Lack of differential sperm acrosome-associated 1 gene expression between X- and Y-bearing spermatozoa in Bali bulls (Bos javanicus domesticus)
Volume 17, Issue 8, August 2026, Pages 553-558
Widjiati Widjiati, Suryo Kuncorojakti, Suherni Susilowati, Muhammad Yusuf, Sahiruddin Sahiruddin, Masturi Masturi, Athhar Manabi Diansyah, Sigit Bintara, Aeni Nurlatifah, Yayuk Kholifah, Riski Lesta Mega, Devia Yoanita Kurniawati, Viski Fitri Hendrawan, Intan Firdha Olien Noor Al Ichsan
Abstract This study aimed to determine whether the sperm acrosome-associated 1 (SPACA1) gene exhibits differential expression between X- and Y-bearing spermatozoa of Bali bulls and assess its potential as an RNA biomarker for sperm sexing. Sexed frozen semen (X or Y fractions) from Bali bulls was obtained from the Singosari National Artificial Insemination Center, Malang, Indonesia. Post-thaw semen quality was evaluated for motility, viability, abnormality, concentration, and plasma membrane integrity. Total RNA was extracted separately from X and Y fractions using easy-BLUE reagent, and SPACA1 expression was quantified by RT-qPCR using GAPDH as an internal control. Relative expression was calculated by the 2−ΔΔCt method, and group differences were analyzed with the Mann-Whitney U test. The SPACA1 expression was numerically higher in X-bearing than Y-bearing spermatozoa (1.00 versus 0.51), but the difference was not significant. Thus, SPACA1 transcripts do not provide a reliable molecular marker for sperm sex differentiation. Future work should focus on protein-level characterization of SPACA1 and exploration of sex-biased surface proteins for immunological sexing. This research supports Sustainable Development Goal 2: Zero Hunger, by contributing to reproductive efficiency in livestock, and Sustainable Development Goal 12: Responsible Consumption and Production, through development of cost-effective, sustainable sperm sexing technologies.