Prof. Dr. J. Vanden Broeck (Animal Physiology and Neurobiology - Dept. of Biology - KU Leuven)

Molecular Developmental Physiology and Signal Transduction

My Research Team

Insect species under study

+ some other species …

Ongoing projects …

Study of ligands, receptors and their cellular signal transduction effectsNeuro-endocrine control of food intake, digestion and reproduction

Phase polyphenism in locusts (phenotypic plasticity)Mechanisms of systemic RNAi in insects

Belspo

IAP

Central themes of interest …

Central Nervous System Behaviour

EnvironmentCo ordination Endocrine systemCo-ordination Endocrine system

Growth Development

Feeding

Growth pMoulting/metamorphosis

Reproduction Ageing

Offspring

Control of feeding, digestion and reproduction

• Regulation of JH and 20E hormone synthesis ?R l f l t tid d t i hibit ?• Role of regulatory peptides and protease inhibitors?

Cloning, mRNA profiling (qRT-PCR), RNAi, peptide production & purification, biological activity, regulation of vitellogenesis, egg laying, sperm production, fecundity/fertility, hormone assays, hormone biosynthesis enzymes, digestive enzyme activities, ...

Behavioural,  Physiological and

solitaryPhysiological and 

Developmental changesgregarious

2D DIGE Microarray-Mass

RNA2D-DIGE↓

Differential proteomics

yanalysis

↓Transcript-

i

spectrometry↓

Peptidomics

RNA interference

↓Gene Silencingp

omicsg

Phenotypic plasticity: 1 genome 2 extreme phenotypes (“phases”)

RNA interference (RNAi)

Bridge betweenSystemic effects

trigger dsRNA

Dicer

Bridge between genomics and phenomics

Cell-autonomous

RNA Induced Silencing Complex siRNAs

1. digestion

g p(RISC)

2. unwinding

target mRNA

3 bi di3. binding

4 d d ti Specific post transcriptional4. degradation Specific post-transcriptional silencing of gene expression

Molecular and cellular mode of action ?

Receptors and signal transduction

‘Functional Genomics’ and evolution of GPCRs‘Functional Genomics’ and evolution of GPCRsCharacterization of ligands for receptors of interest expressed in cell lines

(neuropeptides, biogenic amines, chemical libraries ...)Evolutionary aspects (related GPCRs in other Metazoa)

Molecular and functional characteristicsMolecular and functional characteristicsComparative studies of ligand-receptor couples in insects/mammals

Structural and functional aspectsAnalysis of downstream signaling eventsAnalysis of downstream signaling eventsStudy of knockdown and mutant phenotypes

Sex Peptide Receptor is also activated by MIP-like peptides

Sex Peptide:

WEWPWNRKPTKFPIPSPNPRDKWCRLNLGPAWGGRC

- from male accessory gland- egg laying ↑

i i- receptivity ↓- feeding ↑- lifespan ↓

‘ ff t’- ‘sperm effect’

Overview of LGRs:

Human Fruit fly

Type A FSHRLH/CGR

FSH

LH, CG

dLGR1 GPA2/GPB5

TSHR TSH, Thyrostimulin (GPA2/GPB5) ( )

LGR4 unknown dLGR2 bursiconType BLGR5

LGR6

unknown

unknown

LGR7

LGR8

RLN2, RLN3

INSL3 RLN2

dLGR3

dLGR4

unknown

unknownType C

LGR8 INSL3, RLN2, RLN1

dLGR4 unknown

Thesis topics:

• Molecular genetics of G protein-coupled receptors in the fruit fly, D hil l t

Molecular genetics of signal Drosophila melanogaster

• Molecular genetic analysis of Drosophila melanogaster leucine-rich repeats containing G protein-coupled receptors (LGRs)

• Neural mechanisms of swarming in locusts: a molecular approach

transduction in Drosophila

Neural mechanisms of swarming in locusts: a molecular approach• Molecular study of factors involved in the behavioural phase

transition of the desert locust, Schistocerca gregaria• Control of lipophilic insect hormone biosynthesis in the desert locust

Phase transition in desert locusts

• Functional analysis of neuropeptide-receptor couples involved in the regulation of the reproductive physiology in the desert locust

• The effects of mating on female insect behaviour and reproductive physiology

Control of reproduction + mode of action

physiology• Functional characterization of neuropeptide precursors and G

protein-coupled receptors (GPCR) involved in the regulation of feeding in the desert locust, Schistocerca gregaria Control of feeding and/or

f d di ig , g g

• The role of neuropeptides and protease inhibitors in food digestion• Protease inhibitor induced responses in pest insects• Key mechanisms of systemic RNA interference in the desert locust RNA interference !

food digestion

If you have specific questions: for each topic there is a contact person !

Many thanks for your attention! Many thanks for your attention!