How bat genomes provide insights into immunity and cancer

How bat genomes provide insights into immunity and cancer

Subject: Science and tech

Section: Biotechnology  

Context:

Bats, by many measures, are truly remarkable organisms. Their lives are notably extended, and they enjoy a unique defense against a range of diseases, including cancer.

About Bats

• Significant Population: Bats constitute a substantial part of the mammal world, making up 20% of all mammal species globally. The planet is home to over 1,400 bat species, each exhibiting its own unique characteristics.
• Diverse Characteristics: Bats exhibit a wide range of sizes, from the tiny 2-gram bumblebee bat to the formidable flying foxes, boasting a 1.5-meter wingspan and weighing up to 1.6 kg.
• Ecological Importance: Bats play pivotal roles in maintaining ecological balance by contributing to essential processes such as pollination and insect population control.

Bats as Virus Reservoirs

• Notorious Reputation: Bats have come under scrutiny primarily due to their role as hosts for various deadly viruses, including coronaviruses, Nipah, Ebola, Marburg virus, and Hendra virus.
• COVID-19 Spotlight: The COVID-19 pandemic has thrust bats into the spotlight, raising concerns about their potential impact on human health.
• Natural Pathogen Hosts: Bats are unique in their ability to harbour numerous pathogens without falling victim to infections, sparking scientific interest in understanding the source of their resistance.

Unlocking Bat Genomes

• Genomic Exploration: Scientists have embarked on comprehensive studies of bat genomes, revealing invaluable insights into their distinctive biology.
• Compact Genomes: Bats boast relatively small genomes, typically consisting of around 2 billion bases, making them ideal subjects for genomic research.
• Metagenomic Sequencing: The ambitious Bat1K global genome consortium is currently undertaking the task of sequencing genomes of all bat species worldwide, promising further revelations about their genetic makeup.

Immune Insights from Bat Genomes

• Crucial Immune Genes: The immune-related genes of bats have been a major focus of research, with these creatures exhibiting unique genomic features.
• Reduced Immune Genes: Bats possess a smaller percentage of immune-related genes, approximately 2.7-3.5% compared to humans, who have around 7%.
• Positive Selection: Certain immune genes in bats have undergone positive selection, equipping them to control the spread of viruses while mitigating the inflammatory responses that often prove detrimental to humans.

Long-Read Sequencing and Deeper Insights

• Sequencing Advancements: Long-read sequencing technologies have revolutionized our ability to assemble complete genomes quickly and accurately.
• Immune Response Alterations: Recent research employing long-read technology has revealed significant changes in genes responsible for immune responses in bats.
• Interferon Dynamics: There has been a shift in the relative proportions of interferon-alpha (IFN-α) and interferon-omega (IFN-ω) in bats, impacting their immune properties.
• Tumor Suppression and Longevity: Genes linked to tumor suppression and DNA repair in bats exhibit signs of positive selection, contributing to their extended lifespans and reduced cancer risk.

Future Prospects

• Emerging Zoonotic Threats: The ongoing processes of deforestation, ecological degradation, and heightened human-animal interactions are anticipated to result in more frequent zoonotic disease outbreaks.
• Genomic Tools: Advanced genome sequencing techniques hold the promise of aiding in the management of these outbreaks while preserving ecological balance, providing insights without disrupting the delicate equilibrium of nature.