>From The Worm Breeder's Gazette, 1995, v. 14, No. 1, p. 103.
THE EFFECT OF LOW TEMPERATURES DURING EARLY DEVELOPMENT
ON LONGEVITY AND FECUNDITY IN THE NEMATODE C. elegans
Vladimir V. Bakaev, box 45, Novosibirsk, 630107, USSR
The purpose of the present experiment is to investigate,
how low temperatures in the early stages of development
can influence fecundity, length of prereproductive peri-
od, length of reproductive period, length of postrepro-
ductive period and mean life span in the nematode C. ele-
gans (Bristol, N2, wild type). To microtitre wells were
added 0,75 ml of liquid medium with E. coli (OP 50) and
3 adult nematodes. Animals were kept during 12 hours in
the room temperature, then adult nematodes were discarded
and wells were stored in different temperatures during 2
days, then they were transferred in room temperature. New-
ly appeared worms were transferred in next wells, every
well contains a single nematode. In every following day
these worms were transferred in next wells. All the ex-
periments were done in the darkness. Results are given in
mean+/-S.E.
─────────────────────────────────────────────────────────────
Tempe- Number Length of Mean
rature of ────────────────────────────── life
оC progeny prerepro- reproduc- postrep- span
ductive tive roductive days n
period period period
days days days
─────────────────────────────────────────────────────────────
21,3 79,8+/-5,4 2,2+/-0,1 8,3+/-0,4 12,8+/-1,1 24,4+/-1,1 26
9,0 77,0+/-5,5 3,3+/-0,1 7,7+/-0,6 11,1+/-1,3 22,8+/-1,5 25
6,3 67,8+/-3,4 3,8+/-0,1 7,0+/-0,4 11,7+/-1,5 23,2+/-1,5 23
2,0 68,5+/-5,0 4,3+/-0,2 7,1+/-0,4 8,6+/-1,2 21,1+/-1,1 20
─────────────────────────────────────────────────────────────
Then, lowering of ambient temperatures during early deve-
lopment of nematode C. elegans resulted in decreasing of
progeny. There is a decrease in the mean life span as tem-
perature during larval development decreased, as well as
the length of reproductive and the length of postreproduc-
tive periods. Then, the length of prereproductive period
is increased by diminishing of the temperature of early
development. These results demonstrate, that the higher is
the temperature, the earlier nematodes started reproduc-
tion. These results do not support the widely accepted point
of view, that lowering of temperature increases life span
of different animals. There exist optimal life conditions
for species, in which life span of this species is maximal.
But the problem arises: what must we do in order to obtain
the marked increase of longevity and, probably, immortali-
ty? Undoubtedly, it appeared reasonable to seek a new un-
usual experimental approaches.
Acknowledgment: The author wishes to express his thanks to
CGC for providing C. elegans and E. coli.
