Explaining mitochondrial donation treatment: how a baby has three parents

Baby was born using three persons’ DNA in the U. K. The baby, technically, has three parents, deriving the mitochondria from a donor apart from the genetic material (DNA) from biological parents. Pioneering technology was used to facilitate this, in order to prevent the child from inheriting the mother’s mitochondrial disease.

Three parents?

The baby carried most of its DNA from its parents, and a minor per cent from the donor, whose mitochondria has been used while fertilising the egg.

Mitochondria

• Mitochondria are basically the powerhouses of the cells. They generate energy, and thus are also responsible for cell function in the human body.
• Certain defects might occur impacting the way the mitochondria produces energy for the cells (especially in the ‘energy-hungry’ tissues of the brain, nerves, muscles, kidneys, heart, liver), and thereby impacting cell function. The diseases that arise out of such mitochondrial mutations are called mitochondrial diseases.
• When the mitochondria are impaired and do not produce sufficient energy, it affects how organs function, leading to a broad assortment of symptoms across the body, including brain damage, organ failure and muscle wastage. The symptoms get more and more debilitating as a child grows, and have no cure, but can be treated.
• In this case, the mother had a mitochondrial disease she was intent on not passing on to her baby. She also did not want to have a donor egg, for the baby would carry the genetic material of the donor.

Process

• Mitochondrial diseases are only passed on by the mother, and research has been attempting to find a way for protecting the infant from inheriting the disease.
• Here, through an advanced in vitro fertilisation technique, the baby’s biological father’s sperm was used to fertilise the eggs from the biological mother, who has a mitochondrial disease, and a third, female donor with clear mitochondria, separately.
• Then, the nuclear genetic material from the donor’s egg is removed and replaced with the genetic material from the biological parents’.
• The final product — the egg — which has the genetic material (DNA) from the parents, and the mitochondria from the female donor, is implanted in the uterus, and carried to full term to yield a baby who will be free from the mother’s mitochondrial disease. This process is termed Mitochondrial Donation Treatment (MDT).

IMD issues fourth heatwave alert for the Konkan region

The India Meteorological Department (IMD) has declared a heatwave in various regions of Maharashtra. This is the fourth heatwave alert for the Konkan region and the first in May

• A heatwave is a period of abnormally high temperatures, a common phenomenon in India during the months of May-June and in some rare cases even extends till July.
• India Meteorological Department (IMD) classifies heat waves according to regions and their temperature ranges. As per IMD, the number of heatwave days in India has increased from 413 over 1981-1990 to 600 over 2011-2020.
  • This sharp rise in the number of heatwave days has resulted due to the increasing impact of climate change.

Declaring a Heatwave

• The Heatwave is considered when the maximum temperature of a station reaches at least 40°C for Plains and at least 30°C for Hilly regions.
• If the normal maximum temperature of a station is less than or equal to 40°C, then an increase of 5°C to 6°C from the normal temperature is considered to be heat wave condition.
  • Further, an increase of 7°C or more from the normal temperature is considered a severe heat wave condition.
• If the normal maximum temperature of a station is more than 40°C, then an increase of 4°C to 5°C from the normal temperature is considered to be heat wave condition. Further, an increase of 6°C or more is considered a severe heat wave condition.
  • Additionally, if the actual maximum temperature remains 45°C or more irrespective of normal maximum temperature, a heat wave is declared.
• In 2016, the National Disaster Management Authority (NDMA) issued comprehensive guidelines to prepare national level key strategies for mitigating the impact of heatwaves.

Impacts of Heat Waves In India

• Economic Impacts: The frequent occurrence of heat waves also adversely affects different sectors of the economy.
  • For instance, the livelihood of poor and marginal farmers is negatively impacted due to the loss of working days.
  • Heatwaves also have an adverse impact on daily wage workers’ productivity, impacting the economy.
• Impact on Agriculture Sector: Crop yields suffer when temperatures exceed the ideal range.
  • Farmers in Haryana, Punjab and Uttar Pradesh have reported losses in their wheat crop in the past rabi season. Across India, wheat production could be down 6-7% due to heat waves.
  • Livestock is also vulnerable to heatwaves.
    • Researchers at Cornell University estimate that, by 2100, milk yields in India could drop by 25% (against 2005 levels) in arid and semi-arid dairy farming due to increased heat stress.
• Impact on Electricity Usage: Naturally, heatwaves impact power load.
  • In the North India, the average daily peak demand in April was 13% higher than 2021 and 30% higher in May.
• Human Mortality: Mortality due to heat waves occurs because of rising temperature, lack of public awareness programmes, and inadequate long-term mitigation measures.
  • According to a 2019 report of the Tata Centre for Development and the University of Chicago, by 2100, annually, more than 1.5 million people will be likely to die due to extreme heat caused by climate change.
  • The increased heat will lead to an increase in diseases like diabetes, circulatory and respiratory conditions, as well as mental health challenges.
• Food Insecurity: The concurrence of heat and drought events are causing crop production losses and tree mortality.
  • The risks to health and food production will be made more severe from the sudden food production losses exacerbated by heat-induced labour productivity losses.
    • These interacting impacts will increase food prices, reduce household incomes, and lead to malnutrition and climate-related deaths, especially in tropical regions.
• Impact on Workers: Workers in sectors like agriculture and construction will be severely impacted in 2030 because India’s large population depends on these sectors for their livelihoods.
• Weaker Sections to be Specifically Affected: The climate science community has reported overwhelming evidence that extreme events such as heatwaves are likely to become more intense, more frequent and of longer duration in future unless emissions of greenhouse gases and aerosols are significantly cut globally.
  • It is important to remember that heatwaves in India, such as the current event, have the potential to influence thousands of vulnerable and poor people who contributed very little to the climate crisis.

Allahabad HC allows carbon dating of Gyanvapi ‘Shivling’

The Allahabad High Court on Friday (May 12) ordered a “scientific survey”, including carbon dating, of a “Shivling” said to have been found at the Gyanvapi mosque complex in Varanasi after setting aside a lower court order on the issue.

Carbon Dating

• Carbon dating is a widely-used method to establish the age of organic materials, things that were once living.
• Living things have carbon in them in various forms.
• The dating method is based on the fact that Carbon-14 (C-14) is radioactive, and decays at a well-known rate.
  • C-14 is an isotope of carbon with an atomic mass of 14.
  • The most abundant isotope of carbon in the atmosphere is C-12.
  • A very small amount of C-14 is also present.
    • The ratio of C-12 to C-14 in the atmosphere is almost static, and is known.
• The Carbon Dating method cannot be used to determine the age of non-living things like rocks, for example.
• Also, the age of things that are more than 40,000-50,000 years old cannot be arrived at through carbon dating.
  • This is because after 8-10 cycles of half-lives, the amount of C-14 becomes almost very small and is almost undetectable.
• Uses:
  • It has proved to be a versatile technique of dating fossils and archaeological specimens from 500 to 50,000 years old.
  • The method is widely used by geologists, anthropologists, archaeologists, and investigators in related fields.
• Working of Carbon Dating:
  • Because plants and animals get their carbon from the atmosphere, they too acquire C-12 and C-14 in roughly the same proportion as is available in the atmosphere.
    • Plants get their carbon through photosynthesis; animals get it mainly through food.
  • When they die, their interactions with the atmosphere stops.
  • While C-12 is stable, the radioactive C-14 reduces to one half of itself in about 5,730 years — known as its ‘half-life’.
  • The changing ratio of C-12 to C-14 in the remains of a plant or animal after it dies can be measured and can be used to deduce the approximate time when the organism died.

Other methods

• Radiometric Dating Methods:
  • In this method, decays of other radioactive elements that might be present in the material become the basis for the dating method.
  • Some Types of this Method:

    • Potassium-Argon Dating:

      • The radioactive isotope of potassium decays into argon, and their ratios can give a clue about the age of rocks.

    • Uranium-Thorium-Lead Dating:

      • Uranium and thorium have several radioactive isotopes, and all of them decay into the stable lead atom. The ratios of these elements present in the material can be measured and used to make estimates about age.

      Cosmogenic nuclide dating

      • There are also methods to determine how long an object has remained exposed to sunlight. These apply different techniques, but are again based on radioactive decays and are particularly useful in studying buried objects or changes in topology. The most common of these is called cosmogenic nuclide dating, or CRN, and is regularly applied to study the age of ice cores in polar regions.
      • In some situations, carbon dating can be used indirectly as well.
      • For example, a way in which the age of ice cores in glaciers and polar regions is determined by studying carbon dioxide molecules trapped inside large ice sheets. The trapped molecules have no interaction with the outside atmosphere, and are found in the same state as when they were trapped. Determining their age gives a rough estimate of the time when the ice sheets were formed.
      • How long a rock has been at a particular place can also be determined similarly — organic materials like dead plants or insects trapped underneath can give an indication of when that rock reached that place.