Уважаемые коллеги,
В следующуй четверг 15 июня в 17:00 в аудитории Ц-25 состоится научный семинар, на котором выступит
Sergey Maslov (University of Illinois at Urbana-Champaign, USA)
Population Dynamics of Phage-Bacterial Ecosystems: Kill-the-Winner, Kill-the-Loser, and Kill-the-King
I will present two simple "bottom-down" models that we recently proposed and studied [1,2]. The dynamic Kill-the-Winner model [2] suggests a mechanism explaining high species diversity in microbial ecosystems exposed to predation by phages. These systems are traditionally described in terms of the static equilibrium state of Lotka-Volterra equations in which bacterial growth is exactly balanced by losses due to phage predation. Here we consider a more dynamic scenario in which phage infections give rise to abrupt and severe collapses of bacterial populations whenever they become sufficiently large. Consequently, each bacterial population in our model follows cyclic dynamics of exponential growth interrupted by sudden declines. The combined population of all species/strains stays approximately constant making cycles of individual strains cryptic. While some of the species in our model are driven towards extinction, a finite number of the fastest growing species survives. Thus, in general the ecosystem diversity remains high. The number of surviving species is inversely proportional to the variation in their growth rates but increases with the frequency and severity of phage-induced collapses. Thus counter-intuitively we predict that microbial communities exposed to more violent perturbations should have higher diversity.
[1] Maslov S, Sneppen K (2015) Diversity waves in collapse-driven population dynamics, PLoS Comput Biol 11: e1004440.
[2] Maslov S, Sneppen K (2017) Population cycles and species diversity in dynamic Kill-the-Winner model of microbial ecosystems, Scientific Reports 7, 39642 (bioRxiv: http://dx.doi.org/10.1101/067124)
Приглашаются все желающие. Если кто-то хочет побеседовать с проф. Масловым индивидуально, пожалуйста, сообщите мне об этом.
