Nutrient deprivation induces property variations in spider gluey silk

Area of Science:

• * Biomimetics and materials science.
• * Arachnology and evolutionary biology.
• * Bioadhesives research.

Background:

• * Spider silks are complex biological adhesives with variable properties.
• * Nutritional stress affects orb web silk properties, but gumfoot silk responses are unknown.
• * Understanding silk variability can drive biomimetic innovations.

Purpose of the Study:

• * To investigate if protein deprivation alters gumfoot and spiral silk properties in spiders.
• * To compare the effects of nutritional stress on different types of spider silks.
• * To elucidate mechanisms behind silk property variations.

Main Methods:

• * Protein intake was manipulated for Nephila clavipes (orb weaver) and Latrodectus hesperus (cobweb weaver).
• * Gluey silk properties including diameter, droplet volume, stickiness, and adhesive energy were measured.
• * Load-extension curves analyzed thread properties under varying nutritional conditions.

Main Results:

• * Both species' silks became significantly stickier under protein deprivation.
• * N. clavipes exhibited increased glue droplet volume with protein deficiency.
• * Protein deprivation altered glue properties independently of axial thread extension, with color changes observed in N. clavipes.

Conclusions:

• * Protein deprivation induces significant changes in spider silk stickiness and morphology.
• * Variations in silk properties are linked to biochemical changes, potentially salt composition.
• * Findings offer insights into spider silk adaptation and biomimetic material design.