Desenvolvimento, Evolução e Ambiente

Interesse da Investigação

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.

Size Control:

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.

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 65 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.

Membros do Grupo

Takashi Koyama	Postdoc
	Tel: 21 446 4562
Maria João Carvalho	Postdoc
	Tel: 21 446 4562
Sara Lennox	Research Technician
	Tel: 21 446 4562
Marisa Rodrigues	Trainee
	Tel: 21 446 4562
Marisa Oliveira	2009 PIBS
	Tel: 21 446 4562
Cláudia Mendes	2010 PIBS
	Tel: 21 445 4562

Publicações

Mirth CK, Shingleton, AW. (2012). Integrating body and organ size in Drosophila: recent advances and outstanding problems Frontiers in Experimental Endocrinology 3 :1-13

Riddiford LM, Truman JW, Mirth CK, Shen, Y. (2010). A role for Juvenile Hormone in the prepupal development of Drosophila melanogaster Development 137 :1117-1126

Mirth CK, Truman JW & Riddiford LM. (2009). The Ecdysone Receptor controls the post-critical weight switch to nutrition-independent differentiation in Drosophila wing discs Development 136 :2345-2353

Shingleton AW, Mirth CK & Bates P. (2008). Developmental model of static allometry in holometabolous insects Proceedings of the Royal Society Series B 275 :1875-1885

Mirth CK & Riddiford LM. (2007). Size assessment and growth control: how adult size is determined in insects BioEssays 29 :344-355

Mirth CK, Truman JW & Riddiford LM (2005). The role of the prothoracic gland in determining critical weight for metamorphosis in Drosophila melanogaster Current Biology 15 :1796-1807

Mirth CK. (2005). Ecdysteroid control of metamorphosis in the differentiating adult leg structures of Drosophila melanogaster Developmental Biology 278 :163-174

Mirth CK & ME Akam (2002). Joint development in the Drosophila leg: cell movements and cell populations Developmental Biology 246 :391-406