Extracellular nucleotides (eNTP) occur outside the cytoplasm in the extracellular matrix, were discovered almost 100 years ago in animal cells. These studies showed that the nucleotides are not only building a strand of DNA/RNA or constitute reservoir of energy (eg ATP or GTP) for various biochemical processes, but also may play role in cell growth and development. Extracellular nucleotides are also involved in maintaining homeostasis in the whole animal organism by maintaining adequate blood pressure and immune response.

New models of differentiation of epidermal cells based on proteins transported symplastowo

Plasmodesmata , or cytoplasmic channels that are found in the cell walls provide connectivity symplastową between adjacent protoplasts of plant cells . Numerous studies have shown that plasmodesmata play an important role in the development and differentiation of cells. In turn, by varying the number or the diameter of plasmodesmata , which is associated with regulation of their permeability to specific substances , the plant can control these processes .


The unique feature of plant organisms is the presence of plasmodesmata (PD) between neigh- boring cells. Such plasmodesmatal continuum which exists within the plant body is termed symplasm. Classical view of plasmodesmata as static structures within the cell walls between neighboring cells must be reevaluated. According to our recent knowledge symplast is divided into functional domain. It appeared that symplasmic isolation/communication of cells or group of cells (symplasmic domains or symplasmic fields) is necessary for its proper differentiation within the plant body.

The Editorial Board
Andrzej Łukaszyk - przewodniczący, Zofia Bielańska-Osuchowska, Szczepan Biliński, Mieczysław Chorąży, Aleksander Koj, Włodzimierz Korochoda, Leszek Kuźnicki, Aleksandra Stojałowska, Lech Wojtczak

Editorial address:
Katedra i Zakład Histologii i Embriologii Uniwersytetu Medycznego w Poznaniu, ul. Święcickiego 6, 60-781 Poznań, tel. +48 61 8546453, fax. +48 61 8546440, email:

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