Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Stick insects produce bacterial enzymes themselves

31.05.2016

Many plant-feeding insects need microbial enzymes, such as pectinases, that degrade plant cell walls; yet some insects have overcome this dependency in a surprising way. Researchers at the Max Planck Institute for Chemical Ecology in Jena, Germany, found that stick insects make microbial enzymes themselves. From an ancestral gut microbe, the genes for the essential enzymes simply “jumped” as they are to their insect host.

Many animals depend on their microbiome to digest their food. Symbiotic microorganisms produce enzymes their hosts cannot, and these work alone or together with the animals’ own enzymes to break down their food.


Vietnamese stick insect Ramulus artemis: The insect belongs to one of six stick insect species in which the researchers isolated pectinase genes.

Matan Shelomi / Max Planck Institute for Chemical Ecology

Many plant-feeding insects need microbial enzymes, such as pectinases, that degrade plant cell walls; yet some insects have overcome this dependency in a surprising way. Researchers at the Max Planck Institute for Chemical Ecology in Jena, Germany, found that stick insects make microbial enzymes themselves.

From an ancestral gut microbe, the genes for the essential enzymes simply “jumped” as they are to their insect host. The researchers report this newly discovered “horizontal gene transfer” in a paper recently published in Scientific Reports. (Scientific Reports, May 2016, DOI: 10.1038/srep26388)

“Insects are not supposed to make their own pectinases,” explains Dr. Matan Shelomi, a postdoctoral fellow in the Department of Entomology and lead author of the study. Yet the stick insects make lots, and their genome contains multiple pectinase genes!”

Based on DNA similarity, the source was a gamma-proteobactera, the most common bacteria type in the stick insect microbiome, but commonly found on the leaves they eat too. “We are not sure how it happened, but one or two pectinase genes from a gut bacterium or even just something in the food clearly jumped into the stick insect genome, and then evolved along with the insects,” explains Shelomi. Tests show some of the new pectinases retained their original job degrading pectin, while others have yet unknown functions. But when did the transfer happen?

An international collaboration solves the puzzle

To find out, the team first tested seven different species of stick insect, including a primitive and short species found only in California called Timema cristinae, in the sister group to all the other stick insects. Timema do not have pectinases, while the others, the “Euphasmatodea,” do. It was not clear, however, whether Timema never had the genes or simply lost them. The team then collaborated with the 1K Insect Transcriptome Evolution Project (http://www.1kite.org/). Using 1KITE’s genetic databases from 1000 insect species, including nearly 50 Phasmatodea, the researchers could quickly search multiple groups for these enzymes. The results showed that the gene jump occurred sometime after Timema and Euphasmatodea split, but before the latter diverged into the 3000 or so species it has today: between 110 to 60 million years ago.

Gut microbe genes can change their hosts

Other researchers in the Department of Entomology previously discovered horizontal pectinase transfers in leaf beetles. It may not be a coincidence that these and the stick insects are all specialists on leaves. Nor is it necessarily coincidence that each group experienced a massive species radiation after their horizontal transfer occurred. “Something happened, to make the tiny Timema become a planet-wide group of nearly 3000 species that can be nearly half a meter long,” says Shelomi, referring to the world’s longest insect, a Euphasmatodea called Phoebetica chani. His new theory, the Enzyme Expansion Hypothesis, is that the sudden appearance of new enzyme abilities, either through mutation or horizontal gene transfer, can drive the evolution of a species and change their diets to specialize on a single food source.

Beyond enzymes, horizontal gene transfer can provide any number of new abilities, and our microbiome provides an immense source of potential species-altering proteins. “The idea that genes from microbes living in our guts can suddenly become part of our genomes and change the course of our evolutionary history, that’s an incredible finding,” Shelomi concludes. [MS/AO]

Original Publication:
Shelomi, M., Danchin, E. G. J., Heckel, D. G., Wipfler, B., Bradler, S., Zhou, X., Pauchet, Y. (2016). Horizontal gene transfer of pectinases from bacteria preceded the diversification of stick and leaf insects. Scientific Reports, 6: 26388. doi:10.1038/srep26388.
http://dx.doi.org/10.1038/srep26388

Further Information:
Dr. Matan Shelomi, Max Planck Institute for Chemical Ecology, Hans-Knöll-Str. 8, 07743 Jena, Germany, Tel. +49 3641 57-1560, E-Mail mshelomi@ice.mpg.de

Contact and Media Requests:
Angela Overmeyer M.A., Max Planck Institute for Chemical Ecology, Hans-Knöll-Str. 8, 07743 Jena, +49 3641 57-2110, E-Mail overmeyer@ice.mpg.de

Download high-resolution images via http://www.ice.mpg.de/ext/downloads2016.html

Angela Overmeyer | Max-Planck-Institut für chemische Ökologie

More articles from Life Sciences:

nachricht When Air is in Short Supply - Shedding light on plant stress reactions when oxygen runs short
23.03.2017 | Institut für Pflanzenbiochemie

nachricht WPI team grows heart tissue on spinach leaves
23.03.2017 | Worcester Polytechnic Institute

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

When Air is in Short Supply - Shedding light on plant stress reactions when oxygen runs short

23.03.2017 | Life Sciences

Researchers use light to remotely control curvature of plastics

23.03.2017 | Power and Electrical Engineering

Sea ice extent sinks to record lows at both poles

23.03.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>