title: Conversion of the chill susceptible fruit fly larva (Drosophila melanogaster) to a freeze tolerant organism.
abstract: Among vertebrates, only a few species of amphibians and reptiles tolerate the formation of ice crystals in their body fluids. Freeze tolerance is much more widespread in invertebrates, especially in overwintering insects. Evolutionary adaptations for freeze tolerance are considered to be highly complex. Here we show that surprisingly simple laboratory manipulations can change the chill susceptible insect to the freeze tolerant one. Larvae of Drosophila melanogaster, a fruit fly of tropical origin with a weak innate capacity to tolerate mild chilling, can survive when approximately 50% of their body water freezes. To achieve this goal, synergy of two fundamental prerequisites is required: (i) shutdown of larval development by exposing larvae to low temperatures (dormancy) and (ii) incorporating the free amino acid proline in tissues by feeding larvae a proline-augmented diet (cryopreservation).
authors.affiliation: Institute of Entomology, Biology Centre ASCR (Academy of Sciences of the Czech Republic), Branišovská 31, 370 05 České Budějovice, Czech Republic. kostal@entu.cas.cz
authors.forename: Vladimír
authors.initials: V
authors.lastname: Koštál
authors.forename: Petr
authors.initials: P
authors.lastname: Šimek
authors.forename: Helena
authors.initials: H
authors.lastname: Zahradníčková
authors.forename: Jana
authors.initials: J
authors.lastname: Cimlová
authors.forename: Tomáš
authors.initials: T
authors.lastname: Štětina
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D001834:Body Water; D003451:Cryoprotective Agents / Q000494:pharmacology*; D003460:Crystallization; D004032:Diet; D004331:Drosophila melanogaster / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D005615:Freezing; D007053:Ice; D007814:Larva; D008675:Metamorphosis, Biological; D011392:Proline / Q000494:pharmacology*
chemical_list: D003451:Cryoprotective Agents; D007053:Ice; D011392:Proline