三疣梭子蟹胚胎发育过程中消化系统的发生和发育

对三疣梭子蟹（Portunus trituberculatus)不同发育阶段的胚胎进行连续组织切片,以揭示其消化系统的发生和发育。结果显示前肠,中肠和后肠皆发生于原肠胚期,前肠在第1期卵内蚤状幼体阶段发育成胃与食道,胃开口于卵黄囊,后肠肠上皮细胞在第1,2期卵内无节幼体阶段尚未形成有序排列,至第1期卵内蚤状幼体时始形成后肠腔,到第2期卵蚤状幼体时与中有肠连接,中肠在第2期卵内蚤状幼体阶段发育成杯状结构,孵化前与前肠贯通,形成完整的消化系统。     

三疣梭子蟹胚胎期中枢神经系统的发生和发育

应用组织学方法研究三疣梭子蟹胚胎期中枢神经系统的发生和发育,光学显微镜下镜检切片,在第二期卵内无节幼体阶段开始观察到脑;第二期卵内状幼体阶段,前脑由视神经层、侧原脑和中央原脑组成,与位于食道两侧的中脑和后脑形成完整的脑。三疣梭子蟹胚胎期腹神经链由1对大颚、2对小颚和2对颚足所对应的神经节以及腹部神经链组成。光镜下大颚神经节可于第二期卵内无节幼体阶段观察到,2对小颚和2对颚足神经节则在第二期卵内状幼体阶段观察到;腹部神经链则在第三期卵内状幼体阶段观察到。三疣梭子蟹胚胎期中枢神经系统由脑和腹神经链组成,脑由前脑、中脑和后脑组成,脑位于背部,通过2条围食道神经与腹神经链相连。中枢神经系统的不同部分的形成在胚胎发育过程中具有阶段性差异。     

远海梭子蟹胚胎发育观察

在水温25～26℃、盐度30和pH 7.8～8.4条件下,观察远海梭子蟹胚胎发育全过程,其结果发现,远海梭子蟹胚胎发育经历卵裂、囊胚、原肠胚、无节幼体、后无节幼体和原溞状幼体等六个阶段.远海梭子蟹卵排出约28h开始表面卵裂,约40h,形成囊胚,约60h,预定内胚层细胞出现,并与集中在其周围的细胞一起内陷,形成原肠胚.约90h,3对附肢的无节幼体出现,约110h,5对附肢的后无节幼体出现,约140h,7对附肢的原溞状幼体出现.复眼、心跳、色素形成均在原潘状幼体阶段完成.原溞状幼体孵出时(约300h),颚足长出羽状刚毛,变为溞状幼体.整个胚胎发育过程约300h.     

三疣梭子蟹胚胎发育过程中卵内幼体形态

三疣梭子蟹胚台发育过程中,卵内幼体共经历2期卵内无节幼体和3期卵内tao状幼体,各幼体期的主要特征表现为：第1期卵内无节幼体具小触角,大触角和大颚3对附肢,第2期卵内无节幼体除草1期的3对附肢外,2对小颚开始出现,腹部前端分节,第1期卵内tao状幼体阶段复眼先为棒状,继而变成月牙状,附肢5对,腹部分为6节,第2期卵内tao状幼体阶段2对颚足出现,复眼发育完全,卵黄蝶状,心脏开始跳动,到此阶段末期,附肢分节和分叉,第3期卵内tao状幼体阶段,各器官进一步发育,肌肉明显。     

半滑舌鳎胚胎发育中后期卵黄囊超微结构观察

在胚胎发育中期,半滑舌鳎胚胎由胚体、卵黄囊和卵周液构成.对半滑舌鳎胚胎发育中后期的卵黄囊进行超微结构观察.结果表明,卵黄囊是由卵黄囊膜和包裹其内的卵黄物质组成.在半滑舌鳎胚胎发育过程中,卵黄囊内的卵黄物质逐渐消耗产生低分子量的卵黄磷蛋白分裂小泡.分裂小泡转移到卵黄囊内部消黄细胞中,在消黄细胞的作用下分裂小泡转化成卵黄颗粒.随后卵黄颗粒在卵黄囊内表面聚集成囊状结构并转移运输到卵黄囊膜内部,最后把卵黄物质从卵黄囊膜转移并释放到卵周液中,为胚胎发育提供营养.     

安徽乾山山地麻蜥卵孵化过程中物质和能量的变化

野生成年山地麻蜥捕获后在人工环境中产卵,卵在30℃、－12kPa的条件下孵化;在不同时段称重（整体、卵壳、卵黄、胚胎等）并测定一些成分的能量。胚胎发育以及卵物质和能量转化数据处理结果如下：①卵孵化期为35.0d,孵化时能从外界吸收水分使卵重增加;②在卵孵化0－20、20－30和30-35d,胚胎分别利用新生卵能量的10％、30％和20％;③胚胎在孵化的20d内生长缓慢,此后生长迅速;④卵孵化过程中,干重、非极性脂肪和能量的转化率分别为67.3%、32.7%和59.6%;⑤胚胎发育所需的无机物来自卵黄和卵壳。该种卵内干物质和非极性脂肪（作为主要能量物质）的转化率、幼体内剩余卵黄比例均较有鳞类低;这种转化率差异可能与山地麻蜥胚胎发育缓慢期较长有关。     

三疣梭子蟹胚胎发育过程中生殖腺的形态

对三疣梭子蟹胚胎切片做显微观察,至第二期卵内涵状幼体阶段才见形态结构明显的生殖腺。其外观囊状,内部具空腔,细胞排列成管状,开口于胚胎表面。左右两个生殖腺以管状结构相连。     

中华绒螯蟹卵黄形成的研究

中华绒螯蟹的卵黄形成也受各种相关内分泌激素的调控,卵黄的来源虽然是双重的,一方面在蟹卵内由内质网和高尔基体生产卵黄原,然后卵黄原再融合成为卵黄体。另一方面,蟹卵以胞吞方式直接从血淋巴中接纳卵黄原,同时又通过指状小道由卵泡细胞间接接纳卵黄原。肝胰腺可能会产生卵黄原,这些卵黄原随即进入血淋巴内,再直接或间接被蟹卵接纳。     

水热环境对中国石龙子孵化卵、孵化成功率及孵出幼体特征的影响

用 8种水热条件孵化中国石龙子 (Eumeceschinensis)卵 ,观测孵化卵质量变化、胚胎利用卵内物质和能量及孵出幼体特征。孵化卵因净吸水增重 ,卵增重与入孵卵质量、孵化温度和基质湿度有关。孵出幼体湿重的处理间差异主要是因为幼体水分含量不同。温度显著影响孵化期、孵化卵吸水量、胚胎利用卵内物质和能量几乎所有被检的幼体特征 ;温度甚至影响胚胎动用卵壳无机物。然而 ,在 2 4～ 32℃范围内 ,温度对卵孵化成功率无显著的影响。 32℃孵出幼体比较低于此温度的孵出幼体发育差 ,表现为躯干小、未利用的卵黄多。此外 ,32℃孵出幼体的运动表现比低温孵出幼体差 ,表现为特定体长 (snout ventlength ,SVL)的疾跑速小于低温孵出幼体 ,表明高温孵化卵对孵出幼体的运动能力有不利的影响。潮湿基质中孵出幼体的体长和尾长大于干燥基质中孵出的幼体 ,并特征性地具有较小的剩余卵黄。 2 4℃胚胎发育能耗较大 ,胚胎从卵壳动用的无机物较少。温度影响孵出幼体的体形和头部大小 ,30℃孵出幼体的尾长最大 ,32℃孵出幼体的头部最小。基质湿度对孵出幼体的体形和头部大小无显著的影响。温度对孵出幼体特征的影响与湿度的影响无关。孵化水热环境诱导的幼体大小、质量和形态差异可能对幼体的生存和适应性具有重要的影响。 2     

水热环境对中国石龙子孵化卵、孵化成功率及孵化幼体特征的影响

用8种水热条件孵化中国石龙子（Eumeces chinensis）卵,观测孵化卵质量变化、胚胎利用卵内物质和能量及孵出坳体特征,孵化卵因净吸水增重,卵增重与入孵卵质量、孵化温度和基质湿度有关。孵出幼体湿重的处理间差异主要是因为幼体水分含量不同。温度显著影响孵化期、孵化卵吸水量、胚胎利用孵内物质和能量几乎所有被检的幼体特征;温度甚至影响胚胎动用卵壳无机物。然而,在24－32℃范围内,温度对卵孵化成功率无显著的影响。32℃孵出幼体比较低于此温度的孵出幼体发育差,表现为躯干小、未利用的卵黄多。此外,32℃孵出幼体的运动表现比低温孵出幼体差,表现为特定体长（snout-vent length,SVL）的疾跑速小于低温孵出幼体,表明高温孵化卵对孵出幼体的运动能力有不利的影响,潮湿基质中旗子同幼体的体长和尾长大于干燥基质中孵出的幼体,并特征性地具有较小的剩余卵黄。24℃胚胎发育能耗较大,胚胎从卵壳动用的无机物较少。温度影响孵出幼体的体形和头部大小,30℃孵出幼体的尾长最大,32℃孵出幼体的头部最小,其质湿度对孵出幼体的体形和头部大小无显著的影响。温度对孵出幼体特征的影响与湿度的影响无关。孵化水热环境诱导的幼体大小、质量和形态差异可能对幼体的生存和适应性具有重要的影响。26－30℃为孵化中国石龙子卵的适宜温度范围。     

Fatty acid esterification in the yolk sac membrane of the avian embryo

The transfer of lipid from the yolk to the avian embryo is mediated by the yolk sac membrane (YSM). Some, but not all, of the published morphological evidence supports the view that the lipid undergoes a cycle of hydrolysis and re-esterification during translocation across the YSM. The present study aims to test this view by investigating the capacity of the YSM to perform esterification of free fatty acids to form acyl-lipids. YSM pieces (area vasculosa), obtained from the chicken embryo at day 10 of development, were incubated in vitro in medium containing [¹⁴C]-palmitic acid. Radioactivity was rapidly incorporated into the tissue lipid indicating a high capacity for esterification. The incorporation was linear with time during the 1-h incubation. Approximately 84% of the incorporated label was recovered in triacylglycerol, 12% was incorporated into phospholipid and less than 1% was detected in cholesteryl ester. [¹⁴C]-palmitic acid was incorporated primarily at the sn-1/3 positions in the triacylglycerol molecule and at the sn-1 position of phospholipid. The incorporation of label into tissue pieces obtained from the non-vascularized peripheral region of the YSM (area vitellina) was much more limited than that observed for the area vasculosa. The results support the hypothesis that yolk lipid is hydrolyzed and re-esterified during transfer across the YSM.Abbreviations YSM yolk sac membrane - VLDL very-low density lipoprotein Communicated by G. Heldmaier     

Sequential deposition of yolk components during oogenesis in an insect,Aedes aegypti (Diptera: Culicidae)

Vitellogenesis in Aedes aegypti of uniform body size was followed at 27 degrees C in narrow time intervals throughout their first reproductive cycle by measuring the length, diameter, and volume of follicles and oocytes, the latter as an expression of the yolk mass (vitellus). Independent of all experimental conditions, a two-step process of elongation was recognized for both follicle length and yolk length, so that growth curves were consistently composed of two linear regressions with different slopes against time. Follicle lengths started to increase immediately after the blood meal, while oocytes took up to 6 h to show a measurable increase in yolk length. The first linear phase continued until 30 h, when yolk length reached 268+/-22 micro m. At this point, a transition occurred where the linearity shifted sharply for the next 6 h to 2-4-times higher slopes for both regressions. This second growth phase represented a 40% elongation of oocytes and follicles. Then, both curves leveled off at their final size, characteristic of mature ovaries: 462+/-10 micro m for oocytes, 489+/-11 micro m for follicles. These values remained constant until oviposition.The first linear growth phase was associated with an equicaloric and synchronous protein and lipid incorporation into the oocytes; levels of these substances reached their maximum by the end of this first phase and remained constant until oviposition. The second linear growth phase was characterized by rapid glycogen incorporation into oocytes from 20 to 100% of the maximum. Subsequently, the surface pattern of the exochorion became visible, marking the end of yolk incorporation. Since eggs are always laid on moist substrates, within 2-3 h of oviposition they double in volume and fresh weight, driven by more than tripling of their water content.When blood-fed females were exposed to five different temperatures between 17 and 37 degrees C, the distinction between the two linear growth phases persisted, but the slopes of the respective regressions, and therefore their durations, were affected. Eggs still matured at 37 degrees C but never hatched and at 12 degrees C only 18% hatched, whereas at all the intermittent temperatures hatching was 80-90%. Oogenesis appears to be limited to the range between 12 and about 32 degrees C.The effects of age, maternal body size and the source of the blood on vitellogenesis were also examined. These parameters affected the onset and/or extent of oogenesis in various ways.     

A role played by the vitelline diverticulum in the yolk sac resorption in young post-hatched chickens

Summary Yolk sac resorption, with special reference to the role of the vitelline stalk, was studied in young post-hatched chickens (0, 1, and 2 days old) using a radioactive (¹⁴C-PEG-4000) and coloured (Evans Blue) marker injected into the yolk sac lumen of conscious birds. When the animals were newly-hatched and 1 day old, the radioactive material was recovered from the lumen of the gastrointestinal tract, but not when the vitelline diverticulum was tied. These results suggest a role played by the vitelline diverticulum in the removal of vitelline contents during the first post-hatching 48 h of chick life.Abbreviations DPM decays per minute - GI gastrointestinal - PEG polyethylene glycol     

Immunocytochemical location of vitellin in the egg of the silkworm,Bombyx mori,during early developmental stages

Summary Vitellin was purified from eggs of the silkworm,Bombyx mori, by a new method in which vitellin was extracted from isolated yolk granules. The purified vitellin had a molecular weight of 540,000. An antibody against purified vitellin was prepared in rabbits. It reacted with the hemolymph vitellogenin as well as with purified vitellin, but not with other proteins in the hemolymph or in the extract from yolk granules. The anti-vitellin IgG was used to immunocytochemically locate vitellin in theBombyx non-diapause egg during early developmental stages. In the egg, just after oviposition, vitellin was located in internal yolk granules and in small yolk granules of the periplasm. During the early developmental stages studied, vitellin was not metabolized uniformly throughout the egg. The vitellin of the internal yolk granules located at the posterior-dorsal part and of the small peripheral yolk granules was utilized in 16 h and 2 days, respectively, after oviposition. A thin, very vitellin-poor layer was located between the periplasm and the vitellin-rich interior in the newly laid egg. it was always in close contact with the periphery where blastoderm and germ-band cells developed.     

Sperm selection capacity of the human zona pellucida.

Previous hemizona assay (HZA) results have illustrated a positive and significant correlation between the percentage of morphologically normal spermatozoa in the semen and the number of spermatozoa tightly bound to the zona pellucida. The present study was designed to evaluate the morphologic features using strict criteria of spermatozoa tightly bound to the zona pellucida. Semen samples of 4 normozoospermic and 11 teratozoospermic men were used to compare the percentage of normal spermatozoa in the semen with that found 1) after swim-up separation and 2) bound to the zona under HZA conditions. The mean (+/- SEM) % normal forms for normozoospermic men in semen, after swim-up and zona-bound spermatozoa were 21.5 +/- 1.6, 27.5 +/- 2.9, and 44.8 +/- 3.4, respectively. A significantly higher % of normal forms were found among zona-bound sperm compared to swim-up forms (p = 0.02) and seminal sperm (p = 0.02). The mean % of normal sperm forms present in semen, after swim-up and zona pellucida-binding for teratozoospermic men, were 3.7 +/- 0.9, 5.8 +/- 1.6 and 15.6 +/- 3.1, respectively. Significant differences existed between the % of normal sperm forms found in the swim-up and zona-bound spermatozoa (P = less than 0.01 and P = less than 0.0003, respectively) compared to the original ejaculates. Results indicate that a selective process against abnormal spermatozoa occurs at the site of the zona pellucida.(ABSTRACT TRUNCATED AT 250 WORDS)     

Time-lapse analysis and normal stages of development of cleavage and blastocyst formation in the marsupials the brown antechinus and the stripe-faced dunnart

The first six normal stages of cleavage and blastocyst formation in vitro of the brown antechinus and the stripe-faced dunnart are described based on 429 embryos from 37 dunnarts and 143 embryos from 32 antechinus and an information from previous studies. Embryos were cultured in Dulbecco's modified Eagle's medium with high glucose and 10% foetal calf serum at 35 degrees C and 5% CO2 in air. Seven antechinus and 18 dunnart embryos were cultured in Rose chambers and filmed by time-lapse cinematography, with an exposure of 0.2 sec and at a rate of 1 frame/30 sec. A rim of zona was formed around the yolk mass during early cleavage. Blastomeres attached to this rim, ensuring that the zona in the hemisphere containing the yolk mass was the first to be lined by blastomeres during blastocyst formation, which is completed at about the 32-cell stage. Two foci were established during cleavage. The descendants of the first cell to divide at the four-cell stage included, at both the fourth and fifth division, the first cell to divide and the cell with the shortest cell cycle time and had the shortest average cell cycle time at each division. The descendants of the cell opposite the first cell to divide at the four-cell stage included, at both the fourth and fifth divisions, the last cell to divide and the cell with the longest cell cycle time and had the longest average cell cycle time at each division.     

Formation of primordial yolk granules in the avian oocyte

Summary Electron and light microscopical investigations of early oocytes (between 1.0 mm and 5.0 mm in diameter) from the ovary of 28–30 week-old chickens, suggested the formation of primordial yolk granules from cytoplasmic vesicles. These vesicles formed an aggregation which was observed to be surrounded by membranes, giving the aggregate a multivesicular body-like appearance. At a later stage the vesicles inside the membrane disintegrated and the multivesicular bodies acquired the appearance of primordial yolk granules. The contribution of other structures to the formation of yolk granules is discussed.For constructive criticism I am very grateful to Dr. Hadar Emanuelsson, Institute of Zoophysiology, Lund. The excellent technical assistance of Miss Inger Antonsson and Mrs. Annagreta Petersen is gratefully acknowledgedThis work was supported by Kungliga Fysiografiska Sällskapet, Lund     

Expression of the 14 kDa and 16 kDa galactoside-binding lectins during differentiation of the chick yolk sac

The gastrulating chick embryo expresses two galactoside-binding lectins of 14 kDa and 16 kDa. These lectins are present in the area pellucida and area opaca, and in the latter are concentrated in the endoderm. Since the area opaca is the progenitor of the yolk sac, we studied the galactose-binding lectins during the development of this extraembryonic organ. In the yolk sac, lectin expression surges between 2 and 4 days, and thereafter remains constant throughout development. Using monoclonal antibodies (mAbs) specific to the 16 kDa yolk sac lectin, and a panel of polyclonal antibodies to the 14 kDa and 16 kDa lectins we studied lectin expression. The mAbs inhibit the hermagglutinating activity of extracts from chick yolk sac, embryonic pectoral muscle, and adult liver, but have no effect on the hemagglutinating activity of extracts from the adult intestine. Immunolocalization studies with the mAbs and polyclonal antibodies indicate that in the less differentiated endodermal cells of the area vitellina the 16 kDa lectin is present in discrete lectin-rich inclusions. In contrast, within the maturing endodermal epithelium of area vasculosa the 16 kDa lectin is present around the intracellular yolk platelets, and is associated with the cytoplasmic matrix. The 16 kDa lectin is also found at the apical cell surface of the yolk sac epithelium, in some regions closely associated with the plasma membrane. The 14 kDa lectin is distributed intracellularly surrounding the yolk platelets of the maturing yolk sac endoderm. The surge in expression of the 16 kDa lectin at the time of expansion of the area opaca suggests that it may be involved in the spreading of this area. Our findings also indicate that as the yolk sac endoderm differentiates into an epithelium intracellular lectin expression changes from predominantly organelle associated to cytoplasm associated. The association of both lectins with yolk suggest that the lectins may also be involved in the processing of intracellular and extracellular yolk proteins. These results, in con junction with previous findings indicating the presence of these lectins in the extracellular matrix (Didier et al., Histochemistry 100:485, 1993; Zalik et al., Intl J Dev Biol 38:55–68, 1994) indicate that these lectins play multiple roles in embryonic development.     

胆囊收缩素卵黄抗体在大鼠十二指肠的吸收

为了探讨CCK卵黄抗体能否被动物消化道所吸收 ,我们应用SDS PAGE电泳、ELISA和Westernblot方法 ,检测灌胃CCK卵黄抗体后SD大鼠十二指肠静脉血液中CCK卵黄抗体的免疫活性及存在形式。实验采用1 4只雄性成年SD大鼠 ,随机分成试验组和对照组 ,分别灌胃 1 5 0mg/mlCCK卵黄抗体粉混悬液和生理盐水 (2ml/只 )。安装亚急性十二指肠静脉插管 ,在灌胃后第 2、 3、 4h采集十二指肠静脉血液 ,分离血浆。SDS PAGE结果显示 ,CCK卵黄抗体分子量为 2 0 0kD。ELISA研究表明 ,试验组第 2、 3h的血浆中 ,均检测到CCK卵黄抗体效价 ,效价达 1∶1 2 8以上。同时 ,Westernblot分析发现 ,试验组第 2、 3h血浆中存在完整分子形式的卵黄抗体。研究结果提示 ,CCK卵黄抗体能被SD大鼠十二指肠段吸收或部分吸收进入血液 ,发挥其免疫学活性     

红螯光壳螯虾卵黄磷蛋白的分离纯化和鉴定

采用凝胶层析、聚丙烯酰胺凝胶电泳及SDS-聚丙烯酰胺凝胶电泳法对红螯光壳螯虾(Cherax quadricarinatus)卵巢中的卵黄磷蛋白进行了分离、纯化和鉴定。结果显示该虾的卵黄磷蛋白是一个分子量为369ku的多聚体,由分子量为85．4、80．6、76．6、73．7ku的四个亚基组成。染色分析表明卵黄磷蛋白为糖-磷-类胡萝卜素结合的复合蛋白。氨基酸组成分析显示天冬氨酸(Asp)和谷氨酸(Glu)为主要氨基酸。