Dominant Components of the Giant Panda Seminal Plasma Metabolome, Characterized by 1H-NMR Spectroscopy

Simple Summary As China's flagship animal, the giant panda (Ailuropoda melanoleuca) attracts much attention due to its small population and low natural reproductive rate. Therefore, artificial insemination has become the leading practical approach in the captive breeding programs of giant pandas worldwide. Seminal plasma acts as a medium between spermatozoa and the external stimuli, and its characteristics have been directly linked to fertility in both artificial insemination and natural fertilization. The current work, for the first time, attempts to characterize, by proton magnetic resonance spectroscopy (H-1-NMR), the metabolome of healthy giant panda seminal plasma. A total of 35 molecules were quantified, with distinct age-related trends highlighted by a multivariate analysis, and the concentrations of 2,3-butanediol were significantly different between individuals younger than 8 years and older than 13 years. In addition, isopropanol's concentration was significantly linked to estrus stages. Besides, the variations in the metabolome's profile with storage time were also evaluated. This study may serve as a reference for research wishing to shed light on the biological mechanisms affecting giant panda sperm's overall quality and may ultimately lead to novel approaches to giant panda artificial insemination. As an assisted breeding technique, artificial insemination has become the main effective practical approach in the captive breeding programs of giant panda worldwide. The composition of seminal plasma plays an important role in the success of breeding. The present work is the first attempt to characterize, by proton magnetic resonance spectroscopy (H-1-NMR), the metabolome of healthy giant panda seminal plasma. A total of 35 molecules were quantified, with the concentration of 2,3-butanediol being significantly different between individuals younger than 8 years and older than 13 years, and other distinct age-related trends were highlighted by a multivariate analysis. Isopropanol's concentration was significantly linked to estrus stages. Besides, the variations in the metabolome's profile during storage were also evaluated. This study may serve as a reference for further research wishing to shed light on the biological mechanisms affecting giant panda sperm's overall quality and may ultimately lead to novel approaches to giant panda artificial insemination.