Trauma of life is passed down in SPERM to future generations

The children of people who have experienced extremely traumatic events are more likely to develop mental health problems. And new research shows this is because experiencing trauma leads to changes in the sperm. These changes can cause a man’s children to develop bipolar disorder and are so strong they can even influence the man’s grandchildren. Psychologists have long known that traumatic experiences can induce behavioural disorders that are passed down from one generation to the next. However, they are only just beginning to understand how this happens. Researchers at the University of Zurich and ETH Zurich now think they have come one step closer to understanding how the effects of traumas can be passed down the generations. The researchers found that short RNA molecules – molecules that perform a wide range of vital roles in the body - are made from DNA by enzymes that read specific sections of the DNA and use them as template to produce corresponding RNAs. Other enzymes then trim these RNAs into mature forms. Cells naturally contain a large number of different short RNA molecules called microRNAs. They have regulatory functions, such as controlling how many copies of a particular protein are made. The researchers studied the number and kind of microRNAs expressed by adult mice exposed to traumatic conditions in early life and compared them with non-traumatised mice. They discovered that traumatic stress alters the amount of several microRNAs in the blood, brain and sperm – while some microRNAs were produced in excess, others were lower than in the corresponding tissues or cells of control animals. These alterations resulted in misregulation of cellular processes normally controlled by these microRNAs. After traumatic experiences, the mice behaved markedly differently - they partly lost their natural aversion to open spaces and bright light and showed symptoms of depression. These behavioural symptoms were also transferred to the next generation via sperm, even though the offspring were not exposed to any traumatic stress themselves. The metabolisms of the offspring of stressed mice were also impaired - their insulin and blood sugar levels were lower than in the offspring of non-traumatised parents. ‘We were able to demonstrate for the first time that traumatic experiences affect metabolism in the long-term and that these changes are hereditary,’ said Professor Isabelle Mansuy. ‘With the imbalance in microRNAs in sperm, we have discovered a key factor through which trauma can be passed on.’ However, certain questions remain open, such as how the dysregulation in short RNAs comes about. Professor Mansuy said: ‘Most likely, it is part of a chain of events that begins with the body producing too many stress hormones.’ Importantly, acquired traits other than those induced by trauma could also be inherited through similar mechanisms, the researcher suspects. Article: 23rd April 2014 www.dailymail.co.uk

Men with a poor sense of taste may have poor sperm or be infertile

A poor sense of taste in men may link to a problem with their sperm and fertility. Proteins that allow us to taste flavours play a crucial role in making men fertile, a study shows. American researchers found that two proteins, which allow the body to taste sweet and savoury flavours on the tongue, play a vital part in sperm development. The study, from the Monell Centre in Philadelphia, could suggest new ways to help male infertility or even spark the production of new male contraceptives. The surprising findings were made when mice were bred for taste related studies, without the two proteins known as taste receptors. They were found to be sterile, according to the study published in Proceedings of the National Academies of Sciences. Molecular Biologist Dr Bedrich Mosinger, said: 'This paper highlights a connection between the taste system and male reproduction. 'It is one more demonstration that components of the taste system also play important roles in other organ systems.' The taste receptors are more popularly known to help tongues detect sugars, salts and acids, which lead us to enjoy sweet, bitter, salty and sour tastes. While previous research has shown that taste receptors are located in different parts of the body, including the stomach and intestines, their function remains unclear. To try and work out their purpose, researchers examined the taste receptors that allow taste buds found on the tongue to detect sugars and amino acids that produce savoury and sweet tastes. LITTLE SENSE OF TASTE? COULD MEAN YOU LACK: Zinc. (RDA): 5.5-9.5mg for men Poor zinc intake can affect our sense of taste. In research carried out at the University of Ulster involving 387 people, those who had lower levels of zinc in their red blood cells were less able to detect salty tastes. How low zinc levels affect taste is unclear, but might be because zinc is required for the production of salivary enzymes and development and maintenance of tastebuds in general. Other signs of zinc deficiency can include more frequent infections, such as colds and flu, and delayed healing of wounds, probably because the mineral has a vital role to play in the functioning of the immune system and in the repair and renewal of cells. ZINC is important for sperm Zinc is an antioxidant mineral that is also important in protecting sperm against free radical attack. Semen is rich in zinc, with an estimate of each ejaculate containing as much as 5 mg - one third of the recommended daily nutrient intake. Thus a zinc deficiency would affect the protection of sperm. FOOD SOLUTION: Red meat - beef and lamb are among the best sources of zinc, so aim to eat one to two portions the size of an 8oz steak or equivalent a week. Other sources include nuts, especially cashews and peanuts, oysters, crab and dark chocolate. Article extracts: 2nd July 2013 www.dailymail.co.uk