Month: September 2022

FUNDAMENTAL PROCESS. "Circumnutations are absolutely growth dependent. Because circumnutation is clearly advantageous to the plant only in a small minority of cases (such as in twining plants) but is universally found in the plant kingdom, it is believed that some fundamental growth process underlies the behavior." https://lnkd.in/eNvcnv7 View in LinkedIn

SHELLS from species that are right spiraling (dextral) dominate the world of shell-handedness, and left spiraling in these right-dominated species occur only as rare mutations, ranging from one in hundreds to one in millions. https://lnkd.in/ewEX4X6 View in LinkedIn

DEXTRAL DOMINANCE. "Ninety percent of 70,000 species of Gastropoda shells are right-handed (dextral) in their coiling, and very few species have both right- and left-handed members. The gene NODAL controls their chirality." https://lnkd.in/eaZ3Yhm View in LinkedIn

CADDISFLY LARVAE build curious cases in which they live. In those that build spiral walled tubular cases, the spiral direction is random. But those that build snail-like cases, the direction of coiling is exclusively dextral or right handed, just like snail shells. https://lnkd.in/ef-MGZ9 View in LinkedIn

CHIRAL EVOLUTION. "The interesting evolutionary question of how a species of one chirality can give rise to another of opposite chirality." https://lnkd.in/eedbF-C View in LinkedIn

THE GENETIC BASIS of chirality in shells is quite simple. "Chirality is determined by a single gene or a small set of genes inherited from the mother, with the right-hand twist form being dominant." https://lnkd.in/eWG5ySJ View in LinkedIn

THE SNAIL NODAL GENE controls the body orientation in many (or most) species, discriminating between left and right, top from bottom and back from belly. It is critical in determining symmetry during development. https://lnkd.in/emDBBtm View in LinkedIn

THE CHIRALITY GENE in snails. "The general solution to the problem of symmetry breaking is provided by a pre-existing asymmetric molecular reference, or F-molecule...Asymmetry is thus entirely dependent on the chirality and alignment of the F-molecule," (now called NODAL). https://lnkd.in/eRqXtYc View in LinkedIn

FRAGMENT IN NATURE this weekend focuses on the gut-brain axis, and recent evidence that it is our "second brain", driven by the gut microbiome. This extraordinary new perspective of our most fundamental anatomy and physiology is sure to eventually change the way that we view and manage our health and disease. View in LinkedIn

"THE BRAIN-GUT AXIS is a bidirectional communication system between the central nervous system and the gastrointestinal tract. Serotonin functions as a key neurotransmitter at both terminals of this network. Accumulating evidence points to a critical role for the gut microbiome in regulating normal functioning of this axis." https://lnkd.in/enJwVms View in LinkedIn