The electron microscope reveals in mature sperm that the axial filament doublets have changed configuration and consist of a single whorl which encloses the paracrystalline rod. The process by which the major portion of the nebenkern derivative is eliminated occurs in four identifiable stages. Since...
The fine structure of mature sperm from the spiny lobster ( Panulirus) has been examined. Each sperm comprises a nucleus, lamellar region, and acrosome. The nucleus (Feulgen-positive region) contains uncondensed chromatin and is limited by a nuclear envelope. A variable number of spikes extend ...
Spermiogenesis and sperm cells of the meiobenthic priapulid Tubiluchus were described by means of the transmission electron microscope. The sperm cells are completely different from the male gametes of Priapulus, being elongated and thus indicating a different mode of sperm transfer. The anterior po...
https://www.youtube.com/watch?v=sOVpgmxBiqY 11.4.S2: Annotations of diagrams of mature sperm and egg to indicate functions知识 野生技能协会 精子结构 lichunxinbio 发消息 知乎【李春鑫】DP&AP&A-Level&IG 生物 网址:www.zhihu.com/people/lichunixn...
Structure of ovum The ovum or female gamete is much larger in comparison to male gamete or sperm. It is non-motile and contains reserve food in the form of yolk, glycogen and protein. The ovum has a cell-like structure. The ovum is composed of the following parts: ...
Dudenhausen EE, Talbot P (1982) An ultrastructural analysis of mature sperm from the crayfish Pacifastacus leniusculus, Dana. Int J Invert Reprod 5:149–159 Google Scholar Dupré E, Barros C (1983) Fine structure of the mature spermatozoon of Rhynchocinetes typus, Crustacea Decapoda. Gamete...
At the completion of spermiogenesis the chromatin of mature sperm has a toroidal structure that is tightly compacted and resistant to denaturation. The compaction is necessary to protect sperm chromatin during transit through the epididymis and female reproductive tract. Disruption to chromatin remodelling...
The possible relations between the structures observed and the motility of the spermatozoa are discussed; in addition, some phylogenetic comments are attempted. 展开 关键词: aflagellate spermatozoon Platyhelminthes Pseudostomum sperm ultrastructure sperm motility comparative morphology ...
The sperm chromatin structure assay (SCSA) was used retrospectively to characterize sperm from 18 sexually mature boars having fertility information. Boar fertility was defined by farrowing rate (FR) and average total number of pigs born... DP Evenson,K Kasperson,RL Wixon,... - 《Reproduction ...
The spermatogenesis and sperm structure of Timema poppensis (Insecta: Phasmatodea) Mature spermatids exhibit a derived centriole with microtubule doublets devoid of dynein arms, which is equipped with a dense arc-like outer structure. ... M Gottardo,D Mercati,R Dallai - 《Zoomorphology》 被引...