Expression data from progesterone receptor knockout versus heterozygous mouse oviducts

The oviducts play a critical role in gamete and embryo transport, as well as supporting fertilization and early embryo development. Progesterone receptor (PGR) is a transcription factor highly expressed in oviductal cells, while its activating ligand, progesterone (P4), surges to peak levels as ovulation approaches. P4 is known to regulate oviduct cilia beating and muscular contractions in vitro, but how PGR may mediate this in vivo is poorly understood. We used PGR-knockout (PRKO) mice to determine how PGR regulates oviductal function during the periovulatory period, in particular oviductal transport and embryo support. We used microarrays to identify putative PGR-regulated genes in the oviduct during the periovulatory period, a time when the oviduct is preparing to receive the newly-ovulated COC. The mutant strain used in this experiment were PRlacZ knock-in mice which originated from Assoc Prof John Lydon, Baylor College of Medicine, Houston TX, USA. The lacZ insertion results in disruption of transcription of both isoforms of PGR (Ismail et al, 2002, Mol Endocrinol 16:2475-2489), and therefore mice homozygous for the lacZ insertion are a phenocopy of the knockout strain described by Lydon et al. (1995, Genes Dev. 9:2266-2278) and are hereafter referred to as PRKO. Heterozygous mice (PR+/-) are a phenocopy of WT and have normal fertility (Ismail et al, 2002) and are therefore appropriate controls. Whole oviducts were collected from pre-pubertal PRKO and PR+/- mice 8 h after a standard protocol for hormonal induction of ovulation. Day 21-23 old mice were injected i.p. with 5IU of equine chorionic gonadotropin (eCG) to stimulate follicle growth, followed 44-47 h later by i.p. injection of 5 IU of human chorionic gonadotropin (hCG) to trigger ovulatory processes. Oviducts from 15 animals were collected per genotype, with oviducts from 3 animals pooled per sample for a total of n = 5 samples per genotype.输卵管在配子与胚胎转运、受精支持及早期胚胎发育等过程中发挥关键作用。孕酮受体（progesterone receptor, PGR）是在输卵管细胞中高表达的转录因子，其激活配体孕酮（progesterone, P4）的水平在排卵临近时升至峰值。已知P4可在体外调控输卵管纤毛摆动与肌肉收缩，但PGR如何在体内介导这一过程仍不甚明晰。本研究采用孕酮受体敲除（PGR-knockout, PRKO）小鼠，旨在探究PGR在围排卵期如何调控输卵管功能，尤其是输卵管转运与胚胎支持作用。本研究通过基因芯片技术，鉴定围排卵期输卵管中潜在的PGR调控基因——此阶段输卵管正准备接收新近排出的COC。本实验所用的突变株为PRlacZ敲入小鼠，由美国德克萨斯州休斯顿贝勒医学院John Lydon副教授惠赠。lacZ插入会破坏PGR两种亚型的转录（Ismail等，2002, Mol Endocrinol 16:2475-2489），因此纯合子lacZ插入小鼠的表型与Lydon等（1995, Genes Dev. 9:2266-2278）报道的敲除株一致，后续将其统称为PRKO小鼠。杂合子小鼠（PR+/-）的表型与野生型（wild type, WT）一致，生育能力正常（Ismail等，2002），因此可作为合适的对照。本研究于激素诱导排卵的标准流程处理后8小时，收集青春期前PRKO与PR+/-小鼠的完整输卵管。具体处理为：对21~23日龄小鼠腹腔注射5IU马绒毛膜促性腺激素（equine chorionic gonadotropin, eCG）以刺激卵泡发育，44~47小时后再腹腔注射5IU人绒毛膜促性腺激素（human chorionic gonadotropin, hCG）以触发排卵过程。每个基因型组收集15只动物的输卵管，每3只动物的输卵管混合为一个样本，最终每个基因型组共获得5个样本。