week-07-hw-genetic-circuits-part-ii

Assignment Part 1: Intracellular Artificial Neural Networks (IANNs)

1. Advantages of IANNs over traditional Boolean genetic circuits

IANNs can generate graded, weighted, and more flexible input/output responses instead of only ON/OFF logic. This makes them better suited for integrating multiple noisy biological signals and for approximating complex decision boundaries.

2. Useful application of an IANN

A useful application would be tumor microenvironment sensing. Multiple inputs such as hypoxia, lactate, and acidity could be integrated to produce a selective therapeutic output only when the combined signal pattern matches a tumor-like state. A limitation is that biological components may have leakiness, limited dynamic range, crosstalk, and high variability, which can reduce classification accuracy.

3. Multilayer perceptron concept

In an intracellular multilayer perceptron, the first layer processes the input signals and produces an intermediate regulator, such as an endoribonuclease. That regulator then controls expression of the layer 2 output, for example a fluorescent protein, allowing hierarchical signal processing across layers.

Intracellular multilayer perceptron

Input layer:
  X1 ---> [Tx/Tl] ---\
                      \
                       > Layer 1: endoribonuclease R1
                      /
  X2 ---> [Tx/Tl] ---/

Layer 1 output:
  R1 --| regulates --> Layer 2: fluorescent protein mRNA --> [Tl] --> Y

Assignment Part 2: Fungal Materials

1. Examples of fungal materials

Existing fungal materials include mycelium-based packaging, leather-like textiles, insulation panels, and construction composites. They are used as sustainable alternatives to plastic foams, animal leather, and some building materials. Their main advantages are biodegradability, low-energy production, and renewable growth. Their disadvantages include lower durability, moisture sensitivity, and less standardized performance compared with conventional materials.

2. Why genetically engineer fungi?

Fungi could be engineered to produce stronger, more water-resistant, or more functional materials, or to sense and respond to environmental signals. Synthetic biology in fungi is attractive because fungi naturally grow as structured biomaterials, secrete enzymes efficiently, and can process complex substrates such as agricultural waste. Compared with bacteria, fungi are often better suited for making large, fibrous, and mechanically useful living materials.