The dynamics of cohesins REC8, STAG3, SMC1 beta and SMC3 suggest their participation in sister chromatid cohesion throughout the whole meiotic process in human oocytes. Our data do not support the view that decreased levels of SMC1 beta gene expression in older women are involved in age-related non-disjunction.

Spermatozoa from patients with seminal alterations exhibit a differential miRNA profile. This provides new evidence that miRNAs have an essential role in spermatogenesis, contributing to the mechanisms involved in human fertility.

No abstract

Zygotes morphologically classified as tripronuclear (3PN) after intracytoplasmic sperm injection (ICSI), which are thought to be digynic in their origin, were studied by fluorescent in-situ hybridization (FISH). FISH results allowed us to assess the suspected ploidy after morphological evaluation of the zygote and to determine the origin of the third pronuclei. Our results show that, firstly, 36% of those zygotes classified as 3PN following their morphological evaluation were, in fact, diploid, and secondly, the main cause for triploidy after ICSI is the nonextrusion of the second polar body.

Deciphering the underlying causes of idiopathic male infertility is one of the main challenges in reproductive medicine. This is especially relevant in infertile patients displaying normal seminal parameters and no urogenital or genetic abnormalities. In these cases, the search for additional sperm biomarkers is of high interest. This study was aimed to determine the implications of the sperm miRNA expression profiles in the reproductive capacity of normozoospermic infertile individuals. The expression level of 736 miRNAs was evaluated in spermatozoa from eight normozoospermic infertile males using TaqMan qRT-PCR. Results were contrasted with data from 10 control normozoospermic fertile individuals analyzed under the same conditions. Clustering analysis of miRNA expression data separated the individuals according to their fertility condition (fertile and infertile). Fifty-seven miRNAs were differentially expressed (DE-miRNAs) between populations; 20 of them was regulated by a host gene promoter that in three cases comprised genes involved in fertility. The predicted targets of the DE-miRNAs (n = 8,606) unveiled a significant enrichment of biological processes related to embryonic morphogenesis and chromatin modification. Normozoospermic infertile individuals exhibit a specific sperm miRNA expression profile clearly differentiated from normozoospermic fertile individuals. This miRNA cargo has potential implications in the individuals' reproductive competence.

The influence of aberrant sperm DNA methylation on the reproductive capacity of couples has been postulated as a cause of infertility. This study compared the DNA methylation of spermatozoa of 19 fertile donors and 42 infertile patients using the Illumina 450K array. Clustering analysis of methylation data arranged fertile and infertile patients into two groups. Bivariate clustering analysis identified a differential distribution of samples according to the characteristics of seminogram and age, suggesting a possible link between these parameters and specific methylation profiles. The study identified 696 differentially methylated cytosine-guanine dinucleotides (CpG) associated with 501 genes between fertile donors and infertile patients. Ontological enrichment analysis revealed 13 processes related to spermatogenesis. Data filtering identified a set of 17 differentially methylated genes, some of which had functions relating to spermatogenesis. A significant association was identified between RPS6KA2 hypermethylation and advanced age (P = 0.016); APCS hypermethylation and oligozoospermia (P = 0.041); JAM3/NCAPD3 hypermethylation and numerical chromosome sperm anomalies (P = 0.048); and ANK2 hypermethylation and lower pregnancy rate (P = 0.040). This description of a set of differentially methylated genes provides a framework for further investigation into the influence of such variation in male fertility in larger patient cohorts.

Spinal cord-injured men with ejaculation disorders can have children thanks to assisted reproduction techniques. Spermatozoa from these patients are usually obtained through vibratory stimulation, electroejaculation or by puncturing the seminal duct or the testicle. We present the first published case, as far as we are aware, of spermatozoa obtained through prostatic massage of a paraplegic patient. Penile vibratory stimulation was unsuccessful in this patient. In-vitro fertilization (IVF) with intracytoplasmic sperm injection (ICSI) with spermatozoa obtained through electroejaculation was performed at another centre but pregnancy was not achieved. Through prostatic massage, we obtained a total semen volume of 6 ml containing a total count of 12.32x10(6) spermatozoa (6.24x10(6) with tails), 8% of which had motility (graded + and ++); and 16% of which had normal morphology. The spermatozoa obtained were then used to perform IVF with ICSI and a triplet pregnancy was achieved. Prostatic massage appears to be an easy, non-traumatic and risk-free method to obtain spermatozoa from paraplegic patients.

The way in which the different technical aspects of clinical preimplantation genetic diagnosis affect the survival of the biopsied embryo is not well understood. One of these aspects is the influence of Ca2+/Mg(2+)-free medium on the developmental capacity of the biopsied embryo and the biopsied cell itself. Therefore, we used an experimental design involving 4-cell mouse embryos to evaluate the effect of performing the biopsy procedure under such conditions. Our results indicate that the use of Ca2+/Mg(2+)-free medium has no detrimental effect (at least in mouse embryos) on the viability of the biopsied embryos and their biopsied cells when used during relatively short times of exposure.