Results suggest that meiosis and spermiogenesis can be resumed in vitro, with normal differentiated spermatids showing a low fertilization potential but regular rates of blastocyst formation. However, most of the embryos did not reach the morula stage and showed major sex chromosome abnormalities.

Histopathological subgroups were positively correlated with successful gamete retrieval. No major outcome differences were observed between testicular sperm and elongated spermatids, either fresh or frozen-thawed. However, injection of intact round-spermatids showed very low rates of fertilization and no pregnancies.

Previous studies relating hormone and cytokine concentrations in follicular fluid to oocyte fertilizability were flawed by the uncertainty about the actual oocyte maturity status at the time of recovery and by the possible contribution of the male factor to failures of conventional in-vitro fertilization. This is the first study in which oocyte maturity was assessed immediately after recovery and only mature oocytes were selected for treatment by intracytoplasmic sperm injection. Fertilization outcomes were related to follicular fluid concentrations of 17beta-oestradiol, progesterone, follicle stimulating hormone, luteinizing hormone (LH), growth hormone (GH), prolactin (PRL), interleukin-1 (IL-1) and tumour necrosis factor-alpha (TNF alpha). Those oocytes that subsequently showed normal fertilization were harvested from follicles with higher concentrations of progesterone, GH, PRL, IL-1 and TNF alpha as compared with those of oocytes that failed to fertilize. Among the normally fertilized oocytes, low GH concentrations were associated with the failure of cleavage and with poor morphology of cleaving embryos, whereas rapidly cleaving embryos developed from oocytes recovered from follicles with high concentrations of LH and IL-1. These data suggest important roles for GH, IL-1 and TNF alpha, and of residual LH after pituitary suppression, as positive regulators of the final phase of oocyte intrafollicular development.

In an attempt to determine whether co-culture could promote sperm maturation, three patients with non-obstructive azoospermia, two with maturation arrest at the level of primary spermatocytes and one patient with <1% tubules showing complete spermatogenesis, and one patient with total globozoospermia, gave consent to experimentally co-culture round spermatids retrieved from the testicle on Vero cell monolayers. In all azoospermic patients elongating spermatids could be obtained from round spermatids. In one case of maturation arrest, of 37 round spermatids co-cultured for up to 5 days, 30% developed flagella, 46% matured to elongating and 19% to elongated spermatids, with one mature spermatozoon also obtained (3%). In the same patient, primary cultures of three round spermatids with flagella enabled development of one further mature spermatozoon. In the case with total globozoospermia, of six round spermatids co-cultured for up to 5 days, one mature spermatozoon was obtained, with a flagellum and normal head morphology. These preliminary findings suggest that it may be possible to overcome the round spermatid block, and even the triggering of morphological abnormalities arising at the spermiogenic level, by in-vitro maturation under special environmental conditions.

The incidence of Y/autosome translocations is low. Whereas involvement of non-acrocentric chromosomes often leads to infertility, cases related with acrocentric chromosomes are usually familial with no or minimal effect on fertility. A de novo (Yp/13p) translocation was found in a 32-year-old male referred for severe oligozoospermia. Conventional cytogenetic procedures (GTG, CBG and NOR banding) and molecular cytogenetic techniques (Fluorescence In Situ Hybridization, FISH) were performed on high-resolution chromosomes obtained after peripheral blood lymphocyte culture as also on interphase nuclei of spermatogenic cells from semen samples. Screening of AZF microdeletions in the Yq11.2 region known to be involved with spermatogenesis defects was also performed. GTG banding showed a (Yp/13p) translocation in all scored metaphases. CBG and NOR staining of the derivative chromosome revealed the maintenance of Yq heterochromatin and of the 13p NOR region. FISH with centromeric Y and 13/21 probes, SRY specific probe and X/Y (p and q arms) sub-telomeric probes gave the expected number/location of fluorescent signals. Hybridisation with a pan-telomeric repeat (TTAGGG) probe showed an absence of the telomeric sequences at the fusion point of the rearranged chromosome. FISH analysis with probes to chromosomes X, Y, 13 and 18 showed an abnormal segregation of the translocated chromosome during meiosis I, which explains that only 13.6% of the secondary spermatocytes were normal. Most of these became arrested, as after meiosis II the large majority of the round spermatids were normal (70%), as were in consequence most of the sperm (85.1%). Multiplex-PCR confirmed the intactness of the SRY region and showed absence of AZF microdeletions. We report a novel de novo (Yp;13p) translocation characterised by loss of the 13p and Yp telomeres. Meiotic studies using FISH demonstrated meiosis I chromosome unpairing and mal segregation that justifies the severe oligozoospermia. Although most sperm have a normal chromosomal constitution, preimplantation genetic diagnosis should be considered an option for this patient.