Ongoing Research Projects in LMU

• Histological analysis of an ejaculatory organ for giant sperm in a freshwater ostracod (collaborating with PD Dr Renate Matzke-Karasz)

Some ostracods are famous for giant spermatozoa and have a conspicuous ejaculatory organ in the posterior part of animal body. Few histological studies on this organ have been done from the end of 19th century to the beginning of 20th century, but no ultrastructural investigations have been carried out hitherto. In this project, we are trying to get the detail histological information of this organ with TEM and 3D reconstruction methods to understand an ejaculatory mechanism for giant sperm.

  Image 1: Ejaculatory organ in a freshwater ostracod Pseudocandona marchica

  Image 2: 3D reconstructed image of an ejaculatory organ in P. marchica (proximal 2 segments)

  Image 3: 3D reconstructed image of an ejaculatory organ without muscles

  Image 4: TEM image of an ‘valve’ in an ejaculatory organ in a transverse section

• Morphogenesis of an ejaculatory organ for giant sperm in a freshwater ostracod (collaborating with PD Dr Renate Matzke-Karasz)

An ejaculatory organ consists of numerous muscles, epithelial cells and chitinous units, though it is a part of vas deferens. There is no histological study on formation process of these complicated structures. We use CLSM and TEM methods to understand the morphogenesis of this ejaculatory apparatus and are trying to elucidate its evolutionary pathway in connection with that of giant sperm.

  Image 5: CLSM image of a mature ejaculatory organ stained with DAPI and TaxasRed

  Image 6: CLSM image of an immature ejaculatory organ stained with DAPI and TaxasRed