大竹蛏胚胎发生及稚贝发育基本特征

在人工培育条件下,对大竹蛏(Solen grandis)胚胎发生及稚贝发育进行显微观察,探究大竹蛏胚胎及幼虫发育规律。结果表明,大竹蛏胚胎及幼虫发育过程为:受精卵、卵裂、囊胚期、原肠期、担轮幼虫、D形幼虫、稚贝。在日平均水温为22.4℃时,受精后20～24 h发育成D形幼虫,5～7 d变态为稚贝,38 d稚贝已具备成贝形态,壳长壳高比为2.60。从受精卵到附着所需积温为3 088.79～5 005.19℃.h。稚贝先形成出水管,后形成进水管,最终形成"一管双孔"。壳长与壳高关系式为y=150.37e0.002 7 x,x为壳高(μm),y为壳长(μm),R2=0.985 5,P0.01;壳长与日龄关系式为y=143.38e0.091 6 x,x为日龄(d),y为壳长(μm),R2=0.979 5,P0.01;壳高与日龄关系式为y=33.979 x-15.450,x为日龄(d),y为壳高(μm),R2=0.987 3,P0.01。     

大竹蛏胚胎发生及稚贝发育研究

在人工培育条件下,对大竹蛏(Solen grandis)胚胎发生及稚贝发育进行显微观察,探究大竹蛏胚胎及幼虫发育规律。结果表明,大竹蛏胚胎及幼虫发育过程为：受精卵、卵裂、囊胚期、原肠期、担轮幼虫、D形幼虫、稚贝。在水温为22.4℃时,受精后20~24h发育成D形幼虫,5~7d变态为稚贝,38d稚贝贝壳已具备成贝形态,壳长壳高比为2.60。从受精卵到附着所需积温为3088.79~5005.19℃?h。稚贝先形成出水管后形成进水管,最终形成“一管双孔”。壳长与壳高关系式为     

桃花水母生活史的实验观察

记录了中国产信阳桃花水母(Craspedacusta xinyangensis)的生活史及各阶段主要发育特征。25～28℃条件下,卵受精23h后发育成长0.14～0.21mm的圆棍状浮浪幼虫,养殖环境下,浮浪幼虫在水中漂浮3～5d后固定到人工玻璃底质上,3～4d后发育成长度0.3～0.6mm的螅状体。水螅体产生无纤毛的类浮浪幼虫形成新的螅状体。一个螅状体成熟后产生一个水母芽,新释放的幼水母具有16只触手。     

可口革囊星虫胚胎与幼体的发育

解剖经降温8-10℃刺激30-40h后的可口革囊星虫(Phascolosomaesculenta)亲体取得精、卵,用人工授精法获得的受精卵进行胚胎和幼体发育的研究。结果表明:可口革囊星虫的卵为圆形或椭圆形,卵的大小为120μm×142μm-125μm×148μm。精子由头部、中段和尾部组成,全长约为32-40μm。在海水盐度23.8ppt、pH8.1、温度15℃的条件下,精、卵不能受精;在海水盐度23.8ppt、pH8.1、温度20℃的条件下,精卵能受精,但胚胎发育到原肠胚期停止;在海水盐度23.8ppt、pH8.1条件下,25℃、30℃和35℃的不同水温,精卵均能受精,受精卵发育到初期海球幼虫分别需要72h0min、47h08min和42h53min。在海水盐度23.8-25.5ppt,pH8.1-8.2,温度28-30℃条件下,从初期海球幼虫发育到稚虫需要15-20d。     

利氏才女虫幼体发育的研究

对利氏才女虫Polydora ligni幼体的发育过程及各发育阶段形态结构特点作了观察研究,结果表明在温度(16±3)℃下,卵在卵袋中经过4 d发育成3刚节浮游幼体后进入水体开始浮游生活,13 d后14刚节的浮游幼体开始变态,19 d发育成21刚节后开始沉落转为底栖生活,21 d后23刚节的底栖幼体完成变态营管栖生活.     

仿刺参耳状幼体“烂边症”的病原及其来源分析

【目的】查明仿刺参耳状幼体"烂边症"的病原及其来源,并获得该病的治疗药物。【方法】对烂边症状较为典型的育苗场的发病幼体进行病原学分析,对可疑病原进行人工回接感染并进行形态学、生理生化和16S rDNA序列分析鉴定,对养殖场育苗系统,包括水源、饵料、育苗池水、育苗池底污物和亲参池水进行细菌学分析,对病原菌进行药敏测试。【结果】从患病幼体分离得到1种优势菌株,人工回接感染证明它对健康仿刺参有较强的致病性,且感染发病与自然发病仿刺参幼体的症状相同。鉴定出"烂边症"的病原为弧菌Vibrio lentus。养殖系统中的细菌浓度均较高(2.8×102-8.8×107cells/mL);病原来源较复杂:育苗池水、池底污物和亲参池水均发现了病原菌,病原菌浓度以池底污物中最多,育苗池水次之,亲参池水最少。新霉素等15种常用抗生素可有效抑制该病原菌的生长。【结论】"烂边症"的病原为弧菌Vibrio lentus;池底污物、育苗池及亲参均可能是本次"烂边症"的病原来源;新霉素等15种常用抗生素可用于该病的防治。     

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。     

斑马鱼整体原位杂交法研究MMP15a的发育相关表达的初步观察

克隆斑马鱼基质金属蛋白酶15a（MMP15a）基因,并研究其在斑马鱼胚胎早期发育中的时空表达状况。收集不同发育时期的斑马鱼胚胎,制备DIG标记的MMP15a RNA探针,采用全胚胎原位杂交方法研究MMP15a基因在胚胎斑马鱼的表达。结果MMP15a基因在胚胎受精后一个细胞时期就开始表达,从受精后24h起,在眼睛处表达明显,从受精后48h MMP15a在胸鳍和耳囊有特异性表达至到受精后96h。MMP15a在斑马鱼胚胎发育不同时期表达明显,且在胸鳍和耳囊处有持续表达。     

整体原位杂交法初步研究MMP11b在斑马鱼胚胎发育过程中的表达

克隆斑马鱼基质金属蛋白酶11b（MMP11b）基因,并研究其在斑马鱼胚胎早期发育中的时空表达状况。收集不同发育时期的斑马鱼胚胎,制备DIG标记的MMP11b RNA探针,采用全胚胎原位杂交方法研究MMP11b基因在斑马鱼胚胎的表达。MMP11b基因在胚胎受精后一个细胞时期就开始表达,并且一直持续到96h,从受精后24h起,在耳囊处表达明显,在受精后48h时期在胸鳍和肛门处也有特异性表达。MMP11b在斑马鱼胚胎发育不同时期表达明显,且在耳囊处有持续表达。     

南方鲇脑垂体发育的研究

对不同发育阶段南方鲇脑垂体的显微和超微结构进行了研究。结果表明 :南方鲇脑垂体由两个不同部位的胚胎细胞形成。源自胚胎原始口腔顶壁的上皮细胞团构成垂体的前、中腺垂体和部分后腺垂体 ;从间脑腹面漏斗体分离出来的细胞构成神经垂体和部分后腺垂体。受精后 32h ,原始口腔上皮细胞增生 ,口腔顶壁细胞群内凹 ,开始向内迁移 ;受精后 38h ,上皮细胞与口腔顶壁分离 ,形成实心细胞团 ,并沿着前脑腹面向间脑方向迁移 ;受精后4 5h ,细胞团迁移到间脑底部下方 ;初孵仔鱼原始口腔顶壁上皮细胞团位于间脑底部 ,与漏斗体接触 ;出膜后 36h ,上皮细胞团与漏斗体分离出来的细胞结合 ;出膜后 4 8h ,腺垂体和神经垂体清晰可辨 ;出膜后 4d ,腺垂体可区分前、后两部分 ;出膜后 6d ,GH细胞开始分化 ;出膜后 10d ,前、中、后腺垂体分化形成 ;出膜后 4 8d ,除GTH细胞外 ,其他分泌细胞均已分化 ;6月龄 ,分泌细胞分化完成。 1冬龄和 2冬龄幼鱼脑垂体仅前、中、后腺垂体体积及分泌细胞比例和部分细胞的超微结构与成鱼不同。     

MicroRNA in cell differentiation and development

The regulation of gene expression by microRNAs (miRNAs) is a recently discovered pattern of gene regulation in animals and plants. MiRNAs have been implicated in various aspects of animal development and cell differentiation, such as early embryonic development, neuronal development, muscle development, and lymphocyte development, by the analysis of genetic deletions of individual miRNAs in mammals. These studies show that miRNAs are key regulators in animal development and are potential causes of human diseases. Here we review some recent discoveries about the functions of miRNAs in cell differentiation and development. Supported by National Key Basic Research and Development Program of China (Grant No. 2005CB724602) and Knowledge Innovation Project of the Chinese Academy of Sciences (Grant Nos. KSCX2-YW-R-096, KSCX1-YW-R-64)     

In vitro cultivation of Fasciola hepatica metacercariae and of partially developed flukes recovered from mice

Attempts were made to culture the metacercariae of Fasciola hepatica under a wide variety of conditions. Of the media tested, the most successful was NCTC 135 plus 50% heat inactivated chick serum and sheep red blood cells at 37°–38°C. In this medium, somatic development of newly excysted juveniles was similar to that of flukes recovered from the liver of a mouse 11 days post-infection. There was, however, no corresponding development of the genital rudiment. Various supplements, such as liver extract, bile, yeast extract, embryo extract, egg products, monolayer cells and diphasic media were tested, but none enhanced development. The effects of various physical parameters on growth and development in vitro were examined. Cultured metacercariae appeared to be in a state of ‘suspended animation’; when injected intraperitoneally into mice they developed into egg-producing adults. Flukes recovered from the abdomen and liver of mice continued their somatic growth in vitro but their genitalia failed to develop further.     

Conserving global biological diversity by encouraging alternative development paths: can development coexist with diversity?

The conservation of biological diversity concerns the management of the development process, not only at the national but also at the global level. Individual countries have made their development choices independently but relatedly, too often following the precise form of the choices of other countries preceding them in the development process. Development via imitation is pursuing the form, rather than the substance of a successful development strategy. Countries should instead be developing upon a base of assets that provides them with a relatively unique set of goods and services to place upon global markets. When the first countries developed, this criterion indicated that they should convert their countries to new forms of production; when the last countries are developing, relatively unique goods and services flow from their lands as they stand. What is required is the development of global institutions that encourage countries to see that their best development opportunities lie down these alternative development pathways, based upon their already-existing but relatively unique national assets.     

Characterization of Sgo1 expression in developing and adult mouse

SGO1 has been characterized in its function in correct cell division and its role in centrosome cohesion in the nucleus. However, its organ-specific maturation-related expression pattern in vivo remains largely uncharacterized. Here, we show clear SGO1 expression in post-developmental neuronal cells and cytoplasmic localisation in nucleated cells with a transgenic mice model and immunohistochemistry of wild type mice. We demonstrate extranuclear expression of Sgo1 in the developing heart and gut, which have been shown to be dysregulated in humans with homozygous SGO1 mutation. Additionally, we show Sgo1 expression in select population of retinal cells in developing and post-developmental retina. Our expression analysis strongly suggests that the function of SGO1 goes beyond its well characterized role in cell division.     

Perinatal dental development in the chimpanzee (Pan troglodytes)

The synthesis of both ontogenetic and phylogenetic data should provide the ideal explanation of morphologic variation, but for the primate dentition, this has not yet occurred. Information concerning growth and development of primate teeth is lacking, in part because of the paucity of specimens. We have therefore examined the deciduous second molars (dm2) and tooth buds of the permanent first molar (M1) of 12 chimpanzees (Pan troglodytes), aged 6.5 months of gestation to 4 postnatal months. The ordering of cusp calcification was identical to that of other primates. By regression analysis, correlations of mesial and distal widths with buccal, lingual, and mesiodistal lengths were low, most probably because of decreased rates of change (slopes) and the relatively small sample size. Correlations were, however, greater for mandibular than for maxillary dentition and higher for age than for body weight; for both the dm2 and M1, distal moieties increased faster and were more highly correlated with other dental variables and age than were mesial ones. Comparison with data from humans revealed both differences and similarities in the absolute size and growth rate of dental moieties during the perinatal period. As the reasons for ontogenetic variation become understood for individuals, species, and higher taxa, the phylogenetic implications of differential growth should become clearer as well.     

MicroRNA与动物发育

MicroRNA(miRNA)是一类约22nt大小的内源性非编码RNA,它们通过剪切靶基因的转录产物或者抑制转录产物的翻译从而起到转录后调控靶基因表达的作用。在动物体内,通过基因敲除等方法所进行的大量研究表明了miRNA参与了胚胎早期发育、脑及神经发育、心脏发育、肌肉及骨骼发育等动物发育的各个方面。miRNA是动物发生发育过程中重要的调控因子。主要介绍了近年来miRNA在动物生长发育过程中的研究进展。     

The role of oxygen availability in the embryonation of Heterakis gallinarum eggs.

The importance of oxygen availability in the embryonation of the infective egg stages of the gastrointestinal nematode parasite Heterakis gallinarum was studied in the laboratory. Unembryonated H. gallinarum eggs were kept under either aerobic conditions by gassing with oxygen, or anaerobic conditions by gassing with the inert gas nitrogen, under a range of constant temperatures. Oxygenated eggs embryonated at a rate influenced by temperature. Conversely, eggs treated with nitrogen showed no embryonation although when these eggs were transferred from nitrogen to oxygen gas after 60 days of treatment, embryonation occurred. This demonstrated that oxygen is an essential requirement for H. gallinarum egg development, although undeveloped eggs remain viable, even after 60 days in low oxygen conditions. The effects of climate on the biology of free-living stages studied under constant laboratory conditions cannot be applied directly to the field where climatic factors exhibit daily cycles. The effect of fluctuating temperature on development was investigated by including an additional temperature group in which H. gallinarum eggs were kept under daily temperature cycles between 12 and 22°C. Cycles caused eggs to develop significantly earlier than those in the constant mean cycle temperature, 17°C, but significantly slower than those in constant 22°C suggesting that daily temperature cycles had an accelerating effect on H. gallinarum egg embryonation but did not accelerate to the higher temperature. These results suggest that daily fluctuations in temperature influence development of the free-living stages and so development cannot be accurately predicted on the basis of constant temperature culture.     

A requirement for Fgfr2 in middle ear development

The skeletal structure of the mammalian middle ear, which is composed of three endochondral ossicles suspended within a membranous air‐filled capsule, plays a critical role in conducting sound. Gene mutations that alter skeletal development in the middle ear result in auditory impairment. Mutations in fibroblast growth factor receptor 2 (FGFR2), an important regulator of endochondral and intramembranous bone formation, cause a spectrum of congenital skeletal disorders featuring conductive hearing loss. Although the middle ear malformations in multiple FGFR2 gain‐of‐function disorders are clinically characterized, those in the FGFR2 loss‐of‐function disorder lacrimo‐auriculo‐dento‐digital (LADD) syndrome are relatively undescribed. To better understand conductive hearing loss in LADD, we examined the middle ear skeleton of mice with conditional loss of Fgfr2. We find that decreased auditory function in Fgfr2 mutant mice correlates with hypoplasia of the auditory bulla and ectopic bone growth at sites of tendon/ligament attachment. We show that ectopic bone associated with the intra‐articular ligaments of the incudomalleal joint is derived from Scx‐expressing cells and preceded by decreased expression of the joint progenitor marker Gdf5. Together, these results identify a role for Fgfr2 in development of the middle ear skeletal tissues and suggest potential causes for conductive hearing loss in LADD syndrome.