Comparison of ART outcomes in men with altered mRNA protamine 1/protamine 2 ratio undergoing intracytoplasmic sperm injection with ejaculated and testicular spermatozoa.

Assisted reproductive technologies involving the use of spermatozoa and eggs for in vitro fertilization (IVF) have come as the solution for many infertile couples to become parents. However, in some cases, the use of ejaculated spermatozoa delivers poor IVF performance. Some studies have suggested the use of testicular spermatozoa in severe male infertility cases, but no guidelines regarding their utilization are currently available.

Clinical application of a protocol based on universal next-generation sequencing for the diagnosis of beta-thalassaemia and sickle cell anaemia in preimplantation embryos.

Research Question: Mutations of the beta-globin gene (HBB) cause beta-thalassaemia and sickle cell anaemia. These are the most common cause of severe inherited disease in humans. Traditional preimplantation genetic testing protocols for detecting HBB mutations frequently involve labour intensive, patient-specific test designs owing to the wide diversity of disease-associated HBB mutations.

Polymorphisms in the MTHFR gene influence embryo viability and the incidence of aneuploidy.

MTHFR is an important enzyme in the metabolism of folic acid and is crucial for reproductive function. Variation in the sequence of MTHFR has been implicated in subfertility, but definitive data are lacking. In the present study, a detailed analysis of two common MTHFR polymorphisms (c.

Karyomapping allows preimplantation genetic diagnosis of a de-novo deletion undetectable using conventional PGD technology.

Preimplantation genetic diagnosis (PGD) was carried out for a couple carrying a de-novo deletion in the TSC2 gene, responsible for tuberous sclerosis. Karyomapping, a method employing genome-wide analysis of single nucleotide polymorphisms (SNP), was used as PGD protocol. Analysis of DNA from the affected parent using karyomapping confirmed the region covered by the deletion and revealed more than 30 SNP located within the affected region.

Karyomapping identifies second polar body DNA persisting to the blastocyst stage: implications for embryo biopsy.

Blastocyst biopsy is now widely used for both preimplantation genetic screening (PGS) and preimplantation genetic diagnosis (PGD). Although this approach yields good results, variable embryo quality and rates of development remain a challenge. Here, a case is reported in which a blastocyst was biopsied for PGS by array comparative genomic hybridization on day 6 after insemination, having hatched completely.

Recent ecological selection on regulatory divergence is shaping clinal variation in senecio on Mount Etna.

The hybrid zone on Mount Etna (Sicily) between Senecio aethnensis and Senecio chrysanthemifolius (two morphologically and physiologically distinct species) is a classic example of an altitudinal cline. Hybridization at intermediate altitudes and gradients in phenotypic and life-history traits occur along altitudinal transects of the volcano. The cline is considered to be a good example of ecological selection with species differences arising by divergent selection opposing gene flow.

The origin and impact of embryonic aneuploidy.

Despite the clinical importance of aneuploidy, surprisingly little is known concerning its impact during the earliest stages of human development. This study aimed to shed light on the genesis, progression, and survival of different types of chromosome anomaly from the fertilized oocyte through the final stage of preimplantation development (blastocyst). 2,204 oocytes and embryos were examined using comprehensive cytogenetic methodology.

The ability of sperm selection techniques to remove single- or double-strand DNA damage.

A wide variety of techniques for the preparation of sperm are currently available, of which the most commonly employed are density-gradient centrifugation (DGC) and swim-up (SUP). To date, these methods appear to be effective in selecting functional sperm for assisted reproduction techniques (ART), but they may have negative effects on sperm DNA. In this study, the ability of these semen processing techniques to eliminate spermatozoa containing single- and double-strand DNA damage was assessed by the two-tailed comet assay and the sperm chromatin dispersion test in 157 semen samples from patients seeking assisted reproduction treatment.

A two-tailed Comet assay for assessing DNA damage in spermatozoa.

DNA fragmentation is considered an important parameter of semen quality, and of significant value as a predictor of male fertility. Poor quality chromatin is closely associated with, and highly indicative of, some fertility problems. Many methodologies to assess DNA fragmentation in spermatozoa are available, but they are all unable to differentiate between single-stranded DNA breaks (SSB) and double-stranded DNA breaks (DSB) in the same sperm cell.