USE OF NO AND NO DONORS FOR TERMINATING DORMANCY IN INVERTEBRATES

In the animal kingdom various animals are able to make resting stages characterised by reduced metabolism or even absence of metabolism. Taking into consideration the animal kingdom, there is a lot of variability in the "depth" of the resting stage. Hence the following wording can be found in the literature: diapause, resting stage, dormancy, quiescence. These trems can not be interchanged as they stand for different types of reduced metabolic activity in various phase of the life cycle. The invention describes the phenomenon that in two animals a particular resting stage can be interrupted by the external application of a chemical that releases nitric oxide. Artemia is known to produce cysts, especially at the end of the growing season when the salt concentration in salt lakes or ponds is rising, and food is decreasing. Artemia responds with the production of cysts. Cysts can be dried (naturally or artificially). They maintain viability when stored under the proper conditions. At the moment of production Artemia cysts are in diapause. Diapause breakage can be obtained in some strains by cold storage. In other strains drying is required. In other strains, such as those harvested from the Bolshoye Yarovoe, a very deap diapause is observed. Under certain storage conditions the cyst are very slowly released from diapause, a process that can take months. The invention described the phenomonon that these kinds of cysts can be released from diapause by exposing them to chemicals that release nitric oxide (NO). More in particular the diapause could be released by exposing them to the NO generators Papa NONOate, Spermine NONOate, Sin-1 Chloride. The optimal concentrations are respectively 0.5 µM, 6µM and 6µM. In all three cases the hatching percentage reaches 70%, while in the control experiment without NO exposure the hatching percentage was 25%. Brachionus are rotifer that are leaving in brackish water. They multiply by parthenogenetic reproduction. Under certain stress situation males can be produced, necessary for sexual reproduction. This results in the production of resting eggs. These eggs can be dried and stored. This invention describes that the hatching of Brachionus eggs is accelerated when exposed to chemicals that release NO. The table below illustrates that exposure to 10µM accelerates the hatching reaching 30 after 48 h incubation, while in the control experiment hatching was only 12 % after 48 h. After 72 h incubation there is no difference in hatching, illustrating that in this case NO has an influence on the hatching rate. 48 hrs 72 hrs Blanco 12.84 % (1.36) 34.95 % (2.21) Peroxide treatment 6 ppm 1.44 % (0.99) 2.08 % (0.34) 1 µM Sin-Cl 12.34 % (3.62) 33.11 % (2.66) 6 µM Sin-Cl 18.93 % (1.25) 33.71 % (0.66) 10 µM Sin-Cl 30.04 % (3.10) 37.17 % (2.88) 20 µM Sin-Cl 17.99 % (3.18) 32.38 % (2.63) 60 µM Sin-Cl 14.98 % (3.52) 27.57 % (1.00)

Octrooi-publicatienummer: EP2429298

Jaar aanvraag: 2010

Jaar toekenning: 2013

Jaar van publicatie: 2012

Status: Aangevraagd

Technologiedomeinen: undefined

Gevalideerd voor IOF-sleutel: Ja

Toegewezen aan: Associatie Universiteit Gent