Wolfe Adam D, Rodriguez Adriana M, Downs Karen M
Department of Pediatrics, Division of Pediatric Hematology, Oncology & Bone Marrow Transplant, University of Wisconsin-Madison School of Medicine and Public Health, 1111 Highland Avenue, 4105 WIMR, Madison, WI 53705, United States.
Department of Cell and Regenerative Biology, University of Wisconsin-Madison School of Medicine and Public Health, 1300 University Ave, Madison, WI 53706, United States.
Dev Biol. 2017 May 1;425(1):44-57. doi: 10.1016/j.ydbio.2017.03.014. Epub 2017 Mar 18.
The allantois-derived umbilical component of the chorio-allantoic placenta shuttles fetal blood to and from the chorion, thereby ensuring fetal-maternal exchange. The progenitor populations that establish and supply the fetal-umbilical interface lie, in part, within the base of the allantois, where the germ line is claimed to segregate from the soma. Results of recent studies in the mouse have reported that STELLA (DPPA-3, PGC7) co-localizes with PRDM1 (BLIMP1), the bimolecular signature of putative primordial germ cells (PGCs) throughout the fetal-placental interface. Thus, if PGCs form extragonadally within the posterior region of the mammal, they cannot be distinguished from the soma on the basis of these proteins. We used immunohistochemistry, immunofluorescence, and confocal microscopy of the mouse gastrula to co-localize STELLA with a variety of gene products, including pluripotency factor OCT-3/4, mesendoderm-associated T and MIXl1, mesendoderm- and endoderm-associated FOXa2 and hematopoietic factor Runx1. While a subpopulation of cells localizing OCT-3/4 was always found independently of STELLA, STELLA always co-localized with OCT-3/4. Despite previous reports that T is involved in specification of the germ line, co-localization of STELLA and T was detected only in a small subset of cells in the base of the allantois. Slightly later in the hindgut lip, STELLA+/(OCT-3/4+) co-localized with FOXa2, as well as with RUNX1, indicative of definitive endoderm and hemangioblasts, respectively. STELLA was never found with MIXl1. On the basis of these and previous results, we conclude that STELLA identifies at least five distinct cell subpopulations within the allantois and hindgut, where they may be involved in mesendodermal differentiation and hematopoiesis at the posterior embryonic-extraembryonic interface. These data provide a new point of departure for understanding STELLA's potential roles in building the fetal-placental connection.
绒毛膜尿囊胎盘源自尿囊的脐部成分将胎儿血液输送至绒毛膜并从绒毛膜输送回来，从而确保胎儿与母体之间的物质交换。建立并供应胎儿 - 脐部界面的祖细胞群体部分位于尿囊基部，据说生殖系就是在此处与体细胞分离的。最近对小鼠的研究结果表明，STELLA（DPPA - 3，PGC7）与PRDM1（BLIMP1）共定位，这是整个胎儿 - 胎盘界面中假定原始生殖细胞（PGC）的双分子标记。因此，如果PGC在哺乳动物后部区域的性腺外形成，基于这些蛋白质它们无法与体细胞区分开来。我们使用小鼠原肠胚的免疫组织化学、免疫荧光和共聚焦显微镜技术，将STELLA与多种基因产物共定位，包括多能性因子OCT - 3/4、中内胚层相关的T和MIXl1、中内胚层和内胚层相关的FOXa2以及造血因子Runx1。虽然总是能独立于STELLA发现定位OCT - 3/4的细胞亚群，但STELLA总是与OCT - 3/4共定位。尽管先前有报道称T参与生殖系的特化，但仅在尿囊基部的一小部分细胞中检测到STELLA和T的共定位。在稍后的后肠唇中，STELLA + /(OCT - 3/4 +)与FOXa2以及RUNX1共定位，分别指示确定的内胚层和成血管细胞。从未发现STELLA与MIXl1共定位。基于这些以及先前的结果，我们得出结论，STELLA在尿囊和后肠内识别出至少五个不同的细胞亚群，它们可能在胚胎后 - 胚外界面参与中内胚层分化和造血作用。这些数据为理解STELLA在构建胎儿 - 胎盘连接中的潜在作用提供了新的出发点。
