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VIVID CELLULAR COMMUNICATION. “Intensive gamete crosstalk takes place and, after a process involving recognition, sperm activation, and adhesion of plasma membranes, both gamete pairs fuse (plasmogamy) and sperm contents are released inside female gametes.” http://www.sciencedirect.com/science/article/pii/S1674205214608996 View in LinkedIn

FEMALE TISSUES COME ALIVE. “Thus, in contrast to the handful of gene expression changes during hydration, a very large number of gene expression changes occur when pollen tubes grow through pistil tissues. For example, over 1000 genes had significantly different expression in comparisons between semi-in vivo-grown pollen tubes and dry pollen, and a similar number after 4-h pollen tube growth; expression of a unique set of 383 pollen tube-expressed proteins present in pistil-interacted pollen tubes were identified.” http://www.sciencedirect.com/science/article/pii/S1674205214608996 View in LinkedIn

GENES LIGHT UP. “Transcriptomic analyses have recently revealed an unsurpassed level of complex gene regulation relating to pollen–pistil interactions. Microarray analysis revealed that the transcriptome of Arabidopsis pollen tubes that have grown through pistil tissues using a semi-in vivo pollen tube growth system is significantly distinct from transcriptomes of pollen grains or pollen tubes grown in vitro, and implicate de novo gene expression in pollen tubes due to interactions with the female tissues.” http://www.sciencedirect.com/science/article/pii/S1674205214608996 View in LinkedIn

FRAGMENT FROM NATURE continues from last weekend and concludes this weekend on the theme of double fertilization in flowering plants (Angiosperms). It is an impressively complicated way to reproduce. One interpretation of the why, is that during evolution, various hybrid forms are stitched together, and the survivors are not always efficient, but represent combinations and work-arounds that were just compatible enough to survive. Nature and perfection are not the same thing; she is usually composed of bizarre genetic meldings from disparate beasts glued together by happenstance. View in LinkedIn

SINGLE WINNERS. “In the flowering plants, the mechanism of polyspermy block is unknown. However, the phenomenon was recognized by in vitro fertilization analysis in maize about 20 years ago.” http://www.nature.com/articles/ncomms5722?WT.ec_id=NCOMMS-20140829 View in LinkedIn

ELECTRICAL SIGNALS. “In animals like frogs and several marine invertebrates, polyspermy (the fertilization of an egg by two or more sperm cells) is prevented by an electrical charge across the surface of the egg (fast block in a few seconds) and/or by modification of the extracellular egg coat by a secretion reaction (slow block in dozens of seconds), following gamete fusion. A Ca2+ wave in the fertilized egg triggers the secretion reaction associated with the slow polyspermy block.” http://www.nature.com/articles/ncomms5722?WT.ec_id=NCOMMS-20140829 View in LinkedIn

WAVES OF MESSAGES. “Ca2+ waves and oscillation are key signalling elements during the fertilization process of animals, and are involved, for example, in egg activation. In the unique double fertilization process in flowering plants, both the egg cell and the neighbouring central cell fuse with a sperm cell each. Here we succeeded in imaging cytosolic Ca2+ in these two cells, and in the two synergid cells that accompany the gametes during semi-in vivo double fertilization.” http://www.nature.com/articles/ncomms5722?WT.ec_id=NCOMMS-20140829 View in LinkedIn

MESSENGER. “Ca2+ is important as an intracellular second messenger in the fertilization of many organisms. In animals including mouse, xenopus, ascidian, starfish and sea urchin, various patterns of cytosolic Ca2+ waves and oscillations are involved in fertilization and the subsequent onset of embryogenesis.” http://www.nature.com/articles/ncomms5722?WT.ec_id=NCOMMS-20140829 View in LinkedIn

IONIC WORDS. “More general signaling molecules involved in regulation of many of the pollination processes have also been identified. Ca2+ is now well established as playing a central role, acting in a signaling capacity during pollen germination, pollen tube growth, SI responses, and gamete reception.” http://www.sciencedirect.com/science/article/pii/S1674205214608996 View in LinkedIn