Microarray analysis of gene expression profiles in Map2k1+/-Map2k2+/- and Map2k1flox/-Map2k2+/-Tg+/Sox2Cre placentas

The mammalian genome contains two ERK/MAP kinase kinase genes, Map2k1 and Map2k2, encoding dual-specificity kinases responsible for ERK/MAP kinase activation. Loss of Map2k1 function in mouse causes embryonic lethality due to placental defects, while Map2k2 mutant mice survive with a normal lifespan. The Map2k1 mutation interferes with the growth of the labyrinthine region of the placenta and its vascularization. Map2k1+/-Map2k2+/- embryos also die during gestation of underdevelopment of the labyrinth. In Map2k1+/-Map2k2+/- mutants, the vascularization of the labyrinth is reduced and defects in SynT-II formation lead to the accumulation of multinucleated trophoblasts giant cells (MTG). Deletion of both Map2k1 alleles in allantois-derived tissues in Map2k1+/ Map2k2+/- placenta (Map2k1flox/-Map2k2+/-Tg+/Sox2Cre) increases the penetrance and the expressivity of the MTG placental phenotype. Microarray analysis with RNA extracted from placentas of E12.5 wt, Map2k1+/-Map2k2+/- and Map2k1flox/-Map2k2+/-Tg+/Sox2Cre embryos was performed to evaluate the molecular impact of the loss of Map2k alleles on placenta development. Total RNA was isolated from placentas of E12.5 Map2k1+/+Map2k2+/+(control), from E12.5 Map2k1+/-Map2k2+/- embryos (experimental) and from E12.5 and Map2k1flox/-Map2k2+/-Tg+/Sox2Cre embryos (experimental). Four specimens were analyzed per genotype.哺乳动物基因组中包含两个ERK/MAP激酶激酶基因，即Map2k1与Map2k2，二者编码可介导ERK/MAP激酶激活的双特异性激酶。小鼠中Map2k1功能缺失可因胎盘缺陷导致胚胎致死，而Map2k2突变小鼠可正常存活且寿命无异常。Map2k1突变会干扰胎盘迷路区的生长及其血管化过程。Map2k1+/-Map2k2+/-胚胎同样会因迷路区发育不全在妊娠期死亡。在Map2k1+/-Map2k2+/-突变体中，迷路区的血管化程度降低，且合胞体滋养层-II（SynT-II）形成缺陷会导致多核滋养层巨细胞（MTG）积累。在Map2k1+/-Map2k2+/-胎盘的尿囊衍生组织中删除两个Map2k1等位基因（即基因型Map2k1flox/-Map2k2+/-Tg+/Sox2Cre），可提升MTG胎盘表型的外显率与表现度。研究人员对E12.5天野生型（wt）、Map2k1+/-Map2k2+/-及Map2k1flox/-Map2k2+/-Tg+/Sox2Cre胚胎的胎盘提取RNA开展基因芯片分析，以评估Map2k等位基因缺失对胎盘发育的分子影响。实验分别从E12.5天的Map2k1+/+Map2k2+/+（对照组）、E12.5天Map2k1+/-Map2k2+/-胚胎（实验组）以及E12.5天Map2k1flox/-Map2k2+/-Tg+/Sox2Cre胚胎（实验组）的胎盘中分离总RNA，每种基因型分析4份样本。