Sperm FISH and chromatin integrity in spermatozoa from a t(6;10;11) carrier

Abstract

Complex chromosome rearrangements (CCRs) are structurally balanced or unbalanced aberrations involving more than two breakpoints on two or more chromosomes. CCRs can be a potential reason for genomic imbalance in gametes, which leads to a drastic reduction in fertility. In this study, the meiotic segregation pattern, aneuploidy of seven chromosomes uninvolved in the CCR and chromatin integrity were analysed in the ejaculated spermatozoa of a 46,XY,t(6;10;11)(q25.1;q24.3;q23.1)mat carrier with asthenozoospermia and a lack of conception. The frequency of genetically unbalanced spermatozoa was 78.8% with a prevalence of 4:2 segregants of 38.2%, while the prevalence of the adjacent 3:3 mode was 35.3%. Analysis of the aneuploidy of chromosomes 13, 15, 18, 21, 22, X and Y revealed an approximately fivefold increased level in comparison with that of the control group, indicating the presence of an interchromosomal effect. Sperm chromatin integrity status was evaluated using chromomycin A3 and aniline blue staining (deprotamination), acridine orange test and TUNEL assay (sperm DNA fragmentation). No differences were found when comparisons were made with a control group. We suggest that the accumulation of genetically unbalanced spermatozoa, significantly increased sperm aneuploidy level and decreased sperm motility (20%, progressive) were not responsible for the observed lack of reproductive success in the analysed infertile t(6;10;11) carrier. Interestingly, in the case described herein, a high level of sperm chromosomal imbalance appears not to be linked to sperm chromatin integrity status.

Global methylation status of sperm DNA in carriers of chromosome structural aberrations

“…Sperm DNA fragmentation was evaluated using the TUNEL assay (Flow TACS Apoptosis Detection Kit, R&D Systems, Minneapolis, MN, USA) as previously described 27. The principle of the assay was to identify spermatozoa with fragmented DNA-based complex formation between the biotinylated DNA fragments and streptavidin-conjugated fluorescein (FITC) in the presence of terminal deoxynucleotidyl transferase (TdT).…”

Chromosome (re)positioning in spermatozoa of fathers and sons – carriers of reciprocal chromosome translocation (RCT)

“…To clarify the order in the present study, we have provided a short summary of the data concerning hyperhaploidy, the genetic imbalance ratio, and chromatin integrity for the spermatozoa of the evaluated RCT carriers in Table 1, which have been were previously published [45, 47–49, 51]. Because of the individual characteristics of each RCT, no mean values were estimated, and the obtained results were compared only to mean control values.…”

“…Ideograms of the analysed RCT cases are shown in Additional file 1: Figure S1. The control sperm cells originated from our laboratory group of healthy, fertile, male donors aged between 25 and 30 years with normozoospermia [50], in the following numbers: n = 7 for aneuploidy evaluation (previously published by Olszewska et al, [51]), n = 15 for chromatin integrity tests (previously published by Olszewska et al, [51]) and n = 8 for topology analysis (not published elsewhere). Ejaculated semen samples from all men were collected after 3–5 days of sexual abstinence.…”

Genetic dosage and position effect of small supernumerary marker chromosome (sSMC) in human sperm nuclei in infertile male patient

“…The status of chromatin maturity was determined using two described previously staining methods 59 . The first method, aniline blue staining (AB; Water Blue, Fluka, Germany), relies on the binding of aniline to the lysine-rich residues of histones, resulting in a dark blue color of the sperm chromatin.…”