Gramajo-Bühler María Cecilia, Zelarayán Liliana, López Luis Alberto, Sánchez-Toranzo Graciela
Departamento de Biología del Desarrollo, Instituto Superior de Investigaciones Biológicas (INSIBIO), Chacabuco, San Miguel de Tucumán, Argentina.
J Exp Zool A Ecol Genet Physiol. 2012 Jun;317(5):259-65. doi: 10.1002/jez.1718.
Little is known about the reproductive biology of Chinchilla lanigera in captivity. Currently there are no parameters to evaluate the quality of the semen of males that are sold as breeding stock, so they are selected according to their phenotypic characteristics, which cannot guarantee their reproductive efficiency. We worked with sexually mature males; the sperm were collected from the cauda epididymis by puncture. Capacitated sperm were incubated at 37 °C with different concentrations of progesterone. The results showed a biphasic behavior, where the increase in the percentage of the acrosome reaction (AR) was significant between 2.5-5 μM, and a maximum response with a dose of 20 μM. Also the suspension of sperm incubated with different concentrations of ionophore A23187 inducing response is obtained with a concentration of 10 μM. Stimulation of the Gamma-aminobutyric acid (GABA)A -like receptor by treating the sperm with different concentrations of muscimol, a specific receptor agonist, also induce acrosome reaction. The dose-response curve showed a biphasic effect with a maximum response at a concentration of 2.5 μM. The pretreatment of sperm suspension with a specific receptor antagonist, picrotoxin, a decrease was observed in the percentage of reacted perm. These studies represent a first step towards the establishment of standard parameters to determine the functionality and fertilizing capacity of Chinchilla sperm. In addition, our results indicate that the Chinchilla spermatozoa can undergo the AR when treated with A23187 or progesterone at high percentages. It also shows a clear involvement of GABAA -like receptors in acrosome exocytosis in sperm obtained by epididymal cauda.
关于圈养长尾绒鼠的生殖生物学知之甚少。目前，对于作为种畜出售的雄性长尾绒鼠，尚无评估其精液质量的参数，因此它们是根据表型特征挑选的，而这并不能保证其繁殖效率。我们使用性成熟的雄性长尾绒鼠；通过穿刺从附睾尾部收集精子。将获能的精子在37℃下与不同浓度的孕酮一起孵育。结果显示出双相行为，即顶体反应（AR）百分比在2.5 - 5μM之间显著增加，在20μM剂量时出现最大反应。同样，用不同浓度的离子载体A23187孵育精子诱导反应，在10μM浓度时获得反应。用不同浓度的蝇蕈醇（一种特异性受体激动剂）处理精子以刺激γ-氨基丁酸（GABA）A样受体，也可诱导顶体反应。剂量反应曲线显示出双相效应，在2.5μM浓度时出现最大反应。用特异性受体拮抗剂印防己毒素对精子悬液进行预处理后，观察到发生反应的精子百分比下降。这些研究是朝着建立确定长尾绒鼠精子功能和受精能力的标准参数迈出的第一步。此外，我们的结果表明，长尾绒鼠精子在用A23187或孕酮处理时，能以较高百分比发生顶体反应。这也表明附睾尾部获得的精子中，GABAA样受体明显参与了顶体胞吐作用。
