桂西南褐翅鸦鹃的孵卵行为与节律

2016年3~6月,在广西西南部龙州县弄岗村(22°26′35.20′′~22°30′46.90′′N,106°57′46.35′′~107°03′32.99′′E),通过野外观察和自动温度记录仪相结合的方法对褐翅鸦鹃(Centropus sinensis)的孵卵行为与节律进行了研究。结果表明,1)褐翅鸦鹃边筑巢边产卵,每2 d产1枚卵,卵长径和短径分别为(36.11±0.42)mm和(28.46±0.38)mm,卵重(16.35±0.51)g(n=44枚)。窝卵数3~5枚,孵卵期为(16.75±1.65)d(n=4巢),孵化率为45.45%(n=44枚)。孵卵期与窝卵数之间无显著相关性(r=0.865,P0.05);2)白天双亲共同参与孵卵,夜晚则由其中1只负责。夜间亲鸟的在巢时间从19时左右持续至翌日晨6时左右;3)亲鸟采取离巢次数少和离巢时间长的孵卵策略。亲鸟日活动时间在700 min以上(n=45 d),日离巢次数为(8.82±0.34)次(n=45 d),平均每次离巢持续时间为(52.91±2.35)min(n=397次),每次离巢持续时间与环境温度呈显著负相关关系(r=﹣0.113,P0.05);4)巢内平均孵卵温度为(31.7±0.3)℃(n=4巢),随孵卵天数增加而增加,并与环境温度(最高温r=0.566,最低温r=0.537,平均温r=0.706,P0.01)和日活动时间正相关(r=0.506,P0.01);5)有延迟孵卵行为。延迟孵卵期间夜晚巢内最低温是22.1℃。在桂西南北热带气候环境中,高的环境温度是保障褐翅鸦鹃孵卵成功的主要因素之一。     

四川瓦屋山金色林鸲的繁殖生态及孵卵节律

20 0 3年 4～ 7月 ,在四川省瓦屋山自然保护区对金色林鸲 (Tarsigerchrysaeus)的繁殖生态和孵卵节律进行了较为深入的研究。金色林鸲营巢期从 4月下旬～ 6月中旬 ,孵卵期一般为 1 6～ 1 7d,育雏期为1 6d。窝卵数一般为 3～ 4枚 ,平均为 (3 . 75± 0. 45 )枚 (n =1 2 ) ,孵化率为 60 0 % ,育雏成功率为 85 2 %。仅雌鸟孵卵 ,根据对 3巢的监测 ,发现雌鸟早晨 6:0 0时左右首次离巢 ,晚上 2 0 :0 0时左右回到巢中 ,每天出巢次数 1 8～ 1 9次。孵卵雌鸟每次出巢时间一般少于 2 0min ,异常离巢时最长达到 65 6min。雌鸟出巢时间的长度和环境温度呈明显的正相关 (Spearman,r=0 . 1 1 8,P =0 . 0 0 7,n =5 3 1 )。金色林鸲雄鸟存在羽毛延迟成熟现象 ,亚成体雄鸟可以繁殖。     

灰蓝姬鹟的孵卵节律

2 0 0 2年在莲花山自然保护区使用温度自动记录装置对灰蓝姬的孵卵节律进行了研究。研究表明 ,灰蓝姬雌鸟日平均离巢 31.2 5± 7.5 0次 (n =8天 ) ,平均每次离巢持续时间为 7± 2min (n =2 6 4 ) ,平均在巢持续时间 2 1± 9min (n =2 5 6 )。雌鸟在巢率与环境温度间存在显著的负相关关系 (Spearman相关 ,r =- 0 .30 4 ,P <0 .0 1)。进一步的分析表明 ,灰蓝姬雌鸟每次离巢持续时间与环境温度呈显著的正相关 (Spearman相关 ,r =0 .2 6 1,P <0 .0 1) ,每次在巢时间和离巢次数均与环境温度无关 (在巢时间 ,r =0 .0 2 6 ,P =0 .6 82 ;离巢次数 ,r =0 .0 14 ,P =0 .879)。认为灰蓝姬雌鸟主要通过调节离巢时间的长短来控制孵卵节律     

乌鸫的繁殖行为与坐巢行为初步观察

于2009年3～7月、2010年3～6月,采用焦点动物观察法和全事件行为记录法对乌鸫(Turdusmerula)的孵卵及育雏行为进行了研究。结果表明,乌鸫是雌鸟孵卵,在孵卵期出现卵损失现象,具补卵行为;孵卵前期与后期的坐巢行为存在差异,且其坐巢时间、频次和坐巢率有随孵卵数递增的趋势。双亲育雏但以雌鸟为主,喂食模式3种:雌鸟喂食、雄鸟喂食、雄鸟将食物递给雌鸟由雌鸟喂食。随着雏鸟日龄的增长,喂食次数增多,暖雏行为减少,至育雏后期未观察到暖雏行为。为权衡孵卵期和育雏前期的能量分配,乌鸫在孵卵期及育雏前期分别采取时间长而频次少和时间短而频次多的坐巢策略。     

卧龙血雉繁殖期行为特征分析

1 995年 4～ 6月在四川卧龙自然保护区五一棚地区 ,采用无线电追踪技术结合野外行为观察 ,对血雉繁殖期行为特征进行了研究。结果表明 ,繁殖前期雄鸟在警戒行为的频次及持续时间上均显著地高于雌鸟 (T test,频次 ,t=-4 73 ,P <0 0 1 ;时间 ,t=-2 80 ,P <0 0 5 ) ;孵卵期 ,雄鸟在警戒行为的总持续时间上显著地高于雌鸟 (T test,t=-4 75 ,P <0 0 1 ) ,雌鸟在取食行为的总持续时间上显著地高于雄鸟 (T test,t=3 41 ,P <0 0 5 ) ;对雌雄个体行为同时进行观察的结果表明 ,雌鸟维持行为的时间与雄鸟警戒行为的时间显著正相关 (Y =49 68+0 2 693X ,r=0 71 79,P =0 0 0 2 6)。繁殖前期和孵卵期雄鸟的警戒行为可以提高雌鸟用于取食、理羽、沙浴的时间 ,而减少用于警戒的时间     

甘肃莲花山暗绿柳莺的孵卵行为

2001年5～7月,在甘肃省莲花山自然保护区对暗绿柳莺Phylloscopus trochiloides的孵卵行为进行了初步研究.结果 表明,孵化期内雌鸟日活动期长度平均为(848.5±14.8) min (n=17),每天离巢(16.0±3.0)次(n=15),每次离巢时间为(12.3±5.0) min (n=251),每次在巢时间为(43.6±21.9) min (n=236),在巢率为(78.8±2.4)%.雌鸟在巢时卵温平均为(31.3±3.5)℃ (n=10646),离巢时卵温平均为(26.6±4.8)℃ (n=2876);夜晚的平均卵温为(30.6±3.5)℃ (n=9239).孵卵温度在孵卵期有逐渐上升的趋势.     

莲花山云南柳莺的孵卵行为

20 0 2年 6～ 7月 ,在甘肃省莲花山自然保护区对云南柳莺的孵卵行为进行了研究。结果表明 ,雌鸟孵卵的日活动期为 (80 0 5± 42 8)min (n =1 5 ) ,每天离巢 (3 2 7± 3 9)次 (n =1 5 ) ,每次离巢时间 (6 6±1 8)min (n =5 99) ,每次坐巢时间 (1 8 4± 9 2 )min (n =5 83 ) ,坐巢率为 (73 1± 1 9) %。雌鸟每次坐巢时间和离巢时间的长度均与气温显著相关。日活动期雌鸟在巢的平均卵温为 3 2 3℃ ,夜晚的平均卵温为3 2 7℃。整个孵卵期卵温在发育临界值 2 8℃以上的时间比例为 92 7%。在孵卵后期卵温有逐渐上升的趋势。     

四川雉鹑孵卵行为初步观察

2009年4～5月,在四川省雅江县对四川雉鹑Tetraophasis szechenyii的孵卵行为进行了观察.在孵化过程中,卵重与孵卵剩余天数呈明显的正相关(r=0.939,F=59.585,P<0.001).卵在巢中的位置是不断变化的.雌鸟坐巢的行为主要是孵卵行为(78.7%),其次是离巢(17.4%)和翻卵(3.1%),其他行为(如鸣叫和梳理)偶尔发生(0.8%).孵卵行为全天发生,离巢行为主要发生在7:30～11:30,翻卵行为多发生在13:30～15:30.雌鸟从巢的一个固定位置进出巢.雏鸟出巢时只由雌鸟带领活动.     

江西吉安乌鸫的繁殖生态研究

2009～2010年对江西省吉安地区乌鸫Turdus merula的繁殖进行了调查研究,结果表明:当地乌鸫的营巢时间在3月9日至16日,产卵时间是3月18日至26日,平均窝卵数5.14(4～6)枚(n=14),平均卵大小29.71 mm×21.16 mm,平均卵重6.63 g(n=71).孵卵和暖巢主要由雌鸟承担,但雄鸟也有暖巢行为,孵化率为65.83%,育雏期13～15 d,离巢率高达100%.与高海拔的乌鸫相比,当地乌鸫产大窝小卵,这一特征保证了大窝雏数和高离巢率,繁殖对策属于r-选择.     

甘肃莲花山蓝马鸡孵卵节律的初步研究

2002～2003年5～6月,应用温度自动监测技术,在甘肃省莲花山自然保护区对蓝马鸡（Crossoptilon auritum）的繁殖及孵卵节律进行了初步研究。蓝马鸡的巢址位于海拔2900—3020m的针阔混交林或灌木林中,蓝马鸡的窝卵数为9．5（n=4）,孵卵期的主要天敌为哺乳类。根据对4个巢的监测,蓝马鸡雌鸟在孵卵期的平均日离巢次数在1．25～4.00次,平均日离巢时间在16.6～46．4min之间。雌鸟的平均在巢率为97.0％（n=3）。根据对4号巢雌鸟孵卵节律连续27d的观测,发现雌鸟在每日离巢2次或3次时,其首次离巢时间要显著早于每日仅离巢1次的时间。     

Preparation of hair for measurement of elements by inductively coupled plasma-mass spectrometry (ICP-MS)

The preparation of hair for the determination of elements is a critical component of the analysis procedure. Open-beaker, closedvessel microwave, and flowthrough microwave digestion are methods that have been used for sample preparation and are discussed. A new digestion method for use with inductively coupled plasma-mass spectrometry (ICP-MS) has been developed. The method uses 0.2 g of hair and 3 mL of concentrated nitric acid in an atmospheric pressurelow-temperature microwave digestion (APLTMD) system. This preparation method is useful in handling a large numbers of samples per day and may be adapted to hair sample weights ranging from 0.08 to 0.3 g. After digestion, samples are analyzed by ICP-MS to determine the concentration of Li, Be, B, Na, Mg, Al, P, S, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ge, As, Se, Rb, Sr, Zr, Mo, Pd, Ag, Cd, Sn, Sb, I, Cs, Ba, Pt, Au, Hg, Tl, Pb, Bi, Th, and U. Benefits of the APLTMD include reduced contamination and sample handling, and increased precision, reliability, and sample throughput.     

Genetic Manipulation in Δku80 Strains for Functional Genomic Analysis of Toxoplasma gondii

Targeted genetic manipulation using homologous recombination is the method of choice for functional genomic analysis to obtain a detailed view of gene function and phenotype(s). The development of mutant strains with targeted gene deletions, targeted mutations, complemented gene function, and/or tagged genes provides powerful strategies to address gene function, particularly if these genetic manipulations can be efficiently targeted to the gene locus of interest using integration mediated by double cross over homologous recombination.Due to very high rates of nonhomologous recombination, functional genomic analysis of Toxoplasma gondii has been previously limited by the absence of efficient methods for targeting gene deletions and gene replacements to specific genetic loci. Recently, we abolished the major pathway of nonhomologous recombination in type I and type II strains of T. gondii by deleting the gene encoding the KU80 protein^1,2. The Δku80 strains behave normally during tachyzoite (acute) and bradyzoite (chronic) stages in vitro and in vivo and exhibit essentially a 100% frequency of homologous recombination. The Δku80 strains make functional genomic studies feasible on the single gene as well as on the genome scale^1-4.Here, we report methods for using type I and type II Δku80Δhxgprt strains to advance gene targeting approaches in T. gondii. We outline efficient methods for generating gene deletions, gene replacements, and tagged genes by targeted insertion or deletion of the hypoxanthine-xanthine-guanine phosphoribosyltransferase (HXGPRT) selectable marker. The described gene targeting protocol can be used in a variety of ways in Δku80 strains to advance functional analysis of the parasite genome and to develop single strains that carry multiple targeted genetic manipulations. The application of this genetic method and subsequent phenotypic assays will reveal fundamental and unique aspects of the biology of T. gondii and related significant human pathogens that cause malaria (Plasmodium sp.) and cryptosporidiosis (Cryptosporidium).     

A phylogenetic analysis of 100+ genera and 50+ families of euasterids based on morphological and molecular data with notes on possible higher level morphological synapomorphies

 A data matrix of 143 morphological and chemical characters for 142 genera of euasterids according to the APG system was compiled and complemented with rbcL and ndhF sequences for most of the genera. The data were subjected to parsimony analysis and support was assessed by bootstrapping. Strict consensus trees from analyses of morphology alone and morphology + rbcL + ndhF are presented. The morphological data recover several groups supported by molecular data but at the level of orders and above relationships are only superficially in agreement with molecular studies. The analyses provide support for monophyly of Gentianales, Aquifoliales, Apiales, Asterales, and Dipsacales. All data indicate that Adoxaceae are closely related to Dipsacales and hence they should be included in that order. The trees were used to assess some possible morphological synapomorphies for euasterids I and II and for the orders of the APG system. Euasterids I are generally characterised by opposite leaves, entire leaf margins, hypogynous flowers, “early sympetaly” with a ring-shaped corolla primordium, fusion of stamen filaments with the corolla tube, and capsular fruits. Euasterids II often have alternate leaves, serrate-dentate leaf margins, epigynous flowers, “late sympetaly” with distinct petal primordia, free stamen filaments, and indehiscent fruits. It is unclear which of these characters represent synapomorphies and symplesiomorphies for the two groups, respectively, and there are numerous expections to be interpreted as reversals and parallelisms. Received August 28, 2000 Accepted August 7, 2001     

Mechanisms and ecological consequences of plant defence induction and suppression in herbivore communities

Background Plants are hotbeds for parasites such as arthropod herbivores, which acquire nutrients and energy from their hosts in order to grow and reproduce. Hence plants are selected to evolve resistance, which in turn selects for herbivores that can cope with this resistance. To preserve their fitness when attacked by herbivores, plants can employ complex strategies that include reallocation of resources and the production of defensive metabolites and structures. Plant defences can be either prefabricated or be produced only upon attack. Those that are ready-made are referred to as constitutive defences. Some constitutive defences are operational at any time while others require activation. Defences produced only when herbivores are present are referred to as induced defences. These can be established via de novo biosynthesis of defensive substances or via modifications of prefabricated substances and consequently these are active only when needed. Inducibility of defence may serve to save energy and to prevent self-intoxication but also implies that there is a delay in these defences becoming operational. Induced defences can be characterized by alterations in plant morphology and molecular chemistry and are associated with a decrease in herbivore performance. These alterations are set in motion by signals generated by herbivores. Finally, a subset of induced metabolites are released into the air as volatiles and function as a beacon for foraging natural enemies searching for prey, and this is referred to as induced indirect defence.Scope The objective of this review is to evaluate (1) which strategies plants have evolved to cope with herbivores and (2) which traits herbivores have evolved that enable them to counter these defences. The primary focus is on the induction and suppression of plant defences and the review outlines how the palette of traits that determine induction/suppression of, and resistance/susceptibility of herbivores to, plant defences can give rise to exploitative competition and facilitation within ecological communities “inhabiting” a plant.Conclusions Herbivores have evolved diverse strategies, which are not mutually exclusive, to decrease the negative effects of plant defences in order to maximize the conversion of plant material into offspring. Numerous adaptations have been found in herbivores, enabling them to dismantle or bypass defensive barriers, to avoid tissues with relatively high levels of defensive chemicals or to metabolize these chemicals once ingested. In addition, some herbivores interfere with the onset or completion of induced plant defences, resulting in the plant’s resistance being partly or fully suppressed. The ability to suppress induced plant defences appears to occur across plant parasites from different kingdoms, including herbivorous arthropods, and there is remarkable diversity in suppression mechanisms. Suppression may strongly affect the structure of the food web, because the ability to suppress the activation of defences of a communal host may facilitate competitors, whereas the ability of a herbivore to cope with activated plant defences will not. Further characterization of the mechanisms and traits that give rise to suppression of plant defences will enable us to determine their role in shaping direct and indirect interactions in food webs and the extent to which these determine the coexistence and persistence of species.     

Angiosperm ovules: diversity, development, evolution

Background

Ovules as developmental precursors of seeds are organs of central importance in angiosperm flowers and can be traced back in evolution to the earliest seed plants. Angiosperm ovules are diverse in their position in the ovary, nucellus thickness, number and thickness of integuments, degree and direction of curvature, and histological differentiations. There is a large body of literature on this diversity, and various views on its evolution have been proposed over the course of time. Most recently evo–devo studies have been concentrated on molecular developmental genetics in ovules of model plants.

Scope

The present review provides a synthetic treatment of several aspects of the sporophytic part of ovule diversity, development and evolution, based on extensive research on the vast original literature and on experience from my own comparative studies in a broad range of angiosperm clades.

Conclusions

In angiosperms the presence of an outer integument appears to be instrumental for ovule curvature, as indicated from studies on ovule diversity through the major clades of angiosperms, molecular developmental genetics in model species, abnormal ovules in a broad range of angiosperms, and comparison with gymnosperms with curved ovules. Lobation of integuments is not an atavism indicating evolution from telomes, but simply a morphogenetic constraint from the necessity of closure of the micropyle. Ovule shape is partly dependent on locule architecture, which is especially indicated by the occurrence of orthotropous ovules. Some ovule features are even more conservative than earlier assumed and thus of special interest in angiosperm macrosystematics.     

Genome Similarity Implies that Citrus-Parasitic Burrowing Nematodes do not Represent a Unique Species

Burrowing nematodes from Central America, Dominican Republic, Florida, Guadeloupe, Hawaii, and Puerto Rico were characterized for their ability to parasitize citrus, but citrus parasites were found only in Florida. Sequence tag sites originally amplified from a citrus-parasitic burrowing nematode were polymorphic among 37 burrowing nematode isolates and were not correlated with citrus parasitism, nematode isolate collection site, or amplification of a 2.4-kb sequence tag site (DK#1). Results of a RAPD analysis and characterization of the isozymes phosphoglucose isomerase, lactate dehydrogenase, and malate dehydrogenase indicated that the burrowing nematode isolates were highly similar. Citrus parasitism in Florida appears to be associated with limited changes in the burrowing nematode genome. Findings did not substantiate a previous report that R. citrophilus was present in Hawaii. Overall, these data do not support assignment of sibling species status to burrowing nematodes that differ with respect to citrus parasitism.     

Assessing burrowing, nest construction, and hoarding in mice

Deterioration in the ability to perform "Activities of daily living" (ADL) is an early sign of Alzheimer's disease (AD). Preclinical behavioural screening of possible treatments for AD currently largely focuses on cognitive testing, which frequently demands expensive equipment and lots of experimenter time. However, human episodic memory (the most severely affected aspect of memory in AD) is different to rodent memory, which seems to be largely non-episodic. Therefore the present ways of screening for new AD treatments for AD in rodents are intrinsically unlikely to succeed. A new approach to preclinical screening would be to characterise the ADL of mice. Fortuitously, several such assays have recently been developed at Oxford, and here the three most sensitive and well-characterised are presented. Burrowing was first developed in Oxford. It evolved from a need to develop a mouse hoarding paradigm. Most published rodent hoarding paradigms required a distant food source to be linked to the home cage by a connecting passage. This would involve modifying the home cage as well as making a mouse-proof connecting passage and food source. So it was considered whether it would be possible to put the food source inside the cage. It was found that if a container was placed on the floor it was emptied by the next morning., The food pellets were, however, simply deposited in a heap at the container entrance, rather than placed in a discrete place away from the container, as might be expected if the mice were truly hoarding them. Close inspection showed that the mice were performing digging ("burrowing") movements, not carrying the pellets in their mouths to a selected place as they would if truly hoarding them. Food pellets are not an essential substrate for burrowing; mice will empty tubes filled with sand, gravel, even soiled bedding from their own cage. Moreover, they will empty a full tube even if an empty one is placed next to it. Several nesting protocols exist in the literature. The present Oxford one simplifies the procedure and has a well-defined scoring system for nest quality. A hoarding paradigm was later developed in which the mice, rather than hoarding back to the real home cage, were adapted to living in the "home base" of a hoarding apparatus. This home base was connected to a tube made of wire mesh, the distal end of which contained the food source. This arrangement proved to yield good hoarding behaviour, as long as the mice were adapted to living in the "home base" during the day and only allowed to enter the hoarding tube at night.     

A Simple Protocol for Platelet-mediated Clumping of Plasmodium falciparum-infected Erythrocytes in a Resource Poor Setting

P. falciparum causes the majority of severe malarial infections. The pathophysiological mechanisms underlying cerebral malaria (CM) are not fully understood and several hypotheses have been put forward, including mechanical obstruction of microvessels by P. falciparum-parasitized red blood cells (pRBC). Indeed, during the intra-erythrocytic stage of its life cycle, P. falciparum has the unique ability to modify the surface of the infected erythrocyte by exporting surface antigens with varying adhesive properties onto the RBC membrane. This allows the sequestration of pRBC in multiple tissues and organs by adhesion to endothelial cells lining the microvasculature of post-capillary venules ¹. By doing so, the mature forms of the parasite avoid splenic clearance of the deformed infected erythrocytes ² and restrict their environment to a more favorable low oxygen pressure ³. As a consequence of this sequestration, it is only immature asexual parasites and gametocytes that can be detected in peripheral blood.Cytoadherence and sequestration of mature pRBC to the numerous host receptors expressed on microvascular beds occurs in severe and uncomplicated disease. However, several lines of evidence suggest that only specific adhesive phenotypes are likely to be associated with severe pathological outcomes of malaria. One example of such specific host-parasite interactions has been demonstrated in vitro, where the ability of intercellular adhesion molecule-1 to support binding of pRBC with particular adhesive properties has been linked to development of cerebral malaria ^4,5. The placenta has also been recognized as a site of preferential pRBC accumulation in malaria-infected pregnant women, with chondrotin sulphate A expressed on syncytiotrophoblasts that line the placental intervillous space as the main receptor ⁶. Rosetting of pRBC to uninfected erythrocytes via the complement receptor 1 (CD35)^7,8 has also been associated with severe disease ⁹.One of the most recently described P. falciparum cytoadherence phenotypes is the ability of the pRBC to form platelet-mediated clumps in vitro. The formation of such pRBC clumps requires CD36, a glycoprotein expressed on the surface of platelets. Another human receptor, gC1qR/HABP1/p32, expressed on diverse cell types including endothelial cells and platelets, has also been shown to facilitate pRBC adhesion on platelets to form clumps ¹⁰. Whether clumping occurs in vivo remains unclear, but it may account for the significant accumulation of platelets described in brain microvasculature of Malawian children who died from CM ¹¹. In addition, the ability of clinical isolate cultures to clump in vitro was directly linked to the severity of disease in Malawian ¹² and Mozambican patients ¹³, (although not in Malian ¹⁴).With several aspects of the pRBC clumping phenotype poorly characterized, current studies on this subject have not followed a standardized procedure. This is an important issue because of the known high variability inherent in the assay ¹⁵. Here, we present a method for in vitro platelet-mediated clumping of P. falciparum with hopes that it will provide a platform for a consistent method for other groups and raise awareness of the limitations in investigating this phenotype in future studies. Being based in Malawi, we provide a protocol specifically designed for a limited resource setting, with the advantage that freshly collected clinical isolates can be examined for phenotype without need for cryopreservation.     

日本北海道虻类雌性外生殖器形态(双翅目：虻科)(英文)

【目的】利用日本北海道虻类评估和验证外生殖器在分类学上的意义。【方法】将虻类成虫标本浸渍在生理盐水中并置于双目显微镜下通过针和镊子在培养皿中进行解剖并绘图,观察第9背板、第10背板、尾叶、第8腹板、受精囊、受精囊管及生殖叉器的形态特征。【结果】在日本北海道共记录了虻科(Tabanidae) 3亚科7属38种。我们观察并描述了3亚科其中的6属24种的雌性外生殖器的主要特征。亚科之间存在明显差异;然而在一般情况下属之间很难建立一种方法来确定共同点;种之间只有在斑虻属Chrysops中有相似之处,其他属中则比较多样化。因此,亚科鉴定根据第9背板、第8腹板及受精囊足以进行区分,属及种鉴定需要结合第9背板、第10背板、尾叶、第8腹板、受精囊、受精囊管及生殖叉器各自的特征组合在一起才能区分开来。我们也制作了虻类外生殖器的检索表。【结论】和许多其他昆虫一样,外生殖器是虻科的重要分类特征,对于促进分类学和系统学的发展具有重要意义。本研究首次对分布在日本北海道的虻科雌性外生殖器进行了系统研究。     

外泌体在白血病中的重要调控作用

目前,白血病复发是患者死亡的主要原因之一。肿瘤细胞和微环境的相互作用,以及隐匿在骨髓中的肿瘤干细胞,促进了白血病的复发和向淋巴组织的转移,因此白血病的治疗、转移和复发问题受到广泛关注。外泌体是由绝大多数细胞分泌的双层脂质膜囊泡,可以调控细胞间的交流和信息传递。在白血病细胞、基质细胞和内皮细胞之间的相互联系中都涉及到外泌体,白血病细胞来源的外泌体存在于白血病患者的血浆中,能把其携带的白血病相关抗原及微小RNA呈递给靶细胞,促进白血病肿瘤细胞的增殖,有助于肿瘤细胞实现免疫逃避,保护白血病细胞抵抗化疗药物导致的细胞毒性作用,促进血管生成及肿瘤细胞的迁移。因此,外泌体与白血病的转移、治疗及预后密切相关,可以用来检测和监测白血病的进展。本文综述了外泌体的来源、形成与分泌机制,以及外泌体在白血病发生前、发展中、预后和免疫治疗中所扮演的重要角色。