Worm Breeder's Gazette 15(3): 9 (June 1, 1998)

These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.

Paralysis of worms by 2,3-butanedione monoxime (BDM)

Miriam B. Goodman, Marty Chalfie

1012 Fairchild Center, Columbia University, New York, NY 10027

As noted by Dent & Avery (WBG 15(2):16), drugs used to paralyze worms
either quench GFP fluorescence (Na azide) or create unwanted distortions
in morphology (levamisol, 1-phenoxy-2-propanol, ethanol).  At the
suggestion of Micah Siegal (California Institute of Technology), we
tested whether 2,3-butanedione monoxime (BDM, Aldrich Cat #11, 213-5), a
drug that interferes with stimulus-contraction coupling in vertebrate
muscle , could paralyze intact worms.  We find that BDM is effective for
paralyzing worms and inhibiting pharyngeal muscle contractions.  Both
GFP fluoresence and worm morphology (apart from the occasional vacuole)
are preserved during BDM treatment.  Upon exposure to a buffered
solution of BDM (0. 3M BDM, 10 mM NaHEPES, pH 7.2), worms begin to
twitch and eventually become paralyzed.  Worms readily recover from
brief (< 20 min) exposures and eggs from treated adults appear to hatch
and develop normally.  The effect of BDM is concentration-dependent:  83
+/- 8% (mean +/- s.d., n = 360) and 39 +/- 2% (n = 345) of worms are
paralyzed after 10 min in a buffered solution of  0.3 and 0.1 M BDM,
respectively.  While high concentrations of BDM are needed to paralyze
intact worms within a reasonable amount of time, the effect cannot be
purely osmotic since soaking worms in physiological saline of comparable
osmolarity (323 mOsm) does not result in paralysis.  Since BDM is
effective at millimolar concentrations in vertebrate muscle, we believe
that high concentrations are needed to paralyze intact worms because of
the barrier presented by the cuticle.  

Our current procedure for using BDM is:  (1) wet a small filter disk
(0.25" diameter, punched out of Whatman No. 2 filter paper with a hole
punch) with 6 microliters  of 0.3 M buffered BDM, (2) to transfer worms
in ~4 microliters of M9 to the surface of the filter disk, (3) incubate
for 10 min at room temperature, (4) invert the filter disk on the
surface a 2% agarose pad (in water), remove filter and gently apply a
coverslip.  Worms can also be paralyzed by transferring them to the
surface of a BDM-agarose pad.  A second layer of agarose can be used in
place of the coverslip and may reduce the possibility of crushing worms.