管氏肿腿蜂的胚胎发育观察

管氏肿腿蜂Scleroderma guani Xiao et Wu的卵在24℃和RH60%~70%条件下发育约140h孵化。根据胚胎外形的发育特点,可将整个发育过程可分5个阶段:早期发育阶段、胚胎伸长期、原躯原头分化阶段、器官形成阶段和胚胎成熟期。胚层形成趋于简单化,未形成解剖学上比较完整的呼吸、排泄及循环等系统。口道形成后,胚胎体积逐渐增加,这表明胚胎在发育过程中吸收了寄主的营养物质。     

小鼠体外受精、胚胎培养及胚胎快速冷冻的研究

目的　为扩大胚胎来源并获取特定胚龄胚胎 ,建立小鼠冷冻胚胎库。方法　运用超数排卵、体外受精与胚胎培养及胚胎冷冻技术系统研究了小鼠受精卵的体内发育与运行规律。卵母细胞的体外成熟与受精、单细胞胚胎培养及胚胎快速冷冻。结果　 (1)注射hCG后 12～ 2 0h受精卵发育至原核期 ,4 2～ 4 8h为 2 细胞期 ,4 8～ 6 0h为 4 细胞期 ,6 0～ 6 8h为 8 细胞期 ,以上各期受精卵均处于输卵管中 ;75～ 78h为桑椹胚 ,78～ 80h为致密桑椹胚 ,90～ 92h为早期囊胚 ,92～ 96h为囊胚 ,以上各期均处于子宫角中。 (2 )培养液中添加促性腺激素 (FSH与hCG) ,能显著提高卵母细胞的体外受精率 ,添加FCS和激素组的体外受精率又显著高于单独添加激素组 ,FCS还能显著提高胚胎发育。 (3)在培养液中添加EDTA ,能有效克服小鼠胚胎的 2 细胞阻断 ,其 2 细胞胚的发育率达 10 0 % ,8 细胞胚发育率达 5 5 %以上 ;牛、羊上皮细胞培养液上清也能有效克服 2 细胞阻断。添加乳酸钠和丙酮酸钠可使 2细胞与 8细胞期胚的发育率显著提高。 (4)以D PBS +甘油 +蔗糖为冷冻液 ,以D PBS +蔗糖为稀释液 ,对小鼠胚胎进行快速冷冻 ,桑椹胚的存活率为 6 9 3% ,早期囊胚的存活率为 6 0 4 %。结论　研究为将生物技术应用于小鼠 ,扩大卵子和胚胎来源     

凹耳臭蛙胚胎发育及其分类学意义(英文)

通过人工受精的方法获得的凹耳臭蛙(Odorrana tormota)的早期胚胎及胚后幼体的发育过程,根据胚胎发育过程中的形态及生理特征变化规律进行分期。把凹耳臭蛙的发育过程分成两个阶段:1)早期胚胎发育阶段,即从蛙卵受精到鳃盖完成期,在18～23℃水温下,凹耳臭蛙早期胚胎发育阶段历时324h;2)蝌蚪发育阶段,即从鳃盖完成期结束到尾部被完全吸收,本阶段在20～24℃水温条件下历时1207h。凹耳臭蛙蝌蚪未发现腹吸盘特征,从形态特征上支持了分子系统分类学将之从湍蛙属划出的观点。实验中发现,多数胚胎在8细胞期为纬裂,16细胞期为经裂,同时有小部分胚胎(1.5%)在8细胞期为经裂,16细胞期为纬裂。该文进一步讨论了影响卵裂率、孵化率、发育速度,以及生态适应的因素。     

尖唇散白蚁胚胎发育激光共聚焦扫描显微镜观察

【目的】本研究旨在探究尖唇散白蚁Reticulitermes aculabialis胚胎在不同发育阶段的变化特征。【方法】每日收集尖唇散白蚁的卵,并固定其胚胎发育状态,采用DAPI染剂对白蚁胚胎进行染色,通过激光共聚焦扫描显微镜观察记录尖唇散白蚁胚胎在不同发育阶段的形态特征。【结果】在25℃下尖唇散白蚁胚胎发育过程历经25~30 d,按照发育特征将其划分为12个阶段。胚胎发育早期,卵黄细胞均匀分布在卵内部,卵内细胞核向卵的中间浓缩,在细胞到达卵的后表面时形成浓缩的囊胚细胞作为胚盘;胚胎发育中期,胚胎开始进行“反转型”的囊胚运动,头部和前后轴从后极到前极反转,胚带出现明显的“双弯”结构。胚胎发育中后期,胚胎变宽,内部器官逐渐开始发育,出现明显的伸长与分节;胚胎发育后期,附肢发育明显,内部器官发育成熟。【结论】尖唇散白蚁胚胎发育过程历经12个阶段,属于短胚带型,胚带出现“双弯”结构,发育中期经历两次囊胚反转。本研究为真社会性昆虫白蚁的胚胎发育过程提供了形态学和生物学依据。     

金线蛙早期胚胎发育的初步观察

报道了金线蛙的早期胚胎发育。自受精卵期至鳃盖完成期共分为 2 6个时期 ,其发育历程及各时期胚胎外形特征与黑斑蛙基本相似 ,但孵化期比黑斑蛙推迟三个胚期而早于泽蛙 ,在水温 ( 2 0± 0 5)℃及常温 ( 2 1 5～ 2 4℃ )条件下 ,其胚胎发育的全时程分别为 2 1 2 94小时和 1 70 95小时。     

猪体细胞核移植重构胚的体外发育(英文)

以卵丘细胞为核供体细胞组成重构胚 ,卵裂率达到 5 6.7% ,发育至桑椹胚率达到1 1 .7% ,囊胚率为 6.7% ,显著高于成纤维细胞重构胚 (P <0 .0 5 )。本文还研究了卵母细胞的采集方法、激活程序和卵龄对卵丘细胞核移植重构胚体外发育的影响。以血清饥饿法将卵丘细胞诱导至G0 G1 期 ,抽吸法 解剖法采集卵母细胞 ,体外培养 3 3～ 44h ,将卵丘细胞放至去核卵母细胞的卵周隙中 ,重构胚以钙离子载体A2 3 81 7或电脉冲结合 6 DMAP激活处理 ,体外培养 6d。研究表明 ,卵母细胞采集方法、激活液中细胞松弛素 (CB)、激活程序并不影响重构胚的发育 (以卵龄 44h的卵母细胞为受体 ) ;而以电脉冲结合 6 DMAP激活处理能提高重构胚发育能力 (以卵龄 3 3h的卵母细胞为受体 ) (P <0 .0 5 )。本研究显示 ,以电脉冲结合 6 DMAP激活卵丘细胞重构胚 ,体外能发育至囊胚     

达氏鳇不同发育期胚胎对低温的耐受研究

研究了达氏鳇12个发育期胚胎经过不同低温（2 ℃、3 ℃、5 ℃、7 ℃和8 ℃）处理12 h、24 h、2 d、3 d、6 d、10 d、15 d、20 d和30 d后的孵化率和仔鱼成活率.结果表明,卵黄栓期、隙状胚孔期、神经管闭合期胚胎在2～8 ℃水温下,处理24 h后孵化率为0;卵裂期、囊胚早期、原肠中期胚胎在2～8 ℃水温下,处理3 d后孵化率低于30%;囊胚晚期、原肠早期、眼基期、尾芽期、心跳期和尾达头部期胚胎在5～8 ℃水温下,处理3 d后孵化率、仔鱼成活率超过70%;随低温处理时间延长,胚胎和仔鱼的死亡率增加,处理时间与孵化率、仔鱼成活率呈负相关;囊胚晚期、原肠早期、眼基期胚胎在5 ℃水温下耐受力较强,处理10 d后孵化率、仔鱼成活率超过70%.本研究表明,达氏鳇胚胎发育过程中囊胚晚期、原肠早期和眼基期胚胎可以在某一低温下进行短期保存,其孵化率、仔鱼成活率与常温（16～17 ℃）下没有显著差异.这对于达氏鳇胚胎（受精卵）的长途运输有重要意义.     

鲈鱼胚胎的玻璃化冷冻保存

本文对鲈鱼(Lateolabrax japonicus)胚胎进行了玻璃化冷冻保存研究,筛选出了浓度较低、玻璃化程度较稳定的5种玻璃化液,冷冻时形成玻璃化的概率在48．1％～100％,在35～43℃的水浴中解冻时保持玻璃化的概率在44．4％～63．0％;玻璃化液VSD2在解冻时保持玻璃化的概率最高。对鲈鱼神经胚、20对肌节胚、尾芽胚、心跳胚、出膜前胚在玻璃化液VSD2中的适应能力及适合于玻璃化冷冻的胚胎时期进行了比较,结果显示：不同时期胚胎对玻璃化液的耐受能力不同,鲈鱼神经胚耐受能力最低,心跳胚耐受能力最强,出膜前期胚次之,心跳胚和出膜前胚适合于进行玻璃化冷冻。对0．5mol/L蔗糖的洗脱时间进行了选择,结果显示,洗脱10～20min效果较好。利用玻璃化程度较好的VSD2对鲈鱼不同时期胚胎进行超低温(-196℃)冷冻,获得了2．1％～27．9％的透明胚。将鲈鱼心跳胚冷冻解冻后获2粒复活胚,培养至出膜期,成活42～50h;出膜前期胚在冷冻解冻后有1粒胚复活,并且孵化出鱼苗[动物学报49(6)：843～850,2003]。     

4℃保存的小鼠屠体卵巢GV卵的发育能力

为了探明雌性动物死亡后GV期卵的可利用性,本研究将ICR系雌性小鼠处死,尸体在4～6℃下分别保存16h、24h和48h,取其卵巢GV期卵,体外成熟后,应用常规法进行体外受精或透明带切割法体外受精,获得2细胞期胚,通过体外培养或胚胎移植观察其发育能力。结果显示,4～6℃下保存16h和24h处理组的体外受精率(分别为31%、33%和21%、24%)与来自新鲜的带有颗粒细胞卵的体外受精率(33%)相比无显著差异。与其相比,保存48h处理组的GV卵已丧失发育能力。此外,体外受精中获得的2细胞胚经体外培养,16h处理组和24h处理组的囊胚率(60%、61%和72%、83%)与新鲜GV期卵处理组的囊胚率(72%)相比差异不显著。获得的2细胞胚经胚胎移植可得到正常幼鼠。上述结果表明,如果雌性小鼠死亡后立即在冷藏温度下(4～6℃)保存,其体内的GV卵在24h以内仍保持发育能力。     

多胚发育寄生蜂腰带长体茧蜂在寄主亚洲玉米螟幼虫体内的发育

多胚发育的幼虫内寄生蜂腰带长体茧蜂Macrocentrus cingulum的卵、胚胎和幼虫在寄主亚洲玉米螟Ostrinia furnacalis幼虫血腔内发育，通常1枚卵可以分裂增殖为数百只胚胎。本文通过定时解剖寄生的寄主幼虫，初步了解了腰带长体茧蜂多胚的形成过程及其在寄主体内的发育情况。结果表明：以4龄末期亚洲玉米螟幼虫为寄主时，寄生蜂卵产入寄主体内10 min左右开始卵裂，1天左右，初级胚胎从卵壳中被释放出来。之后胚胎在胚外膜内持续分裂产生大量二级胚胎形成桑葚胚。寄生后3天左右，二级胚胎从胚外膜中被释放出来，进入胚胎发育阶段。寄生后6天左右，胚胎进入胚带形成阶段。寄生后8天左右，胚带伸长，头尾形成。寄生后9天左右，身体分节完成，部分幼虫孵化，蜕去胚外膜。寄生后13天左右，蜂幼虫从寄主体内啮出。胚胎在发育初期体积变化不大，但从胚带形成开始，体积则迅速增大。腰带长体茧蜂与另一多胚发育寄生蜂佛州点缘跳小蜂Copidosoma floridanum在胚胎发育进程上明显不同，体现了它们对各自寄主的适应。     

Development and Fecundity of Reesimermis nielseni,a Nematode Parasite of Mosquitoes

Maturation of the mermithid nematode Reesimermis nielseni to the adult stage began by the tenth day after emergence of the nematodes from their hosts at ambient temperatures (24-27 C). Most postparasitic males and females reached the adult stage after 50 and 70 days, respectively. The first females exhibiting egg development and oviposition were observed 25-30 days after emergence, but some oviposition was still taking place 150 days later. Reesimermis nielseni laid an average 2,480 eggs per female over an 18-day oviposition period. A majority of the mature eggs hatched within 7 h after the cultures were flooded. The preparasites are short-lived, and only a few were able to infect exposed hosts after 72 h.     

中红侧沟茧蜂在粘虫体内的发育 及畸形细胞发生

中红侧沟茧蜂Microplitis mediator的初产卵因受雌蜂产卵器的机械挤压,在形态上有别于未产出的卵,这种机械挤压激活了蜂卵的胚胎发育。产卵后 6 h,胚带和浆膜层开始分化,20 h胚胎成形,包裹在单层细胞的浆膜层内。32～34 h,幼蜂孵化,顶部的浆膜层立即分散形成畸形细胞,尾部的浆膜层则逐渐释放细胞。1龄幼蜂具一对角质的颚,用来消灭同种竞争者。寄生后108～113 h,1龄幼蜂蜕皮进入2龄。2龄幼蜂为无头型,尾囊发达。成熟的畸形细胞(受寄生日龄6天)表面密布微绒毛,细胞内部高尔基体丰富,内质网发达,细胞核多分支。在高尔基体的两侧和细胞膜附近分布了大量的分泌小池。     

真水狼蛛胚胎发育过程中形态和主要化学物质含量的变化

采用常规石蜡切片和液体石蜡透明卵壳的方法,系统地观察了真水狼蛛的胚胎早期,体节期,胚胎速转期和幼虫期4个发育阶段的形态特征和发育过程,并测定了胚胎发育过程中卵的内主要化学物质含量的变化,在28度时,真水狼蛛的卵从产卵到孵化共需144小时,其中胚胎早期42小时,体节期33小时,胚胎逆转期27小时,在胚胎逆转期后进入前幼虫期,前幼虫期42小时,真水狼蛛的胚胎逆转现象很明显,表明真水狼蛛的进化程度较高,在胚胎发育过程中,卵的含水量,含脂量和卵重在胎发育24hr后开始下降,卵的蛋白质含量在48小时后也开始下降,含糖量下降不明显。     

A novel RNA helicase-like protein during early embryonic development in silkworm Bombyx mori: molecular characterization and intracellular localization

In order to understand the molecular mechanism of development during early embryogenesis in diapause and non-diapause of the silkworm, mRNA from diapause and non-diapause eggs was compared using the differential display technique. We cloned the full length of a cDNA encoding a novel RNA helicase-like (RHL) protein by the RACE method using a cDNA fragment which was one of the specific cDNAs in the non-diapause eggs. A BLAST search using the predicted amino acid sequence of RHL revealed a low homology (21–25% identity of its partial length) with that of the DEAD-box RNA helicase. Gene expression of the RHL gene of the diapause and non-diapause eggs was investigated by RT-PCR until 60 h after oviposition. Amplified RHL cDNA was observed through all the stages in the non-diapause eggs, while in the diapause eggs, cDNA was found in eggs 0–12 h after oviposition but disappeared 24–60 h after oviposition. When the diapause eggs were activated by HCl treatment after chilling at 4 °C for 6 days from 48 h after oviposition (artificial diapause termination), cDNA was observed from 12 h after HCl treatment. We also investigated the immunohistochemical distribution and localization of RHL in non-diapause eggs using anti-recombinant His-tag RHL antiserum. RHL was distributed in blastoderm cells and yolk cells and was localized in the nucleus and the cytosol of yolk cells. These data suggest that RHL has an important role in the early embryo of the silkworm.     

Specialized features of Rhynchosciara americana embryogenesis

Insect embryo development is a complex process which requires nuclear and cellular division, cell shape alteration, and cell movement. This process needs to be orchestrated in a specific spatial and temporal fashion. Different insect species, despite similarities, present distinct morphogenetic pathways. We used the dipteran R. americana as a comparative model for embryo morphogenesis studies, following embryo development with different histochemical and immunohistochemical procedures. Despite the phylogenetic proximity with D. melanogaster, R. americana presents a peculiar morphogenesis. We show that at the initial phases of development, from egg fertilization to blastoderm formation, R. americana is similar to Drosophila. The first cleavages are nuclear and cellularization only begins after nuclei spread throughout the egg’s cortex. However after this stage a series of cell movements establishes a short compact germ band anlage, which gastrulates in a pattern quite different from Drosophila. After gastrulation the germ band elongates anterior–posteriorly and segmentation occurs simultaneously along the embryo. Embryo development from egg fertilization to larva hatching takes about 12 days. Our results show that R. americana presents a different morphogenetic pathway which does not fit in the current short, intermediate or long germ band classification.     

Embryogenesis of Heliconius erato (Lepidoptera,Nymphalidae): A contribution to the anatomical development of an evo‐devo model organism

This study reports on the embryogenesis of Heliconius erato phyllis between blastoderm formation and the prehatching larval stage. Syncytial blastoderm formation occurred approximately 2 h after egg laying (AEL) and at about 4 h, the cellular blastoderm was formed. The germ band arose from the entire length of the blastoderm, and rapidly became compacted occupying approximately two‐thirds of the egg length. At about 7 h AEL, protocephalon and protocorm differentiation occurred. Continued proliferation of the germ band was followed by penetration into the yolk mass, forming a C‐shaped embryo at about 10 h. Approximately 12 h AEL, the gnathal, thoracic and abdominal segments became visible. The primordium of the mouthparts and thoracic legs formed as paired evaginations, while the prolegs formed as paired lobes. At about 30 h, the embryo reversed dorsoventrally. Approximately 32 h AEL, the protocephalon and gnathal segments fused, shifting the relative position of the rudimentary appendages in this region. At about 52 h, the embryo was U‐shaped in lateral view and at approximately 56 h, the bristles began evagination from the larval cuticle. Larvae hatched at about 72 h. We found that H. erato phyllis followed an embryonic pattern consistent with long‐germ embryogenesis. Thus, we believe that H. erato phyllis should be classified as a long‐germ lepidopteran. The study of H. erato phyllis embryogenesis provided a structural glimpse into the morphogenetic events that occur in the Heliconius egg period. This study could help future molecular approaches to understanding the evolution of Heliconius development.     

Alcune caratteristiche strutturali dei cromosomi politenici del sospensore embrionale di Phaseolus coccineus in due momenti dell'embriogenesi

Abstract

Some features of polytene chromosomes of Phaseolus coccineus suspensor during two stages of early embryogenesis. – The distribution of DNA and RNA puffs in the whole genome of the giant cells of the Phaseolus coccineus embryo suspensor has been detected in two stages of embryo development. The collected data show that the chromosome regions showing the highest frequency of DNA puffs in both analysed stages are the following: i) band B (the fraction proximal to secondary constriction) of chromosome pair I and band E of chromosome pair V. When the two stages of development are however compared, it is seen that the % of DNA puffs in chromosome pair is at least double in suspensors dissected from the first stage of embryo development (86% in the first stage; 41% in the second stage). As to chromosome pair V band E organizes DNA puffs in 36% and in 50% of observed chromosomes in the first and second stage respectively; ii) band A of chromosome pair II, with a frequency of 52% (first stage) and 27% (second stage); iii) band E of chromosome pair VIII (27% in the first stage and 19% in the second stage). As far as the organization of RNA puffs is concerning it seems possible to outline the following values as the highest percentages:

a) First stage. chromosome b) Second stage. chromosome

I: band B 83% I: band B 91% VI: band E 55%

II: band A 70% II: band A 51% band G 50%

IV: band E 45% band C+D 59% VIII: band E 44%

V: band B+C 57% IV: band E 51% IX: band A 54%

band E 71% band G 51% band E 43%

VI: band E 53% band I 51% band F 53%

VIII: band E 43% V: band E 43%

IX: band E 42%

The differences observed between the two stages are discussed in relation to the function of the suspensor.     

Embryogenesis of the glowworm Rhagophthalmus ohbai Wittmer (Insecta: Coleoptera, Rhagophthalmidae), with emphasis on the germ rudiment formation

The early embryonic development and features of the developing embryo of the glowworm Rhagophthalmus ohbai are described chiefly by light microscopy, with emphasis on the germ rudiment formation and its phylogenetic implication. The egg period is 30-34 days at about 23 degrees C. The newly laid egg is a short ellipsoid, 1.09 by 0.78 mm in size, and the size increases to 1.15 by 0.95 mm by 17 days after oviposition. Cleavage is of the typical superficial type. The germ disk is formed by cell aggregation of the embryonic area at the anterior end of the egg. The central part of the germ disk then sinks into the yolk and the spherical germ rudiment is formed by fusion of the amnioserosal folds extended from all margins of the germ disk. The inner region of the germ rudiment soon becomes slender and develops into the short embryo, whereas the outer region facing the anterior end is extended to form the thin amnion. The embryo then rapidly elongates, the elongation being accompanied by embryo segmentation and formation of appendages. The submerged condition of the embryo persists until about 17 days after oviposition (about 1 day before embryonic revolution) and thereafter the embryo becomes superficial in position. The presence of the following embryonic characters in R. ohbai supports the molecular data placing it within the Lampyridae: 1) formation of a spherical germ rudiment near the anterior end of the egg, and 2) the submerged condition of the developing embryo persists until shortly before revolution.