In this regard, application of bioinformatic tools permitted analyzing the non-disjunction associated to recombination mechanisms and to epigenetic processes in which chromatin undergoes remodeling.
A series of prior reports show that DS caused by meiotic non-disjunction of chromosome 21 is associated to advanced maternal age; however, even though this hypothesis is accepted in general terms, unanswered questions prevail regarding the role played by other associated risk factors (5,12).
Secondly, the two versions of each exercise allow for detecting different non-disjunction
events in the F1 progeny of the cross that generates the dihybrid or trihybrid females for test-crossing.
Whereas most of the aneuploidy could be attributed to trivalent non-disjunction
, three nuclei contained complements that could not be attributed to this phenomenon [ILLUSTRATION FOR FIGURE 3F OMITTED].
The result was confirmed on karyotype analysis (performed to elucidate the mechanism of aneuploidy) as a non-disjunction
Trisomy 13 (47, XX + 13).