Ray S, Golden T, Ray A
Department of Biology, University of Rochester, New York 14627, USA.
Dev Biol. 1996 Nov 25;180(1):365-9. doi: 10.1006/dbio.1996.0309.
Maternal gene products deposited in an animal egg determine the polarity of embryonic axes and regulate embryonic cell-cell communication important for morphogenesis. Here we report the first maternal-effect embryo-defective mutation discovered in a plant. Recessive mutations in the SHORT INTEGUMENT (SIN1) gene in Arabidopsis were previously shown to influence ovule development and flowering time. Here we show that a sin1 mutation has a pronounced maternal effect on zygotic embryo development. A homozygous sin1 mutant embryo is normal when nursed by a sin1/+ heterozygous maternal sporophyte. Strikingly, a sin1 or a sin1/+ embryo that is nursed by a sin1 homozygous maternal sporophyte develops morphogenetic defects in the apical-basal and radial axes. The defects resemble those seen in some zygotic-effect embryonic pattern formation mutants. These results imply that in maternal cells the SIN1 gene either codes for or controls the production of a diffusible morphogen necessary for proper zygotic embryogenesis.
沉积在动物卵子中的母体基因产物决定胚胎轴的极性，并调节对形态发生至关重要的胚胎细胞间通讯。本文我们报道了在植物中发现的首个母体效应胚胎缺陷突变。拟南芥SHORT INTEGUMENT（SIN1）基因中的隐性突变先前已显示会影响胚珠发育和开花时间。本文我们表明，sin1突变对合子胚发育有显著的母体效应。当由sin1/+杂合母体孢子体哺育时，纯合sin1突变体胚胎是正常的。令人惊讶的是，由sin1纯合母体孢子体哺育的sin1或sin1/+胚胎在顶 - 基轴和径向轴上出现形态发生缺陷。这些缺陷类似于在一些合子效应胚胎模式形成突变体中看到的缺陷。这些结果表明，在母体细胞中，SIN1基因要么编码要么控制产生合子胚正常发育所需的可扩散形态发生素。
