New research provides insight about the reason mitochondria — the powerhouse of the cell — pass only from the mother. Scientists have long recognized the fact that mitochondrial DNA, or mtDNA, comes exclusively from egg cells in humans, meaning only the mother contributes the genetic code carried by thousands of mitochondria necessary for energy production in every cell in the body.

Previously, it was believed that paternal mtDNA was eliminated soon after a sperm fuses with an oocyte, or developing egg, during fertilization, possibly through an immune-like search-and-destroy response.

However, the study found that while mature sperm do carry a small number of mitochondria, they lack intact mtDNA.

“We found that each sperm cell ...

Researchers discover excellent thermoelectric properties of nickel-gold alloys. These can be used to efficiently convert heat into electrical energy. Thermoelectrics enable the direct conversion of heat into electrical energy – and vice versa. This makes them interesting for a range of technological applications. In the search for thermoelectric materials with the best possible properties, a research team at TU Wien investigated various metallic alloys. A mixture of nickel and gold proved particularly promising. The researchers recently published their results in the journal Science Advances.

Using thermoelectrics to generate el...

Moon’s permanently shadowed regions are younger than previously estimated. A team including Southwest Research Institute’s Dr. Raluca Rufu recently calculated that most of the Moon’s permanently shadowed regions (PSRs) are at most around 3.4 billion years old and can contain relatively young deposits of water ice...

The gene, dubbed Iditarod, seems responsible for exercise’s ability to clean up damaged cells. As the days get shorter and chillier in the northern hemisphere, those who choose to work out in the mornings might find it harder to get up and running. A new study in PNAS identifies a protein that, when missing, makes exercising in the cold that much harder – that is, at least in fruit flies.

A team from University of Michigan Medical School and Wayne State University School of Medicine discovered the protein in flies, which they named Iditarod after the famous long distance dog sled across Alaska, while studying metabolism and the effect of stress on the body.

They were particularly interested in a physiological process called autophagy wherein damaged...