A new study has identified a gene mutation that could be a key factor in the development of autism spectrum disorder (ASD) in early childhood. The research, led by Dr. Jackson James and his team, at by the Rajiv Gandhi Centre for Biotechnology (RGCB), Kerala, India, highlights how a mutation in the Tlx3 gene may disrupt cerebellum development, leading to autism-related behaviours. The findings were published in the journal iScience.

Autism, a developmental disorder affecting brain function, is known to result from a combination of genetic and environmental factors. Symptoms of ASD can appear as early as the age of two, and the disorder often involves complex genetic mutations, including those affecting early developmental genes.

In their study, the RGCB team focused on the Tlx3 gene, which plays a crucial role in the development of the cerebellum — a brain region responsible for balance, motor skills, and coordination. By deleting the Tlx3 gene in the cerebellum of genetically modified mice embryos, the researchers observed significant disruptions in motor function, which later manifested as hallmark symptoms of autism in adulthood. These included impairments in social skills, repetitive behaviours, and motor movement issues.

Symptoms of ASD can appear as early as the age of two, and the disorder often involves complex genetic mutations, including those affecting early developmental genes

The study also explored the mutation’s potential presence in the human population. In collaboration with the CSIR-IGIB (Institute of Genomics and Integrative Biology) in New Delhi, the team found variants of the TLX3 mutation linked to nine cases of ASD and other neurodevelopmental conditions.

Dr. James emphasized the need for further research, stating, “A genome-wide global cohort analysis is necessary to assess the frequency of this TLX3 mutation and its prevalence in specific populations, such as Indians and others.” The study underscores how improper regulation of early embryonic genes can contribute to the onset of ASDs during early childhood.

Prof. Chandrabhas Narayana, Director of RGCB, said, “Autism is a serious childhood problem across the world. In India, it has emerged as a significant challenge for researchers and the medical community due to its broad social and medical impacts. The RGCB study will offer new insights into this behavioural disorder.”

ASDs are characterized by a range of behavioural deficits, including challenges with social cognition, communication, and repetitive behaviours, which affect individuals’ ability to engage with their environment and peers.

Sarah Amalia Teichmann, a prominent scientist in cellular genetics and stem cell medicine, has been optimistic about the wide potential of the Human Cell Atlas (HCA) project, which she leads, to revolutionize disease diagnosis, treatment, and monitoring. While speaking at the BRIC-Rajiv Gandhi Centre for Biotechnology (RGCB), Teichmann shared insights into how the project could pave the way for engineering cells for research and therapeutic purposes.

Sarah Teichmann is also the current India Academy of Sciences Raman Chair.

“Human Cell Atlas has the potential to help us engineer cells for research and therapeutic purposes. For utilizing this potential, we first need to understand the molecular basis of cells in our body and define the cell types present. If we can achieve this, we have the potential to restore tissues, engineer cells, and that would be a revolution,” Teichmann said.

Teichmann, who also holds the Chair of Stem Cell Medicine at the University of Cambridge, explained that the mission of HCA is to create a comprehensive reference map of human cell types and properties. “This map is a basis for understanding our bodies, our physiology, tissue function, and provides new insights for diagnosing, monitoring, and treating diseases,” she added.

The HCA, a global initiative co-founded by Teichmann and her team in 2016, aims to create detailed reference maps of all human cells. The project focuses on mapping healthy human cells to drive biomedical advancements. “With this reference map, we can compare and integrate disease data with a healthy reference state of our cells and understand in detail what changes are occurring,” Teichmann explained.

One key area of the project’s impact is in understanding viral interactions. Teichmann discussed how HCA can serve as a guidebook for viral entry points in humans, shedding light on important biological questions related to rare and common diseases, hormone receptors, and drug targets. “This knowledge can enable us to ask questions about viral entry factors, gene expressions involved in diseases, and drug-related side effects,” she said, referring to her research during the COVID-19 pandemic.

Teichmann expressed confidence that the collaborative efforts behind the HCA, involving scientists globally—including in India—will lead to significant biomedical breakthroughs. She added, “This project will have a huge impact in biomedical advancement.”

The HCA’s progress has already been marked by significant milestones, including the publication of the first draft of the human cell atlas in Nature, showcasing 40 scientific discoveries.

The Raman Chair, established by the Government of India in 1972 in memory of Sir C.V. Raman, has been held by distinguished scientists such as Nobel laureates Prof. J.B. Goodenough, Prof. Harold E. Varmus, and Prof. Dorothy Hodgkin.

When we think of slow and steady, the image of a tortoise often comes to mind. But behind that unhurried gait lies a remarkable creature capable of defying time itself. The tortoise is among the longest-living animals on the planet. Their extraordinary lifespan has fascinated biologists and storytellers alike, leading us to wonder: how do these creatures live so long? Is it the giant tortoises of the Galápagos or the smaller, land-dwelling species that hold the key to longevity? Let’s take a deeper look.

A Life of Patience and Persistence

The tortoise’s slow walk is not just a quirky trait — it’s a life philosophy, ingrained in their very survival. These creatures are not in a race against time, they are its patient conquerors. Some species of tortoises can live well over a century, and in the case of the Giant Tortoise (known for its immense size), individuals have been documented living for more than 200 years. But why is it that these ancient reptiles live so long, while their cousins, the turtles, tend to have shorter lifespans?

In terms of lifespan, tortoises—especially the giant tortoises—lead the pack. A giant tortoise can outlive many other creatures, including their ocean-dwelling cousins, the turtles. While turtles generally live between 50 to 100 years, giant tortoises surpass this, sometimes even living beyond 150 years. In fact, Jonathan, a Seychelles giant tortoise living on Saint Helena Island in the South Atlantic, holds the record as the world’s oldest living land animal at 189 years old. Jonathan, who was born in 1832, has outlived all of his peers, continuing to thrive on the island where he was discovered.

The Science Behind Their Longevity

The secret to the tortoise’s longevity lies deep within its biology. While there are several factors that contribute to their long lives, two of the most significant are evolutionary adaptations and cellular processes that are finely tuned to conserve energy and maintain health over decades.

From an evolutionary perspective, tortoises face fewer natural threats in their environment compared to faster, more vulnerable animals. For many species of tortoises, survival has been less about outpacing predators and more about outlasting them. Many tortoises lay multiple eggs, often many more than a single clutch, and they continue to reproduce over several decades. This “quality over quantity” approach to reproduction ensures that their genes continue to thrive, while their individual lifespans stretch out.

Moreover, tortoises tend to have slower metabolic rates compared to other animals. Their bodies conserve energy by keeping their metabolic processes at a steady, slow pace. This “slow burn” strategy is key to their extended lifespans. A slow metabolism means that fewer cellular processes are damaged by the wear and tear of daily life, which translates into fewer health issues in old age.

One of the most fascinating aspects of tortoise longevity is the role of their telomeres. Telomeres are the protective caps at the ends of chromosomes that prevent them from fraying and tangling. Every time a cell divides, the telomeres shorten slightly. In most organisms, as the telomeres shorten, cells lose their ability to divide, eventually leading to aging. However, in tortoises, the telomeres wear down at an unusually slow rate, allowing their cells to divide without the usual detrimental effects seen in other animals. This slower rate of telomere shortening helps them avoid age-related diseases such as cancer and ensures that their cells remain healthier for longer.

Furthermore, some studies have revealed that tortoises are capable of a process called apoptosis—a form of programmed cell death—where damaged or dysfunctional cells are destroyed before they can cause harm. This controlled form of self-destruction in damaged cells helps prevent the formation of tumors and other age-related diseases, which is another reason for the tortoise’s impressive lifespan.

The Giants of the Tortoise World

When we talk about longevity in tortoises, we cannot overlook the giant tortoises of the Galápagos Islands and the Seychelles. These remarkable creatures have not only captured our imagination but have also become living symbols of resilience and endurance.

The Galápagos Giant Tortoise, for instance, can live over 150 years, and some individuals have even outlived the scientists who studied them. They were once thought to be heading for extinction, but thanks to conservation efforts, their populations have stabilized.

In India, a rare breed of tortoise known as the Aldabra Giant Tortoise has been known to live up to 255 years. This species, although not as well-known as the Galápagos counterparts, is another testament to the wonders of nature’s design.

Turtles, which are often found in aquatic environments, tend to live shorter lives, averaging about 30 to 50 years

But what about other, lesser-known giants? In Kasaragod, Kerala, India, a giant soft-shell turtle species was discovered in May 2021, which lives in freshwater, weighing over 100 kilograms! These giant creatures are living proof of the astonishing adaptability and longevity that nature has to offer.

The Mystery of Tortoises and Turtles

While all tortoises are technically land-dwelling creatures, there is an interesting distinction between tortoises and turtles. Turtles, which are often found in aquatic environments, tend to live shorter lives, averaging about 30 to 50 years. Tortoises, on the other hand, tend to have larger bodies, longer necks, and more robust shells. Their heavy, often plant-based diet plays a role in the additional years they add to their lifespan.

A surprising discovery made in the Seychelles in recent years has sent shockwaves through the scientific community: certain tortoises, once thought to be herbivorous, have been seen eating birds and other small animals. This has raised questions about the adaptability of tortoises in changing environments and has piqued the interest of researchers studying their survival strategies.

What Lies Ahead?

Despite all that we know about these extraordinary creatures, there is still much to discover. Researchers continue to study tortoises, particularly the giant species, to learn how their unique biological traits could benefit human medicine, particularly in the fight against aging and diseases like cancer. The discovery of their telomere dynamics, coupled with the ability to prevent cell damage through apoptosis, could one day revolutionize the way we approach longevity and healthcare.

For now, we can only marvel at the tortoise’s timeless existence, its slow, steady journey through the ages, and the lessons it teaches us about patience, resilience, and the secrets of life’s most enduring creatures.