Research into the breeding habits of the red flour beetle, published today in Proceedings of the Royal Society B, shows that the reduced fitness of inbred beetles, known as 'inbreeding depression', reveals itself in competitive scenarios.
Inbreeding is a potentially important problem in declining species across the world, and conserving genetic variation is now recognised as a priority by the International Union for Conservation of Nature. The new research is potentially vital for the successful implementation of recovery programmes of inbred species.
When populations deplete or fragment, relatives can be forced into reproduction, often leading to inbreeding depression.
Led by Dr Matt Gage, the new research into the promiscuous red flour beetle (Tribolium castaneum) measured how male reproduction responded to forced inbreeding.
After mating brothers with sisters for eight generations, the research found no changes in male fertility or mating behaviour.
However, inbred male sperm fertilized fewer eggs when in competition with another non-inbred male, and sperm became more variable in size.
Dr Gage said: "The experiment was designed to make comparisons with non-inbred control lines. Using multiple inbred lines, we measured the effect s of inbreeding on pre and post-mating success, in the absence and presence of male-male competition."
The results showed no differences between inbred and non-inbred males in terms of mating success, latency, duration, the number of mounts or persistency in a non-competitive setting.
However inbred males suffered significantly reduced sperm competitiveness, fathering an average of 15 per cent fewer offspring than non-inbred males across 330 sperm competition comparisons.
Dr Gage said: "It seems that inbreeding depression in sperm competitiveness was caused by a decrease in either sperm quantity or quality that is critical for relative competitiveness, but still allows full male fertilization success to be achieved under benign, competition-free conditions.
"We have shown that male fertility and mating competence are not affected by inbreeding and that any decline in sperm quality under inbreeding is only detectable when sperm competition is invoked.
"One limitation to this study is that the ancestral laboratory stock we have used is likely to carry relatively reduced genetic diversity. Also insect sperm do not generally manifest cellular abnormalities akin to those commonly found in more complex mammalian sperm," he added.
The next stage of the research will explore ways that female beetles use multiple mating to generate sperm competition and thereby avoid inbreeding depression of their own fertility.
The research is part of a three-year £400,000 project funded by the Natural Environmental Research Council (NERC). The overall results will help managers of conservation and captive breeding projects recognise when inbreeding is a problem, how it progresses and how best to manage or reverse it.
Lisa Horton | EurekAlert!
Study shines light on brain cells that coordinate movement
26.06.2017 | University of Washington Health Sciences/UW Medicine
New insight into a central biological dogma on ion transport
26.06.2017 | Aarhus University
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
26.06.2017 | Life Sciences
26.06.2017 | Physics and Astronomy
26.06.2017 | Information Technology