The sperm viability of male pseudoscorpions treated with the antibiotic tetracycline may be significantly reduced compared to that of untreated males, a study published in Scientific Reports suggests. The toxic effect was shown to be transmitted to untreated sons but not to grandsons. The findings highlight the need for further investigation of the transgenerational effects of tetracycline on male reproductive function.
Previous research has indicated that male reproductive traits may be sensitive to tetracycline, a broad-spectrum antibiotic, which inhibits mitochondrial translation. Jeanne Zeh and colleagues report a multi-generation study of tetracycline’s effects on the ejaculate traits of the pseudoscorpion (Cordylochernes scorpiodes), a small arachnid resembling a scorpion. Animals were randomly assigned at birth either to control or tetracycline treatments; individuals from the same broods received different treatments to control for genetic influences. The antibiotic had no effect on male or female body size, sperm number or female reproduction, the authors found. However, the sperm viability of tetracycline-treated males and their sons - but not their grandsons - was significantly reduced compared to control males. The authors speculate that tetracycline may induce epigenetic changes in the male germline - changes that do not alter the sequence of DNA but which alter the way genes are expressed.