Sequence variations in human ZP genes as potential modifiers of zona pellucida architecture.

To examine putative associations between zona pellucida (ZP) anomalies and sequence variations in genes expressing structural ZP glycoprotein components, sequence data of 31 volunteers participating in IVF treatments were obtained and analyzed together with morphologic data of the respective oocytes. Our results suggest that some of the most frequent zona anomalies may be at least partly explained by sequence variations in genes expressing the four human ZP proteins, especially those in ZP2 and ZP3.

Zona pellucida components are present in human fetal ovary before follicle formation.

The zona pellucida is a glycoprotein matrix surrounding oocytes and early-stage embryos in mammals. To elucidate the roles of the zona pellucida glycoproteins ZP1 and ZP3 and their key regulatory factor FIGLA in human ovarian development and folliculogenesis, their expression and localization was studied in human fetal and adult ovaries. FIGLA mRNA and ZP3 mRNA/protein were localized mainly in the oocytes, and during fetal development their maximal expression was observed around the 20th week, the time of follicle formation.

Association between sequence variations in genes encoding human zona pellucida glycoproteins and fertilization failure in IVF.

Background: The zona pellucida (ZP) has multiple roles in reproductive processes, including oocyte maturation, fertilization and implantation. We used, for the first time, a genetic approach to study whether human ZP genes possess structural alterations in women with unsuccessful IVF trials. In theory, this may result in gradual reduction of sperm-zona interaction and eventually in total fertilization failure (TFF).

Day 2 elective single embryo transfer in clinical practice: better outcome in ICSI cycles.

Background: Single embryo transfer (SET) after IVF/ICSI has been shown to result in an acceptable pregnancy rate in selected subjects. In our unit, SET is routinely carried out among women under the age of 36 in the first or second treatment cycle when a top-quality embryo is available. In order to define further the selection criteria for SET, we have analysed the outcome of elective SET (eSET), including the cumulative pregnancy rate after frozen embryo transfers, performed in the years 2000-2002 in the Oulu Fertility Center.

Expression of the elastin promoter in novel tissue sites in transgenic mouse embryos.

We have previously shown in a transgenic mouse line, in which 5.2 kb of the elastin promoter was linked to the reporter enzyme chloramphenicol acetyltransferase (CAT), that the highest levels of expression were found in embryonic lungs and aorta, while lower levels were detected in other elastin-containing tissues. Furthermore, in general, expression of the transgene showed developmental regulation similar to that of the endogenous gene.