温度对尖裸鲤胚胎发育及其仔稚鱼生长性状的影响

采用实验生态学方法研究温度对尖裸鲤（Oxygymnocypris stewartii）胚胎发育及仔稚鱼生长性状的影响，旨在掌握温度对其早期发育的影响。结果表明，随着温度的升高，胚胎的孵化时间缩短，发育速度加快。在平均水温5 ℃、8 ℃、11 ℃、14 ℃和17 ℃下，尖裸鲤的胚胎孵化时间分别为530.78 h、366.12 h、214.22 h、220.63 h、153.95 h，温度和孵化时间呈幂函数关系，有效积温在水温为11 ℃时最低，为2 356.4 h ·℃。尖裸鲤胚胎不同发育时期在不同温度下的累计时间均呈现指数函数关系。随着温度的升高，孵化率呈现先降低后升高的趋势，水温范围在11 ~ 17 ℃时，温度系数Q10值和Q13值最接近2。尖裸鲤初孵仔鱼全长与温度间呈现三次多项式函数，全长与温度之间不存在显著性关系；而初孵仔鱼卵黄囊体积与温度间呈现显著性的二次多项式函数。综合各项指标表明，尖裸鲤胚胎的适宜孵化水温为11 ~ 17 ℃，仔稚鱼的适宜生长水温为14 ~ 17 ℃。     

黑龙江流域绥芬河水系野生洛氏鱥胚胎发育

采用活体观察和固定观察2种方法,对野生洛氏鱥胚胎发育进行了系统观察,分析了洛氏鱥胚胎及仔鱼发育过程及各时期特点。结果表明:洛氏鱥成熟卵为圆球形,米黄色,略透明,卵沉粘性,卵膜适中,略有弹性;受精卵吸水后极度膨胀,弹性增大明显;受精卵在水温15.0~17.1℃条件下,历经170 h孵出,整个发育期间所需积温为2612.8℃·h,整个胚胎发育过程可分为受精卵、卵裂、囊胚、原肠胚、神经胚、器官形成至破膜等6个阶段,各阶段发育所需积温分别为17.0、119.0、145.0、132.0、164.0、2035.8℃·h;在胚胎发育期间,许多器官分化形成,至孵化时,胚胎已具有较完善的内部器官,胸鳍、尾鳍、臀鳍均已形成,背鳍原基开始出现;初孵仔鱼卵黄囊为长椭圆形,鱼体透明,无色素,3日龄仔鱼黑斑呈块状,卵黄基本吸收完全,不久便可以摄食单胞藻、草履虫或蛋黄。     

日本鬼鲉胚胎发育及仔、稚鱼形态学观察

对日本鬼鲉的胚胎及仔稚鱼形态发育进行观察,描述了各发育时期的发育时序和形态特征。日本鬼鲉的受精卵呈正圆球形,无色透明,无油球,平均卵径为(1.42±0.04)mm,呈浮性。在水温(22±0.5)℃,盐度31‰的条件下,历时约52h10min完成孵化。初孵仔鱼全长(3.04±0.13)mm,卵黄囊长(2.23±0.08)mm,卵黄囊高为(1.65±0.06)mm,在(21±0.5)℃水温下,仔鱼孵化后3d内营内源性营养(卵黄囊仔鱼),第4天卵黄囊完全消失,开口摄食轮虫。13d全长(7.12±0.35)mm,背鳍鳍条出现进入稚鱼早期,15d全长(7.92±0.61)mm鱼体及各鳍开始出现金黄色斑纹,25d全长(13.66±0.55)mm,整个鱼体呈黄褐色,完成变态进入幼鱼期,开始营底栖生活。同时观察了自胚胎发育至幼鱼期鱼苗体表色素分布的变化及其器官发育的形态变化。     

新疆特克斯河斑重唇鱼胚胎发育和胚后发育观察北大核心CSCD

为保护伊犁河水系特克斯河特有鱼类斑重唇鱼(Distychus maculates)种质资源,探究斑重唇鱼胚胎发育与胚后发育规律。2021年5月,对斑重唇鱼开展人工繁殖,观察其胚胎发育和胚后发育过程,记录各发育阶段形态特征。水温15.0~16.0℃条件下,斑重唇鱼胚胎发育历经受精、卵裂、囊胚、原肠胚、神经胚、器官形成和孵化出膜7个阶段,经过2969.830℃·h破膜而出。斑重唇鱼成熟卵子淡黄色,卵径(2.75±0.24)mm(n=20),卵受精35 min后卵周隙最大,为(3.46±0.16)mm(n=20),其中卵黄约占体积的3/5。胚后发育过程中,仔鱼全长(L_(T),mm)和出膜天数(D)关系式:L_(T)=0.50D+9.15(R^(2)=0.90);卵黄囊全长(L_(Y))和出膜天数(D)关系式:L_(Y)=﹣0.11D^(2)+7.61(R^(2)=0.76);仔鱼全长(LT)和卵黄囊体积(L_(P))关系式:LT=﹣2.35LP+19.96(R2=0.88);卵黄囊全长(LY)和卵黄囊体积(L_(P))关系式:L_(Y)=0.49LP+5.34(R^(2)=0.68);卵黄囊体积(L_(P))和出膜天数(D)关系式:L_(P)=0.002D^(2)﹣0.24D+4.67(R^(2)=0.98)。本研究通过特克斯河斑重唇鱼人工繁殖实验,观察其胚胎和胚后发育特征,丰富斑重唇鱼早期生活史资料,为特有鱼类苗种培育提供理论数据,进一步为种质资源保护和开发奠定基础。     

胡子鲶的胚胎和幼鱼发育的研究

胡子鲶(Clarias fuscus)的胚胎和幼鱼的发育过程与蟾胡子鲶(C.batrachus)类似,器官分化时间和大小比例则有一定的差异。胡子鲶卵呈球形,富含卵黄,卵径1.7—1.9毫米;出膜仔鱼全长4.8—5.1毫米,比蟾胡子鲶约大1/3;幼鱼卵黄囊被吸收消失的时间比蟾胡子鲶迟1—2天。心脏的出现和搏动与开始出现血液循环的间隔时间只有3—5小时;耳石的出现几乎和心脏的出现处在同一时间内,与白鲢有较大的差异。在仔鱼前期居维氏管明显,但出现的时间比蟾胡子鲶稍迟些。仔鱼出膜形式与蟾胡子鲶不同,也与一般鱼类出膜形式不同。仔鱼是以腹部卵黄囊顶破卵膜,以卵黄囊先出膜,一般鱼类多数是以头部或尾部先出膜的。在水温28.5—31℃的条件下,从受精到孵化出膜的时间为28小时25分;幼鱼期共历时12—15天。       

河川沙塘鳢孵化腺的发生及孵化酶的分泌

利用光学显微镜和扫描电镜观察了河川沙塘鳢Odontobutis potamophila(Gnther)孵化腺的发生及孵化酶的分泌过程。河川沙塘鳢的孵化腺为单层细胞腺体,发生于外胚层。孵化腺(Hatching gland,HG)最早发生自眼晶体形成期的胚胎,初发生时孵化腺细胞(Hatching gland cells,HGCs)分布于头部腹面及其与卵黄囊连接处。随着胚胎的发育,HG仍以单层细胞分布于胚体和卵黄囊的外表面,HGCs数量急剧增多,细胞体积增大,分布范围更加广泛。至眼黑色素出现期的胚胎,HGCs的数量达到大约900-1200个,广泛分布于胚胎头部两侧、头部腹面及其与卵黄囊连接处、卵黄囊的前腹面。HGCs大多呈椭圆形,短径为5-8μm,长径为7-12μm,在HE染色中呈粉红色。至孵化前期时,孵化酶颗粒自HGCs顶部的开口分泌出来,分泌颗粒呈圆球形,直径为0.5-1.0μm,有的以单体的形式存在,有的粘结成团。孵化酶进入卵周液,对卵膜内层进行消化和降解,使胚胎破膜而出。孵化后2d,HGCs便从表皮中消失。     

大渡软刺裸裂尻鱼仔鱼形态发育及生长

通过人工干法授精获得大渡软刺裸裂尻鱼的受精卵,观察了实验室孵化培育条件下的仔鱼形态变化过程。结果表明:在平均水温为11.86℃(9.0~16.0℃)下胚胎历时9 d出膜。初孵仔鱼全长11.65 mm±0.27 mm,鳃弓、口凹和肛门原基明显,眼色素和胸鳍原基出现,肌节43对(12+20+11),心跳140~160次/min。出膜9 d,仔鱼肠道贯通,鳔雏形和背鳍原基出现。臀鳍原基出现和尾鳍分叉分别于出膜后13 d和16 d发生。出膜19 d,腹鳍原基出现,此时背鳍鳍条4~6枚,臀鳍鳍条2~4枚。出膜32 d,鱼体全长22.99 mm±0.65 mm,除存在少量鳍褶外,基本具备成鱼的形态特征。仔鱼卵黄于出膜第12天吸收完全,卵黄囊体积与出膜后天数呈显著的多项式相关(P0.01)。体长、全长、头长和肛后长的生长均呈明显的二项式关系。研究结果丰富了大渡软刺裸裂尻鱼早期发育生物学资料,为人工养殖研究等提供参考。     

贝氏高原鳅胚胎和仔鱼的形态发育

通过人工授精获得受精卵,对贝氏高原鳅胚胎和仔鱼的发育过程进行了观察和描述。结果表明,成熟卵淡黄色,卵径较小(直径0.94－1.10mm),遇水后产生强黏性。在水温9.0－12.8℃下,胚盘在受精后4h20min开始分裂,在19h50min和27h40min时达到囊胚期和原肠期,64h40min胚孔封闭,287h时部分胚胎开始出膜,405h30min全部出膜。初孵仔鱼全长(4.32±0.23)mm,肌节36－38对,眼和躯干部黑色素细胞明显,胸鳍原基发育良好。出膜后第5天仔鱼体侧和头部出现浓密的感觉芽。到第8天时全长(6.05±0.41)mm,卵黄吸收完全。仔鱼鳔一室和鳔二室分别于出膜后第30天和第50天形成。第55天的仔鱼全长(14.05±1.01)mm,肌节52－53对,体侧出现7－8条黑色素带,各鳍鳍条数目与成鱼基本一致,但仍有少量鳍褶存在。仔鱼的卵黄囊体积减小速度为0.027mm3/d,鱼体长度生长、鱼体长度性状间的比例关系并不相同,其中,肛后长／全长比例随胚后发育逐渐增加,由初出膜时的31%增加到最后的42％左右。     

赤水河四川华吸鳅的早期发育

四川华吸鳅Sinogastromyzon szechuanensis为长江上游特有鱼类.为了积累其生物学资料,为相关的保护措施提供参考,于2009年通过人工授精获得四川华吸鳅受精卵,对其胚胎和仔鱼的发育过程进行了观察和描述.四川华吸鳅的受精卵呈浅黄色,卵膜径较小(1.85 mm±0.23 mm),具粘性.在水温26.3~27.8℃下,胚体经历22 h 34 min发育成仔鱼出膜;初孵仔鱼全长4.39 mm±0.21 mm,肌节37对;日龄4 d时,卵黄囊吸收完毕,进入外营养期;日龄65 d时,鳞片长齐,进入幼鱼期.整个早期发育过程历时65 d 22 h 34 min.     

雅砻江短须裂腹鱼胚胎和卵黄囊仔鱼的形态发育

当前短须裂腹鱼(Schizothorax wangchiachii)已被列为雅砻江和金沙江的增殖放流保护鱼类,为探讨两水系的环境差异对其早期发育产生的影响,本文以雅砻江短须裂腹鱼为研究对象,通过人工授精获得受精卵,对胚胎和早期仔鱼的形态发育特征进行了观察,并与已有报道的金沙江短须裂腹鱼胚胎与仔鱼早期发育研究进行比较。研究结果显示,雅砻江短须裂腹鱼卵径(2.70±0.02)mm,较金沙江短须裂腹鱼大0.34 mm;初孵仔鱼全长(11.36±0.22)mm,比金沙江短须裂腹鱼长2.7 mm;在水温(14±1)℃时,两水系的短须裂腹鱼胚胎发育时序基本一致,但听囊等部分功能器官的发育时序存在差异;胚胎发育历时181 h,积温2 539.98 h℃,分别比金沙江短须裂腹鱼早73 h和低1 025 h℃;出膜后1~9 d,仔鱼的鳃、口、胸鳍、尾鳍、鳔、肠道等功能器官先后形成,第9天卵黄囊吸收基本完全,与金沙江短须裂腹鱼一致。比较表明,两水系短须裂腹鱼早期发育特征基本相同,但卵径大小、孵化历时、部分器官发育时序存在一定差异,可能是二者为适应环境而做出不同的选择。     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

Interconnection of parameters of regulation system of lipid peroxidation and of morphophysiological parameters of mouse liver

A complex analysis of seasonal fluctuations of the mean group parameters of the system of regulation of lipid peroxidation has been performed in liver of Balb/c mice. Association of lipid characteristics and morphophysiological parameters is studied in the Balb/c mouse liver. An inter-connection is revealed between the liver index and the amount of lysoforms of phospholipids, the scale and character of the interconnection differing essentially depending on proportion of phos-phatidylcholine in mouse liver phospholipids.     

真菌类遗传学分析的知识结构教学

本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.     

Physiological characteristics of various species of strains of carboxydobacteria

Seven strains of aerobic carbon monoxide-oxidizing bacteria (carboxydebacteria) when growing on CO as sole source of carbon and energy had doubling times which ranged from 12–42 h. The activity profiles obtained after discontinuous sucrose density gradient centrifugation indicated that the CO-oxidizing enzymes are soluble and the hydrogenases are membrane-bound in all strains examined. The CO-oxidizing enzymes of Pseudomonas carboxydohydrogena, Pseudomonas carboxydoflava, Comamonas compransoris, and the so far unidentified strains OM2, OM3, and OM4 had a molecular weight of 230,000; that of Achromobacter carboxydus amounted to 170,000. The molecular weights of the CO-oxidizing and H₂-oxidizing enzymes turned out to be identical. The cell sonicates were shown to catalyze the oxidation of both CO and H₂ with methylene blue, thionine, phenazine methosulfate, toluylene blue, dichlorophenolindophenol, cytochrome c or ferricyanide as electron acceptors. Methyl viologen, benzyl viologen, FAD⁺, FMN⁺, and NAD(P)⁺ were not reduced. The spectrum of electron acceptors was identical for all strains tested. Neither free formate, hydrogen nor oxygen gas were involved in the CO-oxidation reaction. Methylene blue was reduced by CO at a 1:1 molar ratio. The results indicate that CO-oxidation by carboxydobacteria is catalyzed by identical or similar enzymes and that the reaction obeys the equation CO+H₂OCO₂+2H⁺+2e^- as previously shown for Pseudomonas carboxydovorans.Dedicated to Otto Kandler remembering almost three decades of enjoyable cooperation     

Modulation of allostery of pyruvate kinase by shifting of an ensemble of microstates

Since the introduction of the concepts of allostery about four decades ago, much advancement has been made in elucidating the structure-function correlation in allostery. However, there are still a number of issues that remain unresolved. In this review we used mammalian pyruvate kinase (PK) as a model system to understand the role of protein dynamics in modulating cooperativity. PK has a triosephosphate isomerase (TIM)(α/β)₈ barrel structural motif. PK is an ideal system to address basic questions regarding regulatory mechanisms about this common (α/β)₈ structural motif. The simplest model accounting for all of the solution thermodynamic and kinetic data on ligand-enzyme interactions involves two conformational states, inactive E^T and active E^R. These conformational states are represented by domain movements. Further studies provide the first evidence for a differential effect of ligand binding on the dynamics of the structural elements, not major secondary structural changes. These data are consistent with our model that allosteric regulation of PK is the consequence of perturbation of the distribution of an ensemble of states in which the inactive E^T and active E^R represent the two extreme end states. Sequence differences and ligands can modulate the distribution of states leading to alterations of functions. The future work includes: defining the network of functionally connected residues; elucidating the chemical principles governing the sequence differences which affect functions; and probing the nature of mutations on the stability of the secondary structural elements, which in turn modulate allostery.