Why women outlive men: It's in our genes, study says

August 2, 2012

Scientists are beginning to understand one of life's enduring mysteries - why women live, on average, longer than men.

Published today in , research led by Monash University, describes how mutations to the DNA of the can account for differences in the life expectancy of . Mitochondria, which exist in almost all , are vital for life because they convert our food into the energy that powers the body.

Dr Damian Dowling and PhD student, Florencia Camus, both from the Monash School of Biological Sciences, worked with Dr David Clancy from Lancaster University to uncover differences in longevity and biological ageing across male and female that carried mitochondria of different origins. They found that across these mitochondria were reliable predictors of life expectancy in males, but not in females.

Dr Dowling said the results point to numerous mutations within mitochondrial DNA that affect how long males live, and the speed at which they age.

"Intriguingly, these same mutations have no effects on patterns of ageing in females. They only affect males," Dr Dowling said.

"All animals possess mitochondria, and the tendency for females to outlive males is common to many different species. Our results therefore suggest that the mitochondrial mutations we have uncovered will generally cause faster male ageing across the ."

The researchers said these mutations can be entirely attributed to a quirk in the way that are passed down from parents to offspring.

"While children receive copies of most of their genes from both their mothers and fathers, they only receive mitochondrial genes from their mothers. This means that evolution's quality control process, known as natural selection, only screens the quality of mitochondrial genes in mothers," Dr Dowling said.

"If a mitochondrial mutation occurs that harms fathers, but has no effect on mothers, this mutation will slip through the gaze of natural selection, unnoticed. Over thousands of generations, many such mutations have accumulated that harm only males, while leaving females unscathed."

The study builds on previous findings by Dr Dowling and his team that investigated the consequences of maternal inheritance of mitochondria in causing male infertility.

"Together, our research shows that the mitochondria are hotspots for mutations affecting male health. What we seek to do now is investigate the genetic mechanisms that males might arm themselves with to nullify the effects of these harmful mutations and remain healthy," Dr Dowling said.

Explore further: Mothers curse linked to male infertility

Related Stories

Mothers curse linked to male infertility

May 16, 2011
(Medical Xpress) -- Researchers have discovered the first real evidence of the 'mother's curse' and its connection to male infertility due to genetic mutations in mitochondria. Led by Dr. Damian Dowling from Monash University ...

Research breakthrough on male infertility

May 13, 2011
(Medical Xpress) -- Around one in 20 men is infertile, but despite the best efforts of scientists, in many cases the underlying causes of infertility have remained a mystery. New findings by a team of Australian and Swedish ...

Genetic map reveals clues to degenerative diseases

August 24, 2011
An international research team, spearheaded by Dr. Tim Mercer from The University of Queensland's Institute for Molecular Bioscience (IMB), has unlocked the blueprints to the ‘power plants' of the cell in an effort that ...

Recommended for you

Genome analysis with near-complete privacy possible, say researchers

August 17, 2017
It is now possible to scour complete human genomes for the presence of disease-associated genes without revealing any genetic information not directly associated with the inquiry, say Stanford University researchers.

Science Says: DNA test results may not change health habits

August 17, 2017
If you learned your DNA made you more susceptible to getting a disease, wouldn't you work to stay healthy?

Genetic variants found to play key role in human immune system

August 16, 2017
It is widely recognized that people respond differently to infections. This can partially be explained by genetics, shows a new study published today in Nature Communications by an international collaboration of researchers ...

Phenotype varies for presumed pathogenic variants in KCNB1

August 16, 2017
(HealthDay)—De novo KCNB1 missense and loss-of-function variants are associated with neurodevelopmental disorders, with or without seizures, according to a study published online Aug. 14 in JAMA Neurology.

Active non-coding DNA might help pinpoint genetic risk for psychiatric disorders

August 16, 2017
Northwestern Medicine scientists have demonstrated a new method of analyzing non-coding regions of DNA in neurons, which may help to pinpoint which genetic variants are most important to the development of schizophrenia and ...

Evolved masculine and feminine behaviors can be inherited from social environment

August 15, 2017
The different ways men and women behave, passed down from generation to generation, can be inherited from our social environment - not just from genes, experts have suggested.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.