滇蛙多盘吸虫精子超微结构

ULTRASTRUCTURE OF SPERMATOZOA IN POLYSTOMA SP.(MONOGENEA POLYOPISTHOCOTYLEA:POLYSTOMATIDAE)

利用透射电镜研究多盘吸虫精子的形态和结构。它属于单殖类中Polyopisthocotylea类型。精子细线形 ,含两根融入精子内的 9+1型轴丝 ,细长的细胞核 ,纤细的线粒体和微管。在第二根轴丝出现前的区段无微管的分布 ,具两根轴丝的主干段轴丝外无外侧管 ;细胞核消失后微管呈整圈排列 ;精子后部含糖原颗粒 ,背腹面中央向髓布内凹呈哑铃状并两侧向外突出形成波动膜 ;

Polystoma sp. were collected from the urinary bladder of frog (Rana pleuruden Boulenger) in Yunnan province in May,1996. Morphology and ultrastructure of the spermatozoa in Polystoma sp. were studied for the first time. According to Justine (1991), the ultrastructure pattern of spermatozoa of Polystomatidae belongs to the group of Polyopisthocotylea. But there is a little variation in Polystoma sp. from the standard pattern of Polyopisthocotylea, firstly,before appearance of the second axonema there are no peripheral microtubules existed. secondly, in the principal region of the sperm where the nucleus,mitochondrion and two axonemes are present. Microtubules were arranged not in a circle,but in two separate groups,which suggests the absence of existing outer lateral microtubules beyond the two axonemes. Besides, in Polystoma sp. we observed the glycogen granules in the distal part of principal region, two lateral undulating membranes and external ornamentation on the surface of the part of sperm originated from the zone of differentiation in spermatid of spermiogenesis. Comparisons of spermatozoa from Polystoma sp. with those from Neopolystoma spratti (Watson and Rohde,1995a) from subfamily Polystomoidinae and Concinnocotyla australensis (Watson and Rohde,1995b) from subfamily Concinnocotylinae were made. The obseruation has clearly showed that the spermatozoa in these three different species from different subfamilies have a series of differences in their morphology and ultrastructure. These data might shed some lights on the phylogeny of Monogenea, especially the relationships amony subfamilies of Polystomatidae.