The use of genetic modification to make animals and plants glow in the dark (bioluminescence) as an alternative to biological lighting involves a number of scientific fields, including synthetic biology, genetic engineering, and biochemistry. The following are the key steps and techniques to achieve this goal： --- ### **1. Select the luminous mechanism** There are two main sources of bioluminescence： -**Fluorescent protein** (such as GFP and its variants): An external light source is required to excite light. -**bioluminescence system** (such as the luciferase of fireflies or the lux system of deep-sea bacteria): It emits light autonomously through enzymatic reactions, which is more suitable for dark environments. **Recommendation**: Priority is given to autonomous bioluminescence systems (such as bacterial lux operons or firefly luciferase systems) because they do not require an external light source. --- ### **2. Genetic modification steps** ####**For plants**： -**Introduction of target genes**： -Transfer **lux operons** (including luxA, luxB, luxC, luxD, luxE genes) or **luciferase genes** (such as the luc gene of fireflies) into the plant genome. -If you use the luciferase system, you need to import ** luciferin substrate synthesis genes** (such as genes related to the coffee acid cycle) at the same time. -**Delivery method**： -Agrobacterium-mediated transformation, gene gun or CRISPR-Cas9 targeted insertion. -**Tissue-specific expression**： -Use specific promoter (such as leaf-specific promoter) to control the expression of luminescent genes to avoid energy waste. ####**For animals**： -**Model selection**: Small transparent creatures (such as zebrafish, nematodes) or insects (such as flies) are easier to observe the luminous effect. -**Gene delivery**： -Microinjection or viral vectors (such as AAV) introduce luminescent genes into embryos or specific tissues. -Case study: The commercialized ** Luminous pet fish** (GloFish) uses fluorescent protein genes. --- ### **3. Optimize luminous efficiency** -**Substrate supply**： -Metabolic pathways need to be modified in plants to continuously produce fluorescein (such as through the methoxyvaleric acid pathway). - Animals can add fluorescein (such as firefly fluorescein) to their feed. -**Energy balance**： - Avoid excessive consumption of ATP during the luminescence process, which affects the survival of the host. Low-energy-consumption systems can be selected (for example, the bacterial lux system only requires FMNH和 and O₂). -**Enhanced brightness**： -Multiple genes are expressed in series or signal peptides are used to localize enzymes to specific organelles (such as mitochondria) to increase local concentrations. --- ### **4. Safety and ethical considerations** -**Ecological risk**： -Prevent genetic pollution: through gene drive or reproductive isolation design (such as sterile individuals). -**Biosafety**： - Avoid using genes of pathogen origin (such as part of the lux system from bacteria). -**Ethical review**： -Animal transformation must comply with the “3R Principle" (reduce, replace, optimize). --- ### **5. Potential application scenarios** -**Short-term**： -Decorative plants (such as luminous potted plants) or ornamental animals. -Low-brightness environmental indication (such as luminous moss on the edge of the road). -**Long-term**： -Urban biological lighting (the brightness needs to be increased by more than 100 times). -Self-powered emergency lighting system (such as an environment without electricity after a disaster). --- ### **6. Current technical limitations** -**Insufficient brightness**: The strongest biological luminescence only reaches ~3000 photons/sec, which is much lower than that of LED (nano-material enhancement required). -**Stability issues**: Enzymes are easy to degrade, and the substrate needs to be replenished regularly (for example, plants can absorb it through the root system). -**Cost**: The cost of large-scale cultivation of genetically modified organisms is higher. --- ###**Case reference** -**Plants**: In 2023, the MIT team embedded the fungal luminescence gene (Neonothopanus nambi) to make tobacco continue to glow for several weeks. - **Animals**: GloFish has been commercialized, but relies on fluorescent proteins (blue light excitation is required). --- ###**Future direction** -**Synthetic biology tools**: Design artificial light-emitting pathways (such as combining quantum dots to enhance efficiency). -**Symbiotic system**: Symbiosis of luminescent bacteria (such as Vibrio Fei) with plants to avoid direct genetic modification. Through the above methods, biological lighting is expected to become a complementary solution for specific scenes, but it needs to break through the bottlenecks of brightness, energy consumption and large-scale production.