Turkey hen sperm storage tubule transcriptome response to artificial insemination and the presence of semen

Authors: Brady, Kristen; HANLON, CHARLENE - Auburn University; KRASNEC, KATINA - National Instiute Of Allergy And Infectious Diseases (NIAID, NIH); Long, Julie

Submitted to: Frontiers in Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/18/2023
Publication Date: 1/8/2024
Citation: Diehl, K.M., Hanlon, C., Krasnec, K., Long, J.A. 2024. Turkey hen sperm storage tubule transcriptome response to artificial insemination and the presence of semen. Frontiers in Physiology. Volume 14, Issue 1, Page 1305168. https://doi.org/10.3389/fphys.2023.1305168.
DOI: https://doi.org/10.3389/fphys.2023.1305168

Interpretive Summary: Avian species can store sperm in specialized structures called sperm storage tubules (SSTs) of the oviduct for extended periods of time, though the mechanisms that allow for sperm survival are currently unknown. In addition, little is known about how poultry industry practices, such as artificial insemination, impact the biological functions of these specialized structures. SST function directly relates to hen fertility rates, which is important for poultry industry efficiency. To further understand how artificial insemination and the presence of sperm impact SST function, we isolated SSTs from turkey hens at one, thirty, and ninety days following three treatments: (1) Control: hens were not artificially inseminated, (2) Sham: hens were artificially inseminated with a sham treatment containing sperm extender but no sperm, or (3) Semen: hens were artificially inseminated with sperm extender containing sperm. Isolated SSTs were subjected to RNA sequencing to gain a global view of gene expression changes due to artificial insemination and the presence of sperm. In the semen-inseminated SSTs, increased expression of reproductive pathways, cellular structure and metabolism, and pH regulation of the oviduct were observed. In the sham-inseminated SSTs, increased expression of immune pathways and non-reproductive endocrine hormones were observed. Results from this study are important for understanding how SSTs function to preserve sperm, and how these functions are impacted by industry practices.

Technical Abstract: Sperm storage within the uterovaginal junction (UVJ) of avian species occurs in specialized structures termed sperm storage tubules (SSTs) and allows for prolonged storage of semen, though the molecular mechanisms involved in semen preservation are not well understood. In particular, there is a lack of understanding on how SST function is impacted by insemination and by semen present in the SSTs. Transcriptome analysis was performed on isolated SSTs from turkey hens receiving no insemination (control), sham-insemination, or semen-insemination at three timepoints (D1, D30, and D90 post-insemination). Bioinformatic analysis and functional annotation analysis were performed using CLC Genomics Workbench, Database for Annotation, Visualization, and Integrated Discovery (DAVID), and Ingenuity Pathway Analysis (IPA). Pairwise comparisons and k-medoids cluster analysis were utilized to decipher differential expression profiles in the treatment groups. The SST transcriptome of the semen-inseminated group exhibited the largest differences, with differences detectable for up to 90 days post-insemination, while control and sham-inseminated groups were more similar. In the semen-inseminated samples, upregulation of pathways relating to classical and non-classical reproductive signaling, cytoskeletal remodeling, physiological parameters of the local UVJ environment, and cellular metabolism was observed. In the sham-inseminated samples, upregulation of immune pathways and non-reproductive endocrine hormones was observed. Through this study, insights are provided on SST molecular responses to the act of insemination as well as to the presence of semen. Results from this study have direct implications on fertility rates as well as potential strategies for avian semen cryopreservation protocols.