Conceptus expansion throughout the uterus of mammalian species with a noninvasive epitheliochorial type of placentation is critical establishing an adequate uterine surface area for nutrient support during gestation. Pig conceptuses undergo a unique rapid morphological transformation to elongate into filamentous threads within 1 h, which provides the uterine surface to support development and maintain functional corpora lutea through the production of estrogen. Conceptus production of a unique interleukin 1β, IL1B2, temporally increases during the period of trophoblast remodeling during elongation. CRISPR/Cas9 gene editing was used to knock out pig conceptus IL1B2 expression and the secretion of IL1B2 during the time of conceptus elongation. Trophoblast elongation occurred on day 14 in wild-type (IL1B2^+/+) conceptuses but did not occur in ILB2-null (IL1B2^−/−) conceptuses. Although the morphological transition of IL1B2^−/− conceptuses was inhibited, expression of a number of conceptus developmental genes was not altered. However, conceptus aromatase expression and estrogen secretion were decreased, indicating that IL1B2 may be involved in the spatiotemporal increase in conceptus estrogen synthesis needed for the establishment of pregnancy in the pig and may serve to regulate the proinflammatory response of endometrium to IL1B2 during conceptus elongation and attachment to the uterine surface.

中文翻译：

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猪白细胞介素 1β 失活导致胚胎快速延长失败

对于具有非侵入性上皮绒毛膜类型胎盘的哺乳动物来说，概念在整个子宫中的扩张对于在妊娠期间建立足够的子宫表面积以提供营养支持至关重要。猪受胎经历独特的快速形态转变，在 1 小时内伸长成丝状线，这提供了子宫表面以支持发育并通过产生雌激素维持功能性黄体。一种独特的白细胞介素 1β (IL1B2) 的概念产生在滋养层伸长期间重塑期间暂时增加。采用CRISPR/Cas9基因编辑技术敲除猪孕体IL1B2的表达以及孕体伸长期间IL1B2的分泌。滋养层伸长发生在野生型（IL1B2 ^{+/+ ）受孕体中第 14 天，但在 ILB2 缺失（IL1B2 −/−} ）受孕体中没有发生。^{尽管IL1B2 −/−}受孕体的形态转变受到抑制，但许多受孕体发育基因的表达并未改变。然而，孕体芳香酶表达和雌激素分泌减少，表明IL1B2可能参与猪妊娠建立所需的孕体雌激素合成的时空增加，并可能在孕体伸长和发育过程中调节子宫内膜对IL1B2的促炎反应。附着于子宫表面。