Females influence the gender of their offspring so they inherit either their mother's or grandfather's qualities. 'High-quality' females - those which produce more offspring - are more likely to have daughters. Weaker females, whose own fathers were stronger and more successful, produce more sons.
The study, by scientists at the University of Exeter (UK), Okayama University and Kyushu University (Japan), is published in the journal Ecology Letters. It shows for the first time that females are able to manipulate the sex of their offspring to compensate for the fact that some of the genes which make a good male make a bad female and vice versa.
Psychiatric disorders can be described on many levels, the most traditional of which are subjective descriptions of the experience of being depressed and the use of rating scales that quantify depressive symptoms. Over the past two decades, research has developed other strategies for describing the biological underpinnings of depression, including volumetric brain measurements using magnetic resonance imaging (MRI) and the patterns of gene expression in white blood cells.
During this period, a great deal of research has attempted to characterize the genes that cause depression as reflected in rating scales of mood states, alterations in brain structure and function as measured by MRI, and gene expression patterns in post-mortem brain tissue from people who had depression.
Providing clues to deafness, researchers at Washington University School of Medicine in St. Louis have identified a gene that is required for proper development of the mouse inner ear.
In humans, this gene, known as FGF20, is located in a portion of the genome that has been associated with inherited deafness in otherwise healthy families.
"When we inactivated FGF20 in mice, we saw they were alive and healthy," says senior author David M. Ornitz, MD, PhD, the Alumni Endowed Professor of Developmental Biology. "But then we figured out that they had absolutely no ability to hear."
Scientists studying a unique collection of human skulls have shown that changes to the skull shape thought to have occurred independently through separate evolutionary events may have actually precipitated each other.
Researchers at the Universities of Manchester and Barcelona examined 390 skulls from the Austrian town of Hallstatt and found evidence that the human skull is highly integrated, meaning variation in one part of the skull is linked to changes throughout the skull.
Scientists at the National Physical Laboratory (NPL) have created a functional model of the native extracellular matrix that provides structural support to cells to aid growth and proliferation. The model could lead to advances in regenerative medicine.
The extracellular matrix (ECM) provides the physical and chemical conditions that enable the development of all biological tissues. It is a complex nano-to-microscale structure made up of protein fibres and serves as a dynamic substrate that supports tissue repair and regeneration.
Man-made structures designed to mimic and replace the native matrix in damaged or diseased tissues are highly sought after to advance our understanding of tissue organisation and to make regenerative medicine a reality.
Scientists from institutions around the nation and the world have collaborated to develop new resources poised to unlock yet another door in the hidden garden of medicinally important compounds found in plants.
The resources were developed by the Medicinal Plant Consortium (MPC) led by Joe Chappell, professor of plant biochemistry at the University of Kentucky, Dean DellaPenna, professor of biochemistry at Michigan State University and Sarah O'Connor, professor of chemistry at Massachusetts Institute of Technology and now at the John Innes Centre in Norwich, England. They grew out of a $6 million initiative from the National Institutes of Health (NIH) to study how plants produce the rich diversity of chemical compounds, some of which are medicinally important.
In a major step that could revolutionize biomedical research, scientists have discovered a way to keep normal cells as well as tumor cells taken from an individual cancer patient alive in the laboratory - which previously had not been possible. Normal cells usually die in the lab after dividing only a few times, and many common cancers will not grow, unaltered, outside of the body.
Cancer growth normally follows a lengthy period of development. Over the course of time, genetic mutations often accumulate in cells, leading first to pre-cancerous conditions and ultimately to tumour growth. Using a mathematical model, scientists at the Max Planck Institute for Dynamics and Self-Organization in Göttingen, University of Pennsylvania and University of California San Francisco, have now shown that spatial tissue structure, such as that found in the colon, slows down the accumulation of genetic mutations, thereby delaying the onset of cancer. Their model could help in the assessment of tissue biopsies and improve predictions of the progression of certain cancer types.
Scientists are about to make publicly available all the data they have so far on the genetic blueprint of medicinal plants and what beneficial properties are encoded by the genes identified.
The resources, follow a $6 million initiative to study how plant genes contribute to producing various chemical compounds, some of which are medicinally important.
Large mammals living in temperate climates frequently have difficulty finding food during winter. It is well known that they lower their metabolism at this time but does this represent a mechanism for coping with less food or is it merely a consequence of having less to eat? The puzzle has been solved at least for the red deer by the group of Walter Arnold at the Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna. The results are published in the "Journal of Experimental Biology".