Tag: genetics

Categories : GeneticsTags :

Diet can Affect Sperm through Epigenetics

On By ModernMedia

A team of researchers have investigated the effect of adding nuts to a Western style diet on epigenetic effects of sperm quality.

The epigenetic effects are expressed through DNA methylation, where methyl groups are added to DNA sequences, altering their activity without changing the actual sequence.

A range of lifestyle and environmental factors have been investigated in the search for the cause in the drop of human sperm fertility observed over the pasty 70years. Specific sperm DNA methylation signatures are associated with sperm quality.

The researchers took data from 72 young non-smoking adults from the FERTINUTS trial. In the assigned nut-eating group, the participants’ sperm was found to have significantly sperm count, viability, motility, and morphology. Additionally, alterations in 36 specific DNA methylation regions were observed compared to the control group, and hypermethylation was seen in 97.2% of them.  

Albert Salas-Huetos, first author of the article stated that, “This work demonstrates that there are some sensitive regions of the sperm epigenome that respond to diet, and which can result in changes in sperm and in its ability to fertilise.”

Source: Science Daily

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COVID Vaccines May Lose Potency as Virus Evolves

On By ModernMedia

Looking to a time beyond the development of COVID vaccines, researchers are attempting to determine how long the SARS-CoV-2 virus will take to develop resistance to those vaccines.

David Kennedy, assistant professor of biology at Pennsylvania State University said, “A COVID-19 vaccine is urgently needed to save lives and help society return to its pre-pandemic normal,” said David Kennedy, assistant professor of biology. “As we have seen with other diseases, such as pneumonia, the evolution of resistance can quickly render vaccines ineffective. By learning from these previous challenges and by implementing this knowledge during vaccine design, we may be able to maximise the long-term impact of COVID-19 vaccines.”

The researchers recommend that vaccines be designed to create multiple immune responses, making it harder for the vaccine to survive the immune system’s attack, much the way multiple antibiotics are used to suppress bacterial infections, by forcing the virus to have multiple mutations to survive.

Strongly suppressing virus transmission through the host is key to minimising the amount of mutation and thereby the lifespan of the vaccine’s  effectiveness.

“According to the World Health Organization, at least 198 COVID-19 vaccines are in the development pipeline, with 44 currently undergoing clinical evaluation,” said Kennedy. “We suggest that the risk of resistance be used to prioritise investment among otherwise similarly promising vaccine candidates.”

Source: SciTech Daily

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New COVID Lineages Found in SA

On By ModernMedia

To study the spread of COVID in South Africa, an interdisciplinary team called the Network for Genomics Surveillance in South Africa (NGS-SA) was formed with members from SA, the UK and Brazil. Analysing 1365 genomes of the SARS-CoV-2 virus, the researchers found 16 new COVID lineages which emerged in SA, which account for 42% of the country’s infections.

As could be expected, the bulk of introductions occurred before the advent of the lockdown and travel bans. Whether these new COVID lineages have any superior attributes relative to the original strains is as yet unknown, although the infectivity appears the same.

The study shows that, despite the lockdown, new strains emerged in localised outbreaks. Nosocomial outbreaks were also studied; in one case an outbreak in a hospital in KZN which went on to infect 16% of the population was brought under control, partly as a result of the investigation.

Source: News-Medical.Net

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New Book on CRISPR Gene-editing Technology

On By ModernMedia

A new book, “Editing Humanity: The Crispr Revolution and the New Era of Genome Editing”, by Kevin Davies lays out the story that led to developing the revolutionary CRISPR gene-editing technology.

It describes the development of the technology involved clearly and succinctly, from the beginnings of gene sequencing to the 2012 discovery that an ancient bacterial immune system could be adapted and become the basis of the CRISPR gene-editing technology.

It also describes the misuse of the technology, such as with early gene therapy being done outside of the US on girls and young women to avoid US oversight. And despite a 2015 consensus that human sperm, eggs or embryos should not be edited, a scientist announced in 2018 that he had used gene editing on a pair of twin girls to confer HIV protection. 

The book however does not address how ethical issues should be resolved, such as releasing genetically engineered mosquitoes into the environment to suppress malaria.

Source: Nature

Categories : Ageing GeneticsTags :

Hyperbaric Oxygen Shown to Increase Telomere Length

On By ModernMedia

In a world first, the length of human telomeres in living subjects has been increased in a prospective clinical trial as part of a broader study of aging. This was accomplished with the use of hyperbaric oxygen therapy (HBOT).

Telomeres place a limit on the number of times cells can be replicated, shortening by 20-40 bases every year and are thought to be one of the causes of aging as shorter telomeres are related to greater vulnerability to disease. Telomere length reduction can be slowed with diet and exercise, but not increased.

The trial recruited 35 participants aged over 63, who did not undergo diet or lifestyle changes. Each patient received 60 HBOT sessions over 90 days. The telomere length of T and B cells significantly increased by over 20%. B cells showed the greatest lengthening at 36.7% post-HBOT.

“After dedicating our HBOT research to exploring its impact on the areas of brain functionality and age related cognitive decline, we have now uncovered for the first time in humans HBOT’s biological effects at the cellular level in healthy aging adults,” said Prof Shai Efrati of the Faculty of Medicine and Sagol School of Neuroscience at Tel Aviv University. “Since telomere shortening is considered the ‘Holy Grail’ of the biology of aging, many pharmacological and environmental interventions are being extensively explored in the hopes of enabling telomere elongation. The significant improvement of telomere length shown during and after these unique HBOT protocols provides the scientific community with a new foundation of understanding that aging can, indeed, be targeted and reversed at the basic cellular-biological level.”

Source: The Sagol Center for Hyperbaric Medicine and Research via PRNewswire

Categories : COVID GeneticsTags :

Spike Protein Mutation May Be COVID’s Achilles Heel

On By ModernMedia

New research suggests that the very spike protein that makes SARS-CoV-2 so infective may also make it more vulnerable to vaccines. The characteristic “crown” of spikes on the virus gives rise to its “coronavirus” name.

A common mutation in the D614G protein makes a flap open in the spike. This spike makes it easier for the virus to latch onto cells, but this same flap opens a pathway directly into the virus’ core. This makes it easier for antibodies, such as those in the vaccines presently undergoing testing, to infiltrate into the virus, and disable it.

Yoshihiro Kawaoka, a virologist at the University of Wisconsin-Madison, explains: “The original spike protein had a ‘D’ at this position, and it was replaced by a ‘G,’ Several papers had already described that this mutation makes the protein more functional and more efficient at getting into cells.”

This mutation, they found, makes the virus replicate 10 times faster and also makes it more infectious.

When hamsters were exposed to the mutated and unmutated coronavirus strains, the ones infected with the mutated strain were found to transmit the virus much faster than those infected with the unmutated strain. Neither strain seemed to make the hamsters sicker, suggesting that the mutation does not make the virus more lethal. Researchers caution that the animal test results may not hold true for humans, and that constant vigilance in observing and documenting mutations in the SARS-CoV-2 virus is necessary. 

Source: Medical Xpress