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IT HAS STARTED. “Biology can be hacked. And it is being hacked, every day.” https://lnkd.in/dkjx-Yi View in LinkedIn

POLYMORPHIC WORDS. “A major advantage of using peptides for intercellular crosstalk is their polymorphism. A single amino acid exchange or modification can easily result in complete loss of binding capability at specific cell surface receptors. The specificity of crosstalk, thus, seems to be often mediated by the polymorphic small secreted protein/peptide ligands expressed by individual cell types. Studies to date have initiated the identification of small proteins that act as signaling ligands, together with some of their functions.” http://www.sciencedirect.com/science/article/pii/S1674205214608996 View in LinkedIn

NEW FRONTIER. “Think of all the trouble that computer hackers cause. Now imagine what DNA hackers could do.” https://lnkd.in/dVFmp9V View in LinkedIn

SO ENDS this two weekend dive into double fertilization in flowering plants. One explanation for its complexity is that we are looking at the survivors of a biological train wreck, the progeny of almost incompatible hybridizations that carry genetic and metabolic baggage that could not be jettisoned in time, and the resulting offspring is still capable of survival. View in LinkedIn

SUPERFLUOUS. “Gymnosperms lacking double fertilization dominate large areas of the Earth, e.g. the Taiga or Northern Coniferous Forest. Therefore, double fertilization is not a requirement for success in seed plants.” https://lnkd.in/dJZ98Vs View in LinkedIn

THE WHY. “We are not positive why double fertilization occurs. Arthur Cronquist (1971) considered double fertilization a "mere evolutionary happenstance." One possible advantage of double fertilization is that the plant does not invest energy in seed nutritive tissue until after an egg has been fertilized. Another possible advantage is that the endosperm nucleus is very active and divides rapidly. It forms the nutritive tissue very quickly. Rapid seed development has obvious advantages.’ https://lnkd.in/dJZ98Vs View in LinkedIn

WHY DOUBLE FERTILIZATION OCCURS. “Of the two sperm cells, one sperm fertilizes the egg cell, forming a diploid zygote; the other sperm fuses with the two polar nuclei, forming a triploid cell that develops into the endosperm. Together, these two fertilization events in angiosperms are known as double fertilization. After fertilization is complete, no other sperm can enter. The fertilized ovule forms the seed, whereas the tissues of the ovary become the fruit, usually enveloping the seed.” https://lnkd.in/dQYs2c2 View in LinkedIn

OPEN ISSUES. “Determination of fertilization targets during the gametic phase of double fertilization is still largely unknown but must require complex gamete recognition and/or blocking polyspermy in both female gametes.” http://www.nature.com/articles/ncomms5722?WT.ec_id=NCOMMS-20140829 View in LinkedIn

NUANCES. “The transcriptional activation of male and female genomes in the zygote is critical for establishing apical–basal cell polarity over a long period of time before the first division. Our data suggest that unlike egg cell functioning in animals such as hamster, in Arabidopsis, a single spike of [Ca2+]cyt at fertilization with a duration that is much shorter than that observed during maize in vitro fertilization, might be sufficient for blocking polyspermy and initiation of the developmental programme.” http://www.nature.com/articles/ncomms5722?WT.ec_id=NCOMMS-20140829 View in LinkedIn

CELL CYCLE SYNCHRONY. “Flowering plants show unique cell cycle control in fertilization among eukaryotes; sperm cells of Arabidopsis in G2 phase have been proposed to fuse with the egg cell in G1/S or G2 phase and with the central cell in G2 phase. Different mechanisms of cell cycle arrest and activation might exist.” http://www.nature.com/articles/ncomms5722?WT.ec_id=NCOMMS-20140829 View in LinkedIn