Lewis Shaye K, Farmer Jennifer L, Burghardt Robert C, Newton Gary R, Johnson Greg A, Adelson David L, Bazer Fuller W, Spencer Thomas E
Center for Animal Biotechnology and Genomics, Department of Animal Science, Texas A&M University, College Station, Texas 77843, USA.
Biol Reprod. 2007 Dec;77(6):1027-36. doi: 10.1095/biolreprod.107.063594. Epub 2007 Sep 12.
Galectins are a family of secreted animal lectins with biological roles in cell adhesion and migration. In sheep, galectin 15 (LGALS15) is expressed specifically in the endometrial luminal (LE) and superficial glandular (sGE) epithelia of the uterus in concert with blastocyst elongation during the peri-implantation period. The present study examined LGALS15 expression in the uterus of cattle, goats, and pigs. Although the bovine genome contains an LGALS15-like gene, expressed sequence tags encoding LGALS15 mRNA were found only for sheep, and full-length LGALS15 cDNAs were cloned only from endometrial total RNA isolated from pregnant sheep and goats, but not pregnant cattle or pigs. Ovine and caprine LGALS15 were highly homologous at the mRNA (95%) and protein (91%) levels, and all contained a conserved carbohydrate recognition domain and RGD recognition sequence for integrin binding. Endometrial LGALS15 mRNA levels increased after Day 11 of both the estrous cycle and pregnancy, and were considerably increased after Day 15 of pregnancy in goats. In situ hybridization detected abundant LGALS15 mRNA in endometrial LE and sGE of early pregnant goats, but not in cattle or pigs. Immunoreactive LGALS15 protein was present in endometrial epithelia and conceptus trophectoderm of goat uteri and detected within intracellular crystal structures in trophectoderm and LE. Recombinant ovine and caprine LGALS15 proteins elicited a dose-dependent increase in ovine trophectoderm cell attachment in vitro that was comparable to bovine fibronectin. These results support the hypothesis that LGALS15 is uniquely expressed in Caprinae endometria and functions as an attachment factor important for peri-implantation blastocyst elongation.
半乳糖凝集素是一类分泌型动物凝集素，在细胞黏附和迁移中发挥生物学作用。在绵羊中，半乳糖凝集素15（LGALS15）在子宫的子宫内膜腔上皮（LE）和浅表腺上皮（sGE）中特异性表达，与着床前期胚泡伸长同步。本研究检测了牛、山羊和猪子宫中LGALS15的表达情况。虽然牛基因组包含一个类似LGALS15的基因，但仅在绵羊中发现了编码LGALS15 mRNA的表达序列标签，并且仅从怀孕绵羊和山羊分离的子宫内膜总RNA中克隆到了全长LGALS15 cDNA，而怀孕牛或猪中未克隆到。绵羊和山羊的LGALS15在mRNA（95%）和蛋白质（91%）水平上高度同源，并且都含有一个保守的碳水化合物识别结构域和用于整合素结合的RGD识别序列。发情周期和怀孕第11天后，子宫内膜LGALS15 mRNA水平升高，山羊怀孕第15天后显著升高。原位杂交在早期怀孕山羊的子宫内膜LE和sGE中检测到大量LGALS15 mRNA，但在牛和猪中未检测到。免疫反应性LGALS15蛋白存在于山羊子宫的子宫内膜上皮和孕体滋养外胚层中，并在滋养外胚层和LE的细胞内晶体结构中检测到。重组绵羊和山羊LGALS15蛋白在体外引起绵羊滋养外胚层细胞附着的剂量依赖性增加，与牛纤连蛋白相当。这些结果支持以下假设：LGALS15在山羊子宫内膜中独特表达，并作为一种对着床前期胚泡伸长重要的附着因子发挥作用。
