Spermatogenesis in the bipolar centric diatom Plagiogrammopsis vanheurckii (Mediophyceae)

Abstract:

We examined gametogenesis and mating behaviour of the cymatosiroid diatom Plagiogrammopsis vanheurckii. A unique type of merogenous spermatogenesis was observed in this species, whereby each spermatid matured into a colourless sperm by detaching a residual body. Spermatogonia developed either directly or by depauperating mitosis from vegetative cells. The mating behaviour observed in this species was more complex than generally reported in homothallic and self-compatible centric diatoms and suggests the existence of mechanisms facilitating out-crossing.

Key Words::

• Cymatosiraceae
• Mating system
• Merogenous
• Polar centric diatoms
• Sexual induction
• Spermatogenesis

ACKNOWLEDGEMENTS

We thank M.E. Kinney for assistance with the clonal culture establishment in 2010. This work was supported by a Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grant to I.K.

SUPPLEMENTARY DATA

Supplementary data associated with this article can be found online at http://dx.doi.org/10.2216/17-107.1.s1.