2种辉蝽的精巢和染色体研究(半翅目:蝽科)

通过探讨中国蝽科Pentatomidae辉蝽属Carbula的红角辉蝽Carbula crassiventris(Dallas,1849)和北方辉蝽C.putoni(Jakovlev,1876)的精巢形态和染色体的核型及减数分裂行为,为蝽科昆虫的细胞分类学提供新资料。采用显微形态解剖法和染色体制片法对其精巢和染色体进行观察。结果表明:2种精巢的位置、外被颜色、形状及精巢叶的数目都一致;染色体组成均为2n(♂)=14(12A+XY),具有X-Y性别决定机制。在减数分裂过程中,常染色体前减数分裂,性染色体后减数分裂且无交叉;在中期-Ⅱ,常染色体排列成环状而性染色体在环中央形成假二价体。但是,2个物种在弥散期常染色体的去固缩程度,终变期常染色体双交叉的个数及中期-Ⅰ常染色体和性染色体的排列方式都各不相同。本文证实了蝽科昆虫的减数分裂行为在不同属间、种间可不相同,而且具有一定的属、种间特异性;同时为精巢在蝽类昆虫分类中的作用提供新的资料。     

蝽科五种昆虫染色体分析(半翅目,异翅亚目)

对蝽科Pentatomidae4属5种——广二星蝽Stollia ventralis(Westwood)、黒腹二星蝽Stollia guttiger(Thunberg)、西北麦蝽Aelia sibirica(Reuter)、紫翅果蝽Carpocoris purpureipennis(De Geer)、赤条蝽Graphosoma rubrolineata(Westwood)昆虫减数分裂各期染色体形态结构及行为进行分析。结果表明:蝽科5种进行交叉减数分裂。花束期5种昆虫染色质变化相似,形态种间有差异。中期染色体排列方式相似,核型种间差异大。精子形态相似,弯曲度大小种间有差异。双线期、终变期染色体交叉形态、频率及历程长短反映物种进化程度。紫翅果蝽X染色体碎斑化。     

蝽科昆虫精巢形态及属种间亲缘关系

为探讨蝽科精巢形态差异,以及据此反映的属种间亲缘关系,对蝽科9属13种昆虫精巢进行了观察和比较研究.结果表明,蝽科精巢形态在属内种间具有相对稳定性,属间、亚科间具有差异性.蝽科输精管种间变异大.基于精巢长度、宽度、面积及长宽比的聚类分析结果显示,斑须蝽属Dolycoris、绿蝽属Nezara、茶翅蝽属Halyomorpha关系较近,并与二星蝽属Eysarcoris形成并列关系.菜蝽属Eurydema、麦蝽属Aelia、珠蝽属Rubiconia亲缘关系密切.而果蝽属Carpocoris与条蝽属Graphosoma形成不同分支的特殊进化关系.因此,蝽科精巢可作为属级、亚科级的形态和数值分类特征.     

小花蝽属两种核型的研究(半翅目: 花蝽科)

本文利用姬姆萨染色空气干燥压片方法,对花蝽科小花蝽属中国2种小花蝽的性细胞核型进行了研究.研究结果表明该2种小花蝽的2倍体均具有24条染色体和X-Y性别机制,但2种间在染色体行为特征方面具有差别,主要表现在细胞减数分裂的晚终变期和中期常染色体以及性染色体的排列形状与位置等方面,该特征可以用于种间的细胞分类.     

四种蝽科昆虫的染色体研究

研究了4种中国蝽科昆虫的核型和染色体的减数分裂行为, 并首次在半翅目中采用核型分析软件对第一次减数分裂中期的染色体进行核型分析。结果表明: 4个种均为2n=14和X-Y性别决定机制; 减数分裂行为比较一致, 但在中期 I 常染色体和性染色体的排列方式各不相同; 核型分析后的结果表现出了种的特异性, 可为蝽科昆虫的形态分类及系统发育提供有用的证据。     

简易制备牛蛙精巢染色体——观察动物细胞减数分裂

简化常规染色体滴片的操作程序,对牛蛙精巢进行染色体制片,基本观察到精巢组织中细胞行减数分裂各阶段的染色体行为。实验结果表明．用牛蛙精巢制备染色体能相对简捷稳定的获得有效的实验结果．是一种观察动物细胞减数分裂行为的好方法。     

缘蝽总科昆虫精巢形态

为比较缘蝽总科昆虫的精巢形态差异,解剖镜下解剖观察拍照,对缘蝽总科3科4亚科6属9种昆虫的精巢进行了观察。结果表明:缘蝽总科精巢、输精管皆被有不同颜色的被膜。姬缘蝽科Rhopalidae姬缘蝽亚科Rhopalinae迷缘蝽属Myrmus精巢为小(中)型卵圆形。缘蝽科Coreidae缘蝽亚科Coreinae棘缘蝽属Cletus精巢近似三角形。巨缘蝽亚科Mictinae安缘蝽属Anoplocnemis小型圆球形。蛛缘蝽科Alydidae蛛缘蝽亚科Alydinae长缘蝽属Megalotomus为小型卵圆形。缘蝽总科姬缘蝽科Rhopalidae姬缘蝽亚科Rhopalinae环缘蝽属Stictopleurus、伊缘蝽属Rhopalus为长圆椎(圆柱)状。精巢大小与个体大小成反比。缘蝽总科精巢形状、大小、颜色及输精管粗细在科级、亚科级、属级具有分类特征。     

五种蝽科昆虫的细胞分类学研究（半翅目：异翅亚目）

研究了5种中国蝽科昆虫的核型和染色体的减数分裂行为,并采用核型分析软件对第一次减数分裂中期的染色体进行核型分析。结果表明：驼蝽Brachycerocoris camalus Costa、滴蝽Dybowskyia reticulata(Dallas）和红玉蝽Hoplistodera pulchra Yang3个种的染色体组成均为2n（♂）＝14,具有X－Y性别决定机制;减数分裂行为比较一致,但在中期－Ⅰ时,常染色体和性染色体的排列方式各不相同,可为蝽科昆虫的形态分类及系统发育提供有用的证据。二星蝽Eysarcoris guttiger(Thunberg）的染色体组成为2n（♂）＝15,具有X1X2Y性别决定机制,进一步证明了在半翅目昆虫的性染色体进化中碎片化过程起着很重要的作用;黑斑二星蝽Eysarcoris fabricii(Kirkaldy）的染色体组成为2n（♂）＝16,具有X－Y性别决定机制。后2种的核型结果,可为二星蝽属分类的进一步研究提供参考。     

六种蝽象的染色体研究（半翅目：蝽科）

研究了6种蝽象的核型和减数分裂行为。结果表明：6个种的染色体组成均为2n(♂)=14, 具有X-Y性别决定机制;减数分裂行为比较一致,但在中期-Ⅰ常染色体和性染色体的排列方式具有种的特异性,可为蝽科昆虫的形态分类及系统发育提供有用的证据。     

山地原花蝽核型研究(半翅目,花蝽科)

采用姬姆萨染色压片法,对花蝽科山地原花蝽性细胞进行了核型研究.结果表明该种单倍染色体组成为n=14A+XY,为无交叉减数分裂,性染色体经历后减数分裂,上述核型特征为阐明臭虫型内不同科的系统发育关系具有重要意义.     

蝽科部分昆虫细胞色素b基因序列及其系统发育关系的探讨

以线粒体细胞色素b(Cyt b)基因作为分子标记,对蝽科蝽亚科3种、益蝽亚科2种、荔蝽亚科1种、盾蝽亚科2种昆虫进行序列测定,获得Cyt b基因432bp的序列片段,该片段中碱基T、C、A、G的平均含量分别为31．3％、12．4％、37．6％和18．7％,A T平均含量为68．9％,明显高于G C含量(30．1％);密码子第三位点A T含量更高达82．7％。属和种间序列变异大,碱基替换多发生在第三位点。以筛豆龟蝽(Megacopta cribraria)为外群构建系统发育树,结合形态特征与序列变异率,赞同将盾蝽亚科、荔蝽亚科从蝽科划分出来并提升为科的观点,它们之间的系统关系为：盾蝽科与荔蝽科形成姊妹群,较蝽科发育得早;蝽科作为一个单系群,是蝽总科中最为进化的类群。     

Cytogenetic studies in Pentatomidae (Heteroptera): A review

The suborder Heteroptera constitutes one of the most important insect groups because most species are plants feeders and cause damage on many plants of economic importance. One of the most important cytogenetic characteristics of Heteroptera is the holokinetic nature of the chromosomes. One particular feature of some species of Pentatomidae is the regular presence of an abnormal meiosis in one testicular lobe (harlequin lobe). From the 28 species cytogenetically analysed from Argentine material, 21 present the diploid number 2 n  = 14, four species present a reduced number (2 n  = 12) and another three species possess an increased diploid number (2 n  = 16); among all these only three present an harlequin lobe. In the present work, a bibliographic review of the chromosome number and sex determining system of 294 species and subspecies belonging to 121 genera within the subfamilies Asopinae, Discocephalinae, Edessinae, Pentatominae, Phyllocephalinae and Podopinae is presented. The male diploid numbers range from six to 27 with a mode in 14 chromosomes; this last diploid number is present in 85% of the species. The sex chromosome determining system is XY/XX except in three species: Macropygium reticulare (Fabricius, 1803), Rhytidolomia senilis (Say, 1832) and Thyanta calceata (Say, 1832) which present derived sex chromosome systems. Furthermore, the cytogenetic relationships with the other families of Pentatomoidea are discussed.     

Pattern of silver nitrate-staining during meiosis and spermiogenesis in testicular lobes of Antiteuchus tripterus (Heteroptera: Pentatomidae)

The pattern of silver nitrate (Ag)-staining differed among testicular lobes of Antiteuchus tripterus. In general, these differences are in regard to the number, size, shape, coloring intensity, and location of the stained bodies or masses, observed during meiosis and spermiogenesis. These characteristics were similar in lobes 1-3. Lobes 4-6, however, differed from each other and from lobes 1-3 as well. Because the Ag-staining method is specific for nucleolar organizing regions and nucleolar material, the observations in meiosis of lobes 1-3 suggested the presence of a single pair of nucleolar organizing region-bearing chromosomes in A. tripterus, as previously found in other Pentatomidae species. In general, the amount of Ag-stained material seen in meiosis of the testicular lobes 1-3 of A. tripterus is smaller than in the other lobes. The differences among lobes observed during spermiogenesis included a striking variation in morphology of the Ag-stained material found in the head and tail of the spermatids. Given that the key role of the nucleolar material is to participate in protein synthesis, interlobular variations seem to be related to the different functions attributed to each lobe (reproduction to lobes 1-3 and basically nutrition to lobes 4-6). To our knowledge, this is the first time that the nucleolar material was studied in each testicular lobe during spermatogenesis. The present observations encourage further studies since, in addition to being of basic biological interest, several Pentatomidae species are agricultural pests and added knowledge of their biology, mainly in reproduction, may be important for the development of control strategies.     

Intraspecific variation in sperm length is negatively related to sperm competition in passerine birds

Spermatozoa are among the most diversified cells in the animal kingdom, but the underlying evolutionary forces affecting intraspecific variation in sperm morphology are poorly understood. It has been hypothesized that sperm competition is a potent selection pressure on sperm variation within species. Here, we examine intraspecific variation in total sperm length of 22 wild passerine bird species (21 genera, 11 families) in relation to the risk of sperm competition, as expressed by the frequency of extrapair paternity and relative testis size. We demonstrate, by using phylogenetic comparative methods, that between-male variation in sperm length within species is closely and negatively linked to the risk of sperm competition. This relationship was even stronger when only considering species in which data on sperm length and extrapair paternity originated from the same populations. Intramale variation in sperm length within species was also negatively, although nonsignificantly, related to sperm competition risk. Our findings suggest that postcopulatory sexual selection is a powerful evolutionary force reducing the intraspecific phenotypic variation in sperm-size traits, potentially driving the diversification of sperm morphology across populations and species.     

三种辉蝽的核型研究（半翅目：蝽科）

本首次研究了采于中国的辉蝽属三个种一辉蝽（Carbula obtusangula Reuter)、北方辉蝽（Carbula putoni(Jakovlev),凹肩辉蝽（Carbula sinica Hsiao et Cheng)的核型,结果表明,三个种均具有典型的蝽科核型即：2n(♂）＝14,具有XY性别决定机制,但是三个种的常染色体和性染色体在减数分裂时期的行为以及核型分析的结果和模式图各不相同,而且在北方辉蝽中出现了1－2条超数染色体,这些特点可为辉蝽属昆虫的形态分类及系统发育提供有用的证据。     

Chromosome numbers, sex determining systems, and patterns of the C-heterochromatin distribution in 13 species of lace bugs (Heteroptera, Tingidae).

The karyotypes, sex chromosome systems, and male meiotic patterns in 13 species belonging to 10 genera of the family Tingidae were studied. Data on eleven species, one subgenus, and 5 genera are presented for the first time, and the chromosome formula of Acalypta parvula is revised. Karyotypes of all species included six pairs of autosomes. Most of the species displayed an XY sex chromosome system, in four species, belonging to genera of Acalypta and Kalama, the X0 system was found. Male meiosis is chiasmatic for autosomes. Sex chromosomes are achiasmatic and undergo pre-reductional meiosis. Using C-banding technique, for the first time constitutive heterochromatin was localized on chromosomes in all the species studied. The heterochromatin was found either in telomeres or in some species in interstitial locations, evidencing that a quite substantial redistribution of chromosome material within chromosomes might occur without fragmentations or fusions. In two species, a supernumerary (B) chromosome was found. In addition, the male reproductive system of four species was examined and the number of testicular follicles was determined as two per testis.     

Comparative morphology of selected characters of the Pentatomidae foreleg (Hemiptera,Heteroptera)

Heteropteran legs are very diverse within and among taxa, and such variation is frequently correlated with life habits. Structural modifications are commonly present in the legs of the Pentatomoidea but are poorly studied. Using scanning electron microscopy, the tibia and pretarsal microstructure of 82 species of Pentatomidae (Heteroptera), three species of Scutelleridae, and ten species of Thyreocoridae were described, focusing on the pretarsal structure, the foretibial apparatus, and the foretibial comb. The Pentatomidae, the Scutelleridae, and the Thyreocoridae have uniform pretarsal structures. Variation can be found in the length of the parempodial setae and in the shape of the parempodial projections. The foretibial combs of the Pentatomidae, the Thyreocoridae, and the Scutelleridae are described for the first time, and we have demonstrated that there is low structural variation in the foretibial comb complex of the studied species. The setae organization and distribution on the foretibial apparatus is uniform in the families studied. However, the Asopinae (Pentatomidae) bear a foretibial apparatus that is uniquely organized. The taxonomic and phylogenetic relevance of the pretarsal traits, the foretibial apparatus, and the foretibial comb are discussed.