Microplastic exposure disturbs sleep structure,reduces lifespan,and decreases ovary size in Drosophila melanogaster

The organ-specific toxicity resulting from microplastic(MP)exposure has been extensively explored,particularly concerning the gut,liver,testis,and lung.However,under natural conditions,these effects are not restricted to specific organs or tissues.Investigating whether MP exposure presents a systemic threat to an entire organism,impacting factors such as lifespan,sleep,and fecundity,is essential.In this study,we investigated the effects of dietary exposure to two different doses of MPs(1–5μm)using the terrestrial model organism Drosophila melanogaster.Results indicated that the particles caused gut damage and remained within the digestive system.Continuous MP exposure significantly shortened the lifespan of adult flies.Even short-term exposure disrupted sleep patterns,increasing the length of daytime sleep episodes.Additionally,one week of MP exposure reduced ovary size,with a trend towards decreased egg-laying in mated females.Although MPs did not penetrate the brain or ovaries,transcriptome analysis revealed altered gene expression in these tissues.In the ovary,Gene Ontology(GO)analysis indicated genotoxic effects impacting inflammation,circadian regulation,and metabolic processes,with significant impacts on extracellular structure-related pathways.In the brain,GO analysis identified changes in pathways associated with proteolysis and carbohydrate metabolism.Overall,this study provides compelling evidence of the systemic negative effects of MP exposure,highlighting the urgent need to address and mitigate environmental MP pollution.

Geroprotection from ergothioneine treatment in Drosophila melanogaster by improving intestinal barrier and activation of intestinal autophagy

Ergothioneine is a natural amino acid with powerful antioxidant activity.Previous studies have demonstrated that ergothioneine can increase the lifespan of Drosophila melanogaster and Caenorhabditis elegans,and enhance telomerase activity.In present study,the metagenomics sequencing and quantitative real-time polymerase chain reaction analysis were employed to characterize the composition and diversity of gut microbiome in aging flies.And the alterations in the gut barrier,gut morphology,and other gut physiological indicators of aging flies were evaluated.Here,the results showed that ergothioneine induced little variations in gut microbiota composition in flies at mid-life,and significant alterations in the gut microbiota populations were only observed in flies at late-life.And ergothioneine attenuated age-related gut injuries,including decreasing reactive oxygen species levels in intestinal enterocytes,reduction of intestinal cells death,and preservation of gut integrity in aging flies.Ergothioneine also improved the gut morphology by preserving the structure and shape of cell organelles and inducing the intestinal autophagy.And activation of intestinal autophagy also contributed to the longevity effect mediated by ergothioneine in an unidentified mechanism.

Effects of Sodium Cyclohexyl Sulfamate on Growth and Development of Drosophila melanogaster

[Objectives]This study was conducted to investigate the effects of different concentrations of sodium cyclohexyl sulfamate on the growth and development of Drosophila melanogaster.[Methods]Different concentrations of sodium cyclohexyl sulfamate were added to the culture medium,and the effects of different concentrations of sodium cyclohexyl sulfamate on the development time and weight of D.melanogaster in various life stages were statistically analyzed.[Results]High concentration of sodium cyclohexyl sulfamate delayed the time of pupation and eclosion of D.melanogaster,which made D.melanogaster lose weight.The number of male D.melanogaster in the first generation was much larger than that of female individuals,which indicated that the effect of sodium cyclohexyl sulfamate on male D.melanogaster was greater than that of female individuals.In a word,high concentration of sodium cyclohexyl sulfamate significantly inhibited the growth and development of D.melanogaster.[Conclusions]This study provides some reference data for the research perspective of food additives and the safe use of sodium cyclohexyl sulfamate.

Naringin ameliorates H_(2)O_(2)-induced oxidative damage in cells and prolongs the lifespan of female Drosophila melanogaster via the insulin signaling pathway

Naringin exists in a wide range of Chinese herbal medicine and has proven to possess several pharmacological properties.In this study,PC12,HepG2 cells,and female Drosophila melanogaster were used to investigate the antioxidative and anti-aging effects of naringin and explore the underlying mechanisms.The results showed that naringin inhibited H_(2)O_(2)-induced decline in cell viability and decreased,the content of reactive oxygen species in cells.Meanwhile,naringin prolonged the lifespan of flies,enhanced the abilities of climbing and the resistance to stress,improved the activities of antioxidant enzymes,and decreased malondialdehyde content.Naringin also improved intestinal barrier dysfunction and reduced abnormal proliferation of intestinal stem cells.Moreover,naringin down-regulated the mRNA expressions of inr,chico,pi 3k,and akt-1,and up-regulated the mRNA expressions of dilp2,dilp3,dilp5,and foxo,thereby activating autophagy-related genes and increasing the number of lysosomes.Furthermore,the mutant stocks assays and computer molecular simulation results further indicated that naringin delayed aging by inhibiting the insulin signaling(IIS)pathway and activating the autophagy pathway,which was consistent with the result of network pharmacological predictions.

Humanization for neurological disease modeling:A roadmap to increase the potential of Drosophila model systems

Neuroscience and neurology research is dominated by experimentation with rodents.Around 75%of neurology disease-associated genes have orthologs in Drosophila mel-anogaster,the fruit fly amenable to complex neurological and behavioral investiga-tions.However,non-vertebrate models including Drosophila have so far been unable to significantly replace mice and rats in this field of studies.One reason for this situ-ation is the predominance of gene overexpression(and gene loss-of-function)meth-odologies used when establishing a Drosophila model of a given neurological disease,a strategy that does not recapitulate accurately enough the genetic disease condi-tions.I argue here the need for a systematic humanization approach,whereby the Drosophila orthologs of human disease genes are replaced with the human sequences.This approach will identify the list of diseases and the underlying genes that can be adequately modeled in the fruit fly.I discuss the neurological disease genes to which this systematic humanization approach should be applied and provide an example of such an application,and consider its importance for subsequent disease modeling and drug discovery in Drosophila.I argue that this paradigm will not only advance our un-derstanding of the molecular etiology of a number of neurological disorders,but will also gradually enable researchers to reduce experimentation using rodent models of multiple neurological diseases and eventually replace these models.

In vivo anti-aging properties on fat diet-induced high fat Drosophila melanogaster of n-butanol extract from Paecilomyces hepiali

The purpose of this study was to explore the potential of the development and application of Paecilomyces hepiali,a fungus with edible and medicinal value,as a foodborne antioxidant and anti-aging agent.Its n-butanol extract(PHE)from rice cultures was selected for anti-aging experiment because of significant free radical scavenging activity in vitro.In vivo,PHE could significantly prolong the mean lifespan,50%survival days,and the maximum lifespan of Drosophila on a high-fat diet.It is amazing that the mean lifespan increased from 19.1 days to 32.9 days,50%survival days increased from 15.7 days to 34.3 days,and the maximum lifespan extended from 44.7 days to 52.7 days,when the high-fat female Drosophila model was fed with 10μg/mL PHE.Further research showed that PHE reduced the accumulation of peroxide products and increased the activity of antioxidant enzymes.Then,through antioxidant activity tracking,dimerumic acid(compound 1,the IC_(50) value of 3.4μg/mL on DPPH free radicals scavenging activity),4,5-dihydroxy-3-methoxypentanoic acid(compound 2,new compound),and thymidine(compound 3)were isolated from PHE.It is worth mentioning that dimerumic acid,the major antioxidant compound of PHE(content up to 3%),was discovered in P.hepiali for the first time.It was concluded that PHE showed excellent anti-aging activity at a very low concentration on fat diet-induced high fat Drosophila melanogaster,and dimerumic acid may be its main material basis.These results indicated that PHE had the potential to be developed as antioxidant and anti-aging agent in the healthcare industry.

Mutation in Ontogene and Emergence of Secondary Chromosome Damages in Drosophila Germline Cells

The conditional mutations in drosophila were obtained by γ-irradiation and selected using the test for dominant lethality. The conditional mutations survive under permissive genetic conditions and, additionally, commence to display novel properties. One of such properties is a recessive lethality. Ten conditional mutations that displayed recessive lethality were mapped with the help of a standard set of deletions. Half mutations contained two and more lethal defects. The fact that a large number of the lethal defects are associated with one mutation suggests that γ-irradiation is the most unlikely cause of the defects. One of the conditional mutations carried four lethal regions and had a Small barrel (Smba) visual phenotype. The Smba phenotype in the Smba/ In(2LR) Cy strain is inherited according to a parental type and disappears in the Smba/In(2LR) Pm strain. Lethality in two of the four lethal regions also disappears in this strain. A separate experiment was conducted to clarify how these regions lost a lethal manifestation after the In(2LR) Cy chromosome in the Smba/In(2LR) Cy strain was replaced with the In(2LR) Pm chromosome. The process of disappearance of the Smba phenotype was also observed in three Smba/In(2LR) Cy substocks. These data suggest that the regions of multiple recessive lethality emerge in a secondary manner under the effect of the earlier formed radiation-induced mutation in ontogene. It is assumed that the recessive lethal regions are the ontogenes with an altered DNA conformation. The conformation in ontogenes is changed in the germline cells during a regular “editing” of the individual development program.

不同日龄毛锤角细蜂寄生黑腹果蝇蛹的生物学特性研究

为了调查不同日龄毛锤角细蜂寄生黑腹果蝇的生物学特性,本研究对1~10日龄毛锤角细蜂成虫对黑腹果蝇蛹的寄生率及其后代的发育历期和雌性比进行统计,同时对寄生后黑腹果蝇蛹重的动态变化进行分析。结果表明,不同日龄毛锤角细蜂对黑腹果蝇蛹的寄生率有显著差异,7日龄寄生率最高,为(58.89±2.94)%,1日龄寄生率最低,仅为(30.00±1.94)%,但对毛锤角细蜂后代的发育历期和雌性比没有显著影响。黑腹果蝇蛹被毛锤角细蜂寄生后,重量显著降低。因此,1~10日龄毛锤角细蜂成虫均可大量寄生黑腹果蝇蛹,以7日龄为最佳寄生时期,这为毛锤角细蜂的大量扩繁和应用提供了理论依据。

一种适用于实验教学的果蝇DNA提取新方法

南开大学遗传学实验课程组将科研中常用的动物组织DNA提取方法改造后用于实验教学,获得了1种适用于实验教学的果蝇DNA提取新方法。该方法由碱裂解、酸中和、离心3个步骤组成,具有操作简单、时间短、成本低、效果稳定等特点,获得的DNA无论是浓度还是纯度均可满足后续PCR扩增的需要,符合实验教学的要求。该方法简化了果蝇DNA的提取流程,为与果蝇基因表达分析相关实验项目的改革奠定了基础,有助于提升实验教学效果,推动课程建设。

果蝇心脏发育研究三十年进展

果蝇(Drosophila melanogaster)作为最早用于研究心脏发育基因调控的模式生物,已经走过三十年的历程。果蝇心脏发育过程经历了胚胎期、幼虫期和成虫期三大阶段。在胚胎早期,Tinman、Dorsocross和Pannier等基因是关键的调控因子。Tinman参与最早的心脏前体细胞分化和心脏细胞形成,而Dorsocross和Pannier则影响心脏前体细胞的定向分化和心脏管腔的形成。进入胚胎晚期和幼虫期,果蝇的心管经历进一步的发展和重塑,该过程主要受到转录因子Hand、Mef2以及Hox基因家族的调控。在成虫期,Hox基因家族和Tinman依旧发挥重要作用。虽然果蝇心脏与脊椎动物成熟心脏存在形态上的差异,但两者心脏的早期发育过程以及调控基因和信号通路都有保守性。本文综述了果蝇心脏发育基因调控研究的三十年进展以及利用果蝇模型研究人类心脏相关疾病的潜在希望。

薏米对果蝇生长发育的影响

以黑腹果蝇为试验材料,设置不同浓度的薏米培养基(0%、10%、15%、20%),探究薏米培养基对果蝇繁殖力、雌雄比例、体重、寿命及过氧化氢酶(CAT)活性的影响,以期为薏米的合理使用提供理论依据.结果显示:随着薏米浓度的逐渐提高,果蝇的成蛹数、羽化数、寿命和体重均呈现先升高后降低的趋势.当薏米浓度在0%~15%区间时,果蝇的成蛹数、羽化数、寿命和体重均呈现为逐渐提高,15%时各项所测指标最高:成蛹数、羽化数分别为64.33只和60.00只,雌、雄果蝇的寿命分别为65 d和62 d,雌、雄果蝇的体重分别达1.382 g和1.180 g.果蝇的过氧化氢酶(CAT)活性也随薏米浓度的增加而增加,当浓度为20%时,过氧化氢酶活性最高,雌、雄果蝇分别达15.77 U/mg和14.96 U/mg.可见,15%的薏米培养基最适宜果蝇的生长发育,20%的薏米培养基对果蝇CAT活性的提高最显著,但薏米浓度对果蝇的雌雄比例影响不明显.

元宝枫油对衰老果蝇生理指标及肠道菌群的影响

探究元宝枫油对衰老果蝇生理指标及肠道菌群的影响。在基础培养基中分别添加10、20 g/kg和40 g/kg的元宝枫油对野生黑腹果蝇进行干预,观察果蝇寿命、爬行能力、嗅觉记忆能力和热耐受能力等行为学变化情况;检测超氧化物歧化酶(superoxide dismutase,SOD)活力和谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)活力;收集果蝇中肠,进行16S rRNA基因扩增子测序,检测肠道微生物组的变化。结果表明,与对照组相比,不同含量的元宝枫油干预均能显著延长果蝇的寿命(P<0.000 1),其中,20 g/kg元宝枫籽油抗衰老效果最佳,平均延长寿命31%。另外,20 g/kg元宝枫油干预可明显改善衰老果蝇的爬行能力、嗅觉记忆能力和热耐受能力,提高SOD和GSH-Px活力。衰老改变了果蝇肠道微生物的组成和结构,线性判别分析结果显示衰老果蝇中Enterobacteriaceae、Gluconobacter和Morganella morganii 3类细菌相对丰度增加,而元宝枫油抑制了衰老过程中以上3类细菌相对丰度的增加。综上,元宝枫油具有抗衰老作用,可改善果蝇的生理功能衰退,延长寿命,其机制可能与改变衰老果蝇肠道微生物的丰富度、均匀度和菌群结构,从而调节肠道菌群和提高抗氧化能力有关。

余甘子水提物对黑腹果蝇寿命及攀爬能力的保护作用

目的:余甘子(PE)是一种富含多种酚类物质和有机酸等化合物的药食两用植物资源。本研究拟探讨PE水提物对正常生理条件和镉(Cd)胁迫条件下果蝇寿命及攀爬能力的影响。方法:采用1.6、8、16 mg/mL PE水提物分别作用于野生型雌雄红黑腹果蝇,寻找有效提高其寿命及攀爬能力的最佳PE水提物浓度和最佳处理时间,并检测最佳浓度PE水提物处理后对雌雄果蝇体内SOD、CAT活性、MDA含量的影响。用5、10、20、40 mg/L CdCl_(2)单独作用于雌雄果蝇,摸索有效降低果蝇寿命的最适CdCl_(2)浓度,在此基础上采用1.6、8、16 mg/mL PE水提物联合最适浓度CdCl_(2)处理雌雄果蝇,探讨PE水提物对Cd胁迫下雌雄果蝇寿命及攀爬能力的影响。结果:与对照组相比,16 mg/mL PE水提物有助于延长正常生理条件下雌雄果蝇寿命(P<0.05);在最佳浓度(雌性1.6 mg/mL、雄性8 mg/mL)PE水提物处理下,有效提高雌雄果蝇攀爬能力的最佳处理时间呈现出性别差异,雌果蝇的最佳处理时间为22 d,雄果蝇为10 d,但最佳浓度PE水提物分别处理雌雄果蝇10、22、33、45 d均不能提高其体内抗氧化酶活性。与对照组相比,40 mg/L CdCl_(2)作用下雌雄果蝇的平均寿命降低最多(P<0.01),后续以40 mg/L作为最适Cd胁迫浓度。与对照组比较,8和16 mg/mL PE水提物有助于延长40 mg/L CdCl_(2)胁迫下雄果蝇的寿命但处理18 d后其攀爬能力显著降低(P<0.05),1.6、8和16 mg/mL PE水提物处理对雌果蝇的寿命和攀爬能力则均无显著影响(P>0.05)。结论:PE水提物有助于延长正常生理条件下雌雄果蝇的寿命和攀爬能力,延长Cd胁迫下雄果蝇的寿命但降低其攀爬能力,表明PE对果蝇的保护作用存在性别差异。

尿酸对果蝇幼虫生长发育的影响及机制分析

目的探讨尿酸(UA)对果蝇幼虫生长发育的影响及其机制。方法收集刚孵化的野生型黑腹果蝇(W1118)1龄幼虫1350只,采用高嘌呤饮食构建高尿酸血症果蝇模型,分为对照组(标准玉米粉培养基)、低浓度干预组(含0.05%腺嘌呤的玉米粉培养基)和高浓度干预组(含0.10%腺嘌呤的玉米粉培养基),每组150只,另设2个平行实验组,观察各组幼虫的生长发育情况,测定果蝇体内UA和激素水平,以及生长发育相关基因的表达情况。结果与对照组比较,低浓度干预组和高浓度干预组果蝇体内UA水平均显著增高(P均<0.001)、果蝇幼虫发育时间显著延长(P=0.024,P<0.001),高浓度干预组果蝇幼虫的生存率、蛹化率、羽化率均显著降低(P均<0.001),而果蝇幼虫体内保幼激素(JH)、20-羟基蜕皮甾酮(20E)水平均显著升高(P均<0.001)。PCR结果显示,与对照组比较,高浓度干预组果蝇幼虫体内活性氧(ROS)、叉头框O亚型(FOXO)、哺乳动物雷帕霉素靶蛋白(mTOR)mRNA的表达水平显著增高,应激诱导蛋白Sestrin、mTOR复合物1(mTORC1)、AMP活化的蛋白激酶mRNA的表达水平显著降低(P均<0.001)。结论高浓度UA可能通过调节果蝇体内JH、20E的表达,促进ROS/FOXO/mTORC1/mTOR信号通路的表达水平,从而抑制果蝇幼虫的生长发育。

斑翅果蝇(Drosophila suzukii)研究现状

斑翅果蝇(Drosophila suzukii Matsumura)传播速度快,危害多种水果,已经引起广泛重视。其形态鉴别特征是雄虫翅翼边缘末端以第1翅脉为中心有一块清晰的黑斑,雌虫产卵器为坚硬的锯齿状,可将卵直接产于成熟或即将成熟的果实内。斑翅果蝇繁殖速度快,1 a可繁殖3~10代,雌蝇终生产卵200~600粒。糖醋液诱捕监测以及果园清洁处理是害虫防治的必要措施。有机磷、拟除虫菊酯、多杀霉素等农药都有很好的局部触杀和残留杀虫活性。

日本细毛环腹瘿蜂对斑翅果蝇的寄生效能

日本细毛环腹瘿蜂Leptopilina japonica是斑翅果蝇Drosophila suzukii的优势寄生性天敌之一,对斑翅果蝇具有良好的生防潜力。为更好地利用日本细毛环腹瘿蜂防控斑翅果蝇,本研究在室内观察了日本细毛环腹瘿蜂的行为活动和生长发育特征。采用室内接虫法研究了该蜂对斑翅果蝇2龄幼虫的寄生能力。分别运用HollingⅡ型圆盘方程、搜寻效应方程和Hassell-Varley模型拟合分析了日本细毛环腹瘿蜂的寄生功能反应、搜寻效应和自身密度干扰效应。结果表明:日本细毛环腹瘿蜂的寄生功能反应符合HollingⅡ模型,其拟合方程为:N_(a)=0.70 N/(1+0.03 N);寄生效能(a/T h)为15.78;在一定空间内,寄生蜂的寄生量随寄主密度增加而增大,至寄主密度达25头/罐后寄生量趋于平稳;寄生蜂的搜寻效应随着寄主密度的增加而减弱;当斑翅果蝇的密度分别为10、20、30头/罐时寄生蜂自身密度干扰模型分别为E_(10)=0.4878 P^(-0.8713),E_(20)=0.4420 P^(-0.6768)和E_(30)=0.3462 P^(-0.4337);在同一寄主密度下,日本细毛环腹瘿蜂的寻找效应均随自身密度的增加而减弱。日本细毛环腹瘿蜂对斑翅果蝇2龄幼虫具有较好的寄生效能,但寄主密度较大会导致日本细毛环腹瘿蜂的寄生效能减弱,随着寄生蜂自身密度的增加,其种内个体间会出现干扰作用。

基于果蝇模型建立的菊苣提取物抗尿酸盐沉积作用研究

目的:建立尿酸盐沉积果蝇模型并确定其造模条件,并初步观察菊苣提取物抗尿酸盐沉积的作用。方法:以5%酵母提取物饲喂诱导果蝇尿酸盐沉积,通过果蝇马氏小管及后肠偏振光成像、六胺银染色及其匀浆液尿酸水平评价果蝇尿酸盐沉积状态,考察雌雄性别、不同造模时间对果蝇尿酸盐沉积的影响,并应用该模型研究菊苣提取物抗尿酸盐沉积的作用。结果:5%酵母提取物饲喂可成功诱导果蝇尿酸盐沉积;雄性果蝇在造模3 d后开始出现尿酸盐沉积,在造模7 d后大部分出现尿酸盐沉积,各造模时间点果蝇马氏小管及后肠匀浆液尿酸水平持续升高,各造模时间点之间差异不明显;雌性果蝇在造模10 d后开始出现尿酸盐沉积,在造模14 d后大部分出现尿酸盐沉积,各造模时间点果蝇马氏小管及后肠匀浆液尿酸水平持续升高,马氏小管及后肠匀浆液尿酸水平持续升高,各造模时间点之间比较,差异有统计学意义(P<0.001);菊苣提取物可减少果蝇马氏小管及后肠偏振光信号,并明显降低其匀浆液的尿酸水平(P<0.001)。结论:以5%酵母提取物饲喂雌性果蝇14 d可较稳定诱导尿酸盐沉积,菊苣提取物可在果蝇模式动物上发挥抗尿酸盐沉积的作用。

金色果蝇复合种(Drosophila auraria species complex)的分子系统学研究

测定了金色果蝇复合种 (Drosophilaaurariaspeciescomplex)的 5个姊妹种 (D .auraria、D .biauraria、D .triaurar ia、D .quadraria和D .subauraria)及其近缘种D .rufa的ITS1片段和COⅡ基因的全序 ,以及Adh基因的部分序列。以D .rufa、D .melanogaster和D .yakuba为外群 ,分别用最大简约 (MP)法和邻接 (NJ)法根据每个分子标记的序列构建金色果蝇复合种系统发生树。在得到的 6棵系统树中 ,D .subauraria总位于系统树的基部。该复合种的ITS1、Adh和COⅡ的综合序列长度为 2 32 7bp(排除插入和缺失位点 ) ,能提供 2 5 5个简约信息位点。根据综合序列构建的系统树较好地揭示了 5个姊妹种间的系统发生关系 :D .subauraria在金色果蝇复合种内最早分支出来 ,随后发生了D .biauraria的分化 ,D .auraria、D .triauraria和D .quadraria之间的亲缘关系较近 ,形成的时间相对较晚。推测金色果蝇复合种的祖先种约在 2 33百万年前与D .rufa发生分歧 ,随后由暖温带侵入寒温带。在寒温带 ,D .subau raria约在 0 88百万年前与其他 4个姊妹种的祖先种发生了分歧 ,D .biauraria约在 0 31百万年前分化出来 ;而分布在较低纬度的D .auraria、D .triauraria和D .

果蝇对不同甜味物质的选择偏好及其感知机制

为了有效应对因过量糖摄入而引发的健康问题,探究甜味物质选择偏好及其感知机制至关重要。本研究以黑腹果蝇为模式动物,通过评估果蝇对能量糖(蔗糖、果糖、葡萄糖)和非能量代糖(山梨醇)的选择偏好,探究糖类偏好的特异性甜味感知受体机制。结果显示:与山梨糖醇相比,能量糖可以刺激雌性果蝇产更多的卵并显著影响产卵位置偏好。在甜味受体Gr5a层面,研究发现该受体在低浓度甜味基质的感知和行为调节中发挥了关键作用。在高浓度甜味基质中,即使Gr5a功能受损,雌性果蝇仍能进行有限的产卵,提示可能存在其它感知机制补偿了部分功能,多样化的感知机制使动物能够更有效地在环境中选择适合其需求的食物,从而优化营养选择。本研究揭示了果蝇在复杂糖环境中的感知和行为响应机制,为代糖在食品中的应用提供了科学依据,并为更广泛地减糖策略和健康饮食研究提供了新的视角和理论支持。

中国大陆拟果蝇(Drosophila simulans)的随机扩增多态性DNA分析

近几年发现了拟果蝇 (Drosophilasimulans)在中国大陆的广泛分布。用随机扩增多态性DNA(RAPD)方法研究了中国大陆 38个不同地理群体的拟果蝇 (D .simulans)在DNA水平上的遗传多样性 ,初步讨论了拟果蝇在中国大陆的起源。以 4 0种 10bp长的寡聚核苷酸随机引物进行PCR扩增 ,根据遗传距离利用UPGMA法作出的相关聚类图显示 :(1) 38个地理群体按纬度以南京 (NJ)为界明显地分为南北两大支系 ,北方支系以北京 (BJ)为界又分为明显的两个亚支 ,一支为东北支系包括漠河、海拉尔、黑河、佳木斯、哈尔滨、长春、沈阳、丹东、延吉、图们等 10个群体 ;另一支包括北京、大同、呼和浩特、银川、西宁、兰州、太原、石家庄、烟台、济南、徐州、连云港等 12个群体。南方支系包括郑州、武汉、上海、南京、杭州、重庆、南昌、温州、长沙、贵阳、福州、昆明、厦门、广州、南宁、海南等 16个群体。(2 )各地理群体之间的遗传距离与地理分布有密切关系 ,基本按地理位置的相关性聚类在一起。根据了解到的事实 ,(1)拟果蝇在中国是一个外来种 ;(2 )拟果蝇在中国大陆的入侵是最近 30年左右的事情 ;(3)拟果蝇在全国的广泛分布是最近 10多年的事情。所以拟果蝇各群体的聚类关系可能并不是地理分化的结果 ,而是由于建立各地方群体的祖先?