长翅目昆虫精子发生和精子超微结构研究

发布时间：2018-05-29 06:02

  本文选题：雄性生殖系统 + 精子形成　； 参考：《西北农林科技大学》2016年博士论文

【摘要】：长翅目Mecoptera是全变态类昆虫Holometabola中较古老的一个小类群,是唯一幼虫期具有复眼的类群,在全变态类昆虫系统发育研究中占据着独特的地位。然而,长翅目的系统发育地位却一直存在有争议,亟需寻找更多的证据。精子是有性生殖动物高度特化的雄配子。昆虫精子具有快速、趋异进化的特性,其形态、结构(尤其是超微结构)复杂多样,在不同类群间表现出显著差异。精子形态的变化可为昆虫分类、进化及其系统发育分析和重建提供有价值的特征。但关于长翅目精子结构的研究迄今仍然很少,仅涉及蝎蛉科Panorpidae、蚊蝎蛉科Bittacidae和雪蝎蛉科Boreidae等3科7种。而长翅目昆虫的精子发生仅在研究蝎蛉科和蚊蝎蛉科精子超微结构时对精子形成过程稍加描述,并未进行详细过程的研究。本文以蝎蛉科、蚊蝎蛉科、和拟蝎蛉科Panorpodidae昆虫为研究对象,采用光学显微镜和电子显微镜技术,研究了长翅目昆虫的雄性生殖系统、精子发生以及精子超微结构,明确了精子发生的过程,比较了长翅目昆虫不同类群间雄性生殖系统的差异以及精子超微结构,丰富了长翅目生殖生物学研究的内容,并在精子结构研究的基础上,首次运用精子超微结构特征对长翅目进行系统发育分析。主要研究结果如下:长翅目昆虫雄性生殖系统主要包括1对对称的精巢及两个附睾,2条分区明显的输精管,1对特化的贮精囊,1对中胚层附腺,1个射精囊及其周围的外胚层附腺(蝎蛉科新蝎蛉属Neopanorpa及拟蝎蛉科除外)和阳茎。其中贮精囊特化为具有强烈分泌功能的器官,并不用于储存精子。雄性生殖系统形态在长翅目科间变异较大,科内变异较小,主要表现在精巢小管的数目,精巢和附睾的相对位置,囊后输精管的长度,中胚层附腺的大小,以及外胚层附腺的有无等方面。首次详细研究了长翅目昆虫的精子发生。结果表明,长翅目昆虫精子发生过程相似。精原细胞在精囊中以2n的方式,共经历7次连续分裂,产生128个精细胞。最后转化形成的精子束中的精子通常低于128个。长翅目昆虫精子各组成部分的形成大致如下:精子顶体由高尔基复合体产生的原顶体颗粒物质形成;线形、致密的细胞核由圆形细胞核伸长及核内染色质凝集形成;轴丝由基体结构产生;2条线粒体衍生物由大量分散的线粒体聚集、融合产生的副核转化形成。精子形成过程中,细胞核核沟侧旁出现2条侧片结构,但该结构在精子成熟后消失。此外,形成过程中在轴丝双微管的外围出现少量微管结构,但后者很快消失,使轴丝呈现9+2型微管结构。研究发现,长翅目昆虫精子较长(1000μm以上),由较短的头部、颈区和长鞭毛组成,且精子质膜外具有一层纵向脊状的多糖-蛋白质鞘结构。精子头部包括两部分,即由外层顶体囊和内层顶体组成的双层顶体,以及具有两条侧沟的细长细胞核。颈区由中心粒和中心粒侧体组成;中心粒顶端通常插入细胞核底部,由9条双微管组成;中心粒侧体位于颈区最外围,为致密的鞘状结构。鞭毛由1条轴丝、2条线粒体衍生物、1或2条副体和2条特殊的附结构组成。其中2条线粒体衍生物大小不等,较小的1条随鞭毛的延伸而消失,较大的1条占据后半部鞭毛的大部分体积。副体较短,来源于中心粒侧体物质。2条附结构细小,横切多呈三角形,延伸至鞭毛末端。鞭毛末端线粒体衍生物逐渐减小,轴丝结构也因缺失双微管的动力蛋白臂和辐射链结构而变得混乱无序,直至消失。研究发现,长翅目精子超微结构科间变异较大,科内变异较小。科间变异主要表现在细胞核形状、核沟尺寸、轴丝结构、副体数目、以及较大线粒体衍生物等。本研究首次发现拟蝎蛉科精子轴丝为9+9+2型结构。我们推测,蝎蛉科和蚊蝎蛉科中出现的9+2型轴丝,很可能是由9+9+2型进化逆转而来的。本文基于精子超微结构,利用最大简约法构建了系统发育树,进行了具泵总目Antliophora的系统发育分析,这是首次利用精子超微结构对长翅目进行系统发育分析。结果表明,长翅目为单系群,与蚤目Siphonaptera互为姊妹群关系;长翅目内拟蝎蛉科与蝎蛉科互为姊妹群关系,而非蚊蝎蛉科。
[Abstract]:The long winged Mecoptera is a relatively old group of all metamorphosis insect Holometabola, and it is the only group with compound eyes in the only larval stage. It occupies a unique position in the phylogenetic study of all metamorphosis insects. However, the phylogenetic status of long wings has always been controversial, and it is urgent to find more evidence. Sperm is sexual. The highly specialized male gamete of colonies. Insect sperm has the characteristics of rapid and heterogeneous evolution, its morphology, structure (especially ultramicrostructure) is complex and diverse, showing significant differences among different groups. The changes in sperm morphology can provide valuable characteristics for the classification of insects, evolution, phylogenetic analysis and reconstruction. The study of substructure is still rare, involving only 3 families, 7 species, such as Panorpidae, mosquitididididididididididididididididididididididididididididididididididididididididididididididididididididididididididididididididididididididididididididididididididididididididididididididido, and the spermatogenesis of the long winged insects are only slightly described in the study of spermatogenesis in the spermatozoa of the family scorpiididididaand mosquitoes. The male reproductive system, spermatogenesis and sperm ultrastructure of the long winged insects were studied by optical microscopy and electron microscopy. The differences in male reproductive system between different groups of long winged insects and spermatogenesis were compared and the spermatogenesis of Panorpodidae were compared. The ultrastructure of the substructure enriches the research of the reproductive biology of the long dteroptera. On the basis of the study of the sperm structure, the phylogenetic analysis of the long wterptera is used for the first time. The main results are as follows: the male reproductive system of the long winged insects mainly consists of 1 pairs of symmetrical sperms and two epididymis, 2 distinct divisions. The vas deferens, 1 pairs of seminal vesicles, 1 pairs of mesoderm glands, 1 eminal vesicles and the surrounding ectodermal attachment (except for the genus Neopanorpa and pheididido) and Yang stems. The seminal vesicles are specially secreted as organs that have strong secretory functions and are not used for storage of sperm. The variation of Kone is small, mainly in the number of the seminiferous tubules, the relative position of the spermary and epididymis, the length of the spermatogonial duct, the size of the mesoderm glands, and the presence of the ectoderm gland. The spermatogenesis of the long winged insects is studied in detail for the first time. The results show that the spermatogenesis of the long winged insects is similar. In the seminal vesicle, a total of 7 continuous divisions and 128 spermatozoa are produced in a total of 7 successive divisions. The sperm in the spermatozoa is usually lower than 128. The formation of the sperm components of the long winged insects is as follows: the sperm acrosome formed by the PRODIC particles produced by the Golgi complex; the linear, compact nuclei are round and thin. The nucleus is elongated and the chromatin agglutination is formed in the nucleus; the shaft filament is produced by the matrix structure, and the 2 mitochondrial derivatives are formed by a large number of dispersed mitochondria and the paramuclear fusion produced by the fusion. In the process of sperm formation, 2 side segments appear on the side of the nucleus furrow, but the structure disappears after the spermatozoon is mature. In addition, in the formation process, the axis wire is double. A small number of microtubules appear on the periphery of the microtubule, but the latter quickly disappears, making the shaft filament present 9+2 microtubule structure. It is found that the sperm of the long winged insect is longer (more than 1000 mu m), consisting of a shorter head, the neck region and the long flagellum, and the sperm plasma membrane has a longitudinal ridge like polysaccharide protein sheath structure. The sperm head consists of two parts, that is, the sperm head consists of the sperm head. The bilayer acrosome consisting of the outer apical sac and the inner apical body and the elongated nuclei with two side trenches. The neck region is composed of central particles and central granular bodies; the tip of the central kernel usually inserts the bottom of the nucleus and consists of 9 double microtubules; the central granulocyte is located at the periphery of the neck region and is a dense sheath. The flagellum consists of 1 axes and 2 lines. Body derivatives, 1 or 2 pairs of accessory bodies and 2 special attached structures, of which 2 mitochondrial derivatives vary in size, the smaller 1 strips disappear with the extension of the flagellum, and the larger 1 strips occupy most of the volume of the posterior half of the flagellum. The side body is short, and the.2 strips from the central granular substance are small in structure, and in the transverse section, extending to the end of flagellum. The mitochondrial derivative at the end of the flagellum gradually decreased, and the structure of the axis filament became chaotic and disordered by the deletion of the two microtubule's brachial arm and the structure of the radiation chain. It was found that the ultrastructural variations of the spermatozoa were larger and the Kone variation was smaller. The interfamily variation mainly manifested in the shape of the nucleus, the size of the nuclear furrow, the structure of the axis silk. The number of side bodies, as well as the larger mitochondrial derivatives. For the first time, the sperm axis of the paramedicinic family was found to be a 9+9+2 type structure. We speculated that the 9+2 type axis in the scorpion and mosquitoes may be reversed by the evolution of the 9+9+2 type. The phylogenetic analysis of the Antliophora was performed. This is the first time to analyze the phylogenetic analysis of the long wterptera using sperm ultrastructure. The results show that the long winged group is a monophyletic group and a sister group with the flea Siphonaptera, and the pteroptera is a sister group relationship with the family scorpiidido, not the mosquito.
【学位授予单位】：西北农林科技大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：Q964
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本文编号：1949773