侧肠锡叶吸虫的精子发生和中期染色体的超微结构  

SPERMATOGENESIS AND ULTRASTRUCTURE OF THE METAPHASE CHROMOSOMES IN CEYLONOCOTYLE SCOLIOCOELIUM(DIGENEA: PARAMPHISTOMIDAE)

作　　者：李敏敏[1] 王溪云[2] 

机构地区：[1]中国科学院动物研究所,北京100080 [2]江西省科学院微生物研究所,南昌330029

出　　处：《动物学报》1997年第1期1-9,共9页ACTA ZOOLOGICA SINICA

基　　金：中国科学院1994年特别支持项目;国家自然科学基金

摘　　要：利用透射电镜详细研究寄生在牛瘤胃中的同盘科侧肠锡叶吸虫的精子发生、精子形成及精母细胞第一次减数分裂时分裂中期染色体的超微结构。发现侧肠锡叶吸虫精子发生,形成过程和形态与过去研究过的多数吸虫种类相同,不同处仅在中央间体最外侧一对条带是由颗粒组成。该吸虫染色体为染色质纤维反复折叠形成的多级螺旋围中央轴区缠绕而成。染色质纤维直径为107～179A,其组成的环长0.43～0.50μm,染色体的整体形态,基本结构,空间构筑与其他各门类动物相同,仅染色质纤维直径相对较细。The present paper deals with the observations on the spermatogenesis in Ceylonocotyle scoliocoelium (family Paramphistomidac), obtained in Nanjing, Jiangsu Province in 1995. A description of the ultrastructure of meiaphase chromosomes at the first meiotic division of primary spermatocytes is made for the first time. The process and morphology of the spermatogenesis occurred in trematode C. scoliocoelium is the same as that of other trematodes investigated previously. It has the typical pattern summarized by Ehlers (1983). The only difference which should be pointed out in present trematode is that the outer pair of the bands in intercentriolar body consists of a row of granules, rather than a continuous band in most trematodes. The significance of spermatogenesis in the phylogeny of trematode groups is discussed in the Chinese text. We agree with the point of view that the ultrastructure of sperm and spermatogenesis, particularly spermiogenesis, has significantly contributed to our understanding of platyhelminth phylogeny (Rohde et al., 1991). Based on the different types of spermiogenesis in Didymozoon and Gona podasmius sp. from Didymozoidae, it is suggested that Gonapodasmius sp. and Didymozoon probably do not belong to the same natural group respectively, and there is no close phylogenetic relationship between them.During the first meiotic division of the spermatocytes in Ceylonocotyle scoliocoelium, the multi-order helical structure of coiling chromosomal fibres can be seen clearly in the nucleus. The diameters of chromatin fibers are in a range of 107- 179A , thinner than that of mouse and human (mouse: 200 -300 A : Rattner and Hamkalo, 1978; human: 300 A : Bak et al., 1977; Marsden and Laemmli, 1979). The diameters of chromatin fibres of C. scoliocoelium are nearly the same as that obtained from the metaphase chromosomes of Fiachoederius sp. reported by Li et al. (1995). The length of radial loops of chromatin fibres are between 0.43 - 0.50μm also shorter than these of mouse and human (mouse: 1 -5μm: Rat

关 键 词：吸虫纲 侧肠锡叶吸虫 精子发生 染色体 超微结构 

分 类 号：Q959.152[生物学—动物学]