Project description:Dormancy is displayed by several organisms when environmental conditions cannot support their regular life activities. Numerous aquatic invertebrates survive for decades in a hydrated state as encysted embryos. In search for functional pathways that are associated with this form of dormancy, we used label-free quantitative proteome profiling and compared the proteomes of encysted dormant embryos (“resting eggs”; RE) with non-dormant embryos (amictic eggs; AM) of the rotifer Brachionus plicatilis. We also compared resting eggs (RE) before and after an obligatory dormant period (E0). A total of 2,631 proteins were identified in AM, RE and E0 eggs. Significantly lower numbers of proteins were determined for RE and E0, compared with AM. About 80% of the proteins were upregulated in AM, in the comparisons of AM vs. RE and AM vs. E0. The differentially expressed proteins were assigned to a large number of putative functional pathways, demonstrating the dramatic changes occurring during dormancy.
Project description:Plant-parasitic nematodes (PPN) need to be adapted to survive in the absence of a suitable host or in hostile environmental conditions. Various forms of developmental arrest (including desiccation, cryopreservation, hatching inhibition and dauer stages) are used by PPN in order to survive these conditions and spread to other areas. Potato cyst nematodes (PCN) (Globodera pallida and G. rostochiensis) are frequently in a dessicated state unhatched nematodes within the egg dispersal unit inside the cyst. Long term survival seems to be associated primarily with species that have a very restricted host range which requires surviving unhatched in the absence of the host for extended periods of time. This paper shows fundamental changes in the response of quiescent and diapaused eggs of G.pallida to hydration and following exposure to tomato root diffusate using microarray gene expression analysis from a broad set of genes. Surprisingly, many unique genes were activated in the population of diapaused eggs. Transport activity was activated in both quiescent and diapaused eggs; however, the transport function genes were very different between them. Hydrated quiescent and diapaused eggs were markedly different indicating differences in adaptation for long term survival.
