[Functional specialization of the nuclei in tip-growing coenocytic algae Vaucheria sessilis].

The availability of numerous nuclei in coenocytic thalli creates a problem of their activity and division cycle coordination. An apparent random distribution of nuclei in tip-growing cells is regulated by some principles associated with physiological compartmentalization in the absence of true septae. In vegetative thallome of Vaucheria sessilis the nuclei are distributed equally in proximal parts, to be accumulated in a high density cluster in the apical zone.

Influence of modified gravity on growth and structure of Vaucheria sessilis (Xanthopyceae).

The constant presence of gravity force in the evolution of life on Earth caused the adaptation for its pressure and dependence of growth and morphogenesis of high plants on gravity, and appearance of gravitaxises of unicellular organisms. The modern investigations demonstrated the ability even of prokaryotic organisms for sensitivity of gravity modifications Erdmann et al., 1997).

[Response of siphoneal alga (Vaucheria sessilis) to the gravity factor].

Growth and development of siphonal alga Vaucheria sessilis under changed gravity and the role of cytoskeletal structures in gravitational response were studied. Hypergravity (3 g) and "hypogravity" were generated by slow clinostating at 7-8 rev/min and rapid clinostating at 35, 70, 135 rev/min, respectively. The experiments in microgravity were flown aboard biosatellite Bion-11.

[Peculiarities of growth and morphogenesis of syphoneal alga vaucheria sessilis in microgravity].

The space experiment was aimed at studying the dependence on the gravity of intracellular processes in an autotrophic organism deprived of pronounced gravitropisms and gravitaxis. The experiment demonstrated an immediate gravitational effect on intercellular processes involving the syphoneal alga Vausheira sessilis cytoskeleton. In the absence of the force of gravity algal growth and morphogenesis are inhibited more significantly than under the condition of the Earth's gravity.

The position of nuclei and the role of cytoskeleton in graviresponse of siphonaceous algae Vaucheria sessilis.

Gravity has always been present during evolution. Through the process of natural selection, contemporary organisms could show evidence of having turned gravity to their advantage as an adjunct to development. In recent time great success has been achieved in description and analysis of gravitaxis mechanism of algae Chara (Sievers et.