Duarte-Méndez Melissa, Quintero-Silva Jennifer, Ramírez-Pinilla Martha Patricia
Laboratorio de Biología Reproductiva de Vertebrados, Escuela de Biología, Universidad Industrial de Santander, Bucaramanga Santander, Colombia.
Laboratorio de Biología Reproductiva de Vertebrados, Escuela de Biología, Universidad Industrial de Santander, Bucaramanga Santander, Colombia; Grupo de Estudios en Biodiversidad, Escuela de Biología, Universidad Industrial de Santander, Bucaramanga Santander, Colombia.
Gen Comp Endocrinol. 2018 May 15;261:136-147. doi: 10.1016/j.ygcen.2018.02.017. Epub 2018 Mar 2.
In squamates, progesterone (P) plays a key role in the inhibition of uterine mobility during egg retention in oviparous species, and during gestation in viviparous species. The corpus luteum (CL) is the main organ responsible for the production of P; however, in some species, the CL degenerates early and the P needed for gestation maintenance should be produced in other tissues. Mabuya sp (Scincidae) is a viviparous lizard with a prolonged gestation, it produces microlecithal eggs and, consequently, has an obligate placentotrophy related with a highly complex placenta. Its CL degenerates at early stages of gestation and therefore, other sources of P should exist. The aim of this study was to determine and localize by immunohistochemistry the production of P by detection of the enzyme 3β-Hydroxysteroid dehydrogenase (3β-HSD) and P receptors (PR) during gestation in the ovary and placenta of Mabuya sp. Positive and negative control sections were used. The ovary of this species localizes 3β-HSD and PR in the same tissues. The CL of the ovaries of females at early stages of gestation were positive for both molecules, whereas they did not localize from mid gestation to the end of pregnancy. Previtellogenic and vitellogenic follicles labelled for both molecules in the follicular epithelium and thecae. The placenta of Mabuya sp. demonstrated the potential for P production from mid gestation to the end of gestation in the uterine and chorionic tissues. PR were located in the uterine tissues throughout gestation, with a decrease towards its completion. Western blot analysis confirmed the presence of 3β-HSD mainly in the ovary of early pregnant females and in the placental tissues at mid gestation stages. Therefore, the chorioallantoic placenta of Mabuya sp. has an endocrine function producing the P needed for gestation and replacing the CL from mid gestation to the end of pregnancy.
在有鳞目动物中，孕酮（P）在卵生动物卵滞留期间以及胎生动物妊娠期间抑制子宫活动方面发挥着关键作用。黄体（CL）是负责产生P的主要器官；然而，在某些物种中，黄体早期退化，维持妊娠所需的P应由其他组织产生。 Mabuya sp（石龙子科）是一种妊娠期延长的胎生蜥蜴，它产生少黄卵，因此具有与高度复杂胎盘相关的专性胎盘营养。其黄体在妊娠早期退化，因此，应该存在其他P来源。本研究的目的是通过免疫组织化学，通过检测妊娠期Mabuya sp卵巢和胎盘中的3β-羟基类固醇脱氢酶（3β-HSD）和P受体（PR）来确定和定位P的产生。使用了阳性和阴性对照切片。该物种的卵巢在相同组织中定位3β-HSD和PR。妊娠早期雌性卵巢的黄体对这两种分子均呈阳性，而从妊娠中期到妊娠末期则未定位。卵黄形成前和卵黄形成期的卵泡在卵泡上皮和卵泡膜中对这两种分子均有标记。Mabuya sp的胎盘在妊娠中期到妊娠末期在子宫和绒毛膜组织中显示出产生P的潜力。PR在整个妊娠期都位于子宫组织中，在妊娠结束时减少。蛋白质印迹分析证实3β-HSD主要存在于妊娠早期雌性的卵巢和妊娠中期的胎盘组织中。因此，Mabuya sp的绒毛膜尿囊胎盘具有内分泌功能，产生妊娠所需的P，并在妊娠中期到妊娠末期替代黄体。
