Year: 2022

NEW CHROMOSOMES. "If a gene from elsewhere in the genome becomes the new male sex-determining gene, then a new chromosome will evolve to become the Y (nonhomologous turnover). An increasing number of systems are described where this may have happened." http://www.pnas.org/content/112/34/10575.full View in LinkedIn

TRANSITION OF SETS. "The emergence of a new master sex-determining gene on a different chromosome can also lead to a shift of the heterogametic sex, [e.g., transforming a XY system into ZW (nonhomologous transition)]. Such a situation is again represented in the ricefishes. Two species have ZW sex determination on two linkage groups, which are different from those that became the X and the Y in the other five species." http://www.pnas.org/content/112/34/10575.full View in LinkedIn

FRAGMENT FROM NATURE contemplates the question of how animals differ from plants. This may seem like a quaint and perhaps academic question, but it is far from the case. Imagine a creature that continues to form body parts throughout its life, in a quasi pluripotent state, forever capable of regeneration of an adult from a fragment of tissue. This creature can morph its anatomy and physiology according to the conditions. And the delineation of an individual in this creature is essentially a group of cells, not the organism. Read on. View in LinkedIn

PLANTS ARE REALLY ALIENS. When compared to animals, plants seem like creatures from another planet, organized in ways that have little semblance to animals. They stand apart in the natural world. View in LinkedIn

“A DEFINING FEATURE of plants is of course their mostly postembryonic development, which displays substantial plasticity with respect to endogenous as well as environmental cues.” https://lnkd.in/gVFjvM2 View in LinkedIn

POSTEMBRYONIC DEVELOPMENT is “the period in the ontogenesis of multicellular animals that follows the period of embryonic development and usually ends with the onset of sexual maturity and, in most animals, the cessation of growth.” https://lnkd.in/g_83yR2 View in LinkedIn

INDEPENDENT EXISTENCE. “Postembryonic development begins after the emergence of the embryo from the egg and embryonic membranes, when the organism becomes capable of active feeding and locomotion.” http://encyclopedia2.thefreedictionary.com/Postembryonic+Development View in LinkedIn

DEVELOPMENT OPTIONS. “Upon transition to the postembryonic state the organism either immediately possesses the principal pubertal morphological characteristics (direct development) or essentially differs from the pubertal form, in which case the larva that hatches out of the egg must undergo a metamorphosis before it reaches its adult state.” http://encyclopedia2.thefreedictionary.com/Postembryonic+Development View in LinkedIn

CELL CYCLE. “Plant genome projects have revealed that both the cell-cycle components and the overall cell-cycle architecture are highly evolutionarily conserved. In addition to the temporal and spatial regulation of cell-cycle progression in individual cells, multicellularity has imposed extra layers of complexity that impinge on the balance of cell proliferation and growth, differentiation and organogenesis.” https://lnkd.in/g8-4Y_M View in LinkedIn

ORGAN GROWTH IN PLANTS. “In contrast to animals, organogenesis in plants is a postembryonic and continuous process. Differentiated plant cells can revert to a pluripotent state, proliferate and transdifferentiate. This unique potential is strikingly illustrated by the ability of certain cells to produce a mass of undifferentiated cells or a fully totipotent embryo, which can regenerate mature plants.” https://lnkd.in/g8-4Y_M View in LinkedIn