Season of collection and sperm head shape impacts expression of CARHSP and FTL from motile-rich boar sperm

The objective of the current study was to evaluate transcript activity of motile-rich sperm collected from June (spring) or August (summer), stored as cooled-extended (ExT) or cryopreserved (FrZ), and selected for least or most sperm head shape change, using Fourier harmonic analysis techniques, between June and August. Even with the lack of an extended heat stress, motile-rich sperm transcripts were influenced by season and putatively by sperm head shape change. Transcripts that had previously been associated with seasonality of sperm collection and methylation pathway transcripts were evaluated among semen samples. Calcium-regulated heat-stable protein 1-like transcript from motile-rich sperm tended (P = 0.0829) to be greater in samples collected in June in comparison to August samples. Ferritin light polypeptide transcript tended (P = 0.0838) to be greater from motile-rich sperm with least head shape change from June collection in contrast to sperm collected in August. Both transcripts have a functional role in cytoprotection and may serve to improve boar semen activity and quality during thermal stress or seasonal changes.