Christen Mirth

@cmirth
active 6 years, 2 months ago

Base

Full Name

Christen Mirth

Current position

Group Leader

Affiliation

Instituto Gulbenkian de Ciencia

Location

Oeiras, Portugal

Research interests

Our lab studies the regulation and evolution of environmentally-dependent traits in species from the genus Drosophila. Recently, our efforts have focused on two traits that depend on nutritional cues:
1) Body and Organ Size,
2) Larval Foraging Behaviour.
We use the genetic tools available in Drosophila melanogaster to dissect how environmental signals, like nutrition, regulate larval growth and foraging choices. By analyzing the changes in these mechanisms across species, we hope to identify how these environmentally-dependent traits evolve to create species-specific differences in foraging behaviour and adult body size.

Webpage

http://www.igc.pt/research/unit/109

Research activity

Research

Our research focuses on the developmental regulation and evolution of environmentally dependent traits in species of the genus Drosophila. In particular, we explore how nutritional cues affect body size and determine larval foraging behaviour.

THE CONTROL OF BODY AND ORGAN SIZE:

Most organisms tightly regulate their body size; however, we understand very little about the developmental mechanisms controlling size. Body size results from two interacting processes: growth rate and the cessation of growth. Although we know that nutrition regulates growth rates via the insulin and target of rapamycin pathways, how larvae determine when they have reached the appropriate size to begin adult development has been, until recently, unclear.

We, and others, have found that the prothoracic gland (PG) regulates a size-dependent checkpoint for the cessation of growth in Drosophila melanogaster. This checkpoint, called critical weight, depends on ecdysone, the hormone synthesized by the PG. Currently, our studies aim to identify how ecdysone interacts with both the nutrition pathways and with known patterning mechanisms to control size-dependent development. Furthermore, we are interested in how these mechanisms evolve to generate species of different sizes.

ONTOGENY AND EVOLUTION OF FORAGING BEHAVIOUR:

In our studies of larval foraging behaviour, we seek to discover the environmental cues that larvae use to make foraging decisions and to identify the neural circuits that allow these cues to be interpreted by the larval brain. Recently, we identified a switch in larval tolerance to the bitter flavour quinine that occurs at critical weight in D. melanogaster. We are working to identify the neuronal populations that increase quinine tolerance in post-critical weight larvae. These studies will fuel future research exploring the range of cues larvae use to make foraging decisions.

Lastly, we are interested in how species-specific foraging behaviours evolve. Currently, we are surveying the behavioural repertoire of foraging larvae from 46 species within the genus Drosophila. We find that larvae exhibit a similar repertoire of foraging behaviours; however, species vary in the frequencies of specific components of this repertoire. We aim to identify the genetic loci that determine these differences in foraging strategies.

Representative publications

22654869, 20181742, 19515698, 18460425, 17373657, 16182527, 15649469, 12051824

Research keywords

phenotypic plasticity, environmentally-dependent traits, control of body and organ size, evolution of body and organ size, ontogeny of behaviour, foraging behaviour, behavioural evolution, developmental physiology, insect hormones, ecdysone signalling,

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Latitude and Longitude

38.6915434277587,-9.31614272035881