1. A trade-off between thickness and length in the zebra finch sperm mid-piece.
- Author
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Mendonca, Tania, Birkhead, Tim R., Cadby, Ashley J., Forstmeier, Wolfgang, and Hemmings, Nicola
- Subjects
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ZEBRA finch , *SPERMATOZOA , *THREE-dimensional imaging , *MITOCHONDRIA , *TRANSMISSION electron microscopy , *REPRODUCTION - Abstract
The sperm mid-piece has traditionally been considered to be the engine that powers sperm. Larger mid-pieces have therefore been assumed to provide greater energetic capacity. However, in the zebra finch Taeniopygia guttata, a recent study showed a surprising negative relationship between mid-piece length and sperm energy content. Using a multi-dimensional approach to study mid-piece structure, we tested whether this unexpected relationship can be explained by a trade-off between mid-piece length and mid-piece thickness and/or cristae density inside the mitochondrial helix. We used selective plane illumination microscopy to study mid-piece structure from three-dimensional images of zebra finch sperm and used high-resolution transmission electron microscopy to quantifymitochondrial density. Contrary to the assumption that longer mid-pieces are larger and therefore produce or contain a greater amount of energy, our results indicate that the amount of mitochondrial material is consistent across mid-pieces of varying lengths, and longer mid-pieces are simply proportionately 'thinner'. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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