The potential role of the mobile and non-coding genomes in adaptive response

Experimentally altering microRNA levels in embryos alters adult phenotypes

We previously identified a unique genetic feature of Autism Spectrum Disorder (ASD) in human patients and established mouse models, a low to very low level of six microRNAs, miR-19a-3p, miR-361-5p, miR-3613-3p, miR-150-5p, miR-126-3p and miR-499a-5p. We attempted to interfere experimentally in mice with two of them, miR19a-3p and miR499a-5p by microinjecting into zygote pronuclei either the complementary sequence or an excess of the microRNA. Both resulted in low levels in the tissues and sperm of the targeted microRNAs and their pri and pre precursors. This method stably modify predetermined levels of miRNAs and identify miRNA alterations that cause changes in autistic behavior and predispose the individual to an inherited disease. Excess miRNA results in single-stranded miRNA variations in both free and DNA-bound RNA (R-loop) fractions in mouse models thus appearing to affect their own transcription. Analysis of miRNAs fractions in human patients blood samples confirm low level of six microRNAs also in R-loop fractions.

"If I Were in Nature's Place, I Would Do It Like This..." Life and Hypotheses of Alexey Olovnikov

In this article, we commemorate the life and scientific journey of the brilliant gerontologist-theorist Alexey Olovnikov (1936-2022). In 1971, he published his famous "marginotomy" hypothesis, in which he predicted the replicative shortening of telomeres and its role as a counter of cell divisions and biological age of an organism. This work put forth several remarkable assumptions, including the existence of telomerase, which were confirmed two decades later. Despite this, Alexey Olovnikov moved further in his theoretical studies of aging and proposed a series of new hypotheses that seem no less exotic than the marginotomy hypothesis once appeared. Alexey Olovnikov had an extraordinary way of looking at biological problems and, in addition to aging, authored striking concepts about development, biorhythms, and evolution.