Seasonal chronobiology

This work package includes 6 projects.

We shall study the photoperiodic seasonal responses of several insects, some of which are pest species, and use the recently developed CRISPR/Cas9 method to knock out clock genes in these species and to examine any effects on seasonal behaviour. We will use a number of different approaches, some comparing robustly diapausing northern European Drosophilids such as D. ezoana to D. melanogaster in terms of differences in their clock function and related neuropeptide expression in order to test long-standing ideas about differences in circadian function in species living in northern versus southern latitudes.

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Title: Temperature compensation and the D. ezoana clock
Host Institution: Wuerzburg University
Supervisor: Prof Charlotte Helfrich-Foerster
Secondment: University of Groningen to model internal/external coincidence and for CRISPR/Cas9 mutagenesis for 5 months.
Objectives: To discover the role played by the circadian clock in night-length measurement and induction of diapause in the northern European fruifly D. ezoana. The role and distribution of clock proteins and relevant clock-related neuropeptides will be studied under different photoperiodic and temperature conditions and mutagenesis (CRISPR/Cas9) of canonical clock genes will be used to examine whether clock genes measure night-length (which mediates diapause).

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Title: Seasonal clock in pea aphids
ESR: Francesca Sara Colizzi
Host Institution: Wuerzburg University
Supervisor: Prof Charlotte Helfrich-Foerster
Secondment: Universidad de Valencia for 2 months to learn aphid biology and BCAS České Budějovice for two months to learn CRISPR/Cas9 technology.
Objectives: To discover the role played by the circadian clock in the induction of diapause in the pea aphid Acyrthosiphon pisum. Circadian behaviour will be characterised as will neuronal clock gene expression both temporally and spatially. CRISPR/Cas9 mutagenesis will be used to investigate whether clock mutations disrupt diapause.

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Title: Seasonal/circadian biology of aphids light input
Host Institution: Universidad de Valencia
Supervisor: Dr David Martinez-Torres
Secondment: Wuerzburg University for 3 months for neuroanatomy and in situ hybridisation and 2 months to BCAS České Budějovice for CRISPR/Cas9 mutagenesis.
Objectives: To elucidate whether the reproductive status modifies the expression of clock-related genes in aphids and to investigate the effect of knocking down clock genes in the production of alternative aphid morphs. This will be done by examining clock and neuropeptide gene expression in different photoperiodically induced alternative morphs, examining their spatial and temporal expression in aphid brains and using CRISP/Cas9 mutagenesis to knock out clock genes and examine their effects on photoperiodically induced reproductive states (diapause).

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Title: Seasonal clocks in linden bugs
ESR: Magdalena Kaniewska

Host Institution: BCAS České Budějovice
Supervisor: Dr David Dolezel
Secondment: Jagiellonian University for 4 months for neuroanatomy and gene expression studies.
Objectives: To discover which hormones affect photoperiodically-induced reproductive (diapause) and related behaviours (such as copulation, inter-male aggression, dispersal and migratory behaviour), where these neuropeptides are expressed in the brain and does photoperiod influence the timing of these sex-related behaviours? Using a candidate gene approach, neuropeptide genes will be studied in terms of temporal and spatial expression at different photoperiods, and candidates will be knocked out using CRISPR/Cas9 mutagenesis or RNAi and the effects on diapause and associated reproductive behaviours will be examined. Application of synthetic peptides will clarify the roles of the candidate neurohormones.

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Title: Seasonal light signalling in Nasonia
ESR: Philipp Greiner
Host Institution: University of Haifa
Supervisor: Prof Eran Tauber
Secondment: Groningen for 3 months for CRISPR/Cas9 mutagenesis and Wuerzburg University for 3 months for neuroanatomy and gene expression studies.
Objectives: To identify the dedicated photoreceptors for seasonality in Nasonia, where are they expressed, and to identify natural variants for these photoreceptors. Four candidate opsins have been uncovered in the Nasonia genome, and their expression patterns, temporally and spatially will be studied in the brain followed by CRISPR/Cas9 mutagenesis to examine their effects on diapause. A second approach will be to use natural strains with differing photoperiodic sensitivities and using GWAS (genome wide association study) to map any gene(s) responsible.

Title: Ultradian, circadian and seasonal clocks in Nasonia
ESR: Pauline Romeyer
Host Institution: University of Groningen
Supervisor: Prof Leo Beukeboom and Dr Louis Van de Zande
Secondment: University of Haifa for 4 months to analyse the population data and haplotypes and 1 month to University of Jerusalem to compare Nasonia with bumblebee biology, another hymenopteran.
Objectives: To investigate the expression and allelic variation of clock genes that govern ultradian, circadian, and annual rhythmicity of physiological traits in Nasonia. Clock gene expression in the brain will be analysed at different timepoints throughout the year from natural isolates and annual changes in clock gene haplotype frequencies will be recorded in natural populations. CRISPR/Cas9 mutagenesis of clock genes will reveal their effects on circadian, annual (seasonal) and ultradian (courtship) phenotypes,

See other Work Packages:
Circadian Chonobiology
Metabolic Chonobiology
Commercial Chonobiology