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"古翅类"系统发育关系研究进展(昆虫纲,有翅类) 总被引:4,自引:2,他引:4
古翅类的系统发育问题是六足总纲中有争议的热点问题之一。对现存古翅类(孵蝣目 蜻蜒目)与新翅类之间的系统发育关系有3种主要观点:古翅类(=蜉蝣目 蜻蜒目) 新翅类,蜉蝣目 (蜻蜒目 新翅类),蜻蜒目 (蜉蝣目 新翅类)。第1种观点得到化石、形态和部分基因证据支持,第2种观点得到较多形态特征支持,支持第3种观点的证据较少。这一问题的解决有赖于更多昆虫种类、化石以及分子证据的发现和研究。 相似文献
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根据产自缅甸北部白垩纪中期克钦琥珀中的一块昆虫化石标本,建立了1新种——克钦雅翅蝉(Ornatiala kachinensis sp. nov.),归于华翅蝉科(Sinoalidae Wang and Szwedo, 2012)。根据新化石材料,对雅翅蝉属的鉴别特征进行了修订。此外,利用支序分类学分析手段对新种的生物系统学地位进行了确定,并对华翅蝉前翅色型、翅脉变异等问题进行了探讨。新材料的发现进一步证实克钦琥珀生物群中的华翅蝉生物多样性程度较高,为优势昆虫类群。 相似文献
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记述了同蝽科板同蝽属3新种:戟板同蝽Lindbergicoris hastatus sp.nov.、黑线板同蝽Lindbergicoris nigrolineatus sp.nov.和散刻板同蝽Lindbergicolis sparsus sp.nov.。指出萧彩瑜等(1977)报道的Platacantha forfex(Dallas)属错误鉴定。研究材料及模式标本均保存在南开大学昆虫学研究所。文中量度单位为mm。 相似文献
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随着PCR技术的发展以及大量DNA序列的累积,昆虫分子系统学近年来快速发展。线粒体DNA(mtDNA)序列相对于核内DNA序列进化速率较快,常被用于昆虫的系统发育研究。本文综述了国内外学者利用各种线粒体DNA序列来研究半翅目异翅亚目昆虫系统发育的研究概况。总结发现,COⅠ、COⅡ、12S rDNA、16S rDNA、Cytb、ND1、ND2和ND5等线粒体区段被用于半翅目异翅亚目系统发育的研究,其中以COI、COⅡ、16S rDNA和Cytb应用最广泛,但目前尚缺乏不同分子标记间的联合分析。进一步的研究最好在选定半翅目异翅亚目昆虫的分类阶元(如科间、亚科间、科内属间、种间或种内)后,集中测定线粒体某几个区段的DNA序列,然后进行单一分析和联合分析,并与传统形态学研究结果进行比较,可望全面分析半翅目异翅亚目昆虫的系统发育关系。 相似文献
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记述我国宽翅网蝽属昆虫2种,即华宽翅网蝽Lepturga chinai Takeya, 1962和吉隆宽翅网蝽Lepturga gyirongensis Li, sp. nov.。分析了宽翅网蝽属与广翅网蝽属的共有特征和差异。模式标本保存于北京中国科学院动物研究所。 相似文献
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现存蜉蝣翅基纵脉走向及愈合模式(昆虫纲:蜉蝣目) 总被引:1,自引:0,他引:1
有翅昆虫翅基纵脉的走向及愈合模式在系统发育重建中占有重要地位。然而,现存蜉蝣翅基纵脉的走向及愈合状况在大部分种类变化极大,无法推测其原始状况,只在极少数种类保留有部分可见残迹。中国拟短丝蜉Siphluriscus chinensis的翅基保留有独立的亚前缘脉弓、部分中脉M和肘脉Cu主干以及前中脉MA及径分脉Rs的走向痕迹。据此并结合红斑蜉Ephemera rufomaculata 和大网脉蜉Chromarcys magnifica翅基的相关特征,本文提出了蜉蝣目主要纵脉基部走向及愈合的基本模式,其要点有:中脉主干在基部与径脉主干独自发出后先接近或愈合后又分离、它们各自分成两支后的前中脉及径分脉又先愈合再分离、肘脉始终独立。这种中脉与径脉先接近或愈合后分离的模式非常接近新翅类的情况而与蜻蜓很不相同(在蜻蜓,中脉与肘脉在基部愈合) 。亚前缘脉弓的作用相信是加强了因翅基骨板发达而相互远离的纵脉间的连结作用。这个假说也可以来解释蜻蜓复杂脉相的形成原因。 相似文献
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中国蚜虫类昆虫物种多样性与分布特点(半翅目,蚜总科) 总被引:3,自引:0,他引:3
研究了蚜虫类昆虫在中国的物种多样性、区系成分和分布特点.基于多年的标本采集记录和已发表文献,建立了中国蚜虫物种数据库和中国蚜虫地理分布数据库.应用GIS的空间分析功能对中国蚜虫的地理分布和分布密度进行了分析.结果表明中国记录蚜虫类昆虫268属1 099种/亚种,其中特有种518种,占中国蚜虫物种总数的47.1%.中国蚜虫的区系成分十分复杂,主要分为9种类型,其中以典型古北种、典型东洋种、跨古北界和东洋界分布的物种为主,同时与新北界、澳洲界的关系也较为密切.在自然地理区划上,蚜虫在中国东部地区的分布多于西部地区,中部地区多于南北两端.基于物种多样性和分布密度,确定了蚜虫在中国的5个多样性中心,即甘南山地、横断山区、天山山地、东部平原和台湾岛. 相似文献
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Sperm from mice of the PL/J strain have a high frequency of sperm-head morphology abnormalities. Fluorescence in situ hybridization (FISH) methods revealed that PL/J sperm are also characterized by a high frequency of aneuploidy. The traits of abnormal sperm head morphology and aneuploidy are associated with numerous meiotic abnormalities. Spermatocytes of PL/J mice exhibit chromosome asynapsis during meiotic prophase as well as reduced crossing over, revealed by analysis of both MLH1 foci in pachytene spermatocytes and chiasmata seen at the first meiotic metaphase. During the first meiotic division, roughly one-third of the PL/J spermatocytes exhibit aberrant spindle morphology, with abnormalities including monopolar spindles, split spindle poles, and incomplete spindle formation and centrosomal abnormalities. F1 progeny of a cross between PL/J and C57BL/6J did not exhibit a high frequency of either sperm aneuploidy or sperm head morphology aberrations, as would be expected if the PL/J traits were dominant. Among progeny of a backcross of F1 mice to PL/J, none of 16 males assessed exhibited elevated frequencies of sperm head morphology abnormalities. Four of the individuals exhibited elevated sperm aneuploidy, but not at the levels of the PL/J parents. Thus, it is likely that the aberrant PL/J traits are due to several genes and/or modifiers affecting the generation of both sperm aneuploidy and abnormal sperm head morphology. 相似文献
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Exposure of mice to an environment of approximately 35°C and 65% relative humidity for 2–5 days caused dissociation of the X-Y chromosome bivalent in diakinesis-metaphase I (primary) spermatocytes. Dissociation of autosomal bivalents, chromosome fragmentation, aneuploidy, and polyploidy were not significantly affected by heat stress. Heat stress also caused formation of multinucleated giant cells in the mouse testis. Giant cell formation followed a distribution similar to X-Y dissociation, reaching highest levels 5 days after heat stress and returning to control levels 50–70 days after heat stress. Spermatogonial activity was not permanently damaged by these conditions, and the germinal epithelium was able to repopulate. We believe that cell aberration or cell death resulting from either or both of these anomalies causes much of the decreased fertility found after subjecting scrotal mammals to high temperatures. 相似文献
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Xuexia Liu Qian Li Zhixin Wang Fujun Liu 《Journal of cellular and molecular medicine》2021,25(3):1624-1632
Cyclophosphamide (CP) is a clinical anticancer drug that can cause male reproductive abnormalities, but the underlying mechanisms for this remain unknown. The present study aimed to explore the potential toxicity induced by CP in spermatogenesis events of germ cell proliferation, meiosis, and blood-testis barrier integrity at the molecular level. CP-treated mice showed significantly reduced serum testosterone levels, sperm motility and concentration. The results of immunohistochemistry and Western blot showed that CP reduced the proliferation of germ cells (PCNA, PLZF) and increased germ cell apoptosis (Bax and TUNEL-positive cells) in CP-treated mice testes. The expression of meiotic related proteins (SYCP3, REC8, MLH1) decreased significantly in the fourth week after administration, and the expression of blood-testis barrier related proteins (β-catenin, ZO-1) and sperm quality-associated proteins (PGK2, HSPA4) decreased significantly in the first week after administration. CP leads to the apoptosis of male germ cells, inhibits the proliferation of germ cells, and affects meiosis and the blood-testis barrier, resulting in the decline of sperm quality. This study provides information to further the study of molecular mechanism and protective strategy of CP influence. 相似文献
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Steven A. Ramm Lukas Schärer 《Biological reviews of the Cambridge Philosophical Society》2014,89(4):874-888
Larger testes are considered the quintessential adaptation to sperm competition. However, the strong focus on testis size in evolutionary research risks ignoring other potentially adaptive features of testicular function, many of which will also be shaped by post‐mating sexual selection. Here we advocate a more integrated research programme that simultaneously takes into account the developmental machinery of spermatogenesis and the various selection pressures that act on this machinery and its products. The testis is a complex organ, and so we begin by outlining how we can think about the evolution of testicular function both in terms of the composition and spatial organisation of the testis (‘testicular histology’), as well as in terms of the logical organisation of cell division during spermatogenesis (‘testicular architecture’). We then apply these concepts to ask which aspects of testicular function we can expect to be shaped by post‐mating sexual selection. We first assess the impact of selection on those traits most strongly associated with sperm competition, namely the number and kind of sperm produced. A broad range of studies now support our contention that post‐mating sexual selection affects many aspects of testicular function besides gross testis size, for example, to maximise spermatogenic efficiency or to enable the production of particular sperm morphologies. We then broaden our focus to ask how testicular function is affected by fluctuation in sperm demand. Such fluctuation can occur over an individual's lifetime (for example due to seasonality in reproduction) and may select for particular types of testicular histology and architecture depending on the particular reproductive ecology of the species in question. Fluctuation in sperm demand also occurs over evolutionary time, due to shifts in the mating system, and this may have various consequences for testicular function, for example on rates of proliferation‐induced mutation and for dealing with intragenomic conflict. We end by suggesting additional approaches that could be applied to study testicular function, and conclude that simultaneously considering the machinery, products and scheduling of spermatogenesis will be crucial as we seek to understand more fully the evolution of this most fundamental of male reproductive traits. 相似文献
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报道了2种中国木虱的精子发生,即香椿巴木虱Bharatiana setentrionalis Yang et Li,n=7(XO);合欢羞木虱Acizzia jamatonica(Kuwayama),n=13(XO)。研究表明木虱的减数分裂具有3个显著的特征:1)前期I具有弥散期,此时常染色体疏松化,分散于整个细胞核,仅可以观察到异固缩化的性染色体,推测存在基因转录现象,同样的现象存在于蜡蝉和异翅类(Heteroptera)昆虫;2)中期Ⅰ姊妹染色体联合定向,第一次分裂为减数分裂;3)第二次分裂不发生胞质分裂,形成双核精子。从生殖系统的结构和减数分裂中染色体的行为来看,木虱与蜡蝉的关系更为密切。 相似文献
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Meiotic spindles in males of higher Lepidotera are unusual in that the bulk of the spindle microtubules (MTs) ends about halfway between the equatorial plate and the centrosomes in metaphase. It appears worthwhile to determine how the MTs are nucleated, while their pole proximal ends are distant from the centrosomes. To this end, spermatocytes of Phragmatobia fuliginosa (Arctiidae), collected in the field, were double-labeled with antibodies to beta- and gamma-tubulin. The former antibody reveals the entire microtubular cytoskeleton, and the latter is directed against a newly-discovered tublin isoform that is prevalent in microtubule-organizing centers (MTOCs). The immunocytochemical work was supplemented by a fine structural analysis of MTOCs and spindles. Gamma-tubulin was clearly detected at the spindle poles, and prominent microtubular asters originated from these sites. Additionally, MT arrays at both sides of the equatorial plate in metaphase spermatocytes contained gamma-tubulin. The staining persisted in late anaphase, when kinetochore MTs are depolymerized. This indicates that at least nonkinetochore MTs contain gamma-tubulin. The analysis of ultrathin sections through spindles revealed large amounts of pericentriolar material at the spindles poles, in prometaphase through anaphase. The spindle MTs appeared as regular, straight elements in longitudinal sections. We assume that gamma-tubulin is located at the pole proximal ends of the MTs and/or is associated with the spindle MTs throughout their lengths. In order to distinguish between these possibilities, testes of Ephestia kuehniella (Pyralidae), a laboratory species, were cold-treated prior to double-labeling with antibodies to beta- and gamma-tubulin. The treatment was expected to depolymerize MTs. Astral MTs, which were nucleated end-on by gamma-tubulin-containing material, indeed depolymerized. In contrast, the gamma-tubulin-containing spindle MTs persisted. It is, therefore, conceivable that gamma-tubulin is associated with MTs throughout their lengths in male meiosis of Lepidoptera species. It is plausible that this association stabilizes the MTs against cold-induced disassembly. © 1996 Wiley-Liss, Inc. 相似文献
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观察了同翅目头喙亚目12种沫蝉雄性的染色体数目和减数分裂行为。通过对沫蝉总科现有核型资料的分析,认为沫蝉总科的核型特点是:①染色体较小,数目较多,总科内染色体数目变化范围较大,众数为2n=26(24+XO);②染色体的易位现象极为普遍,因此可以推测,通过染色体的易位导致染色体数目增加是核型进化的主要机制;③减数分裂前期Ⅰ具有典型的花束期,但没有弥散期。因此从精子发生来看沫蝉总科与叶蝉总科、角蝉总科和蝉总科的关系更为密切,而与蜡蝉总科的关系较远。头喙亚目的亲缘关系可能是:蜡蝉总科+{蝉总科+[沫蝉总科+(叶蝉总科+角蝉总科)]}。 相似文献
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Halton D. W. &; Hardcastle A. 1976. Spermatogenesis in a monogenean, Diclidophora merlangi. International Journal for Parasitology6: 43–53. Development of the spermatozoa in the testis of a polyopisthocotylean fish-gill fluke, Diclidophora merlangi, has been examined by light and electron microscopy. Spermatogonial cells are typically undifferentiated and display numerous free ribosomes and relatively little cytoplasm. Successive mitotic divisions produce spermatocytes which are characterized by expansion of the ER and the development of Golgi complexes. Nuclear division is followed by incomplete cytokinesis so that spermatocytes and subsequent stages are joined and develop syncytially. Nuclear synaptonemal complexes mark the first division of the meiotic phase, the second giving rise to a rosette of 32 spermatids. During spermateleosis, the spermatid nucleus condenses and migrates into a conical-shaped projection of cytoplasm. A centriole-like structure and basal bodies, anchored by a pair of attached rootlets, produce axial filaments that grow out from the spermatid and eventually fuse with the nuclear projection. Spermatozoa are then released from the residual cytoplasm. Each spermatozoon is approximately 325 μm in length and 2 μm maximum diameter and in section shows a nucleus, mitochondrion, paired axial units which conform to the “9 +1” pattern described for other platylelminthes, particles of β-glycogen, and a line of micro-tubules around the inner aspect of the limiting membrane. 相似文献
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A high frequency (42%) of sperm from the inbred homozygous mouse strain PL/J are abnormal. Head shape abnormalities occur in 15% of the total sperm; and 27% of the sperm are headless, with the mitochondria condensed into a mass at the caudal end of the midpiece region. The sperm without heads exhibit relatively normal motility. Electron microscopy of the testes indicates that some of the abnormal sperm in PL/J males result from a failure of the paired centrioles to attain a normal position on the nucleus opposite the acrosome prior to implantation, or to attach at all. The centrioles that are not attached to the nuclear envelope can differentiate to form the principal piece and midpiece region. The frequency of headless variants in heterozygous F1 indicates that the trait is mainly recessive. The offspring from the backcross of the F1 to homozygous PL/J parents did not give a clear-cut segregation pattern. The frequency of abnormal sperm in the F1 and the backcross is higher when the female parent is a PL/J. 相似文献