Cross-environment temporal dynamics of the human post-deposition semen stain microbiome

Accurately inferring the time since deposition (TsD) of semen stains is critical in forensic investigations but is often confounded by environmental fluctuations. This project investigates the temporal dynamics and microbial succession of the human semen stain microbiome ex vivo under varying environmental exposures. Human semen samples were deposited and exposed to three distinct environments (a controlled incubator, an indoor setting, and an outdoor setting). Samples were longitudinally collected over a 28-day period (at 0 h, 12 h, 1 d, 2 d, 7 d, 14 d, and 28 d) for 16S rRNA gene sequencing. The primary objective of this project is to characterize environment-dependent microbial community restructuring during semen degradation and to provide a foundational dataset for developing robust, environment-resilient predictive models for forensic TsD inference.