Seminario 18 Segregación de los cromosomas y cromosomopatías numéricas - Rodolfo Rey

Hello, my name is Rodolfo Rey and in this molecular biology and genetics class we are going to look at chromosome segregation and its influence on numerical chromosomal abnormalities. The seminar plan is as follows. Let's start by reviewing chromosome segregation and crossing over during meiosis. So, what is the concept and how are numerical and structural chromosomal abnormalities classified?

But then we're going to focus specifically on numerical chromosomal disorders , that is, their types and the mechanisms involved, since the structural ones will be covered in another seminar, and we'll finish with some clinical examples of numerical chromosomal disorders. We then began to review some things that have already been seen, how chromosomes behave during

cell division, during mitosis and during meiosis. So, how do autosomes behave during mitosis, for example? We know that a diploid cell, which in the case of humans has 23 pairs of chromosomes, the 22 pairs of autosomes that are homologous, let's say they have two homologous chromosomes per pair and thus form a diploid cell, after cell division

will give two identical diploid daughter cells , while meiosis The diploid cell when dividing will give four haploid daughter cells that will have differences between them and that is what gives rise to that genetic diversity that exists in the population thanks to recombination. We begin then with the chromosomes during meiosis, during mitosis,

sorry, in interphase. Here we have a diagram of two simple homologous chromosomes, for example, chromosome 19. The maternal chromosome 19, the paternal chromosome 19, which in the G1 phase of interphase, these homologous chromosomes are simple, that is, we have a diploid number 2n of chromosomes. and a quantity of 2 of DNA. Then in