Shimamoto Tatsuki, Suzuki Kei K, Hamada Mizuho, Furukawa Ryuji, Matsui Motozumi, Yanagawa Hisashi
J Zoo Wildl Med. 2018 Mar;49(1):237-241. doi: 10.1638/2016-0273R2.1.
The Siberian flying squirrel ( Pteromys volans) produces up to two litters a year. To deliver second litters in breeding season, P. volans may have a postpartum estrus similarly to that of a variety of small mammals. If this were the case, females would have periods of elevated progesterone levels because of the formation of corpora lutea (CL) after postpartum ovulation. To test this hypothesis, fecal progesterone metabolite dynamics was investigated during lactation in this species using an enzyme immunoassay. In five of the six lactating females, periods of high fecal progesterone metabolite concentration were observed, and, furthermore, progesterone secretion patterns were periodic. Therefore, the source of progesterone during lactation could be arising CL from postpartum ovulation, indicating that ovarian activity was reinitiated after parturition and the CL that formed began secreting progesterone. This study thus showed that P. volans likely has the physiologic potential to mate during lactation.
西伯利亚飞鼠（Pteromys volans）一年最多产两窝。为了在繁殖季节产下第二窝，西伯利亚飞鼠可能会像多种小型哺乳动物一样出现产后发情。如果是这样的话，由于产后排卵后黄体（CL）的形成，雌性的孕酮水平会升高。为了验证这一假设，使用酶免疫分析法研究了该物种哺乳期粪便中孕酮代谢物的动态变化。在六只哺乳期雌性中的五只中，观察到粪便中孕酮代谢物浓度较高的时期，此外，孕酮分泌模式呈周期性。因此，哺乳期孕酮的来源可能是产后排卵产生的黄体，这表明分娩后卵巢活动重新开始，形成的黄体开始分泌孕酮。这项研究因此表明，西伯利亚飞鼠在哺乳期可能具有交配的生理潜能。
