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VARIABLE. "Two main sex chromosome systems can be found in vertebrates with genetic sex determination: XX/XY (in which males are heterogametic) and ZZ/ZW (with heterogametic females). Nevertheless, sex chromosomes are extraordinarily variable, and other combinations also can be found, ranging from female heterogamety with 00/0W or ZZ/Z0 sex chromosomes to male heterogamety with XX/X0 sex chromosomes. Furthermore, complex XY and ZW systems are possible when fusions, fissions, and translocations between sex chromosomes and autosomes take place (e.g., X1X2Y, XY1Y2, or Z1Z2W)." https://lnkd.in/gvD548n View in LinkedIn

HOMOLOGS. "In mammals, only a few X-linked genes have homologues on the Y chromosome, and several Y-linked genes are known that do not have homology to X-linked genes and have presumably been translocated to the Y from elsewhere; in D. melanogaster, all known Y-linked genes are in this latter category." http://www.nature.com/hdy/journal/v95/n2/full/6800697a.html View in LinkedIn

1,516 mass shootings in 1,735 days: America's gun crisis – in one chart https://www.theguardian.com/us-news/ng-interactive/2017/oct/02/america-mass-shootings-gun-violence?CMP=Share_iOSApp_Other View in LinkedIn

ANCIENT VIRUSES AND SEX. “Our results highlight the role of TEs in the initial steps of differentiation and evolution of sex chromosomes.” (TE = transposable elements). https://lnkd.in/gMXukbs View in LinkedIn

VIRAL BITS. "In many organisms, the sex chromosome pair can be recognized due to heteromorphy; the Y and W chromosomes have often lost many genes due to the absence of recombination during meiosis and are frequently heterochromatic. Repetitive sequences are found at a high proportion on such heterochromatic sex chromosomes and the evolution and emergence of sex chromosomes has been connected to the dynamics of repeats and transposable elements." https://lnkd.in/gMXukbs View in LinkedIn

GENE LOSS. "It is also well established that such nonrecombining Y or W chromosomes have lost many genes that are carried on the ancestrally homologous X or Z chromosomes (genetic degeneration." http://www.nature.com/hdy/journal/v95/n2/full/6800697a.html View in LinkedIn

CELL CYCLE REGULATION. “Although plant cell division shares basic mechanisms with all eukaryotes, plants have evolved novel molecules orchestrating the cell cycle. Some regulatory proteins, such as cyclins and inhibitors of cyclin-dependent kinases, are particularly numerous in plants, possibly reflecting the remarkable ability of plants to modulate their postembryonic development.” https://lnkd.in/gMU_Jac View in LinkedIn

“EMBRYOGENESIS in higher plants, therefore, serves (i) to specify meristems and the shoot-root body pattern, (ii) to differentiate the primary plant tissue types, (iii) to generate a specialized storage organ essential for seed germination and seedling development, and (iv) to enable the sporophyte to lie dormant until conditions are favorable for postembryonic development.” http://www.jstor.org/stable/pdf/2885440.pdf?seq=1#page_scan_tab_contents View in LinkedIn

HORMONES. “Similar to animal hormones, small endogenous signaling molecules coordinate developmental and physiological processes in plants. As with their animal counterparts, plant hormones act at low concentrations and are often not synthesized where they act.” http://www.sciencedirect.com/science/article/pii/S009286740900258X View in LinkedIn

GERM CELL SET-ASIDES. “Imagine a textbook entitled Developmental Biology that focuses entirely on plants, mentioning animals only for their peculiar way of making germ cells by setting aside a group of precursor cells early in the embryo. The converse has been, and still is, common practice.” http://ac.els-cdn.com/0092867495900659/1-s2.0-0092867495900659-main.pdf?_tid=4d4ebb00-9318-11e7-86e1-00000aacb362&acdnat=1504712004_432302d5e397300b77a7d0a78440aca5 View in LinkedIn