Month: September 2022

SOME CONSENSUS: "eukaryotic genomes have a chimaeric nature: genes for information storage and processing are archaea-related, and genes for metabolic or ‘operational’ processes are mostly bacterial in nature (but not necessarily derived from the mitochondrial progenitor)." https://lnkd.in/dtPERjK View in LinkedIn

EVOLUTION. "Salvador Luria mused about the viral influence on evolution in 1959. “May we not feel,” he wrote, “that in the virus, in their merging with the cellular genome and reemerging from them, we observe the units and process which, in the course of evolution, have created the successful genetic patterns that underlie all living cells?” http://www.scientificamerican.com/article.cfm?id=are-viruses-alive-2004&page=3 View in LinkedIn

VIRUSES ARE US. "The human genome is full of transposable elements (TEs), endogenous viruses and various retroelements, which correspond to almost 50 % of the human genome. Infection of germline cells led to the accumulation of viral genes during evolution and made the human genome a “graveyard” of retroviral fossils." https://lnkd.in/eGaw2Kq View in LinkedIn

VIRAL DNA IS ACTIVE IN OUR GENOMES. "35-Mio-year-old endogenous HERVs can play a role in gene regulation and cancer formation to this very day. Only about 2% of the human DNA codes for protein products. This is only twice as much as in flies, worms and weeds. However, the genes are about 100-fold larger in humans, allowing complex regulation of gene expression, and with splicing, the number of coding genes is even higher. The human genome contains about 40,000 HERVs today." https://lnkd.in/eGaw2Kq View in LinkedIn

COMPLEX VIRAL SYMBIOSIS. "The wasps use their onboard viruses, called bracoviruses, to control the development and immunity of the caterpillars they parasitize. The wasps use the viral genes to make virus-like particles containing genes for a toxin, which they insert into their caterpillar prey when they lay their eggs. The infected caterpillar then acts as an incubator for the wasp eggs. Meanwhile, the toxin is made by the caterpillar and poisons its immune system, causes paralysis and stops the caterpillar from pupating." https://lnkd.in/d-szGeg View in LinkedIn

VIRAL MACHINERY MIRROR OPPOSITE. "Coevolution between retroviruses and cells resulted in a surprising phenomenon: similarities between viruses and host anti-viral defense machineries. Each component of the virus has an equivalent in the cellular antiviral defense system." https://lnkd.in/eGaw2Kq View in LinkedIn

FRAGMENT FROM NATURE continues from last weekend on the evo-devo concept. This paper examines the genetic basis for flower morphological adaptive changes. These include genetic redundancy, the fact that morphology genetic drivers are different from metabolic pathway drivers. The multi-level and nuanced capacities of the plant genome are exemplified in how flowers may change shape to adapt to new conditions. View in LinkedIn

EVODEVO ADAPTIVE EVOLUTION. "We discuss how regulatory hypotheses of developmental evolution can be used to investigate the phenotypic changes associated with adaptive diversification, providing an evolutionary developmental biology (evodevo) approach for the study of adaptive evolution." https://lnkd.in/dD4GcAS View in LinkedIn

COMPARATIVE REGULATORY NETWORKS. "We argue that only by understanding the regulatory networks that underlie organismal form and function in a comparative context can we determine how developmental evolution can lead to adaptive changes in morphology." https://lnkd.in/dD4GcAS View in LinkedIn

"THE REGULATORY HYPOTHESIS predicts that phenotypic evolution is, in most cases, associated with changes in gene expression. Unlike the more stringent cis-regulatory hypothesis championed by Carroll, the more general regulatory hypothesis makes no clear prediction about the molecular nature of the genetic changes underlying regulatory evolution (i.e. whether they are cis or trans), emphasizing only that regulation is key to developmental evolution." https://lnkd.in/dD4GcAS View in LinkedIn