Non-invasive molecular species identification using spider silk proteomics.

Abstract

Accurate species identification is essential in biology, ecology, medicine, and agriculture, yet traditional methods relying on morphological characteristics often fail due to phenotypic plasticity and cryptic species. These limitations are particularly pronounced in small organisms with minimal distinguishing features. DNA barcoding has become a popular alternative; however, it requires invasive tissue sampling, making it unsuitable for delicate or rare organisms like insects and spiders. To address this challenge, we propose a non-invasive molecular method using proteomic analysis focused on species-specific protein sequences in spider silk, offering a viable solution for species identification without harming specimens. We developed a universal silk-dissolving method, followed by sequence similarity analysis to classify species into those identifiable at the species level and those distinguishable only to a group of closely related species. A bioinformatics pipeline was established to analyze peptide sequences, achieving 96% accuracy across 15 spider species, even in the presence of contaminants. This technique complements DNA barcoding and can be extended to other organisms producing biological materials. It holds promise in pest management, medical diagnostics, and improving public health by enabling accurate species identification without invasive procedures.