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Subject: Science and Technology

  • What is Zero Debris Charter?

    Why in the News?

    • The Zero Debris Charter was signed by twelve nations and the European Space Agency (ESA) at the ESA/EU Space Council.

    Zero Debris Charter

      • The Zero Debris Charter was unveiled at the ESA Space Summit in Seville, Spain, in November 2023.
      • The Charter was facilitated by ESA’s “Protection of Space Assets” Accelerator and developed through extensive collaboration among various space actors.
    • Objectives:
    • To achieve debris neutrality in space by 2030.
    • Long-term sustainability of human activities in Earth orbit.
    • Members:
      • The signatory countries are Austria, Belgium, Cyprus, Estonia, Germany, Lithuania, Poland, Portugal, Romania, Slovakia, Sweden, and the United Kingdom.
      • The ESA signed as an International Organization.

    Community Support and Leadership

    • Over 100 organizations are expected to sign the Charter in the coming months.
    • This includes national space agencies, satellite manufacturers, space startups, and astronomical societies.

    Space Debris Challenges

    • ESA estimates over one million pieces of space debris larger than 1 cm in Earth orbit.
    • These debris pieces pose significant risks to satellites and astronauts.

    Threats posed by Space Debris

    Space debris also leads to two major risks:

    1. It creates unusable regions of the orbit due to excessive debris, and
    2. Leads to the ‘Kessler syndrome’ – the creation of more debris due to cascading collisions resulting from one collision.

  • [pib] Central Council for Research in Ayurvedic Sciences (CCRAS) launches PRAGATI-2024

    Why in the news?

    • The Central Council for Research in Ayurvedic Sciences (CCRAS) is hosting “PRAGATI-2024” at the India Habitat Centre, New Delhi, to promote collaboration and research opportunities between CCRAS and the Ayurveda drug industry.

    About Central Council for Research in Ayurvedic Sciences (CCRAS)  

      • The CCRAS is an autonomous body of the Ministry of AYUSH (Ayurveda, Yoga & Naturopathy, Unani, Siddha and Homeopathy), Government of India.
      • It was established in 1978 to formulate, coordinate, develop, and promote research on scientific lines in the Ayurveda and Sowa-Rigpa system of medicine.
    • Primary Objectives:
      • Research: To undertake research to scientifically establish the efficacy of Ayurvedic practices.
      • Development: To develop and promote Ayurveda science through research and education.
      • Integration: To integrate traditional Ayurvedic methods with modern medicine for more comprehensive healthcare.

    Functions of CCRAS

    • Research Studies: Conducting various types of research studies like drug research, fundamental research, clinical research, literary research, and medicinal plant research.
    • Publication: Publishing scientific journals, research papers, and other documentation to disseminate knowledge.
    • Medicinal Plant Development: Focusing on the cultivation and conservation of medicinal plants used in Ayurveda.
    • Public Health Initiatives: Implementing public health programs and providing training to practitioners.

    Achievements of CCRAS:

    • Development of Ayurvedic Formulations: CCRAS has developed several notable Ayurvedic formulations and technologies, which have been patented and commercialised.
    • National Ayurveda Morbidity Codes: CCRAS has developed morbidity codes and standard terminologies to standardise the practice of Ayurveda.
    • AYUSH Research Portal: A comprehensive database of research on Ayurveda, which includes information on drugs, case studies, and clinical trials.

    Notable Projects:

    • Golden Triangle Partnership: A collaborative project with CSIR (Council of Scientific and Industrial Research) and ICMR (Indian Council of Medical Research) for enhancing the scientific validation of Ayurveda.
    • Tribal Health Care Research Program: Aimed at documenting ethno-medical knowledge and validating it for scientific purposes.

    PYQ:

    [2019] How is the Government of India protecting traditional knowledge of medicine from patenting by pharmaceutical companies?

  • Omega-3 Fatty Acids and its Health Impacts

    Why in the News?

    • Fish oil supplements, highly regarded for their high omega-3 fatty acid content, have long been associated with heart health benefits.
      • A recent study has caused controversy by raising the possibility that these supplements may be as harmful as previously thought.

    What are Fatty Acids?


    Fatty acids are crucial lipids (fats and oils) essential for various biological functions (Fatty Acid + Glycerol = Fats). They are carboxylic acids with a long aliphatic chain, either saturated or unsaturated.

    • Basic Structure: Consists of a hydrocarbon chain with a terminal carboxyl group (-COOH). The length and degree of saturation of the hydrocarbon chain can vary.
    • Roles in the Body: Serve as energy sources, components of cell membranes, and precursors for bioactive lipids.

    Types of Fatty Acids

    Fatty acids are classified based on the presence and number of double bonds in their hydrocarbon chain:

    1. Saturated Fatty Acids (SFA)
      • Structure: Contain no double bonds between carbon atoms; the hydrocarbon chain is saturated with hydrogen atoms.
      • Properties: Typically solid at room temperature.
      • Sources: Animal fats, coconut oil, palm oil, dairy products.
      • Examples: Palmitic acid, stearic acid.
    2. Monounsaturated Fatty Acids (MUFA)
      • Structure: Contain one double bond in the hydrocarbon chain.
      • Properties: Generally liquid at room temperature but solidify when chilled.
      • Sources: Olive oil, canola oil, peanut oil, avocados, nuts.
      • Examples: Oleic acid.
    3. Polyunsaturated Fatty Acids (PUFA)
      • Structure: Contain two or more double bonds in the hydrocarbon chain.
      • Properties: Liquid at room temperature and in the refrigerator.
      • Sources: Fish, flax seeds, walnuts, sunflower oil, corn oil.
      • Examples:
    1. Omega-3 Fatty Acids: Alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA).
    2. Omega-6 Fatty Acids: Linoleic acid, arachidonic acid.
    1. Trans Fatty Acids
      • Formation: Produced by the industrial process of hydrogenation of unsaturated fats, or naturally in the guts of some animals.
      • Properties: Similar to saturated fats, solid at room temperature.
      • Health Impact: Associated with negative cardiovascular effects.
      • Sources: Margarine, partially hydrogenated oils, and some baked goods.

    What are Omega-3 Fatty Acids?

    • Omega-3 fatty acids (omega-3s) are polyunsaturated fats that perform important functions in the human body.
    • There are three main types of omega-3 fatty acids:
      • EPA (eicosapentaenoic acid). EPA is a “marine omega-3” because it’s found in fish.
      • DHA (docosahexaenoic acid). DHA is also a marine omega-3 found in fish.
      • ALA (alpha-linolenic acid). ALA is the form of omega-3 found in plants.
      • When we get ALA from food, the human body can turn some of the ALA into EPA and subsequently to DHA. However, this process provides just a small amount of EPA and DHA. So, dietary sources of EPA and DHA (like fish) are essential.

    Functions of Omega-s fatty acids:

      • They help to provide structure and supporting interactions between cells.
      • Omega-3s are concentrated in high levels in cells in human eyes and brain.
      • They provide the human body with energy (calories) and support the health of many body systems.  These include the human cardiovascular system and endocrine system.

    Significance of Omega-3 fatty acids:

    • Omega-3 fatty acids have many potential benefits for human cardiovascular health.
    • One key benefit is that they help lower human triglyceride levels.
      • Too many triglycerides in human blood (hypertriglyceridemia) raise human risk of atherosclerosis, and through this, can increase human risk of heart disease and stroke. So, it’s important to keep triglyceride levels under control.
    • Omega-3s may help us by raising human HDL (good) cholesterol and lowering human blood pressure.
      • Some studies show omega-3s may lower human risk for Cardiovascular disease (CVD), and hence lowering the sudden death caused by an abnormal heart rhythm (arrhythmia), and blood clots.
    • Beyond heart health, omega-3s may help lower the human risk of developing some forms of cancer, including breast cancer, Alzheimer’s disease, and dementia, age-related macular degeneration (AMD), research continues to investigate these and other possible benefits.

    PYQ:

    [2011] A company marketing food products advertises that its items do not contain trans-fats. What does this campaign signify to the customers?

    1. The food products are not made out of hydrogenated oils.
    2. The food products are not made out of animal fats/ oils.
    3. The oils used are not likely to damage the cardiovascular health of the consumers.

    Which of the statements given above is/are correct?

    (a) 1 only

    (b) 2 and 3 only

    (c) 1 and 3 only

    (d) 1, 2 and 3

  • Ferroptosis Cases in Severe Covid Patients

    Why in the News?

    Columbia University study on COVID-19 fatalities found ferroptosis as the main cause of lung cell death, advancing understanding of lung disease development.

    What is Ferroptosis?

    • Ferroptosis is a type of regulated cell death characterized by the iron-dependent accumulation of lipid peroxides to lethal levels.

    Other forms of cell death: 

    1. Apoptosis (highly regulated process that occurs in multicellular organisms to eliminate unwanted or damaged cells without causing inflammation),
    2. Necrosis (cell death characterized by rapid and uncontrolled cell lysis, often accompanied by inflammation and tissue damage).
    3. Autophagy (involves the degradation and recycling of cellular components through lysosomal machinery).

    Mechanism of Ferroptosis:

    The precise molecular mechanism underlying ferroptosis is still being elucidated, but it involves the deregulation of iron metabolism and lipid peroxidation. Here’s a simplified overview of how ferroptosis occurs:

    1. Iron Accumulation: Ferroptosis is characterized by the accumulation of iron within cells, particularly in the form of labile iron pools. Excess iron can lead to the generation of reactive oxygen species (ROS) through Fenton chemistry.
    2. Lipid Peroxidation: ROS generated from excess iron promotes lipid peroxidation, particularly of polyunsaturated fatty acids (PUFAs) within cell membranes. Lipid peroxides accumulate and propagate, leading to membrane damage and loss of membrane integrity.
    3. Glutathione Depletion: Glutathione (GSH) is an antioxidant that helps to neutralize ROS and prevent lipid peroxidation. In ferroptosis, there is a depletion of cellular GSH levels, which impairs the cell’s ability to counteract oxidative stress.
    4. GPX4 Inhibition: Glutathione peroxidase 4 (GPX4) is an enzyme that catalyzes the reduction of lipid hydroperoxides to their corresponding alcohols, thereby protecting cells from lipid peroxidation. In ferroptosis, GPX4 activity is inhibited, leading to the accumulation of lipid peroxides and cell death.
    5. Mitochondrial Dysfunction: Ferroptosis is associated with mitochondrial dysfunction, including alterations in mitochondrial membrane potential and morphology, as well as disruption of mitochondrial metabolism and bioenergetics.
    6. Cellular Consequences: The accumulation of lipid peroxides and mitochondrial dysfunction ultimately leads to cellular damage, loss of cell membrane integrity, and cell death by ferroptosis.

    Significance of the Study

    • Targeting and preventing ferroptosis could offer novel treatment avenues for COVID-19 lung disease and its possible future mutations.
    • Inhibiting this form of cell death may help improve the treatment outcomes for severe cases of COVID-19.

    PYQ:

    [2020] COVID-19 pandemic has caused unprecedented devastation worldwide. However, technological advancements are being availed readily to win over the crisis. Give an account of how technology was sought to aid management of the pandemic.

  • Xenotransplantation: Prospects and Challenges

    Why in the News?

    The recent passing away of Richard Slayman, the first recipient of a modified pig kidney transplant, has drawn attention to xenotransplantation—an innovative medical procedure with the potential to revolutionise organ transplantation.

    What is Xenotransplantation?

    • It involves transplanting live cells, tissues, or organs from nonhuman animal sources into human recipients.
    • It seeks to address the critical gap between organ demand and supply.
    • Xenotransplantation, pioneered in the 1980s with heart transplants, has emerged as a promising solution to alleviate the organ shortage crisis, particularly prevalent in kidney transplantation.

    Examples:

    • Chimpanzee-to-Human Transplants: In the 1960s, there were attempts at chimpanzee-to-human kidney transplants, heart transplants, and liver transplants.
    • Pig-to-Human Heart Transplant: In 2022, a groundbreaking milestone was achieved with the first successful transplantation of a pig heart into a human with end-stage heart disease

    Procedural Details

    • Xenotransplantation involves genetic modifications to animal organs, like 69 CRISPR-Cas9 edits to a pig kidney, removing pig genes and adding human genes for compatibility.

    Why is the Pig a Preferred Source?

    • Anatomical Resemblance: Pigs are favoured for xenotransplantation due to their physiological similarities to humans, facilitating successful integration. Pig organs, like heart valves, have been used in human medicine for over 50 years.
    • Breeding Advantages: Extensive pig farming ensures a readily available and cost-effective supply of organs, with diverse breeds offering size-matching opportunities.

    Challenges associated

    • The main challenge is preventing organ rejection. Innovative methods, such as embedding the pig’s thymus gland under the kidney’s outer layer, help manage immune responses.
    • There are also significant concerns regarding potential infections from both recognised and unrecognised infectious agents that could affect not only the recipient but also the wider population.
    • Retroviruses present in the animal organs pose a risk of cross-species infection, which could remain latent and cause diseases years after the transplantation.

    PYQ: 

    [2017] With reference to agriculture in India, how can the technique of ‘genome sequencing’, often seen in the news, be used in the immediate future?

    1. Genome sequencing can be used to identify genetic markers for disease resistance and drought tolerance in various crop plants.
    2. This technique helps in reducing the time required to develop new varieties of crop plants.
    3. It can be used to decipher the host-pathogen relationships in crops.

    Select the correct answer using the code given below:

    (a) 1 only
    (b) 2 and 3 only
    (c) 1 and 3 only
    (d) 1, 2 and 3

  • EU activated Copernicus EMS to Locate Crashed Iranian Helicopter

    Why in the News?

    • In response to the helicopter crash involving Iranian President Ebrahim Raisi, the European Union had activated its Copernicus Emergency Management Service (EMS) to aid in search and rescue efforts.

    About the Copernicus Programme

    • This Programme was launched in 1998 by the European Union’s earth observation
    • Named for Copernicus, it uses satellites and ground systems for environmental data.
    • It is implemented by EU member states with support from entities like the European Space Agency (ESA) and the European Environment Agency (EEA).

    Utility of GMES: Rapid Response Mapping Service

    • The Copernicus EMS offers rapid response mapping, a crucial component activated during emergencies like natural disasters or accidents.

    How Rapid Mapping Works?

    • Rapid mapping involves acquiring, processing, and analyzing satellite images and relevant data to provide timely information.
    • It offers several products, including pre-event reference and post-event assessments like first estimates, delineation, and grading of the impacted area.

    Application in the Iranian President’s Case

    • In the case of the Iranian President’s helicopter crash, the EU activated the rapid response mapping service to aid search and rescue operations.
    • This technology helps locate the crash site and assess the extent of the impact, facilitating swift response efforts.

    PYQ:

    [2018] With reference to the Indian Regional Navigation Satellite System (IRNSS), consider the following statements:

    1. IRNSS has three satellites in geostationary and four satellites in geosynchronous orbits.
    2. IRNSS covers entire India and about 5500 sq. km beyond its borders.
    3. India will have its own satellite navigation system with full global coverage by the middle of 2021.

    Which of the statements given above is/are correct?

    (a) 1 only

    (b) 1 and 2 only

    (c) 2 and 3 only

    (d) None

  • PM WANI Wi-Fi Scheme: All you need to know

    Why in the News?

    • Under the PM-WANI scheme, India witnesses a swift rise in public Wi-Fi hotspots, reaching approximately 1,99,896 hotspots nationwide, according to government data.

    What is the PM WANI Initiative?

    • PM Modi launched the Prime Minister Wi-Fi Access Network Interface (PM WANI) in December 2020.
    • It is an initiative under the Department of Telecommunications (DoT).
    • It takes forward the goal of the National Digital Communications Policy, 2018 (NDCP) of creating a robust digital communications infrastructure.
      • Objective: To democratize internet access, particularly in remote and underserved areas.
      • Implementation: Leverages Public Data Offices (PDOs) established in public spaces like railway stations, banks, post offices, and more. Users can access the internet via Wi-Fi at these locations without requiring a SIM card.

    PM-WANI ecosystem consists of four parts: 

    1. Public Data Office (PDO): It establishes the Wi-Fi Hotspots and provides internet access to users
    2. Public Data Office Aggregator (PDOA):  It provides authorisation and accounting services to PDOs.
    3. App Provider: It displays the available hotspots in the phone’s proximity.
    4. Central Registry: This overseen by the Centre for Development of Telematics maintains details of App Providers, PDOs, and PDOAs.

    How to Utilize PM WANI?

    • To access PM WANI services, users must install the Data PM WANI app on their smartphones.
    • Through the app, users can connect to nearby public Wi-Fi PDOs.
    • This application facilitates seamless connectivity to PM-WANI-compliant Wi-Fi hotspots, empowering users to access broadband services conveniently.

    Data Plans Offered

    PM WANI offers various data plans to suit different usage needs:

    • Rs 6 plan: 1GB data for 1 day
    • Rs 9 plan: 2GB data for 2 days
    • Rs 18 plan: 5GB data for 3 days
    • Rs 25 plan: 20GB data for 7 days
    • Rs 49 plan: 40GB data for 14 days
    • Rs 99 plan: 100GB data for 30 days

    Role of Public Data Offices (PDOs)

    • The PM-WANI scheme includes a provision for establishing Public Data Offices (PDOs) by rural entrepreneurs in remote regions.
    • These PDOs procure internet bandwidth from telecom service providers or ISPs to offer Wi-Fi services at minimal charges.
    • This model enables individuals to access the internet even in areas with limited or no data connectivity.

    PYQ:

    [2018] Which of the following is/are the aim/aims of “Digital India” Plan of the Government of India?

    1. Formation of India’s own Internet companies like China did.
    2. Establish a policy framework to encourage overseas multinational corporations that collect Big Data to build their large data centres within our national geographical boundaries.
    3. Connect many of our villages to the Internet and bring Wi-Fi to many of our school, public places and major tourists.

    Select the correct answer using the codes given below:

    (a) 1 and 2 only

    (b) 3 only

    (c) 2 and 3 only

    (d) 1, 2 and 3

  • Spotlighting Pre-eclampsia, ensuring safe motherhood

    Why in the News?

    The prevalence of Congenital Anomalies and Neurological Challenges in newborns highlights the need for adequate Antenatal and Perinatal care to address them.

    Key observations made by the National Family Health Survey (NFHS-5):

    Perinatal mortality rates stand at 32 for 1,000 pregnancies, neonatal mortality rates at 25 for 1,000 live births, and hypertensive disorders in pregnancy remain a leading cause of maternal death.

    • Cause of Maternal and Perinatal Mortality: Preeclampsia (PE) is a significant cause of maternal and perinatal morbidity and mortality, with early onset PE posing higher risks.  
    • Combination of Maternal factors and Biomarkers: Screening based on maternal risk factors alone has suboptimal performance, while a combination of maternal factors and biomarkers like mean arterial pressure, uterine artery pulsatility index, and serum placental growth factor can improve detection rates significantly.
    • Early Intervention with Aspirin Prophylaxis: First-trimester screening models, like the FMF prediction algorithm, have been effective in identifying high-risk pregnancies for preterm PE, allowing for early intervention with aspirin prophylaxis to reduce the incidence of preeclampsia.

    What is Pre-eclampsia?

    • Preeclampsia is a complication of pregnancy. Preeclampsia, high blood pressure, and high levels of protein in urine indicate kidney damage (proteinuria), or other signs of organ damage. 
    • Preeclampsia usually begins after 20 weeks of pregnancy in women whose blood pressure had previously been in the standard range.

     

    Challenges to cure Pre-eclampsia (PE):

    • Complex Screening Protocols: Effective screening requires a combination of maternal history, demographics, color Doppler ultrasound, mean arterial pressure, and placental biomarkers, which may not be uniformly available or implemented.
    • Limited Resources: Not all healthcare facilities have access to advanced screening tools and technologies like color Doppler ultrasound and placental biomarker testing.
    • Lack of Awareness: Pregnant women may not be aware of the symptoms and risks associated with pre-eclampsia, leading to delayed presentation and diagnosis.
    • Delayed Intervention: Identifying high-risk pregnancies early is crucial, but delays in screening and diagnosis can lead to missed opportunities for timely intervention.
    • Pharmacological Challenges: Ensuring timely pharmacological intervention, such as aspirin prophylaxis, requires adherence to established protocols, which may only sometimes be followed.
    • Logistical Issues: Implementing widespread screening and management protocols involves logistical challenges, including training healthcare providers and ensuring the availability of necessary equipment.
    • Complexity of the Disorder: The systemic nature of pre-eclampsia, affecting multiple organs, complicates its management and requires a multidisciplinary approach.

    Programs in India:

    • “Samrakshan” program: The Indian Radiological and Imaging Association’s (IRIA) “Samrakshan” program aims to reduce pre-eclampsia from 8%-10% to 3% and fetal growth restriction from 25%-30% to 10% by the end of the decade.
    • The program focuses on spreading awareness, screening for pre-eclampsia and fetal growth restriction, and ensuring comprehensive care throughout pregnancy.

    Way Forward: 

    • Early Detection and Management: Early detection through regular prenatal care, including blood pressure monitoring and urine testing for protein, is crucial in managing pre-eclampsia.
      • Timely intervention can help prevent severe complications and ensure the well-being of both mother and baby.
    • Promoting Awareness and Education: Raising awareness about the signs and symptoms of pre-eclampsia among pregnant women is essential for early recognition and prompt action.
      • Education on risk factors, preventive measures, and the importance of regular antenatal check-ups can significantly impact maternal and neonatal outcomes.
    • Ensuring Access to Quality Maternal Healthcare: Access to quality maternal healthcare services, including skilled antenatal care, monitoring, and timely interventions, is vital in addressing pre-eclampsia and reducing maternal mortality rates.
      • Empowering healthcare providers with the knowledge and resources to manage pre-eclampsia effectively is key to ensuring safe motherhood.
    • Collaborative Efforts for Maternal Health: Collaboration between governments, healthcare institutions, non-profit organisations, and the private sector is essential in implementing comprehensive maternal health programs that prioritise the prevention, early detection, and management of pre-eclampsia.

    Conclusion: By spotlighting pre-eclampsia and emphasising the importance of early detection, awareness, access to quality care, and collaborative efforts, we can strive towards ensuring safe motherhood for all women, safeguarding the health and well-being of mothers and their babies.

    Mains PYQ:

    Q Identify the Millennium Development Goals (MDGs) that are related to health.Discuss the success of the actions taken by the Government for achieving the same.(UPSC IAS/2013)

     

  • Naegleria fowleri: the Brain-eating Amoeba

    Why in the news?

    • A five-year-old girl in Kozhikode, Kerala has succumbed to primary Amoebic Meningoencephalitis (PAM), caused by Naegleria fowleri.
      • India has recorded 20 reported cases of PAM, with the recent case marking the seventh infection in Kerala.

    What is Primary Amoebic Meningoencephalitis (PAM)?

    • PAM is a rare brain infection caused by Naegleria fowleri, a free-living amoeba found in warm freshwater and soil worldwide.
      • An amoeba is a type of cell or unicellular organism with the ability to alter its shape, primarily by extending and retracting pseudopods.
      • Higher temperatures of up to 115°F (46°C) are conducive to its growth and it can survive for short periods in warm environments.
    • The amoeba enters the body through the nose, typically during activities like swimming, and travels to the brain, causing severe damage.
    • PAM is also non-communicable.
    • Symptoms: Headache, fever, nausea, vomiting, stiff neck, confusion, seizures, hallucinations, and coma.
      • According to the US Centers for Disease Control and Prevention (CDC), most people with PAM die within 1 to 18 days after symptoms begin. It usually leads to coma and death after 5 days.

    Treatment Challenges

    • Currently, there are no established effective treatments for PAM.
    • Medical interventions typically involve a combination of drugs, including amphotericin B, azithromycin, fluconazole, rifampin, miltefosine, and dexamethasone.

  • X chromosome revival in older Women increases Autoimmune Disease risk

    Why in the News?

    The X chromosome influences biological functions and disease susceptibilities, affecting genetic disorders, autoimmune diseases, and Alzheimer’s, with research offering potential new treatments and therapies.

    Back2Basics: Chromosomes

    • Chromosomes are fundamental components of cells that play a vital role in storing and transmitting genetic information.
    • These structures contain genes, which carry instructions for the development, functioning, and inheritance of traits.
    • Chromosomes consist of tightly coiled DNA molecules wrapped around proteins called histones, forming chromatin.
    • Before cell division, chromosomes replicate into identical sister chromatids held together at the centromere.

    Types of Chromosomes:

    1. Autosomes: Non-sex chromosomes (22 pairs in humans) determine most traits.
    2. Sex Chromosomes: Determine biological sex (XX for females, XY for males).

    Functions of Chromosomes

    • Genetic Information Storage: Genes on chromosomes encode instructions for protein production and cellular processes.
    • Inheritance: Chromosomes transmit genetic information during sexual reproduction through meiosis, ensuring genetic diversity in offspring.
    • Gene Expression Regulation: Chromosomes control gene activation or silencing, crucial for development and cell functioning.

    Genetic Landscape of the X chromosome:

    • The human X chromosome encodes around 800 genes, producing proteins.
    • Loss of function in these genes can lead to various genetic diseases.
    • Diseases influenced by the X chromosome fall into three categories:
    1. X-linked genetic diseases
    2. Diseases influenced by XCI (X chromosome inactivation) escape
    3. Diseases linked to X-chromosome aneuploidy

    What is the X chromosome?

    • It is one of the two sex chromosomes in humans, the other being the Y chromosome.
    • Females have two X chromosomes (XX), while males have one X and one Y chromosome (XY).
    • Significance:
      • Encodes around 800 genes that are crucial for various biological processes.
      • Plays a significant role in determining sex and influencing many physiological functions.
      • Loss of function or mutations in X chromosome genes can lead to several genetic disorders.

    What are Autoimmune Diseases?

    • Diseases where the immune system mistakenly attacks the body’s own cells and tissues.
    • Normally, the immune system defends against infections by targeting harmful pathogens.
    • Common Autoimmune Diseases:
      • Systemic Lupus Erythematosus (SLE): Chronic inflammation affecting various body parts.
      • Rheumatoid Arthritis (RA): Inflammation of joints and surrounding tissues.
      • Sjogren’s Syndrome: Affects glands that produce moisture, leading to dry mouth and eyes.

    How does the X chromosome cause Autoimmune Diseases?

    • X Chromosome Inactivation (XCI):
      • In females, one of the two X chromosomes is randomly inactivated during early embryonic development to balance gene expression between males and females.
      • This process is crucial to prevent overexpression of X-linked genes.
    • XCI Escape:
      • Not all genes on the inactive X chromosome are completely silenced.
      • Up to a fourth of these genes may escape inactivation and continue to be expressed.
    • Link to Autoimmune Diseases:
      • Skewed XCI: Uneven inactivation of X chromosomes may lead to an imbalance in gene expression, contributing to autoimmune disorders.
      • Incomplete XCI: Reactivation of genes that should be silenced can result in abnormal immune responses.

    Studies, such as one published in Science Advances (May 3, 2023), have shown that reactivation of X-linked genes in immune cells can lead to lupus-like symptoms in mice.

    Linkage between X chromosome and Alzheimer’s disease

    • Sex Bias in Alzheimer’s:
      • Women are almost twice as likely as men to develop Alzheimer’s disease.
    • Role of X-Linked Genes:
      • Researchers have identified a gene called ubiquitin-specific peptidase 11 (USP11) on the X chromosome.
      • USP11 Gene: Involved in protein modification processes and thought to influence the accumulation of tau proteins in the brain.
      • XCI Escape: USP11 may escape XCI in females, leading to higher expression levels and contributing to Alzheimer’s pathology.
      • A study from Case Western Reserve University (Cell, October 2022) highlighted this mechanism, suggesting it as a target for new treatments.

    PYQ:

    [2011] At present, scientists can determine the arrangement or relative positions of genes or DNA sequences on a chromosome. How does this knowledge benefit us?

    1. It is possible to know the pedigree of livestock.
    2. It is possible to understand the causes of all human diseases.
    3. It is possible to develop disease-resistant animal breeds.

    Which of the statements given above is/are correct?

    (a) 1 and 2 only

    (b) 2 only

    (c) 1 and 3 only

    (d) 1, 2 and 3