Ever wondered why श्राद्ध पक्ष fall in to शरद ऋतू?

Ever wondered how remembering and paying homage to our ancestors help us?

There are several reasons why we remember and worship our ancestors during this time of the year but I would like to focus on very gross reason.

Pitru Paksha
Pitru Paksha

Remember one thing: You and your body, is gift from last several generations. Your genetic imprints carry entire history of at least 7 generations. It has recording of environmental changes happened during 7 generations (from mother and father side). It also had instructions to tackle future.

Under the toxic influence of mass mediums like movies, newspapers and TV news, we now really don’t remember and respect our ancestors.

श्राद्ध & पितृ तर्पण (tarapana) – We do it every year and get invisible help from ancestors legacy. This season (Sharad) is season of epidemics. It is also season when our immunity is all time low for the year due to vata prakop of monsoon. It is also now known fact that our mind drives and shapes body. So remembering 7 generations also activates memories (yeah, gross living won’t give that sensitivity but do perform pitru tarpana with faith!)

“Roughly eight percent of our DNA comes from viruses that infected our ancestors millions of years ago. New research by geneticists shows that more than an oddity, the viral DNA switches on genes responsible for initiating an immune response. When removed, the innate immune system — a first-responder to infection by pathogens including viruses — does not function properly. The study shows that viral DNA functions in our body by helping us fight infections.”

To activate or deactivate these genes is really a mental task. And a weak mind cannot receive help from the past. Nor the future can help.



Ancient Viral Invaders in Our DNA Help Fight Today’s Infections

Ancestors in DNA IMAGE SOURCE:
Ancestors in DNA

The human innate immune system’s ability to defeat foreign invaders depends on a well-coordinated response. Upon infection, cells dispatch a silent alarm by releasing interferons, a molecular signal that triggers nearby cells to activate an arsenal of hundreds of genes that fight off intruders. By analyzing publicly available genomic datasets from human cells, the authors discovered thousands of endogenous retroviruses that appeared to be activated by interferons. However, because these retroviruses crash-landed into our genomes many millions of years ago, they have long lost the ability to produce infectious particles. One clue to a potential modern-day function of some of these interferon-inducible elements came from their location in the genome. Instead of being distributed randomly, they were enriched near genes with known functions in immunity.

“These were the first signs to us that some of these elements may be truly involved in switching on immunity genes,” says Feschotte who collaborated on the project with assistant professor of human genetics and co-senior author Nels Elde, Ph.D., and lead author Edward Chuong, Ph.D., a Jane Coffin Childs postdoctoral fellow.

To test whether the pieces of viral DNA were indeed important for immunity, the scientists used the gene-editing tool CRISPR/Cas9 in cell culture to remove one by one several of these viral sequences, each located near known immune genes.  In mutant cells lacking the foreign code the adjacent immune genes could not turn on properly in response to interferon, demonstrating that they act as virus-derived switches. Further, when cells lacking the viral DNA element near the AIM2 immune defense gene were infected with virus, their ability to execute an effective immune response was greatly reduced. Taken together, the results indicate that ancient viral DNA has become important for mounting a proper defense against today’s viral infections.

Regulatory evolution of innate immunity through co-option of endogenous retroviruses

Regulatory use of endogenous retroviruses

Mammalian genomes contain many endogenous retroviruses (ERVs), which have a range of evolutionary ages. The propagation and maintenance of these genetic elements have been attributed to their ability to contribute to gene regulation. Chuong et al.demonstrate that some ERV families are enriched in regulatory elements, so that they act as independently evolved enhancers for immune genes in both humans and mice (see the Perspective by Lynch). The analysis revealed a primate-specific element that orchestrates the transcriptional response to interferons. Selection can therefore act on selfish genetic elements to generate novel gene networks.


Endogenous retroviruses (ERVs) are abundant in mammalian genomes and contain sequences modulating transcription. The impact of ERV propagation on the evolution of gene regulation remains poorly understood. We found that ERVs have shaped the evolution of a transcriptional network underlying the interferon (IFN) response, a major branch of innate immunity, and that lineage-specific ERVs have dispersed numerous IFN-inducible enhancers independently in diverse mammalian genomes. CRISPR-Cas9 deletion of a subset of these ERV elements in the human genome impaired expression of adjacent IFN-induced genes and revealed their involvement in the regulation of essential immune functions, including activation of the AIM2 inflammasome. Although these regulatory sequences likely arose in ancient viruses, they now constitute a dynamic reservoir of IFN-inducible enhancers fueling genetic innovation in mammalian immune defenses.