DNAJB13 is a radial spoke protein of mouse '9+2' axoneme.

It has been shown that DNAJB13, a type II heat shock protein 40, is highly expressed in the testis and is an axonemal component of mouse mature spermatozoa. By multi-tissue reverse transcription polymerase chain reaction, we found that Dnajb13 gene was expressed not only in the testis but also in several other ciliated cell-containing tissues like brain, lung and oviduct. Immunohistochemistry on mouse trachea and oviduct sections shown that DNAJB13 was present in the motile cilia of those tissues. To define further its localization in the axoneme, immunoelectron microscopy of mouse sperm flagella was performed and shown that DNAJB13 was localized to radial spokes of the axoneme. Taken together, our data indicate that DNAJB13 is a radial spoke protein of the mouse '9+2' axoneme.

Trisomy 5q12-->q13.3 in a patient with add(13q): characterization of an interchromosomal insertion by forward and reverse chromosome painting.

We report on a patient with azoospermia, mild mental retardation, and minor physical anomalies. Chromosome analysis demonstrated the presence of additional material on the long arm of one chromosome 13. Forward chromosome painting using chromosome-specific libraries showed an insertion of material from chromosome 5. Further characterization with flow sorting of the aberrant chromosome and amplification by DOP-PCR followed by reverse chromosome painting showed specific trisomy of 5q12-->q13.3.

Greig syndrome in a large kindred due to reciprocal chromosome translocation t(6;7)(q27;p13).

We report on cases of Greig syndrome segregating in a large kindred over four generations due to reciprocal translocation t(6;7)(q27;p13) and on a patient from this pedigree with a severe malformation syndrome due to duplication 7(p13----pter). The clinical findings are discussed as possible consequence of a gene mutation due to the break at 7p13.

Human fertility does not decline: evidence from Sweden.

OBJECTIVE: To assess changes in human fertility over time. DESIGN: Time-trend analyses and age-period-cohort modeling. SETTING: Sweden, 1983-1993. PATIENT(S): All primiparous women aged > or =20 years during the study period. There were 401,653 women who were identified through the nationwide Medical Birth Register. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Risk of subfertility, defined as > or =1 year of involuntary childlessness. RESULT(S): Subfertility problems decreased dramatically over successive maternal birth cohorts. Further, the risk of subfertility increased with age and decreased with increasing formal education. CONCLUSION(S): A decrease in male fertility cannot be ruled out on the basis of these results, but if present, it is minor and totally outweighed by other favorable developments. As the main explanation for our findings, we propose a decrease in the prevalence of secondary subfertility as a result of the eradication of gonorrhea.

Anatomy of the prostate. Aspects of the secretory function in relation to lobar structure.

Anatomic studies have shown the prostate to be a heterogeneous organ in which at least three morphologically differing zones or lobes are identifiable. This indicates that the endocrinologic sensitivity of the prostate is not uniform, and that there may also be intraprostatic functional variations. Few studies have so far been done to prove such differences. Although interlobar differences in zinc content have been observed, their significance is not clear. The field is therefore open for further studies concerning both the anatomic and the functional heterogeneity of the human prostate.

The physiological roles of the boar ejaculate.

During ejaculation in the boar, sperm cohorts emitted in epididymal cauda fluid are sequentially exposed and resuspended in different mixtures of accessory sex gland secretion. This paper reviews the relevance of such unevenly composed fractions of seminal plasma (SP) in vivo on sperm transport and sperm function and how this knowledge could benefit boar semen processing for artificial insemination (AI). The firstly ejaculated spermatozoa (first 10 ml of the sperm-rich fraction, SRF [P1]) remain mainly exposed to epididymal cauda fluid and its specific proteins i.e. various lipocalins, including the fertility-related prostaglandin D synthase; than to prostatic and initial vesicular gland secretions. P1-spermatozoa are hence exposed to less bicarbonate, zinc or fructose and mainly to PSP-I spermadhesin; than if they were in the rest of the SRF and the post-SRF (P2). Since the P1-SP is less destabilizing for sperm membrane and chromatin, P1-spermatozoa sustain most in vitro procedures, including cryopreservation, the best. Moreover, ejaculated firstly, the P1-spermatozoa seem also those deposited by the boar as a vanguard cohort, thus becoming overrepresented in the oviductal sperm reservoir (SR). This vanguard SR-entry occurs before the endometrial signalling of SP components (as PSP-I/PSP-II and cytokines) causes a massive influx of the innate defensive PMNs to cleanse the uterus from eventual pathogens, superfluous spermatozoa and the allogeneic SP. The SP also conditions the mucosal immunity of the female genital tract, to tolerate the SR-spermatozoa and the semi-allogeneic conceptus. These in vivo gathered data can be extrapolated into procedures for handling boar spermatozoa in vitro for AI and other biotechnologies, including simplified cryopreservation.

Rapid post-ejaculatory inhibitory effect of seminal plasma on sperm nuclear chromatin decondensation ability in man.

The stability of the nuclear chromatin in human spermatozoa soon after ejaculation was studied by exposing the cells to sodium dodecyl sulphate (SDS) one to 20 min after ejaculation. Semen samples were obtained both from men with apparently normal, and from men with impaired prostatic secretion (= subnormal seminal plasma [Zn]). The sperm nuclear resistance to decondensation in SDS increased in both groups during the first 15 min after ejaculation, but was significantly lower in the semen samples with subnormal [Zn]. This fast post-ejaculatory increment in sperm SDS resistance was significantly reduced by a 5-fold saline dilution of the semen at the time of ejaculation. It is discussed if the observed stabilization with time was illusory and that a prostatic component instead counteracted an intrinsic nuclear chromatin decondensation (NCD) process initiated by SDS derangement of spermatozoal membranes.

Reversible inhibition of nuclear chromatin decondensation (NCD) ability of human spermatozoa induced by prostatic fluid.

In semen from donors with adequate secretory function of the prostate, spermatozoa in the first ("prostatic") portion of the ejaculate were more resistant to nuclear swelling in sodium dodecyl sulphate (SDS) than spermatozoa from the second ("vesicular") portion. No such difference was revealed by a donor with severely impaired prostatic function. This demonstrates that some sperm nuclear chromatin stabilizing factor(s) is present in normal prostatic fluid. The chromatin stabilizing factor(s) could largely be removed by washing the spermatozoa in saline containing albumin. Spermatozoa sensitized to SDS in this manner regained their SDS resistance upon exposure to normal (zinc-rich) "prostatic fluid". Such exposure also induced a high degree of resistance in natively SDS sensitive spermatozoa. The possibility is discussed that zinc of prostatic or other origin reversibly inhibits a nuclear chromatin decondensation ability (NCD-ability). It is suggested that such a mechanism may be of essential importance for male genome transfer.

Importance of spermatozoal zinc as temporary inhibitor of sperm nuclear chromatin decondensation ability in man.

Nuclear chromatin decondensation (NCD) of ejaculated human spermatozoa was studied in vitro. Spermatozoa subjected to membrane disintegration induced by the detergent sodium dodecyl sulphate (SDS) were found to undergo NCD if previously or afterwards treated with substances known to deplete the spermatozoa of zinc (albumin and EDTA). Zn2+, but not other, "prostatic" cations (Ca2+, Mg2+), inhibited the experimentally induced NCD and the NCD of spermatozoa from men with impaired prostatic function. It is suggested that the human spermatozoon has an intrinsic mechanism for NCD, that is preserved by temporary zinc inhibition and might be reactivated by zinc removal within the female genital tract.

Influence of seminal plasma on the chromatin stability of ejaculated human spermatozoa.

Nuclear chromatin decondensation (NCD) of human ejaculated spermatozoa exposed to sodium dodecyl sulphate (SDS) has been studied. A high proportion of NCD reacting spermatozoa was only found in semen samples with a relatively low activity of some prostatic factor(s) (i.e. zinc/fructose ratio below 0.18) in the seminal plasma. Exposure to SDS for one h was found sufficient to reveal the main proportion of spermatozoa undergoing NCD in such a solution. Addition of seminal plasma with an apparently normal composition to a sperm population with a high NCD reactivity restored the sperm SDS resistance to normal, i.e. blocked the NCD-response. Other results indicated that NCD reactivity was decreased or abolished upon prolonged storage of the spermatozoa in the seminal plasma. The various results indicated that some factor(s) in the seminal plasma can preserve the nuclear chromatin stability of human spermatozoa and that this factor most likely is of prostatic origin.

Influence of seminal vesicular fluid on the zinc content of human sperm chromatin.

Chromatin zinc was studied using X-ray microanalysis of spermatozoa obtained from split-ejaculate fractions. Chromatin zinc, expressed as intensity ratio between zinc and sulphur (Zn/S), was unrelated to seminal zinc concentration, but was related inversely to markers of seminal vesicular secretion (fructose concentration and the proportion of zinc bound to ligands of seminal vesicular origin). It is concluded that the content of zinc in sperm chromatin can be reduced by the action of zinc ligands of seminal vesicular origin. An abnormally high contribution of seminal vesicular fluid to sperm-rich fractions of the ejaculate thus creates a risk of depleting chromatin zinc and thereby impairing zinc-dependent chromatin stability.

Loss of an intrinsic capacity for human sperm chromatin decondensation.

Chromatin decondensation of human ejaculated spermatozoa was studied in vitro, at various points of time after ejaculation, by sperm exposure to the detergent sodium dodecyl sulphate (SDS) containing zinc chelating EDTA. Within 5 min after ejaculation EDTA revealed a capacity for decondensation in 90% of the spermatozoa. This sperm capacity decreased rapidly upon storage. The results support the concept that the capacity to decondense is a normal property of freshly ejaculated spermatozoa and that this property may be rapidly lost. The loss is most probably due to an inability of thiol groups to take part in a thiol-disulphide exchange in the sperm chromatin. A loss of functional thiols may hinder a capacity for chromatin decondensation inherent to the spermatozoon. A loss of thiols due to oxidation, that is, surplus S-S bridge formation, may also delay hypothetical extrinsic S-S cleaving factors in the ooplasm. In either case, the complete and non-delayed sperm chromatin decondensation in the ovum may be hindered. This may result in the abnormal embryonic development observed in ova fertilized with aged spermatozoa.

Zinc preserves an inherent capacity for human sperm chromatin decondensation.

The effect of zinc on the nuclear chromatin decondensation ability of human, ejaculated spermatozoa was studied by exposing washed spermatozoa to the detergent sodium dodecyl sulphate (SDS) before and after sperm storage. Treatment with EDTA increased the proportion of decondensing spermatozoa before storage. Zinc supplementation before storage reversibly inhibited spontaneous decondensation as well as EDTA-enhanced decondensation. Treatment with EDTA before storage decreased the proportion of spermatozoa decondensing after storage. Zinc supplementation during storage reduced the decrease in the proportion of spermatozoa decondensing after storage. Two effects of zinc were observed: one immediate effect (reversible inhibition of the decondensation) and one long-term effect (protection of the intrinsic capacity for decondensation during storage). Both effects may be explained by a zinc-thiol interaction in the chromatin. Spermatozoal zinc is suggested to protect an inherent capacity for decondensation, thereby helping to extend the functional life-span of the ejaculated spermatozoon.

Importance of zinc for human sperm head-tail connection.

Head-tail detachment of ejaculated human spermatozoa was studied with phase contrast microscopy. The frequency of head-tail detachment was assessed after sperm exposure to the anionic detergent sodium dodecyl sulfate (SDS) for 60 min at 22 degrees C. Decapitation was enhanced by EDTA. Zinc reversibly inhibited native as well as EDTA induced head-tail disconnection. Still a certain proportion of spermatozoa were resistant to EDTA-treatment and this proportion significantly increased upon 24 h of saline storage. The development of EDTA resistance was enhanced by EDTA treatment before storage. A physiological role for zinc as a preserver of an inherent mechanism for head-tail detachment is suggested.

Evaluation of the one-step eosin-nigrosin staining technique for human sperm vitality assessment.

BACKGROUND: The one-step eosin-nigrosin staining technique for assessment of sperm vitality was developed in the 1950s for various mammalian species. Although commonly used on human sperm in semen, a validation for this use has not previously been published. METHODS: The technique was evaluated on 1235 consecutive semen samples. RESULTS: The one-step eosin-nigrosin staining technique gave valid results when evaluated with sperm motility data obtained according to World Health Organization standard (1992, 1999). The mean for the sums of stained (i.e. supposedly dead) and motile sperm using the one-step eosin-nigrosin technique was 91% (SD +/- 10%). The distribution of sums for percentage stained and percentage motile sperm was similar, regardless of whether the samples had many or few dead sperm. CONCLUSIONS: Standardization and quality control of basic semen analysis demands robust, reliable and simple techniques that are easy to learn, and easy to continue to perform in the same way. The one-step eosin-nigrosin technique does not need negative phase contrast optics but can be run with ordinary bright-field microscopy. Since it also includes fewer methodological steps to control, it seems preferable in terms of standardization and quality control management. It should therefore be recommended in the basic semen analysis when sperm vitality is to be assessed.

Ejaculatory sequence in men with low sperm chromatin-zinc.

The composition of seminal plasma in the sperm-rich split ejaculate fraction was studied in a group of men with a low zinc content in their sperm chromatin, to evaluate the availability of zinc at ejaculation. Men with low-chromatin zinc had, in the sperm-rich split-ejaculate fraction, high amounts of seminal-vesicular fluid, a low zinc:fructose molar ratio, and a high percentage of zinc bound to high molecular weight ligands of seminal vesicular origin (HMW-Zn). This indicates premature admixture of vesicular fluid at ejaculation. It is suggested that the zinc:fructose molar ratio and HMW-Zn in the sperm-rich fractions could be used as a measure of the availability of zinc in seminal plasma.

Sperm nuclear zinc, chromatin stability, and male fertility.

Zinc excreted from the human prostate secures a high content of zinc in the sperm nucleus and contributes to the stability of the quaternary structure of the chromatin. After ejaculation, in vitro, a second type of stability, most probably involving disulfide-bridge crosslinks, supersedes the zinc-dependent stability. Normally, the nucleus of the ejaculated spermatozoon remains stable, i.e., it does not decondense when exposed to a detergent (e.g., sodium dodecyl sulfate - SDS), whereas a spermatozoon which has been exposed to a zinc-chelating medium becomes destabilized and decondenses in SDS. Spontaneous decondensation in SDS, i.e., without prior treatment with zinc-chelators, occurs among many spermatozoa from some infertile men, especially men with impaired secretory function of the prostate. This indicates that spontaneously decondensing spermatozoa have an inadequate content of zinc at ejaculation. Here, zinc in the sperm nucleus and chromatin stability was studied in semen samples from a group of men living in marriages with hitherto unexplained cause for infertility, and a group of fertile donors, who participated in an insemination program. Sperm nuclear zinc was studied with X-ray microanalysis and chromatin stability was assessed as percentage spermatozoa with stable sperm heads after exposure to SDS. Fertile donors had higher content of zinc in the sperm nuclei and had also higher proportions spermatozoa with a stabilized chromatin, than had the men living in infertile marriages.(ABSTRACT TRUNCATED AT 250 WORDS)