI分别以FM、SPI作为主要蛋白源;饲料FMO、SPIO分别在饲料FM、SPI基础上添加10%SBOS(水苏糖：2.61%;棉籽糖：0.61%)。试验表明：①饲料中添加SBOS普遍降低了牙鲆消化道和肝脏蛋白酶活性,但差异均不显著(p > 0.05)。FM基础饲料中添加SBOS显著降低了肝脏脂肪酶活性(p < 0.05),而对消化道脂肪酶活性无显著影响;SPI基础饲料中添加SBOS显著提高了前肠脂肪酶活性,降低了胃和中肠脂肪酶的活性,而对幽门盲囊、后肠和肝脏脂肪酶活性均无显著影响。FM基础饲料中添加SBOS显著降低了中肠淀粉酶活性,提高了胃淀粉酶活性(p < 0.05),而对幽门盲囊、前肠、后肠和肝脏淀粉酶活性无显著影响;SPI基础饲料中添加SBOS显著提高了胃和前肠淀粉酶活性,降低了中肠脂肪酶活性(p < 0.05),而对幽门盲囊、后肠和肝脏淀粉酶活性无显著影响;②FM基础饲料中添加SBOS显著降低了饲料干物质表观消化率(p < 0.05),而对粗蛋白、粗脂肪和能量表观消化率均无显著影响(p > 0.05)。SPI基础饲料中添加SBOS对干物质、粗蛋白、粗脂肪和能量表观消化率均无显著影响;③饲料中添加SBOS对牙鲆胃和小肠组织结构均无明显负面影响。试验结果表明,饲料中添加SBOS对牙鲆消化道和肝脏消化酶活性、饲料表观消化率和消化道组织结构均没有表现出明显的负面效应;大豆蛋白源中含有的SBOS不是影响牙鲆对其利用率差的主要因素。     

中华真地鳖低龄若虫消化道结构及取食习性

解剖喂食不同饲料中华真地鳖EupolyphagasinensisWalker的低龄若虫 ,结果表明 ,低龄若虫消化道与成虫消化道结构相同 ,具有胃盲囊和马氏管 ;嗉囊、中肠和后肠分别占消化道总长的比率与中龄若虫相同 ,具有消化食物的能力。观察消化道各部分的滞留物变化情况 ,发现 1龄若虫取食了饲养土中的腐殖质和配合饲料 ,表明孵化后的若虫需要喂食以满足营养需要。     

中华稻蝗消化道内分泌细胞的鉴别与定位

采用整块组织Grimelius银染法和过氧化物酶标记的链霉亲和素免疫组织化学技术,结合生物统计学分析,对中华稻蝗Oxya chinensis消化道内分泌细胞进行鉴别与定位。结果表明：嗜银细胞分布于中华稻蝗的胃盲囊、中肠和后肠各段,以中肠和直肠中最多（P<0.05）, 前肠中未见分布。免疫组织化学法检测出了五羟色胺（5-hydroxytryptamine, 5-HT）、 胃泌素（gastrin, Gas）、 胰高血糖素（glucagon, Glu）和胰多肽（pancreatic polypeptide, PP）细胞, 未检出生长抑素（somatostatin, SS）细胞。免疫阳性细胞分布于中肠和后肠中, 前肠中未见分布。5-HT细胞和Gas细胞均主要分布于胃盲囊、中肠及直肠中,且均以直肠中最多（P<0.05）。Glu细胞在胃盲囊及整个中、后肠均有分布, 在中肠和直肠中最多（P<0.05）。PP细胞主要分布于中肠、回肠和直肠中,中肠中分布密度最大（P<0.05）。本研究显示中华稻蝗消化道中存在多种内分泌细胞,它们的分布情况与其他节肢动物相比存在一定的共性,也有其一定的特异性,可能与中华稻蝗特定的消化道结构和消化生理功能有关。     

The adult Drosophila gastric and stomach organs are maintained by a multipotent stem cell pool at the foregut/midgut junction in the cardia (proventriculus)

Stomach cancer is the second most frequent cause of cancer-related death worldwide. Thus, it is important to elucidate the properties of gastric stem cells, including their regulation and transformation. To date, such stem cells have not been identified in Drosophila. Here, using clonal analysis and molecular marker labeling, we identify a multipotent stem-cell pool at the foregut/midgut junction in the cardia (proventriculus). We found that daughter cells migrate upward either to anterior midgut or downward to esophagus and crop. The cardia functions as a gastric valve and the anterior midgut and crop together function as a stomach in Drosophila; therefore, we named the foregut/midgut stem cells as gastric stem cells (GaSC). We further found that JAK-STAT signaling regulates GaSCs'' proliferation, Wingless signaling regulates GaSCs'' self-renewal, and hedgehog signaling regulates GaSCs'' differentiation. The differentiation pattern and genetic control of the Drosophila GaSCs suggest the possible similarity to mouse gastric stem cells. The identification of the multipotent stem cell pool in the gastric gland in Drosophila will facilitate studies of gastric stem cell regulation and transformation in mammal.Key words: gastric stem cells, foregut/midgut junction, cardia, proventriculus, stomach, Drosophila     

The adult Drosophila gastric and stomach organs are maintained by a multipotent stem cell pool at the foregut/midgut junction in the cardia (proventriculus)

Stomach cancer is the second most frequent cause of cancer-related death worldwide. Thus, it is important to elucidate the properties of gastric stem cells, including their regulation and transformation. To date, such stem cells have not been identified in Drosophila. Here, using clonal analysis and molecular marker labeling, we identify a multipotent stem-cell pool at the foregut/midgut junction in the cardia (proventriculus). We found that daughter cells migrate upward either to anterior midgut or downward to esophagus and crop. The cardia functions as a gastric valve and the anterior midgut and crop together function as a stomach in Drosophila; therefore, we named the foregut/midgut stem cells as gastric stem cells (GaSC). We further found that JAK-STAT signaling regulates GaSCs’ proliferation, Wingless signaling regulates GaSCs’ self-renewal, and hedgehog signaling regulates GaSCs’ differentiation. The differentiation pattern and genetic control of the Drosophila GaSCs suggest the possible similarity to mouse gastric stem cells. The identification of the multipotent stem cell pool in the gastric gland in Drosophila will facilitate studies of gastric stem cell regulation and transformation in mammal.     

庭疾灶螽中肠及马氏管结构

【目的】本研究旨在以庭疾灶螽Tachycines asynamorus为例探索驼螽消化系统和排泄系统在结构上与其生活环境的适应关系。【方法】运用解剖学方法、石蜡切片技术、冰冻切片技术及超薄切片技术对庭疾灶螽中肠及马氏管的结构进行研究。【结果】庭疾灶螽中肠向前延伸出3个胃盲囊包围着前胃。中肠上皮由再生细胞、柱状上皮细胞和内分泌细胞构成,具有典型的再生细胞龛;闭合型内分泌细胞紧贴在再生细胞龛的外围,基底区聚集大量的分泌颗粒。柱状上皮细胞内聚集有2类大的分泌颗粒：线团状颗粒和电子密度很高的球状颗粒;中肠管腔内有明显的围食膜结构,中肠基底部由基膜和肌肉层组成。马氏管着生在中后肠的交界处,从横切面看马氏管管壁具有3~5个细胞,细胞近管腔端部具有大量长微绒毛,细胞质内分布着电子致密的同心圆球晶体,基底膜内折形成膜迷路。【结论】庭疾灶螽中肠柱状上皮细胞的线团状颗粒由微丝包裹;内分泌细胞由再生细胞龛中的细胞分化而来,产生内分泌颗粒并将其排到血腔;中肠基膜发达,包含微丝与复合糖成分,基膜通过对中肠上皮细胞的支撑作用为肠道蠕动提供保障。庭疾灶螽马氏管细胞中可见大量颗粒和大量同心圆球晶体,推测可能是一种储存排泄。     

Fine structure of the larval midgut of the fly Rhynchosciara and its physiological implications

The midgut of Rhynchosciara americana larvae consists of a cylindrical ventriculus from which protrudes two gastric caeca formed by polyhedral cells with microvilli covering their apical faces. The basal plasma membrane of these cells is infolded and displays associated mitochondria which are, nevertheless, more conspicuous in the apical cytoplasm. The anterior ventricular cells possess elaborate mitochondria-associated basal plasma membrane infoldings extending almost to the tips of the cells, and small microvilli disposed in the cell apexes. Distal posterior ventricular cells with long apical microvilli are grouped into major epithelial foldings forming multicellular crypts. In these cells the majority of the mitochondria are dispersed in the apical cytoplasm, minor amounts being associated with moderately-developed basal plasma membrane infoldings. The proximal posterior ventriculus represents a transition region between the anterior ventriculus and the distal posterior ventriculus. The resemblance between the gastric caeca and distal posterior ventricular cells is stressed by the finding that their microvilli preparations display similar alkaline phosphatase-specific activities. The results lend support to the proposal, based mainly on previous data on enzyme excretion rates, that the endo-ectoperitrophic circulation of digestive enzymes is a consequence of fluid fluxes caused by the transport of water into the first two thirds of midgut lumen, and its transference back to the haemolymph in the gastric caeca and in the distal posterior ventriculus.     

太白蝎蛉消化道形态学与组织学研究

利用光学显微镜和扫描电子显微镜, 在形态学和组织学水平上研究了太白蝎蛉Panorpa obtusa Cheng成虫消化道的结构。结果表明： 蝎蛉消化道由前肠、中肠、和后肠组成。前肠包括咽喉、食道、和前胃, 但没有嗉囊,其中咽喉可分为骨化的前咽和附着扩肌的后咽（咽喉唧筒）; 前胃壁很厚,内膜上长有许多排列整齐、紧密的棕色胃刺,司过滤、暂时储存和磨碎食物的功能; 前肠末端有6个贲门瓣伸入中肠。中肠较长且膨大,其肠壁细胞由柱状细胞和再生细胞组成; 肠壁细胞外分别为环肌和纵肌,无胃盲囊,也未观察到围食膜。6根棕红色的马氏管位于中、 后肠分界处。后肠分为不对称的“V”字型回肠、环状结肠、以及膨大透明的直肠, 直肠内壁上有6个交替排列的直肠垫。最后简要讨论了蝎蛉消化道的结构与功能,及其在蝎蛉科昆虫分类中的意义。     

臭腹腺蝗（直翅目：锥头蝗科）消化道对食物储存、消化和吸收相适应的显微结构

显微观察发现臭腹腺蝗Zonocerus variegatus（直翅目：锥头蝗科）嗉囊、中肠和后肠的肠壁结构有所不同。嗉囊为空时纵向折叠。中肠上皮层的厚度随龄期有明显变化,1龄和2龄时明显大于3龄、4龄和5龄。后肠具有帮助消化和吸收的功能。     

Histopathology of a nuclear polyhedrosis infection in Aedes epactius with observations in four additional mosquito species

Aedes epactius larvae were utilized to study the infection sequence of the nuclear polyhedrosis virus (NPV) from Aedes sollicitans. From 30 min to 6 hr postinoculation, polyhedra and many free virions were observed in the larval midgut lumen. Penetration of the midgut cells by virions was not observed. The first infected nuclei were observed 12 hr postinoculation. Nucleocapsids initially exhibited electron translucent cores which became electron dense before the nucleocapsids acquired an envelope. Envelope acquisition occurred through a process of de novo membrane morphogenesis. Occlusion of the singly embedded virions began by 18 hr postinoculation with the mature rough-surfaced polyhedra averaging approximately 1 by 2 μm. Unusually long nucleocapsids (approximately two or three times the length of other nucleocapsids) were only observed in late infection period nuclei. There was no evidence that long nucleocapsids represented an early developmental stage for nucleocapsids of standard length. Infection was restricted to midgut nuclei and gastric caecae cells. Infected early instar A. epactius larvae became moribund 36 to 40 hr postinoculation and infected midgut nuclei were observed to undergo lysis. The late stages of NPV infection were observed in larvae of A. annandalei, Wyeomyia smithii, Toxorhynchites brevipalpus, and Eretmapodites quinquevittatus. Virion development and occlusion in these species was basically identical to the sequence observed in A. epactius larvae.