Comparative transcriptome analysis of bull X- and Y-spermatozoa

Area of Science:

• Reproductive Biology
• Genomics
• Dairy Science

Background:

• Sex-sorted bovine semen is vital for dairy production but current methods are costly and inefficient.
• A lack of comprehensive omics data hinders understanding of sperm sex differences and biomarker discovery.
• Developing alternative sex-sorting technologies is essential for global milk production.

Purpose of the Study:

• To perform RNA-Seq analysis on unsorted, X-, and Y-sperm in Bos indicus cattle.
• To identify differentially expressed genes between X- and Y-sperm.
• To generate a foundational transcriptome dataset for biomarker discovery in bovine semen sex-sorting.

Main Methods:

• RNA-Sequencing (RNA-Seq) was performed on unsorted, X-sperm, and Y-sperm from Bos indicus.
• Differential gene expression analysis was conducted to identify significant gene expression changes.
• Quantitative PCR (qPCR) was used to validate the expression of key differentially expressed genes.

Main Results:

• Significant upregulation of 47 genes and downregulation of 20 genes were observed in Y-sperm compared to X-sperm (adjusted p < 0.05).
• 16% of transcripts were unique to X-sperm, and 20.7% were unique to Y-sperm.
• Validation using qPCR confirmed significant differential expression in 21 out of 22 tested genes between Y- and X-sperm.

Conclusions:

• This study presents the first transcriptome dataset for bovine X- and Y-sperm.
• The identified differentially expressed genes can serve as potential biomarkers for sex-sorting technologies.
• The findings will contribute to the development of improved sex-sorting methods and enhanced fertility outcomes in cattle.