Forum for Science, Industry and Business

Masters of disguise: secrets of nature's 'great pretenders' revealed

The mocker swallowtail butterfly, Papilio dardanus, is unusual because it emerges from its chrysalis with one of a large number of different possible wing patterns and colours. This is different from most butterfly species which are identified by a common wing pattern and colour. Furthermore, some of the different patterns that the mocker swallowtail exhibits mimic those of poisonous species, which affords this harmless insect a valuable disguise which scares off predators.

Biologists are interested in finding out exactly how wing pattern isdetermined in the mocker swallowtail, because they believe thatunderstanding how these different mimic patterns evolved may shed newlight on whether such evolutionary changes occur in small gradual steps, or sudden leaps.

In the 1950s scientists realised there must be a genetic 'switch' controlling which of the numerous possible wing patterns is expressed in each individual mocker swallowtail, but until now the location and identity of the genes involved have remained a mystery.

The new study, published in Proceedings of the Royal Society B, shows how a team of biologists used molecular tags and DNA sequencing in order to pinpoint the part of its genetic code that determines wing pattern and colour. Their study suggests that a developmental gene called 'invected', which was already known to be involved in the early embryonic development of butterflies, is behind the allocation of different wing patterns in mocker swallowtails.

Professor Alfried Vogler of Imperial College London's Department of Life Sciences and the Natural History Museum, one of the authors on the paper, explains, however, that further investigation is needed to figure out exactly how this gene works.

"We've taken a big step here towards identifying exactly how this fascinating insect species is endowed with such a wide variety of extremely useful wing patterns. However, identifying the area of the genome involved in this process is just the first step - we now need to look in more detail at the differences in the invected gene, and another gene located next to it, to find out exactly how they produce the different forms," he said.

He goes on to emphasise the significance of studying the mocker swallowtail, saying: "You could argue that there would be little point in a species which slowly evolved to mimic a poisonous butterfly over the course of generations - the disguise is only useful if full and complete. This could suggest the possibility of sudden leaps in evolution occurring in this species, which would be an incredibly exciting discovery - by studying the changes in gene sequences we will find out if this happened or not."

The mocker swallowtail is found in sub-Saharan Africa and has a wingspan of between three-and-a-half, and four-and-a-quarter inches. Only females of the species exhibit the wing patterns that mimic other butterflies. All the males are yellow, with black markings and have the typical tails of most swallowtail butterflies.

Danielle Reeves | alfa
Further information:
http://www.imperial.ac.uk

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

Im Focus: Like a wedge in a hinge

Researchers lay groundwork to tailor drugs for new targets in cancer therapy

In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...