# Proteomic Characterization of Bottlenose Dolphin (Tursiops truncatus) Urine

## TL;DR

This study identifies proteins in bottlenose dolphin urine, offering insights into kidney health and immune defenses.

## Contribution

The first comprehensive proteomic analysis of wild bottlenose dolphin urine, revealing sex-specific and health-related proteins.

## Key findings

- Cystatin 11 was found in male dolphin urine but absent in females.
- Antimicrobial proteins cathelicidin and lysozyme were detected, suggesting immune defense roles.
- 27 proteins linked to kidney injury and 12 related to stone formation were identified in dolphin urine.

## Abstract

Urinary proteins
offer multifaceted insights into tissue repair,
dysfunction, and renal health, with significant implications for both
human and veterinary medicine. However, marine mammal medicine lacks
comprehensive studies on urine protein composition. This study aimed
to describe the urine proteome of wild common bottlenose dolphins
(Tursiops truncatus) at two Gulf of
Mexico sites (Sarasota Bay, FL, and Barataria Bay, LA) and to compare
urine proteins by sex. Ten urine samples (Barataria Bay, LA: N = 6; Sarasota Bay, FL: N = 4) were analyzed
by nano LC-MS/MS. Peptide spectral matching identified 1872 protein
families across all individuals (FDR < 0.01). Cystatin 11 was notably
present in males (median rank abundance: 8.1%) and absent in females
(median: 0.0%), with semen contamination elevating protein diversity
in male urine. Two putative antimicrobial proteins, cathelicidin and
lysozyme, accounted for 2.66% of the urine proteome, suggesting an
innate immune defense mechanism. In total, 27 proteins that are recognized
as acute kidney injury markers in humans, and 12 putative stone formation
proteins were detected in dolphin urine. This research provides a
reference database of urinary proteins that can be used to develop
advanced methods for investigating dolphin renal health. Data are
available via ProteomeXchange with identifier PXD054283.