Pollen tube are tolerant and even pollen damaged by X-rays and gamma rays can still grow pollen tubes. The interaction between the stigma-style and the pollen grain is a vital piece that contributes to the growth. The elongation of the tube is achieved with elongation of the cytoskeleton and it extends from the tip, which is regulated by high levels of calcium in the cytosol. The calcium levels help the synaptic vesicles in the membranes grow and extend at the tip. Polypeptides found in the style also regulate growth of tube and specific peptides that play a role in signaling for growth
Development of Spore survive in a strange world, with elements of "Nintendogs". The mobile phone version of "Spore", called "Spore Origins", was based on the tide pool phase, in which players try to survive as a multicellular organism, with gameplay similar to "flOw". On March 6, 2008, an iPhone version was demonstrated at Apple's iPhone SDK press event, though there was no commitment to ship such a product given at that event. The iPhone-Spore demo made use of the device's touch capabilities and 3-axis accelerometer. Electronic Arts confirmed on March 31, 2008 that "Spore" would be receiving post-release expansion packs. Only one expansion