RT info:eu-repo/semantics/article T1 Influence of telomerase activity and initial distribution on human follicular aging: Moving from a discrete to a continuum model A1 Portillo de la Fuente, Ana María A1 Varela, E. A1 García Velasco, J.A. K1 Matemáticas K1 Telomere K1 Follicle K1 Aging K1 Partial differential equation K1 Telómero K1 Folículo K1 Envejecimiento K1 Ecuación diferencial parcial K1 12 Matemáticas AB A discrete model is proposed for the temporal evolution of a population of cells sorted according to their telomeric length. This model assumes that, during cell division, the distribution of the genetic material to daughter cells is asymmetric, i.e. chromosomes of one daughter cell have the same telomere length as the mother, while in the other daughter cell telomeres are shorter. Telomerase activity and cell death are also taken into account. The continuous model is derived from the discrete model by introducing the generational age as a continuous variable in , being the Hayflick limit, i.e. the number of times that a cell can divide before reaching the senescent state. A partial differential equation with boundary conditions is obtained. The solution to this equation depends on the initial telomere length distribution. The initial and boundary value problem is solved exactly when the initial distribution is of exponential type. For other types of initial distributions, a numerical solution is proposed. The model is applied to the human follicular growth from preantral to preovulatory follicle as a case study and the aging rate is studied as a function of telomerase activity, the initial distribution and the Hayflick limit. Young, middle and old cell-aged initial normal distributions are considered. In all cases, when telomerase activity decreases, the population ages and the smaller the value, the higher the aging rate becomes. However, the influence of these two parameters is different depending on the initial distribution. In conclusion, the worst-case scenario corresponds to an aged initial telomere distribution. PB Elsevier SN 0025-5564 YR 2023 FD 2023 LK https://uvadoc.uva.es/handle/10324/58819 UL https://uvadoc.uva.es/handle/10324/58819 LA eng NO Mathematical BiosciencesVolume 358, 2023, 108985 NO Producción Científica DS UVaDOC RD 17-jul-2024