Open Reading Frame brings together a selection of recent publication highlights from elsewhere in the open access ecosystem. This week we take a look at the past few weeks in biology.
Using flies to perform post-mortems
In the field of forensic entomology, identification of the insect species found on a corpse can be used to infer time of death, since different species colonise bodies at different stages of their decomposition. Larval stages are most frequently found, since they remain feeding on the body until pupation. However, species identification can prove tricky without an adult specimen. This is where DNA barcodes can help. By sampling fly species found on corpses in France and Belgium, researchers have found that the public reference libraries, Genbank and the Barcode of Life Data Systems (BOLD) archive, are able to accurately identify most specimens. However, they caution that improved reference libraries for specific geographic regions may still be needed before the technique can be applied to formal forensic investigations.
Soner et al. ZooKeys
Sniffing out cancer…with flies
Part of what makes flies so successful at finding corpses is their fantastically sensitive olfactory system. Current technology is still far behind the chemical sensitivity offered by a fly’s antenna, and this ability might soon be put to clinical use in detecting cancer. Metabolism in cancer cells differs from healthy cells, and as a result they emit characteristically different volatile chemicals. By using a technique called calcium imaging to investigate the antennal response of fruit flies to these distinct chemical signatures, researchers have identified a strong ability to discriminate between healthy mammary epithelial tissue and cancerous cell types.
Strauch et al. Scientific Reports
Deleterious deletion proves deadly at the dairy
Artificial selection for higher milk yield in dairy cattle could be maintaining genetic mutations that cause increased mortality among calves in the embryonic stage. Genetic analysis of more than 4000 Nordic Red Cattle has identified a recessively lethal deletion encompassing four genes conferring a high risk of mortality among embryos when carrier cows are mated with carrier bulls. Despite the lethality of this mutation, its high prevalence may have continued to be maintained in cattle by artificial selection, as a result of an unfortunate association with favourable milk yield traits. As a result, a doubling of milk yields in these cows since the 1960’s may have been offset by a halving of first-insemination conception rates.
Kadri et al. PLoS Genetics
A centenary of statistics
Pioneering biostatistician Sir Ronald Fisher famously once stated “To consult the statistician after an experiment is finished is often merely to ask him to conduct a post mortem examination. He can perhaps say what the experiment died of”. Fisher was employed as the first statistician at Rothamsted Research (UK) in 1919, and is best known for developing many statistical techniques still in use across most fields of biology and medicine today, including the near-ubiquitous Analysis of Variance, or ANOVA. Looking back at more than 100 years of development in the use of statistics in biological research, statistician Roger Payne gives an engaging account of the birth of analytical techniques that many researchers take for granted, and a glimpse into a non-linear future.
Payne, Annals of Applied Biology
Fatty acids key to a worm’s soft touch
Touch sensations are detected by sensory neurons in the skin, and signals sent through channels embedded in their cell membranes. The constituent parts of these membranes may play a crucial role in mediating how signals are transmitted, yet a lack of methods to manipulate their components remains a barrier to finding out which chemicals are key. Polyunsaturated fatty acids are known to be crucial for sensory and motor function in the model organism Caenorhabditis elegans, a nematode worm, which is able to synthesise them with the help of specific enzymes. By comparing how mutant worms lacking these enzymes react to being stroked with a single hair, researchers from Stanford University (US) have established that the presence of the polyunsaturated fatty acid arachidonic acid in neuronal membranes is critical for touch sensitivity, and that this is mediated by mechanically-induced chemical changes rather than electrical signalling.
Vasquez et al. Cell Reports
Metagenomics and marine microbes
Gokushoviruses derive their name from the Japanese for ‘very small’, and are a subfamily of single-stranded DNA viruses that infect bacteria such as Chlamydia. Although they are known to inhabit a wide variety of environments, little is currently known about their genetic diversity and evolutionary relatedness to other groups of viruses. Now, a metagenomic analysis of samples taken from both temperate and tropical marine environments has revealed at least five new groups among this subfamily, and confirmed their close evolutionary relationship with other viruses that infect intracellular parasitic bacteria.
Labonté & Suttle, Frontiers in Microbiology
Written by Simon Harold, Senior Executive Editor for the BMC Series.