Chávez-García A, Vázquez-Martínez E R, Murcia C, Rodríguez A, Cerbón M, Mejía O
J Anim Sci. 2015 Oct;93(10):4692-701. doi: 10.2527/jas.2015-9181.
Interspecies pregnancies between closely related species are usually performed in livestock to obtain improved and enriched offspring. Indeed, different hybrids have been obtained for research purposes since many years ago, and the maternal-fetal interactions have been studied as a possible strategy for species preservation. The aim of this study was to characterize by physiological and molecular approaches the interspecies pregnancy between bighorn sheep () and domestic sheep (). Hybrids were obtained by artificial insemination; the blood pressure and protein urine levels were measured during the last two-thirds of gestation. After parturition, offspring and placentas were weighed and measured and cotyledons were counted and weighed and their surface area determined. Plasma samples were obtained between wk 8 and 21 of gestation to assess progesterone (P4), vascular endothelial growth factor (VEGF), and placental growth factor (PlGF) levels and cell-free RNA was isolated during the same period to assess hypoxia-inducible factor-1 α (α) gene expression. Hybrid and normal pregnancies were analyzed using physiological and molecular parameters during the last two-thirds of gestation (wk 8-21). The results show that during the measurement period, ewes with a hybrid pregnancy presented normal blood pressure and no alteration in urinary protein content. However, compared with sheep with a normal pregnancy, those with a hybrid pregnancy had a decrease in fetal and placental growth as well as in the cotyledonary surface area. Furthermore, in the hybrid group, there was placental insufficiency, characterized by a decrease in P4 production, as well as indications of endothelial dysfunction, characterized an increase in plasma levels of VEGF and PlGF as well as in plasma gene expression of α. Overall, the results indicate that hybrids of and presented intrauterine growth restriction, essentially due to altered endothelial function and chronic placental insufficiency. Further studies are necessary to overcome this primary placental dysfunction and thus obtain improved offspring for future molecular and genomic evaluations.
在密切相关的物种之间进行种间妊娠通常是在牲畜中进行，以获得改良和优质的后代。事实上，多年来已经为研究目的获得了不同的杂种，并且母胎相互作用已作为物种保护的一种可能策略进行了研究。本研究的目的是通过生理和分子方法对大角羊（ ）和家羊（ ）之间的种间妊娠进行表征。通过人工授精获得杂种；在妊娠的后三分之二期间测量血压和尿蛋白水平。分娩后，对后代和胎盘进行称重和测量，并对绒毛叶进行计数、称重并确定其表面积。在妊娠第8至21周期间采集血浆样本以评估孕酮（P4）、血管内皮生长因子（VEGF）和胎盘生长因子（PlGF）水平，并在同一时期分离无细胞RNA以评估缺氧诱导因子-1α（α）基因表达。在妊娠的后三分之二（第8 - 21周）期间，使用生理和分子参数对杂种妊娠和正常妊娠进行分析。结果表明，在测量期间，杂种妊娠的母羊血压正常，尿蛋白含量无变化。然而，与正常妊娠的绵羊相比，杂种妊娠的绵羊胎儿和胎盘生长以及绒毛叶表面积减少。此外，在杂种组中，存在胎盘功能不全，其特征是P4产生减少，以及内皮功能障碍的迹象，其特征是血浆VEGF和PlGF水平以及血浆α基因表达增加。总体而言，结果表明 和 的杂种存在宫内生长受限，主要是由于内皮功能改变和慢性胎盘功能不全。有必要进行进一步研究以克服这种原发性胎盘功能障碍，从而获得改良的后代用于未来的分子和基因组评估。
