Generation and Characterization of Mouse Aneuploid Cells

Changes in cell chromosome content and normal status are called ploidy or aneuploidy. The polyploid is a fold change in haploid chromosome content, while non-aneuploidy is a change in chromosome content, which is not a multiple of a haploid. There are many examples showing that hyplplples are fairly well tolerated at the biological level and that whole genome duplication may help to promote species evolution (1). However, this is not the case in nonhaploid cases where acquisition or loss of individual chromosomes has been shown to result in lethality and disease progression (1).

Cells with a complete genome are called euploidy, and cells with deletions or extra chromosomes are called aneuploidies. The most common aneuploidy condition is the change in the number of sex chromosomes: XO (only one copy of X), XXX or XYY. No X chromosome causes early embryonic death. Two copies of a particular chromosome, such as chromosome 1, are called homologs. The above karyotype shows all autosomal homologous pairs. Unlike sister chromatids, homologous chromosomes are not identical to each other. They often have different variants of the same genetic information - eg blue eyes color and brown eyes color, or blood type A and blood type B

The most common error that occurs during cell division is not separation, it is not possible to separate homologous chromosomes (meiosis) or sister chromatids (during meiosis or mitosis). The resulting cells are aneuploid and have abnormal genomes. Cells with extra chromosomes are called trisomy, and cells lacking the corresponding chromosome are called monomers.

Errors may occur during mitosis, especially during early human embryonic development. A mitotic error may produce aneuploid cells with one or more chromosomes that are too few or too many that are cancer related. Early human embryos, cancer cells, infected cells or intoxicated cells also undergo pathological division (tri- or multipolar mitosis) into three or more daughter cells and serious mistakes in their chromosomal complementarity . Sister chromatids can not be separated at a later stage unless separated. One daughter cell receives a sister chromatid from a non-isolated chromosome and the other does not receive a cell chromatid at all. As a result, the previous cells acquire three chromosomal copies. One is called trisomy, the latter is a state called monomer, with only one copy. Sometimes when cells undergo non-separation, they can not complete cytokinesis and retain two nuclei in one cell, resulting in binucleated cells.