果蝇Microsoft Word 文档

20世纪初，孟德尔的遗传理论重新被发现以后，成了生物学工作者谈论的主要问题。

而美国的生物学家摩尔根对孟德尔的遗传理论提出了疑问。

难道生物的相对性状是这样遗传的吗？性状是受基因控制的吗？这是压在摩尔根心头上的疑团。

怎样解决问题呢？依靠写文章进行讨论吗？不行。

在科学问题上，空谈是不行的。

写文章讨论问题，要有科学根据。

而科学根据要来自科学实验。

特别是要利用新的材料进行精密的科学实验，才能进一步印证孟德尔的遗传规律是否正确。

1909年，有人把果蝇介绍给摩尔根做实验。

摩尔根当时已经是一个很有成就的胚胎学家了，可是他对这个小昆虫很感兴趣，就在自己的实验室里养起果蝇来。

果蝇是比苍蝇小得多的昆虫。

它有一对翅，能够自由飞翔。

夏天，它常常在腐烂的水果堆上飞来飞去。

果蝇有雌雄之别。

雌果蝇的腹部末端比较尖，是黑色的。

这一点跟豌豆不同，豌豆和许多其他植物是雌雄同体的，也就是同一朵花里有雌蕊，也有雄蕊，或者同一植株上有雌花，也有雄花。

图3-7-1果蝇跟其他许多昆虫一样，发育过程是完全变态的类型，分为卵、幼虫、蛹和成虫4个阶段。

果蝇还有一个最突出的特点是世代短。

在适宜的温度和充分的食物条件下，两个星期就可以完成一代。

摩尔根考虑，用果蝇来研究性状遗传的规律，要比豌豆适宜得多。

在果蝇的自然繁殖过程中，摩尔根发现果蝇有许多变异。

于是他决定用果蝇来进行杂交的遗传实验。

摩尔根从果蝇杂交实验中获得的知识比豌豆多得多。

他除了论证孟德尔的遗传规律以外，还发现了遗传单位（基因）就在细胞核的染色体上。

另外，还发现了新的遗传规律。

他的实验是这样进行的。

首先，他发现果蝇翅的形状有几种变异。

有一种变异是残翅的，即翅很小很小，这种果蝇不能飞。

还有一种能飞的，是长翅的果蝇。

摩尔根让长翅果蝇跟残翅果蝇杂交，所产生的杂种果蝇全部是长翅的。

亲代长翅×残翅↓子1代长翅↓子2代长翅残翅（多数）（少数）这说明长翅对于残翅是显性性状。

如果让这个杂种的长翅雌果蝇和长翅雄果蝇杂交，也就是子1代自交，所产生的后代是什么样的呢？结果产生的后代是：3/4长翅：1/4残翅这说明长翅和残翅这一对性状是受一对基因控制的，在杂交中，它们表现为：亲代长翅×残翅↓子1代长翅×长翅↓子2代长翅（3/4）残翅（1/4）摩尔根用残翅果蝇跟第一代杂种果蝇进行测交，得到了预期的结果：杂种长翅×残翅↓长翅（1/2）残翅（1/2）摩尔根证明了孟德尔的分离规律不仅适用于植物界，也适用于动物界。

果蝇的采集、饲养与性状观察实验八果蝇的采集、饲养与性状观察【实验目的】了解果蝇的生活史，学会果蝇的采集饲养和管理方法。

区别果蝇的雌雄及某些性状，为做果蝇的遗传实验练好基本功。

【实验原理】是双翅目昆虫，具有生活史短，繁殖率高、饲养简便等特点，是研究遗传学的经典好材料。

果蝇的生活史：卵→幼虫→蛹→成虫，最适温度20－25℃。

从卵到成虫约10天，在25 ℃时成虫约活15天。

连续30 ℃以上的温度能使果蝇不孕或死亡。

卵：果蝇卵约长0.5毫米，外围是一层由细胞组成的六角形小格的包膜的卵壳，在背面的前端伸出一对触丝，使卵生产在柔软的食物不致下沉。

幼虫期：幼虫从卵中孵化出来要经过两次脱皮，所以幼虫包括三个阶段（令）。

蛹化：当幼虫准备准备化蛹时，它们从培养基中爬出来附在较干燥的表面，果蝇在末令幼虫的皮中化蛹，起初白、软，后渐色深、硬，最后发育成一个有成虫体型与器官的人体，这些转变完成以后，成体就从蛹壳的前端强挤出来。

【实验材料及用具】1、果蝇（若干品种）：残翅；18＃野生型（5组）；22＃白眼（6－8组）；6＃短翅白眼；e＃黑檀体。

2、用具：放大镜、培养瓶（可用纱布包裹的棉花球塞与牛奶瓶或大、中型指管做成）、三角瓶、软木塞、火柴、大头针、酒精灯、三角架、石棉网、烧杯、电子天平、玻璃棒，白纸、废洋铁罐头盒、标签纸、胶水、乙醚、红糖或白糖、琼脂、玉米粉（或面粉）、95％（或70～75％）酒精酵母菌液（用量极少，勿须另行培养，可向附近酒厂索取）。

【实验方法】（一）果蝇的观察：①果蝇的生活史果蝇是完全变态发育的昆虫。

它的生活史包括卵、幼虫、蛹及成虫四个发育时期。

果蝇生活周期及各个发育阶段的时间长短与温度关系十分密切。

超过30℃，能使果蝇不育和死亡。

温度降低，会使果蝇生活周期延长，生活力降低。

一般在20℃～25℃下培养最为合适。

在适宜的温度下，大约经过10～14天即可繁殖一代。

②雌雄果蝇的鉴别将麻醉的果蝇置于载波片，在显微镜下（4倍或10倍）鉴别雌雄果蝇。

一、实验课题名称果蝇相关遗传性状的分析二、文献综述黑腹果蝇，属于昆虫纲，双翅目，果蝇科。

它是生物学研究中最重要的模式生物之一。

果蝇作为模式生物已广泛应用于细胞生物学、遗传学、发育生物学、分子生物学、人类疾病研究等领域。

【1】黑腹果蝇其虫体小，饲养简便、经济，凡能发酵的食料都能成为它的良好培养基，而且成虫的繁殖力强，生活周期短，恒温25℃一个世代平均约10天，染色体数目为2n=8，且形态特点十分明显，突变种类极多，为各种杂交实验提供了丰富的材料，是一种十分有利于遗传学研究的理想的模式生物。

【2】通过选取果蝇的两对相对性状，通过果蝇的正交和反交，统计F1代，F2代相关性状的数量，并通过卡方值的检验，比较实际值与理论值的差异，来验证基因的分离定律，基因的自由组合定律和伴性遗传规律。

【3】【1】牟国鹏黑腹果蝇热激蛋白基因家庭的生物信息学分J 《重庆师范大学》 2011年 Q811.4【2】戴灼华王亚馥，《遗传学》第2版，高等教育出版社【3】张文霞戴灼华《遗传学实验指导》 M 高等教育出版社三、实验目的和要求（1）通过果蝇单因子、二因子的杂交实验，理解孟德尔分离和自由组合定律的基本内容；掌握基本的遗传结果记录及统计分析方法。

（2）通过果蝇野生型和白眼突变型杂交实验，了解由性染色体上基因所控制的性状遗传规律，以及伴性遗传在正反交中的差异。

（3）初步掌握设计实验的方法步骤。

四、实验条件1、仪器：显微镜、双筒解剖镜或放大镜、恒温培养箱、高压灭菌锅、培养瓶、麻醉瓶、白磁板、毛笔、石棉网、棉花、纱布、吸水纸、滤纸片、牛皮纸、小镊子等。

2、材料：野生型(+)、黑体白眼（wb）两种突变体果蝇3、试剂：乙醚、玉米粉、糖、酵母粉、琼脂、丙酸五、实验原理在遗传学实验中我们可以用果蝇来验证许多遗传规律，如：分离规律、自由组合规律、伴性遗传规律及连锁互换规律。

本次实验中我们通过选取果蝇的两对相对性状，通过果蝇的正交和反交，统计F1代，F2代相关性状的数量，并通过卡方值的检验，比较实际值与理论值的差异，来验证基因的分离定律，基因的自由组合定律和伴性遗传规律。

5种常用杀虫剂对樱桃果蝇成虫的室内毒力测定Indoor Toxicity Determination of Five Insecticides to Fruit FliesLai Shouguo1，2，Lin Qingcai2，Zhai Yifan2，Zheng Li2，Chen Hao2，Zhang Sicong2，Li Lili2，Yu Yi2，Zheng Fangqiang1 （1. College of Plant Protection， Shandong Agricultural University， Taian 271018， China；2. Institute of Plant Protection， Shandong Academy of Agricultural Sciences， Jinan 250100，China）AbstractIn order to screen out effective insecticides against fruit flies， stomach-contact combination toxicity method was used indoor to test the virulence of 5 types of pesticides on adults of Drosophila melanogaster and Drosophila suzukii laboratory populations. The results showed that the order of the toxicity on Drosophila suzukii from high to low was beta cypermethrin，spinosad， emamectin， chlorantraniliprole and avermectins； the order of the toxicity on Drosophila melanogaster from high to low was spinosad， emamectin， beta cypermethrin， chlorantraniliprole and avermectins.KeywordsFruit flies； Pesticides； Indoor toxicity determination果蝇属双翅目（Diptera）果蝇科（Drosophilidae）昆虫，多数种类仅以腐烂的果实为食物，对健康果实不构成威胁，少数可为害健康果实，如斑翅果蝇、黑腹果蝇等[1]。

多种原因造成了杨梅果蝇的发生
果蝇是一种以蜂蜜、果实为食的虫子，本身不会携带病菌。

在种植杨梅的过程中，杨梅果蝇发生频繁，这是什么原因造成的呢？
杨梅果蝇，雌果蝇产卵于成熟的杨梅果实乳柱上，孵化后的幼虫蛀食危害，受害果实凸凹不平，果汁外溢和落果，使产量下降，质量变劣，严重影响鲜销、贮藏、加工及商品价格。

注意：在气温21-25℃，湿度75-85℃条件下易发生，一个世代历期4―7天，世代重迭交替，在果实成熟期危害严重。

因此，为了提高杨梅的质量以及产量，做好杨梅果蝇的防治是很有必要的。

Figure D.1 A colorized scanning electron mi-crograph of a Drosophila adult’s head and wings.Figure D.2The fountainhead of Drosophila genetics.Thomas Hunt Mor-gan and his students in the fly room at Columbia University, at a party in 1919 celebrating the return of Alfred Sturtevant from World War I military service. Individuals whose work is discussed in this book include Morgan (back row, far left), Sturtevant (front row, third from the right), Calvin Bridges (back row, third from the right), and Herman J. Muller (back row, second from the left). The “honored guest” between Muller and Bridges has clearly seen better days.gastrulation that produce the endoderm, mesoderm, and ectoderm tissue layers take only 20 minutes. Embryogene-sis ends with the hatching of a wormlike first instar (or first-stage) larva that is specialized for feeding and grows dramatically. To allow for an increase in body size, the larva molts 24 and 48 hours after hatching to produce second and third instar larvae.About three days after the second molt, third instar larvae complete their growth, crawl out of the food, and pupate. The timing of each larval molt and pupation is con-trolled by pulses of a steroid molting hormone called ecdysone. How growth is regulated and how ecdysone con-trols molting are currently areas of very active investiga-tion. Once inside the protective pupal case, the larvae undergo metamorphosis:a dramatic reorganization of the fly body plan. This reorganization takes about four days and consists of the disintegration of most larval tissues and their replacement through the proliferation and differentia-tion of cells that produce adult structures. Most structures specific to adults, such as the wings, legs, eyes, and geni-talia, are generated from imaginal discs:flattened epithe-lial sacs that develop from small groups of cells set aside in Drosophila life cycleAdult FertilizationEmbryo1 dayFirstinstar larva1 day1 daySecond instar larvaThirdinstar larva21/2 - 3 daysPupa31/2 - 41/2 days in pupal stageFigure D.4The Drosophila life cycle.The transition from anembryo to a first instar larva is called hatching.The transitions between larval instars are molts.The process that converts a third instar larva to a pupa is pupariation.Emergence of the adult from the pupal case is called eclosion.emerges from the pupal case, its wings expand and the entire exoskeleton hardens and becomes pigmented.Techniques of Genetic AnalysisThe practice of genetics in acter that in part reflects the tools created by searchers over many years and in part reflects certain Imaginal LarvaAdultAbdomenThoraxHead Frontal plate and upper lip MetamorphosisFigure D.5Many adult structures develop from imaginaldiscs in larvae and pupae.discs in the larva with the structures they generate in the adult.Transformation: The Introduction of Cloned DNA into Fruit FliesDrosophila geneticists realized from the following experi-ment that P elements can serve as vectors to introduce cloned DNA into the organism. Researchers first con-structed a recombinant plasmid that contained a fragment Drosophila genomic DNA including an intact P ele-ment. When they injected this plasmid into early syncytialGerm-line pole cellsGerm-line cellGrows intoEmbryoSemisterile fly P or M mateProgeny with many mutations and chromosome rearrangements due to P-element transpositionsP elements transposeP M(c) P-element transposition in dysgenic crossesFigure D.7P elements and hybrid dysgenesis.(a) Transposi-tion requires the action of the P-element transposase enzyme on the inverted repeats at P-element ends. (b)Hybrid dysgenesis occurs only when P males mate with M females. The progeny of such a mating appear wild type but are semisterile. (c)P elements on sperm brought into embryos derived from M females trans-pose at high rates, but only in germ-line cells.Gene of w+Amp R interestP-element endsM w–Grows intow+Genegenomic DNAembryoP-element-mediated transformation of(a)A transgene (Gene) is cloned into a transforma-tion vector (pCaSpeR) containing the whiteϩ(wϩ) marker genelacZ w+Figure D.10Enhancer trapping.(a)This “enhancer trap”␤-galactosidase contains a lacZ reporter gene encoding down-␤-galactosidaseFLPCompartmentAnterior Minute+ cloneCompartmentPosterior Minute+ cloneMosaic analysis demonstrates the existence of developmental compartments.8boss+sev+1234567123456234525(b) Recruitment of cells into an ommatidiumGAL4UAS GUAS G cDNA cDNAMultinucleate syncytiumMitotic cycle 7Mitotic cycle 10End of mitotic cycle 1330min1h101h302h303h153h15min 2h 45min 2h 30min3h Syncytial blastodermCellular blastodermMost nuclei migrate out to cortex(b) Early embryonic stages in cross sectionFigure D.18Early Drosophila development: From fertiliza-tion to formation of the cellular blastoderm.(a)The original zygotic nucleus undergoes 13 very rapid mitotic divisions in a single syncytium. A few nuclei at the posterior end of the embryo become the germ-line pole cells.At the syncytial blastoderm stage, the egg surface is covered by a monolayer of nuclei (except for the pole cellscomponents needed for the earliest stages of development would result in embryos so defective that they could never vfcfCL PCOD MxLbMa T1T2T3A1A2A3A4A5A6A7A8(b) Gastrulation(c) SegmentationBicoid protein Head fold AnteriorPosteriorPosteriorAnteriorAnteriorPosterior(b) A gradient of Bicoid protein) mRNA (visualized by in situ hybridization ingreen antibody staining) is distributed in a70605040302010gtKrgtT 1T 2T 3A 1A 2A 3A 4A 5A 6A 7A 868%12%Anterior(c) Gap genes: a summary PosteriorAnterior Posterior Even-skipped (Eve)Fushi tarazu (Ftz)(b) Proteins regulating eve transcriptionGt( )Kr( )(b) Segment polarity genes establish compartment borders.WinglessproteinWing HaltereWild typemutantpostbithoraxbithorax mutantHomeotic transformations.(a)In animals homozygous for the mutationConnectionsEssential Concepts1.Several characteristics of Drosophila are useful forgenetic analysis.a.The life cycle is relatively short, and each fly canproduce thousands of progeny.b.A moderate amount of crossing-over occurs infemales and no crossing-over occurs in males.c.Balancer chromosomes help preserve linkage.d.P-element transposons are tools of molecularmanipulation useful for transformation, genetagging, and enhancer trapping.e.Genetic mosaics resulting from mitotic recombi-nation help track the roles of individual genes inthe development of specific body structures.f.Ectopic expression can help pin down the functionof a gene by making it possible to examine theeffects of overexpressing the gene product orexpressing the gene product in the wrong tissues.2.The Drosophila Genome Project has alreadysequenced the euchromatic portion of the genome.Analysis of this sequence suggests that there are approximately 13,600 genes in the fly genome. A ma-jor remaining goal of the Drosophila Genome Project is to obtain information about the function of each of these genes. Large collections of transposon-induced mutations, as well as new techniques for targeted gene knockouts by homologous recombination and RNA intereference, should make the inactivation of each of these 13,600 genes possible in the near future.3.The development of the anterior-posterior (AP) axisin the fruit fly depends on the coordinated action of the segmentation genes,which divide the body into three head, three thoracic, and eight abdominalsegments; and the homeotic genes,which assign a unique identity to each segment.4.The four classes of segmentation genes are expressedin the order maternal, gap, pair-rule, and segment polarity. The maternal genes produce gradients of morphogens.The gap genes,the first zygotic seg-mentation genes, are expressed in broad zones along the anterior-posterior axis. The pair-rule genes sub-divide those broad areas into units that span two of the ultimate body segments. The segment polarity genes subdivide the two-segment units into individ-ual segments. In the hierarchy of segmentation gene expression, each gene class is controlled by classes of genes higher in the hierarchy or by members of the same class.5.The homeotic genes are master regulators of othergenes that control the development of segment-specific structures. The homeobox in each homeotic gene en-codes a homeodomain that allows the gene products to bind to specific target genes and control their expression. The homeotic genes are, in turn, regu-lated by the earlier acting gap, pair-rule, and segment polarity genes. Homeotic mutations cause particular segments, or parts of them, to develop as if they were located elsewhere in the body. Most homeotic muta-tions map to the bithorax and the Antennapedia complexes.6.The finding of homeobox genes in other organismssuch as the mouse has made it possible to identify de-velopmentally important genes shared by all animals, demonstrating the evolutionary conservation of gene function.Solved ProblemsI.Drosophila geneticists try to minimize the work b.You want mel/mel females, which can be recog-ProblemsD-1For each of the terms in the left column, choose the best matching phrase in the right column.Mutation12345678910 10。

生物书果蝇原文果蝇科(Drosophilidae)果蝇属(Drosophila)昆虫。

约1,000种。

广泛用作遗传和演化的室内外研究材料，尤其是黄果蝇(D.melanogaster)易於培育。

其生活史短，在室温下不到两周。

关於果蝇的遗传资料收集得比任何动物都多。

用果蝇的染色体，尤其是成熟幼虫中最大的染色体，研究遗传特性和的基础。

对果蝇在自然界的生物学了解得还不够。

有些种生活以腐烂水果上。

有些种则在真菌或肉质的花中生活。

体型较小，身长3～4mm。

近似种鉴定困难，主要特征是具有硕大的红色复眼。

雌性体长2.5毫米,雄性较之还要小。

雄性有深色后肢，可以此来与雌性作区别。

果蝇类昆虫与人类一样分布于全世界，并且在人类的居室内过冬。

由於体型小，很容易穿过砂窗，因此居家环境内也很常见。

有些种生活以腐烂水果上。

有些种则在真菌或肉质的花中生活。

在垃圾筒边或久置的水果上，只要发现许多红眼的小蝇，即是果蝇；果蝇类幼虫习惯孳生於垃圾堆或腐果上。

黑腹果蝇在1830年首次被描述。

而它第一次被用作试验研究对象则要到1901年，试验者是动物学家和遗传学家威廉.恩斯特.卡斯特。

他通过对果蝇的种系研究，设法了解多代近亲繁殖的结果和取自其中某一代进行杂交所出现的现象。

1910年，汤玛斯.亨特.摩尔根开始在实验室内培育果蝇并对它进行系统的研究。

之后，很多遗传学家就开始用果蝇作研究，并且取得了很多遗传学方面的知识，包括这种蝇类基因组里的基因在染色体上的分布。

雌蝇可以一次产下400个0.5毫米大小的卵，它们有绒毛膜和一层卵黄膜包被。

其发育速度受环境温度影响。

在25℃环境下，22小时后幼虫就会破壳而出,并且立刻觅食。

因为母体会将它们放在腐烂的水果上或其他发酵的有机物上，所以它们的首要食物来源是使水果腐烂的微生物，如酵母和细菌，其次是含糖的水果。

幼虫24小时后就会第一次蜕皮，并且不断生长，以到达第二期。

经过三个幼虫发育阶段和四天的蛹期，在25℃下过一天，就会发育为成虫。