C-Fern sperm can swim for over two hours at 25 °C in the Sperm Release Buffer (SRB) as described in the C-Fern Chemotaxis exercise – Chemical Attraction. (See also the C-Fern Manual for the formulation of SRB.) Sperm will swim a much shorter time in plain distilled water, although it is more than sufficient to […]
C-Fern spores are quite large for fern spores, about 120 µm (microns). Surprisingly, human eggs, i.e. secondary oocytes, and C-Fern spores are similar in size and shape. A vial containing 300,000 C-Fern spores (ca. 240 mg) is a graphic demonstration of the number of eggs (primary oocytes) in the ovaries of a 7-year-old girl. Only […]
Standard C-Fern sowing density is 300 spores/dish (60×15 mm Petri dish). This standard sowing density gives more consistent results with respect to the ratio (or proportion) of male to hermaphroditic gametophytes). At lower densities, proportions of these types can be highly variable. Density can be reduced by adding more water before sowing or by using […]
C-Fern is derived from tropical / subtropical species and requires warm temperatures, 28 °C (82° F) for optimal and consistent growth and development. The C-Fern Growth Pod and a simple light are all that are needed to achieve this. For large number of cultures, you can use the C-Fern Culture Dome with a light bank.
Temperatures below the optimum of 28 °C (82 °F), but above 20 ° C (68 °F), will not kill C-Fern cultures. However, spore germination and both gametophyte and sporophyte growth will be delayed. The cooler it is, the slower development will be.
In C-Fern, many male gametophytes are determinate in growth, that is, they grow, develop many antheridia, release sperm, and die. However, male gametophytes can regenerate as hermaphrodites if transferred to isolated cultures from multi-gametophyte cultures as old as 21 days.
Because gametophytes are only a single cell thick, a simple wet mount of C-Fern gameophgytes can show cellular details that are only visible in other systems by making thin sections. You also can use wet mounts of very young sporophytes.
C-Fern sperm can be seen at magnifications as low as 20X. The critical factor is light from below and proper adjustment of the light source. If all else fails, try placing a piece of aluminum foil with a pencil lead-sized hole in it under the Petri dish culture or slide. View sperm swimming in the […]