Combined use of proacrosin immunocytochemistry and autosomal DNA in situ hybridisation for evaluation of human ejaculated germ cells

The recently reported human pregnancies and births after fertilising oocytes with round spermatids recovered from the ejaculate of men with non-obstructive azoospermia have underscored the need for a more accurate evaluation of the nuclear and cytoplasmic maturation status of ejaculated germ cells. In this study we describe our first experience with a method combining the immunocytochemical visualisation of proacrosin with autosomal DNA fluorescence in situ hybridisation (FISH) to assess ejaculated germ cells from patients with a spermiogenesis defect. The proacrosin immunoreactivity, analysed with the use of the monoclonal antibody 4D4, has been detected in cells of round spermatid size presenting a haploid FISH figure as well as in larger cells whose ploidy corresponds to primary and secondary spermatocytes. These observations are in agreement with previously published results obtained, with the use of the same antibody, by immunocytochemical analysis of histological sections of testicular tissue. All the cells of round spermatid size possessing proacrosin immunoreactivity were found to be haploid by FISH. On the other hand, some of the haploid cells of round spermatid size did not possess proacrosin immunoreactivity. The structural pattern of proacrosin immunoreactivity was highly variable both in spermatids and in younger spermatogenic cells. These data show that cell size is the main criterion to be used for the identification of ejaculated round spermatids, whereas the presence of the developing acrosome represents only an auxiliary criterion. The scoring of acrosomal development in ejaculated spermatids may be useful as part of pre-treatment diagnosis before the inclusion of infertile couples in a spermatid conception programme.

Cytogenetics of uncleaved oocytes and arrested zygotes in IVF programs

PURPOSE

Cytogenetic studies of arrested oocytes and zygotes were used to understand in vitro fertilization (IVF) failures.

METHODS

We investigated the cytogenetics (Giemsa banding and FISH) of 710 uncleaved oocytes and 94 arrested zygotes from 208 patients undergoing IVF procedures.

RESULTS AND CONCLUSIONS

Of uncleaved oocytes without a polar body, 39% were judged cytogenetically abnormal (17% unbalanced predivision and 21.5% diploid). Of 575 oocytes with a polar body, 124 (21.5%) showed numerical or structural chromosome aberrations. In arrested zygotes, approximately equal cases were found with separate condensed haploid complements (no syngamy), nuclear asynchrony and pulverized DNA, and apparently cytogenetically normal zygotes arrested at mitosis. These data on chromosome abnormalities were also analyzed with respect to two ovarian stimulation protocols and to maternal age. Both ovarian stimulation protocols and to maternal age. Both ovarian stimulation protocols showed the same levels of chromosome abnormalities. Overall chromosome abnormalities and premature chromosome condensation were also unchanged with maternal age. These data illustrate the significance of chromosome aberrations in IVF failures.

Nonrandom changes of chromosome 10 in bladder cancer. Detection by FISH to interphase nuclei

Fluorescence in situ hybridization (FISH) to interphase nuclei has been a valuable method for examining the chromosome copies in tumor cells in clinical practice. Twelve cases of transitional cell carcinoma (TCC) of the bladder were investigated with a biotin-labeled repetitive DNA probe to detect numerical aberrations of chromosome 10 in interphase nuclei. The cells containing one fluorescent signal were screened in two of seven non-invasive tumors and in four of five invasive tumors. Two patients presented two FISH spots of different sizes. More than two signals were seen in one invasive tumor. The findings suggest that partial or complete loss of a chromosome 10 is a nonrandom aberration in bladder cancer.

Karyotype and FISH analysis of a newly established cell line derived from a human bladder carcinoma

A new human malignant urologic cell line was established in vitro from a moderately differentiated transitional cell carcinoma of the bladder and cytogenetically characterized. Repeated chromosome analyses of the cell line using conventional RHG and GTG banding and non-radioactive in situ hybridization showed a stable karyotype with a modal number of 48 and chromosomal rearrangements, some of which have not been previously described. Numerical deviation included three trisomies (+7, +8, +9) and one nullisomy (-19, -19). Structural changes involved a balanced translocation (1;5)(q12;q12), an isochromosome 3q, a 14p+, and two markers. Fluorescence in situ hybridization (FISH), using biotin-labeled alpha satellite probes for chromosome 9 or painting for chromosomes 1 and 8, applied to interphase nuclei or metaphases showed similar results to those found by conventional cytogenetic study. This cell line may be an interesting model for fuller characterization by molecular biology studies and for testing anti-cancer drugs in vitro.

Assessment of polyploidy in human morulae and blastocysts using co-culture and fluorescent in-situ hybridization

Fluorescence in-situ hybridization with DNA probes for X, Y and no. 18 chromosomes was used to analyse human morulae (n = 13) and blastocysts (n = 41), obtained after co-culture on Vero cells. On the basis of the number of hybridization signals, the proportion of embryos with more than five polyploid cells was 30.8% for morulae and 29.3% for blastocysts. These values are similar to those for mixoploidy (mosaicism of diploid and polyploid cells) observed in blastocysts of animal species. The results were confirmed by scanning electron microscopy, which showed a wide variation in the size of blastocyst nuclei, and by classical cytogenetic analysis. Mixoploidy seems to be a normal feature in preimplantation embryos and to occur very early in human embryo development. This lays open to doubt the preimplantation diagnosis of genetic errors at these stages, since results obtained from single cell analysis may not be representative of the whole embryo.