Abstract
Asymmetric cell division generates two different daughter cells. Although unequal distribution of mRNA or proteins has been known to play a pivotal role to specialize each daughter cell, such molecules in plants remain largely unknown. The moss, Physcomitrella patens assures a good system for the study of molecular mechanisms for asymmetric cell division. The protoplast divides asymmetrically to generate apical stem cell and differentiated protonemal, non-stem cell, thereafter the apical stem cell continues to divide asymmetrically to generate a row of differentiated protonemal cells. We have devised a systematic overexpression screening and identified 58 cDNAs as candidates for genes that are involved in asymmetric cell division. For those candidates, we made cDNA-YFP knock-in transgenic plants by using gene targeting technique to investigate protein localization during asymmetric cell division under a control of native promoters. We found several fusion proteins preferentially accumulated in apical stem cells.
