High prevalence of AZFb microdeletion in Iranian patients with idiopathic non-obstructive azoospermia.

Background & objectives: Genetic factors contribute about 10 per cent of male infertility. Among these, genes in azoospermia factor (AZF) region including AZFa, AZFb, AZFc and AZFd on the long arm of Y chromosome are considered most important for spermatogenesis. Deletions in these regions are thought to be involved in some cases of male infertility associated with azoospermia or oligozoospermia. We studied the incidence of AZF deletions among Iranian infertile men with idiopathic non-obstructive azoospermia. Methods: A total of 100 Iranian azoospermic infertile men were selected for the molecular study of Y chromosome microdeletions. The presence of 13 sequence tagged site (STS) markers from AZF region was investigated using multiplex polymerase chain reaction (M-PCR). One hundred fertile men were also studied as control group. Results: Twelve (12%) patients showed Y chromosome microdeletions and among these, deletion in AZFb region was the most frequent (66.67%) followed by AZFc (41.67%), AZFd (33.33%) and AZFa (8.33%), respectively. Interpretation & conclusions: Because of relatively high incidence of Y chromosome microdeletions among Iranian azoospermic patients, molecular screening may be advised to infertile men before using assisted reproductive treatments.

Evaluation of a Multiplex PCR Kit Used for Detecting Y Chromosome Microdeletions / 대한진단검사의학회지

BACKGROUND: In addition to Klinefelter's syndrome, microdeletion of Yq is the most common genetic cause of male infertility; 15% of azoospermic or 5-10% of oligozoospermic males have Yq deletions. We evaluated a Yq microdeletion kit (LG Life Sciences, Korea) for identifying microdeletions in the azoospermic factor (AZF) regions of the Yq. METHODS: The kit was designed to amplify 3 regions of the AZF gene (AZFa, AZFb, and AZFc) using 15 sequence-tagged sites. We evaluated the preclinical performance of the kit. For clinical validation, 58 patients including 25 idiopathic azoospermic or oligozoospermic patients were examined. RESULTS: We observed clear bands on electrophoresis of DNA, up to a DNA concentration of 3.12 ng/microliter; the known microdeletion regions of all 6 reference cell-lines (Coriell, USA) were accurately detected and no false positive/negative results showed with normal female (n=11) and fertile male (n=15) specimens. This kit could identify the same microdeletions in the common regions, similar to another commercial kit. Among the 58 male infertile patients, 7 (12.1%) had microdeletions of the Yq. Among the idiopathic azoospermic (n=22) and oligozoospermic (n=3) patients, 3 (12.0%) had microdeletions. Further, 2 of 21 varicocele patients (9.5%), 1 of 4 patients with testicular failure, and 1 patient with a 45,X/46,XY mosaic had microdeletions. CONCLUSIONS: The kit was effective for detecting microdeletions of the Yq. We identified microdeletions in 12% of the infertile patients. This Y chromosome microdeletion detection kit is useful for screening Yq microdeletions in infertile patients.

Ion-exchange chromatography used to isolate a spermadhesin-related protein from domestic goat (Capra hircus) seminal plasma

Mammalian seminal plasma contains among others, proteins called spermadhesins, which are the major proteins of boar and stallion seminal plasma. These proteins appear to be involved in capacitation and sperm-egg interaction. Previously, we reported the presence of a protein related to spermadhesins in goat seminal plasma. In the present study, we have further characterized this protein, and we propose ion-exchange chromatography to isolate this seminal protein. Semen was obtained from four adult Saanen bucks. Seminal plasma was pooled, dialyzed against distilled water and freeze-dried. Lyophilized proteins were loaded onto an ion-exchange chromatography column. Dialyzed-lyophilized proteins from the main peak of DEAE-Sephacel were applied to a C2/C18 column coupled to an RP-HPLC system, and the eluted proteins were lyophilized for electrophoresis. The N-terminal was sequenced and amino acid sequence similarity was determined using CLUSTAL W. Additionally, proteins from DEAE-Sephacel chromatography step were dialyzed and submitted to a heparin-Sepharose high-performance liquid chromatography. Goat seminal plasma after ion-exchange chromatography yielded 6.47 +/- 0.63 mg (mean +/- SEM) of the major retained fraction. The protein was designated BSFP (buck seminal fluid protein). BSFP exhibited N-terminal sequence homology to boar, stallion and bull spermadhesins. BSFP showed no heparin-binding capabilities. These results together with our previous data indicate that goat seminal plasma contains a protein that is structurally related to proteins of the spermadhesin family. Finally, this protein can be efficiently isolated by ion-exchange and reverse-phase chromatography.

Application of DNA chip techniques for Yq microdeletion analysis in infertile males

Our aim was to apply DNA chip technology as a diagnostic tool in infertility research and clinics. Six loci, including a sex-determining region on the Y chromosome and five sequence-tagged sites in azoospermia-factor regions were investigated in infertile male patients. Our method produced a sensitive signal, which showed the presence or absence of the STS regions on the Y chromosome. The results from 93 patients with non- obstructive azoospermia, oligoathenoteratozoospermia, or oligozoospermia were identical when analyzed with either the DNA chip technique or conventional PCR-gel electrophoresis. We have demonstrated its application in the molecular diagnosis of male infertility. This system provides an economic and high-throughput method for detecting the deletion of genomic DNA sequences of large groups of infertile patients, and a completely new approach to male infertility screening. The application of DNA chip technology to identify Yq deletions can also facilitate our understanding of male infertility.