# Seasonal Changes in the Seminal Plasma Proteome of the Crab-Eating Fox (Cerdocyon thous)

## TL;DR

This study found seasonal changes in the seminal plasma proteome of crab-eating foxes, identifying potential biomarkers for reproductive seasons.

## Contribution

The first study to describe the seminal plasma proteome and its seasonal variation in the crab-eating fox.

## Key findings

- 408 proteins were identified, with 219 exclusive to the reproductive season and 90 to the nonreproductive season.
- Proteins related to sperm metabolism were more abundant in the reproductive season, while oxidoreductase functions were more common in the nonreproductive season.
- Potential biomarkers like olfactory receptor and zinc finger protein showed AUC > 0.80 in distinguishing seasons.

## Abstract

The
objective was to analyze seasonal changes in the
seminal plasma
proteome of crab-eating fox (Cerdocyon thous). Semen was collected in Brazil from March 2021 to March 2022 from
five healthy adult males housed individually. Collections were performed
without chemical or physical restraint by digital manipulation of
the penis, and seminal plasma proteomics were assessed by mass spectrometry
(ESI Q-Tof MS/MS) on 43 ejaculates from the reproductive season and
four from the nonreproductive season. A total of 408 proteins were
identified: 219 exclusives to the reproductive season (June–September),
90 to the nonreproductive season (October–May), and 99 shared
between both. Protein abundance differed significantly between seasons.
Proteins related to enzymatic and oxidoreductase functions predominated
in the nonreproductive season, whereas those linked to sperm metabolism
and reproductive processes were more abundant in the reproductive
season. Among these, olfactory receptor, strawberry notch homologue,
and zinc finger protein were considered potential reproductive season
biomarkers, with AUC > 0.80 in the receiver operating characteristic
analysis. This is the first study describing the seminal plasma proteome
and its seasonal variation in the crab-eating fox, identifying biomarkers
with potential applications in conservation and reproductive management
of this and other endangered canids.