Laboratori de Parasitologia, Departament de Microbiologia i Parasitologia Sanitàries, Facultat de Farmàcia, Universitat de Barcelona, Spain.
C R Biol. 2012 Jul;335(7):435-44. doi: 10.1016/j.crvi.2012.06.003. Epub 2012 Jul 15.
Spermiogenesis in Robphildollfusium fractum begins with the formation of a differentiation zone containing: two centrioles, each bearing striated rootlets, nucleus, several mitochondria and an intercentriolar body constituted by seven electron-dense layers. The two centrioles originate two free flagella growing orthogonally to the median cytoplasmic process. Later, the free flagella rotate and undergo proximodistal fusion with the median cytoplasmic process. Nuclear and mitochondrial migrations occur before this proximodistal fusion. Finally, the young spermatozoon detaches from the residual cytoplasm after the constriction of the ring of arched membranes. The spermatozoon of R. fractum exhibits two axonemes of different length of the 9+'1' trepaxonematan pattern, nucleus, two mitochondria, two bundles of parallel cortical microtubules, external ornamentation of the plasma membrane, spine-like bodies and granules of glycogen. Additionally, a shorter axoneme, which does not reach the nuclear region, the presence of an electron-dense material in the anterior spermatozoon extremity and the morphologies of both spermatozoon extremities characterize the mature sperm of R. fractum.
裂殖龟纹藻的精子发生始于一个分化区的形成，该分化区包含：两个中心粒，每个中心粒都有纹状根，核，几个线粒体和由七个电子致密层构成的中心粒间体。这两个中心粒起源于两个正交于中央细胞质突起生长的自由鞭毛。随后，自由鞭毛旋转并与中央细胞质突起进行近-远融合。在这个近-远融合之前发生核和线粒体迁移。最后，在弧形膜环收缩后，年轻的精子从残留细胞质中分离出来。裂殖龟纹藻的精子表现出两种不同长度的 9+1 微管三联体轴丝、核、两个线粒体、两个平行的皮质微管束、质膜的外部装饰、棘状体和糖原颗粒。此外，较短的轴丝没有到达核区，在前部精子的末端存在电子致密物质，以及两个精子末端的形态特征，都表明裂殖龟纹藻的成熟精子。
