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bioRxiv · 10.1101/456863

Loss of mitochondrial proline catabolism depletes FAD, impairing sperm function, and male reproductive advantage

Yen, C.-A.·Ruter, D. L.·Mih, N.·Pang, S.·Curran, S. P.
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Abstract

Exposure to environmental stress is clinically established to influence male reproductive health, but the impact of normal cellular metabolism on sperm quality is less well-defined. Here we show that impaired mitochondrial proline catabolism, reduces energy-storing flavin adenine dinucleotide (FAD) levels, alters mitochondrial dynamics toward fusion, and leads to age-related loss of sperm quality (size and activity), which reduces competitive fitness. Loss of the 1-pyrroline-5-carboxylate dehydrogenase enzyme alh-6 that catalyzes the second step in mitochondrial proline catabolism, leads to premature male reproductive senescence. Reducing the expression of the proline catabolism enzyme alh-6 or FAD biosynthesis pathway genes in the germline is sufficient to recapitulate the sperm-related phenotypes observed in alh-6 loss-of-function mutants. These sperm-specific defects are suppressed by feeding diets that restore FAD levels. Our results define a cell autonomous role for mitochondrial proline catabolism and FAD homeostasis on sperm function and specify strategies to pharmacologically reverse these defects.

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Yen, C.-A., Ruter, D. L., Mih, N., Pang, S., Curran, S. P.. 2018-10-30. Loss of mitochondrial proline catabolism depletes FAD, impairing sperm function, and male reproductive advantage. https://doi.org/10.1101/456863

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