Author Archives: Kathy Bennet

Malnourished flies preserve genital size to ensure mating

In the vast majority of animals, when food is scarce, the first effects are on the body, which shrinks more and more to run out of fat until it wrinkles. However, there are some parts of the body that are preserved from this “shrinkage,” parts usually considered essential for life. For example, in humans, the head is always the same size because it contains the brain, the primary organ for our survival.

In other animals, this part may be different. In fruit flies, for example, whose life span is only about 45 days and whose purpose of existence is only to reproduce in order to keep the species going, it is the genitals that are considered as the primary organ, one of those that should not be affected by the lack of food and nutrients. When the availability of food is low, in fact, fruit flies keep the size of their genitals constant in order to be more likely to reproduce. Never as in this case, does size really matter.

This is what researchers at the University of Illinois and Loyola University in Chicago have discovered. In fact, scientists have discovered lower levels of a protein in the genitals of these small insects that act as a negative growth factor, called FOXO, a clear sign of maintaining reproductive success. The study, published in Biology Letters, describes how this negative growth factor, which counteracts the growth of other parts of the body due to lack of nutrients and food, acts much less in the genital area.

By artificially increasing the activity of the FOXO protein in the genitals of these malnourished gnats, the genitals themselves began to decrease in size, up to 29%, like other parts of the body.

“Our results suggest that there was significant selective pressure to limit the amount of FOXO in the genitals of the fruit flies, a way to ensure reproductive success, given the female’s preference for mating with males with larger genitalia,” reports Alexander Shingleton, professor of biological sciences and author of the study together with colleague Austin Dreyer.

Ultrasound to produce insulin to the pancreas seems to be working

A new technology that uses ultrasound to stimulate the release of insulin into the body of mice was developed by a group of researchers at George Washington University in Washington. The technique involves exposure of the pancreas to ultrasound from outside the body, a technique that stimulates the production of insulin that then circulates in the bloodstream.

This technique, presented at the 177th meeting of the Acoustical Society of America in Louisville, USA, was defined as “an important first step in stimulating endocrine tissue” by Tania Singh, lead author of the study.

Until now ultrasound has been used more as a diagnostic tool, for example during pregnancy, but significant technical advances in the field have also led to possible use in the therapeutic field, for example for the treatment of kidney stones or for in-depth analysis of Parkinson’s disease.

However, this is the first time that ultrasound has been proposed to treat diabetes. Early experiments in mice have shown significant increases in insulin levels after ultrasound therapy that mimic those drugs that help beta cells, i.e. cells specializing in the pancreas for insulin production, to produce insulin.

However, since the pancreas has other properties and also plays other roles in the human body, researchers hope to use this technique for other purposes, such as the release of antagonist hormones and digestive enzymes, as Singh herself points out.

Chewing gum was used already 10,000 years ago

Chewing gum was already used by humans 10,000 years ago according to a study published in Communications Biology. Researchers from Uppsala University, Stockholm University and the Museum of Cultural History in Oslo analyzed the DNA in ancient chewing gum used by human tribes that settled in Scandinavia more than 10,000 years ago.

These gums were mostly composed of lumps made of birch bark and are thought to have been used as glue in the production of tools or other types of tools. It was precisely these lumps, chewed and then spit out by humans at the time, that provided a unique opportunity to analyse the DNA of these humans, DNA that is currently the oldest ever sequenced DNA belonging to humans from this area.

The DNA analyzed comes from three individuals, two females and a male, and was taken from chewed birch bark found near Huseby-Klev, an ancient site of Mesolithic hunters and fishermen on Sweden’s west coast. The excavation at this site began in the early 90s but only today, with today’s techniques, was it possible to analyze this ancient DNA.

The results show that these people share a genetic affinity with other hunter-gatherers who settled in the area of present-day Sweden and with the first populations from the Mesolithic period until the Ice Age.

“The DNA of these ancient chewing gums has enormous potential not only to trace the origin and movement of peoples long ago, but also to provide insights into their social relationships, diseases and food,” says Persson, a researcher at the Museum of Cultural History in Oslo.