A simple DNA disc chip in a microarray design based on modified comparative genomic hybridization for sperm DNA analysis

"One cell-one well": a new approach to inkjet printing single cell microarrays

A new approach to prepare arrays of sessile droplets of living single cell cultures using a liquid hydrophobic barrier prevents the samples from dehydrating, and allows for spatially addressable arrays for statistical quantitative single cell studies. By carefully advancing a thin layer of mineral oil on the substrate over the droplets during the printing, dehydration of the droplets can be prevented, and the vitality of the cells can be maintained. The net result of this confluence of submerged cell culturing and inkjet printing is facile access to spatially addressable arrays of isolated single cells on surfaces. Such single cell arrays may be particularly useful as high-throughput tools in the rapidly emerging "omics" fields of cell biology.

SPERM APOPTOSIS IN NONPREGNANT LUTEALPHASE SERA AFTER IN VITRO FERTILIZATION AS ASSESSED BY COMPARATIVE GENOMIC HYBRIDIZATION

Toxicity in serum has been reported in cases of recurrent spontaneous abortions and endometriosis. The null hypothesis was that serum toxicity was not involved in failed pregnancies after in vitro fertilization procedures. The objective was to expose donor sperm to pregnant versus nonpregnant patient sera and analyze for sperm DNA damaging effects using a novel comparative genomic hybridization method. Luteal phase sera (N = 21 cases) were drawn one week after embryo transfer. Colloid-washed donor sperm were incubated (48 h, 37 degrees C, 5% CO2 in air) in 0% or 50% sera. Single-stranded DNA (ssDNA) of control sperm were stained in Hoechst 33342 and hybridized to Sybr Gold-stained ssDNA of sera-treated sperm. Image analyses were performed and fluorescent intensities analyzed. Nonpregnant patient sera (57% of cases) were associated with DNA fragmentation (64.4 +/- 8.8 pixels; mean +/- S.E.M.) when compared with pregnant patient sera (106.3 +/- 8.4 pixels). There were no differences in the sera of biochemical (108.2 +/- 15.3) versus clinical pregnancy cases (105.3 +/- 11.4). The results suggest that nonpregnant patient sera contained factor(s) that cause DNA fragmentation leading to pregnancy losses.

In vitro spermatogenesis as a method to bypass pre-meiotic or post-meiotic barriers blocking the spermatogenetic process: genetic and epigenetic implications in assisted reproductive technology

Pregnancies achieved by assisted reproduction technologies and particularly by ooplasmic injections of either in vivo or in vitro generated immature male germ cells are susceptible to genetic risks inherent to the male population treated with assisted reproduction and additional risks inherent to these innovative procedures. The documented, as well as the theoretical risks, are discussed in this review. These risks represent mainly the consequences of genetic abnormalities underlying male infertility and may become stimulators for the development of novel approaches and applications in the treatment of infertility. Recent data suggest that techniques employed for in vitro spermatogenesis, male somatic cell haploidization, stem cell differentiation in vitro and assisted reproductive technology may also affect the epigenetic characteristics of the male gamete, the female gamete, or may have an impact on early embryogenesis. They may be also associated with an increased risk for genomic imprinting abnormalities. Production of haploid male gametes in vitro may not allow the male gamete to undergo all the genetic and epigenetic alterations that the male gamete normally undergoes during in vivo spermatogenesis.

Cyclooxygenase (COX)-2 and granulosa cell apoptosis in vitro

PURPOSE

C-myc was studied in cyclooxygenase (COX)-2 associated granulosa cell apoptosis,

METHODS

Granulosa cells (N = 5 cases) were incubated for 24 h in either 1 or 50 microM COX-2 inhibitor, 1 or 50 microM COX-1/COX-2 inhibitor, negative or positive controls Single primer polymerase chain reaction of c-myc exon 1 were performed. Bisbenzimide-stained control single-stranded (ssDNA) were hybridized to SYBR Gold-stained ssDNA and fluorescent images analyzed.

RESULTS

C-myc was disrupted by the high-dose COX-2 inhibitor. Cell viability decreased with COX-1 and COX-2 inhibition. However, cell viability was similar for the positive control and at low-dose COX-2 inhibition.

CONCLUSIONS

Inhibition of both COX-1 and COX-2 initiated apoptosis without disrupting c-myc suggesting a protective effect on c-myc. The low dosage of the COX-2 inhibitor did not disrupt c-myc and cell viability. C-myc sensitization was not part of apoptosis.

Differential effects of human papillomavirus DNA types on p53 tumor-suppressor gene apoptosis in sperm

OBJECTIVE

Sperm DNA undergoes apoptotic fragmentation when exposed to HPV DNA. Details of the specific gene regions targeted by HPV in sperm are lacking. The objective of this study was to determine the integrity of exons 5 and 8 of the p53 gene in sperm exposed to HPV DNA.

METHODS

Washed sperm were exposed to either HLA-DQA1 (control) or HPV type 6b/11, 16, 18, 31, or 33 DNA fragments for 24 h at 37 degrees C. The integrity of sperm p53 exons 5 and 8 was assessed using a novel DNA disc chip assay based on comparative genomic hybridization.

RESULTS

Fragmentation of exon 5 occurred after exposure to HPV DNA type 18. In contrast, only exon 8 was affected by HPV type 16. HPV DNA from type 31 or 33 was without effect on the p53 exons. Sperm motility but not hyperactivation was reduced in all HPV groups.

CONCLUSION

The data suggest that different HPV types preferentially degrade different exons of important genes. Decreased motility but not hyperactivation in HPV-exposed sperm suggests retention of some fertilizing capacity and the possibility of transmitting virus-destabilized genes through fertilization.