• polarity
  • Here, we show that cell polarity in Nicotiana tabacum pollen is associated with the exclusion of a novel pollen-specific H + -ATPase, Nt AHA, from the growing apex. (plantcell.org)
  • Pollen tubes are cells that display an extreme example of cellular polarity and growth control, growing exclusively at the tip by means of apical exocytosis. (plantcell.org)
  • The establishment and maintenance of cell and tissue polarity is crucial for a range of biological processes, such as oriented division, migration, adhesion and barrier function. (biologists.org)
  • The molecular pathways that regulate cell and tissue polarity have been extensively studied in lower organisms as well as in mammalian cell culture. (biologists.org)
  • Several recent papers have identified crucial roles for mammalian polarity proteins in a range of in vivo processes, including stem cell behavior, cell fate determination, junction formation and maintenance and organ development. (biologists.org)
  • Using the epidermis of the skin as a model system, this Commentary aims to discuss the in vivo significance of cell and tissue polarity in the regulation of mammalian tissue morphogenesis, homeostasis and disease. (biologists.org)
  • Polarity is defined as the unequal distribution of molecules (RNAs, lipids, proteins) within a cell to produce asymmetry in its structure and function at the cellular, tissue and organismal level. (biologists.org)
  • Polarity comes in two main forms: cell polarity and tissue polarity. (biologists.org)
  • In cell polarity, asymmetry is achieved in individual cells, such as for instance the leading and trailing edge of a migrating cell or apicobasal polarity ( Fig. 1A ). (biologists.org)
  • maintain
  • They maintain impressive growth rates of up to 4 μm/s for several millimeters or centimeters, depending on the species, without ever dividing and are one of the fastest elongating cells in nature. (plantcell.org)