Year: 2022

SEPARATION. "Although both autophagy and apoptosis can be activated by 20E, it must be emphasized that, while both 20E commitment and metamorphic peak are required to trigger apoptosis, which produces an increase in apoptosis-related gene expression and activation of the apoptotic pathway, respectively, autophagy might be controlled exclusively by the first 20E peak." (20E = 20-hydroxyecdysone). https://lnkd.in/eED2fPx View in LinkedIn

THE UNIVERSAL ADULT SPECIFIER. "Here, we report that a single factor, E93, controls juvenile-to-adult transition in hemimetabolous and holometabolous insects, thus acting as the universal adult specifier in winged insects. Interestingly, we find that E93 not only promotes adult metamorphosis but also represses the expression of the antimetamorphic genes Krüppel-homolog 1 and Broad-Complex, ensuring the proper juvenile–adult transition." (E93= a transcription factor). http://www.pnas.org/content/111/19/7024.full View in LinkedIn

MASTER FACTOR. "Our study has demonstrated that, despite the evolutionary distance and the differences in the developmental strategies of reaching adulthood, E93 is the universal adult specifier that acts as the “master factor” of adult metamorphosis in hemimetabolous and holometabolous insects." (E93= a transcription factor). http://www.pnas.org/content/111/19/7024.full View in LinkedIn

ORTHOLOGS. "Similar to the last juvenile stages in insects, mammalian puberty, including that of humans, is characterized by a number of hormonal events, resulting in the attainment of adult reproductive capacity. Two mammalian E93 orthologs, ligand-dependent corepressor (LCoR) and its paralog LCoR-like, have been identified." (E93= a transcription factor). http://www.pnas.org/content/111/19/7024.full View in LinkedIn

TRANSCRIPTION FACTORS. "The genetic switch between immature and adult forms in both types of insects relies on the disappearance of the antimetamorphic juvenile hormone (JH) and the transcription factors Krüppel-homolog 1 (Kr-h1) and Broad-Complex (BR-C) during the last juvenile instar." http://www.pnas.org/content/111/19/7024.full View in LinkedIn

GENE ACTIVATION. "Insect metamorphosis is hormonally regulated, and the most important hormones are the ecdysteroid 20-hydroxyecdysone (20E), which determines the successive moults, and the terpenoid juvenile hormone (JH), which represses the expression of adult features. Each hormone exerts its respective action through a cascade of transcription factors that transduce the hormonal signal to the effector genes." https://lnkd.in/e-GPevs View in LinkedIn

MICRO-RNAs. "Recently, a number of reports have pointed to microRNAs (miRNAs) as important players in the metamorphic transition, in hemimetabolan as well as in holometabolan species. One of the more dramatic demonstrations that miRNAs are involved in insect metamorphosis was reported by Gomez-Orte & Belles, who silenced dicer-1 expression by RNAi in the last nymphal instar of the cockroach Blattella germanica, and obtained supernumerary nymphs after the following moult, instead of adults." https://lnkd.in/e-GPevs View in LinkedIn

SO ENDS this peek at the most curious of rights of passage to enter new niches, avoid kin competition, and use new foods. Surely, there must be more to have gone to that much trouble for? While the how is deeply intriguing, the why remains elusive. Despite our ignorance, this lifestyle is widespread among some of the most successful insects on this planet. For science, how is often easier to answer than why. View in LinkedIn

SONG OF DARWIN. "The more I study nature, the more I become impressed […] that the contrivances and beautiful adaptations [acquired through natural selection] transcend in an incomparable degree [those] which the most fertile imagination of the most imaginative man could suggest with unlimited time at his disposal." https://lnkd.in/eykUy37 View in LinkedIn

IF PASSIONATE ABOUT STUDYING NATURE, you will need to gird yourself with a systematic approach. First, collect the invaluable natural gems. Second, permit their internal logic to become revealed. Without this grid, it is easy to get lost in the forest of endless imagination. However, with this, you will have a hunting dog to inform and enthrall for the remaining hours of this all to brief life. View in LinkedIn