Abstract Detail

Frontiers in fern gametophyte research

Lopez-Smith, Renee [1].

Immunolocalizations of Arabinogalactan Proteins During Spermatogenesis in Ceratopteris richardii.

The spatial and temporal distribution of arabinogalactan proteins (AGPs) during spermatogenesis was investigated in the model fern, Ceratopteris richardii. Developing sperm cells within their special wall stain intensely with Yariv phenylglycosides (ßGlcY), colormetric histochemical probes that specifically bind to AGPs, demonstrating the presence of AGPs during spermatogenesis. For more precise localization, AGP epitopes were gold-labeled at the TEM level using monoclonal antibodies JIM13, JIM8, and LM6, epitopes known to be involved in sexual reproduction in seed plants. At the onset of spermiogenesis, JIM13 and LM6 antibodies label the sperm cell plasmalemma. As the locomotory apparatus forms, the nucleus becomes a cylindrical coil, excess cytoplasm is eliminated and an extra protoplasmic matrix (EPM) forms between the sperm cell plasmalemma and special cell wall. From this stage of development onward both JIM13 and JIM8 AGP-epitopes are abundantly present in the EPM while LM6 labels remain associated with the sperm plasmalemma, especially that of the flagella. The abundance and specificity of AGPs epitopes, along with the spatial and temporal changes in their distribution during development, suggest that AGPs play diverse roles in gametogenesis in ferns. Among these are involvement in cell signally during development as has been documented in other plant systems. Uniquely, AGPs in motile gamete development may function in coordinating the complex events required to shape sperm cells and position 70+ flagella around cell coils. The results of these studies are compatible with immunolocalizations on male gametophytes of seed plants and point to a likely role for AGPs during sexual reproduction in seed-free plants.

Broader Impacts:

1 - Southern Illinois University Carbondale, Plant Biology, 1125 Lincoln Drive, Life Sciences II 459, Carbondale, IL, 62901-6509, USA

Keywords:
arabinogalactan proteins
spermatogenesis
fern gametophyte.

Presentation Type: Symposium or Colloquium Presentation
Session: C4
Location: Prince of Wales/Riverside Hilton
Date: Tuesday, July 30th, 2013
Time: 8:45 AM
Number: C4003
Abstract ID:731
Candidate for Awards:None