Mortality caused by extracellular freezing is associated with fragmentation of nuclear DNA in larval haemocytes of two drosophilid flies.

Autor: Štětina T; Institute of Entomology, Biology Centre, Czech Academy of Sciences, Branišovská 1160-31, 370505 České Budějovice, Czech Republic., Koštál V; Institute of Entomology, Biology Centre, Czech Academy of Sciences, Branišovská 1160-31, 370505 České Budějovice, Czech Republic.
Jazyk: angličtina
Zdroj: The Journal of experimental biology [J Exp Biol] 2023 Nov 01; Vol. 226 (21). Date of Electronic Publication: 2023 Nov 06.
DOI: 10.1242/jeb.246456
Abstrakt: The great complexity of extracellular freezing stress, involving mechanical, osmotic, dehydration and chemical perturbations of the cellular milieu, hampers progress in understanding the nature of freezing injury and the mechanisms to cope with it in naturally freeze-tolerant insects. Here, we show that nuclear DNA fragmentation begins to occur in larval haemocytes of two fly species, Chymomyza costata and Drosophila melanogaster, before or at the same time as the sub-zero temperature is reached that causes irreparable freezing injury and mortality in freeze-sensitive larval phenotypes. However, when larvae of the freeze-tolerant phenotype (diapausing-cold acclimated-hyperprolinemic) of C. costata were subjected to severe freezing stress in liquid nitrogen, no DNA damage was observed. Artificially increasing the proline concentration in freeze-sensitive larvae of both species by feeding them a proline-enriched diet resulted in a decrease in the proportion of nuclei with fragmented DNA during freezing stress. Our results suggest that proline accumulated in diapausing C. costata larvae during cold acclimation may contribute to the protection of nuclear DNA against fragmentation associated with freezing stress.
Competing Interests: Competing interests The authors declare no competing or financial interests.
(© 2023. Published by The Company of Biologists Ltd.)
Databáze: MEDLINE
Externí odkaz: