Effects of Progesterone, Testosterone, and Estrogen on Sexual Reproduction of the Rotifer Brachionus calyciflorus

✍ Scribed by Jiaxin Yang; Terry W. Snell

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 161 KB
• Volume: 95
• Category: Article
• ISSN: 1434-2944
• DOI: 10.1002/iroh.201011267

✦ Synopsis

It is known that some vertebrate reproductive hormones have effects on rotifer reproduction, but little is known about their effects in combination. This motivated us to examine the effects of waterborne progesterone (P), testosterone (T), and estradiol (E) on reproduction of the rotifer Brachionus calyciflorus, comparing exposures to single hormones and mixtures with a total concentration of 1000 μg/L. Asexual population growth (r) was high in all treatments, ranging from 1.28 to 1.43 d -1 (P-E), and from 0.99 to 1.22 d -1 (P-T). These results indicate that E, P, or T alone, or in combinations of P-E and P-T totaling 1000 μg/L, and the 3-way combination P-E-T at 1200 μg/L do not reduce the asexual reproduction of B. calyciflorus. However, significant effects were detected on sexual reproduction with exposure to these hormone concentrations. Exposure to P-T and P-E at 1000 μg/L decreased resting egg production significantly. Analysis of mating indicated that fertilization was 5.3 times higher in the control than in treatments where females were exposed to 500 μg/L each P-T. A similar result was observed when both females and males were exposed to 500 μg/L each of P-T. When males alone were treated with 500 μg/L each of P-T, there was no significant difference in male fertility compared to the control. These results suggest that B. calyciflorus uses oxidized sterols similar to P and T to regulate sexual reproduction and waterborne exposure of females to these compounds interferes with fertilization and resting egg production.