Plant life cycle -- Ceratopteris

Thomas R. Warne twarne at UTK.EDU
Fri Oct 3 15:32:46 EST 1997

I guess that the discussion involving Ceratopteris is my cue! 

Les Hickok and I have developed a special strain of Ceratopteris -- C-Fern
-- that is ideal for classroom use, hands-on investigation, and
student-initiated research.  C-Fern spores, culture supplies and equipment,
the C-Fern Manual, and several classroom size  Kit-form Investigations will
be available through Carolina Biological Supply starting this winter
(1997).  C-Fern cultures are easy to establish and simple to grow --
gametophytes are sexually mature in 12 days or less.  If you have decent
stereomicroscopes (40x or greater), students can observe the events
associated with fertilization (release of swimming spermatozoids and their
chemotaxis to receptive archegonia) and early embryo development directly
from the Petri dish.

Spores (wild type and a variety of mutant strains) will be available as Kit
size pre-measured and presterilized units (enough to sow up to 35 Petri
dishes with 300+ spores per dish) and as unsterilized, bulk units, enough
to sow 140 Petri dishes with 300+ spores per dish. 

Single gene mutant strains and F1 hybrids will be available as listed below:
-polka dot	(cp) -Chloroplasts form clumps that resemble polka dots in both
gametophyte and sporophyte tissue.  Recessive in porophytes.
-glyphosate tolerant (glt 1) -Gametophytes and sporophytes tolerant to the
active ingredient in glyphosate containing herbicides, e.g. RoundUp
(Monsanto).  Incomplete dominance in sporophytes.
-paraquat tolerant (pq45) - Gametophytes and sporophytes tolerant to the
herbicide paraquat.  Recessive in sporophytes.
-dark germinator (dkg) - Does not require light to initiate spore germination.
-abscisic acid tolerant (abr48) - Gametophytes tolerant to the plant growth
regulator, abscisic acid.
-maleless (her1)- Does not form male gametophytes.  Insensitive to the
male-inducing pheromone.
-non-etiolated (det30) - Gametophytes do not show elongation response when
grown in the dark.
-salt tolerant (stl2) - Gametophytes and sporophytes tolerant to Na + and
Mg 2+  salts
-FUDR tolerant  (fdr1) - Gametophytes tolerant to the nucleotide analog
- F1 polka dot (cp/CP) - F1 gametophytes segregate in a ratio of 1 wild
type to 1 polka dot.  F2 sporophytes segregate in a ratio of 3 wild type to
1 polka dot.

Available Kits are listed below:
Meet the C-Fern Kit -- This kit provides all needed materials to allow
observation of the various phases of the life cycle as well as the ability
to observe segregation of the polka-dot trait from spores of an F1 hybrid.
Materials for one individual or group.  Experiment time is 21 days. 
Sex in a Dish: The C-Fern Life Cycle Kit  -- A dynamic introduction to the
life cycle of this unique plant!  This exercise provides a clear
illustration of organ and tissue differentiation in the developmentally
simple gametophytes. Unlike many higher plants, gametophyte sexual
development, swimming sperm, fertilization and embryo development are
directly visible using a dissecting microscope and simple culture
equipment.  Materials for 30 individuals.  Experiment time is 21 days with
optional extended observations over three months.

The Pressures of Life - Population Density and C-Fern Development Kit --
Two distinct investigations - carried out sequentially (Two Kits in one!).
Quantitatively explore the effects of population density.  First the
influence density has on gametophyte sex ratio and second the effects of
sporophyte competition.  Materials for 30 individuals.  Experiment time is
14 - 28 days. 

More Pressures of Life Kit -- Includes material in The Pressures of Life
Kit above and an investigation in which students use serial dilution of
spore suspensions to estimate the weight of an individual spore. Materials
for 30 individuals.  Experiment time is 14 - 28 days.  

Genetics in Action - Mendelian Genetics Kit -- Students visualize basic
principles of Mendelian Inheritance in C-Fern by following the segregation
of a visible marker, polka dot, in both the F1 gametophyte and F2
sporophyte generations.  Students sow spores of an F1 hybrid (wild type X
polka dot) to produce F1 gametophytes. By adding water to mature F1
gametophytes, students visualize random fertilization events that produce
the F2 sporophyte generation.  Hypotheses generated from observations of F1
gametophytes are then tested by analysis of phenotypes and ratios in the F2
sporophyte generation.  The large sample numbers provided from class and
individual data sets allow meaningful use of the Chi-square test.  This
investigation demonstrates the Mendelian principles of segregation, random
fertilization and dominance/recessiveness and provides hands-on experience
in data acquisition, hypothesis formation and testing.  Materials for 30
individuals.  Experiment time is 14 -28 days.  

Battle of the Sexes - C-Fern Sexual Differentiation Kit  -- Students
actively explore the nature of sexual differentiation in C-Fern.  Although
all C-Fern gametophytes develop from genetically identical spores, their
development into males or hermaphrodites is environmentally controlled by a
pheromone-like system.  Students investigate this phenomenon experimentally
by repeatedly inoculating culture dishes over a period of 7 days and
analyzing the resulting sex ratios.  Students formulate testable hypotheses
to account for the presence and frequency of each sexual type in different
aged inoculations.  In addition to the wild type, this exercise uses a
maleless strain (her1) which is insensitive to the pheromonal system.
Materials for 30 individuals.  Experiment time is 14 days.  

If you would like additional information on C-Fern, please contact us!

At 01:08 PM 03-10-97 -0500, you wrote:
>I agree Jon, but where can one get such sprores? I would very much like to 
>do this in the next week for my class!
>Grant Cramer
>Jon Monroe wrote:
>> Ross Koning wrote:
>> >Ceratopteris spores germinate quickly, develop
>> >gametangia rapidly and predictably on 1.5% agar.
>> >Wet mounting some female and male-dominant
>> >gametophytes under one coverslip will quickly
>> >show swimming sperm, and (with the right prep)
>> >show them in chemotaxis near archegonium necks
>> >and even wriggling down the neck!
>> Thanks Ross!  I've never grown these organisms but I will now try.  Upon
>> reading this I remembered that I inherited a number of vials of fern and
>> moss spores from my predecessor but I have never tried growing any of 
>> Do you Ross, or anyone else have any tips for growing Dryopteris,
>> Asplenium, Polypodium, or Polystichum?  How about the moss Polytricum?
>> Thanks.  Students will surely develop a stronger interest if they grow the
>> plants themselves and then get to take them home...
>> Jon
>> -----------------------------------------------------------------
>>   Jonathan Monroe                voice:  540-568-6649 (office)
>>   Department of Biology                  540-568-6045 (lab)
>>   James Madison University       fax:    540-568-3333
>>   Harrisonburg, VA 22807-0001    e-mail: monroejd at
>> -----------------------------------------------------------------

C-Fern Project
Department of Botany	
The University of Tennessee	
Knoxville, TN 37996	

Thomas R. Warne
 twarne at

Les G. Hickok
 lhickok at

C-Fern Web --

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