# Metabolomic Analysis of Environmental Biomarkers Reveals Markers of Mate Preference in Female Giant Pandas

## TL;DR

This study identifies metabolites linked to mate preference in female giant pandas, offering insights for improving their natural mating success.

## Contribution

The study identifies specific metabolites and metabolic pathways associated with mate preference in female giant pandas.

## Key findings

- Prostaglandin G2, prostaglandin E2, and estrone are potential markers of female mate preference.
- Steroid hormone biosynthesis and phenylalanine metabolism are key pathways linked to mate preference.
- Anal gland secretions play a role in the chemical communication system during mate selection.

## Abstract

Giant pandas are conservation reliant. Natural mating is more successful than artificial insemination. Mate preference is a critical factor in the natural reproduction of giant pandas, but it is poorly understood. Given the importance of improving the reproductive efficiency of the giant panda, this study focused on the physiological and metabolic changes in female giant pandas during mate preference trials conducted at estrus. In this study, we collected environmental biomarkers from 19 female pandas during mate preference trials with 3 males and performed metabolomics analysis. We identified several differential metabolites, including prostaglandin G2, prostaglandin E2, and estrone, which are potentially associated with female mate preference. In addition, through KEGG pathway enrichment analysis, we found that female mate preference was related to steroid hormone biosynthesis, phenylalanine metabolism, and tropane, piperidine and pyridine alkaloid biosynthesis. These results reveal potential physiological markers related to female mate preference, providing insights for formulating effective conservation and breeding strategies for the giant panda.

The giant panda (Ailuropoda melanoleuca) is a vulnerable animal in China, and it is crucial to improve the reproduction efficiency of the giant panda. Mate preference is an important part of natural mating. We hypothesized that AGS metabolites differ according to their mate preference. In this study, we determined estrus-associated hormone levels in the urine of 19 female giant pandas. After confirming estrus via hormone levels and behavioral observation, we collected environmental biomarkers for metabolomics analysis. A total of 19 samples were divided to two groups according to the mating preference of female giant pandas. Metabolomics analysis by LC-MS/MS showed that a total of 115 differentially expressed metabolites were identified, including 97 upregulated metabolites and 18 downregulated metabolites. We found that prostaglandin B2, palmitoylcarnitine, prostaglandin G2, and estrone may be the potential markers of female mate preference. Pathway enrichment analysis showed that steroid hormone biosynthesis, phenylalanine metabolism, and tropane, piperidine, and pyridine alkaloid biosynthesis were the top three pathways. These results revealed the physiological changes in female giant pandas during mate preference trials, providing a perspective for understanding their chemical communication system reliant on anal gland secretions and improving the success rate of natural mating of giant pandas.