From owner-celegans@net.bio.net Sat Aug 23 23:00:00 1997 Path: biosci!daresbury!uninett.no!Norway.EU.net!EU.net!news.maxwell.syr.edu!Radio-MSU.net!Gamma.RU!srcc!newsserv From: "Vladimir V. Bakaev" Newsgroups: bionet.celegans Subject: longevity in C. elegans 2 Date: 24 Aug 1997 13:00:02 +0400 Organization: Private Person Lines: 56 Distribution: world Message-ID: Reply-To: vlad@bakaev.nsk.ru NNTP-Posting-Host: news.gamma.ru Mime-Version: 1.0 Content-Type: text/plain; charset=koi8-r Content-Transfer-Encoding: 8bit Summary: no Keywords: longevity, C. elegans X-Return-Path: bakaev!bakaev.nsk.ru!vlad@sinor.ru >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 ĪC 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. .