Gene banks are specialized facilities that store and preserve the genetic material of various organisms, including plants, animals, and microorganisms. They serve as repositories for genetic information, often in the form of reproductive material like seeds, sperm, eggs, embryos, cells, or DNA. Their primary purpose is to safeguard biodiversity and genetic resources for present and future generations, acting as a protective measure against threats such as extinction, diseases, and climate change.
What are Gene Banks?
Gene banks function as living libraries of genetic diversity, meticulously cataloging and preserving the genetic blueprints of life. The most common form of genetic material stored is seeds, particularly from major crop species and their wild relatives, due to their ease of storage and relatively long lifespan when kept cool and dry. These facilities also maintain tissue cultures, which are small plantlets grown slowly in test tubes under specialized conditions, especially for plants that cannot be preserved as seeds, like bananas or potatoes.
Beyond plants, gene banks preserve animal genetic material, including sperm, eggs, and embryos, often through cryopreservation at extremely low temperatures. DNA samples from diverse organisms and cultures of microorganisms like bacteria and fungi are also stored.
Why Gene Banks are Crucial
Gene banks play an important role in preserving biodiversity. They serve as an insurance policy against unforeseen environmental threats, diseases, or natural disasters that could devastate current populations. By maintaining a broad spectrum of genetic traits, these banks help ensure the resilience of ecosystems.
Their significance extends directly to global food security. They preserve a vast array of crop varieties and livestock breeds, including those that might possess natural resistance to emerging diseases or adaptability to changing climate conditions, such as drought or increased flooding. This genetic diversity is the foundation for developing new, more resilient food sources, supporting agricultural adaptation and ensuring a stable food supply for a growing global population. Gene banks also provide resources for scientific research, allowing scientists to study evolutionary processes, understand genetic traits, and develop new insights into life.
How Genetic Material is Stored
Genetic material in gene banks is preserved using several specialized methods, each tailored to the specific type of biological sample. Seed banking is a widely used technique where seeds are dried to a low moisture content, typically around 4%, and then stored at low temperatures, often below 0°C (32°F). This process significantly slows down metabolic activity, allowing seeds to remain viable for decades.
For plants that do not produce viable seeds or cannot tolerate drying, such as bananas or sweet potatoes, in vitro collections are employed. This method involves growing plant cells, embryos, or tissues in a controlled laboratory environment, often in nutrient-rich gels or liquid mediums within test tubes or culture dishes. Another effective method is cryopreservation, which involves freezing genetic material at ultra-low temperatures, typically around -196°C (-320.8°F) in liquid nitrogen. This technique is used for long-term storage of seeds, animal cells like sperm and eggs, and microorganisms, effectively suspending their biological activity and maintaining genetic stability for a century or more.
Impact and Applications
Gene banks have a wide-ranging impact, providing tangible benefits across various fields. A primary application is in developing new crop varieties with enhanced traits. For instance, genetic material from gene banks has been used to breed crops with improved yields, greater disease resistance, or increased tolerance to environmental stressors like drought and salinity. The International Maize and Wheat Improvement Center (CIMMYT) gene bank, for example, has contributed to new wheat and maize varieties with better disease resistance and drought tolerance.
These repositories also play a role in the restoration of endangered species and habitats by providing genetic resources for breeding programs aimed at increasing population numbers or reintroducing species into the wild. In medical research, access to diverse genetic material from gene banks can support studies on human genetics, disease mechanisms, and the development of new treatments. Gene banks also serve as foundational resources for basic scientific studies in genetics and evolution.