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A karyometric study of heat-shocked HeLa cells^*

Silvia R.P. Miranda^I; Maria Luiza S. Mello^I; Aquiles E. Piedrabuena^II

^IDepartamento de Biologia Celular, Instituto de Biologia, UNICAMP, 13081-970, Campinas, SP, Brasil. Send correspondence to M.L.S.M.
^IIDepartamento de Genética e Evolução, Instituto de Biologia, UNICAMP, 13081-970, Campinas, SP, Brasil

ABSTRACT

HeLa cells exposed to heat shock at temperatures of 40°C and 43°C for 1 hour and also cells 4h after returning to control conditions (37°C) were studied comparatively with respect to nuclear and nucleolar sizes, using karyometric procedures. Some alterations especially involving nucleolar areas were found to be promoted by the shock, though mostly detectable during the post-shock period held at control temperature. These alterations when elicited by the shock at 43°C were assumed to be associated with transcriptional activities involved in recovery of the ordinary cellular activities, whereas those related to the shock at 40°C were suggested to be due to karyoskeletal proteins appearing late with the stress and which could be mechanically restraining the nucleolar area increase. These proteins also appear in the HeLa cells exposed to the heat shock at 43°C and equally seem to affect the increase in nucleolar area inn comparison to nuclear area, however they are disassembled when the cells are returned to control temperature.

Keywords: Karyometric study; Hela cells.

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* Part of a thesis presented by SRPM to the Instituto de Biologia, UNICAMP, Campinas, in partial fulfillment of requirements for the Masters degree.