Meiotic Segregation, Recombination, and Gamete Aneuploidy Assessed in a t(1;10)(p22.1;q22.3) Reciprocal Translocation Carrier by Three- and Four-Probe Multicolor FISH in Sperm

Abstract

Meiotic segregation, recombination, and aneuploidy was assessed for sperm from a t(1;10)(p22.1;q22.3) reciprocal translocation carrier, by use of two multicolor FISH methods. The first method utilized three DNA probes (a telomeric and a centromeric probe on chromosome 1 plus a centromeric probe on chromosome 10) to analyze segregation patterns, in sperm, of the chromosomes involved in the translocation. The aggregate frequency of sperm products from alternate and adjacent I segregation was 90.5%, and the total frequency of normal and chromosomally balanced sperm was 48.1%. The frequencies of sperm products from adjacent II segregation and from 3:1 segregation were 4.9% and 3.9%, respectively. Reciprocal sperm products from adjacent I segregation deviated significantly from the expected 1:1 ratio (P < .0001). Our assay allowed us to evaluate recombination events in the interstitial segments at adjacent II segregation. The frequencies of sperm products resulting from interstitial recombination in chromosome 10 were significantly higher than those resulting from interstitial recombination in chromosome 1 (P < .006). No evidence of an interchromosomal effect on aneuploidy was found by use of a second FISH method that simultaneously utilized four chromosome-specific DNA probes to quantify the frequencies of aneuploid sperm for chromosomes X, Y, 18, and 21. However, a significant higher frequency of diploid sperm was detected in the translocation carrier than was detected in chromosomally normal and healthy controls. This study illustrates the advantages of multicolor FISH for assessment of the reproductive risk associated with translocation carriers and for investigation of the mechanisms of meiotic segregation of chromosomes.

Fluorescence in situ hybridisation (FISH) analysis of chromosome segregation and interchromosomal effect in spermatozoa of a reciprocal translocation t(9,10)(q11;p11.1) carrier

“…Dual-colour FISH with centromeric probes enabled the authors to differentiate between alternate and adjacent-1 segregation because one of the breakpoints had a centromeric position. In our study, as in other published data (Cifuentes et al 1999;Van Hummelen et al 1997;Estop et al 1998;Blanco et al 1998Martini et al 1998Geneix et al 2002), a three-colour FISH analysis using a locusspecific probe for the translocated fragment and centromeric probes has enabled the detection of all types of segregations. The differentiation of adjacent-1 and alternate segregation was also possible because the interstitial segment at meiosis 1 is short, reducing considerably the probability of an interstitial chiasma (Armstrong and Hulten 1998).…”

Meiotic outcomes in reciprocal translocation carriers ascertained in 3-day human embryos

“…Alternate segregation was the most frequent mode, and adjacent-1 the most frequent mode leading to imbalance, in sperm of a t(4;8) carrier 14 and in the sperm of a t(1;10) carrier. 12 The Meiotic outcomes in reciprocal translocation carriers CM Ogilvie and PN Scriven 804 conclusion from these studies was that the mode predicted by pachytene shape algorithms was likely to reflect selection for the least genetic imbalance and hence to give the most likely viable outcome of any translocation. 5 We describe the investigation of segregation modes in male and female translocation carriers by FISH on cleavage stage embryos.…”

Linear increase of diploidy in human sperm with age: A four-colour FISH study

“…Moreover, our data are in agreement with the high percentage of triploids of paternal origin (among which over 10% originate from diploid sperm). 38 Significant frequencies of diploid sperm have also been found in some carriers of balanced chromosome reorganisations, 39 in fathers of children with Down syndrome, 40 and in infertile patients, specially oligoasthenoteratozoospermic patients. 41,42 One possible explanation for this increase of diploid sperm frequency in older men would be the tendency of these individuals to show synaptic anomalies related to a progressively deteriorating testicular environment.…”