Velasquez L A, Ojeda S R, Croxatto H B
Unidad de Reproducción y Desarrollo, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.
J Reprod Fertil. 1997 Mar;109(2):349-54. doi: 10.1530/jrf.0.1090349.
Platelet-activating factor (PAF) is a lipid mediator that has a range of biological effects on various cells and tissues. PAF-like activity has been detected in the spent media of two-cell to morula stage hamster embryos, leading to the suggestion that PAF may be the embryonic signal that hastens embryo transport to the uterus in this species. The present study was undertaken to examine whether the PAF receptor (PAFr) gene is expressed in hamster oviduct, and to identify the cell types in which the gene is expressed. DNA fragments complementary to the coding region of mRNA encoding hamster PAFr were cloned by reverse transcription-polymerase chain reaction (RT-PCR), identified by sequencing and used to prepare hamster specific cRNA probes. The presence of mRNA transcripts encoding the PAFr receptor in the oviduct was investigated by subjecting oviduct mRNA to RT-PCR. Southern blot analysis of the RT-PCR products verified the identity of the presumptive PAFr cDNAs. The cloned cDNA fragment of hamster PAFr was found to be highly conserved with respect to the receptor of other species, having 94.3% sequence similarity to the rat PAFr receptor. Hybridization histochemistry demonstrated that PAFr is expressed in the subepithelial cells and occasionally in the epithelium. In conclusion, expression of PAFr in the hamster oviduct is compatible with the proposed paracrine role of early embryo-derived PAF.
血小板活化因子（PAF）是一种脂质介质，对各种细胞和组织具有一系列生物学效应。在二细胞至桑椹胚阶段仓鼠胚胎的培养液中检测到了PAF样活性，这表明PAF可能是促使该物种胚胎向子宫运输的胚胎信号。本研究旨在检测PAF受体（PAFr）基因是否在仓鼠输卵管中表达，并确定表达该基因的细胞类型。通过逆转录-聚合酶链反应（RT-PCR）克隆与编码仓鼠PAFr的mRNA编码区互补的DNA片段，经测序鉴定后用于制备仓鼠特异性cRNA探针。通过对输卵管mRNA进行RT-PCR来研究输卵管中编码PAFr受体的mRNA转录本的存在情况。对RT-PCR产物进行Southern印迹分析，验证了推定的PAFr cDNA的身份。发现克隆的仓鼠PAFr cDNA片段与其他物种的受体高度保守，与大鼠PAFr受体的序列相似性为94.3%。杂交组织化学表明，PAFr在上皮细胞下层表达，偶尔也在上皮中表达。总之，PAFr在仓鼠输卵管中的表达与早期胚胎来源的PAF所提出的旁分泌作用相符。
