Search results for "sperma"
showing 10 items of 296 documents
Energy metabolism and intracellular pH in boar spermatozoa
2003
The effect of energy metabolism on intracellular pH was studied in boar spermatozoa using nuclear magnetic resonance (NMR) spectroscopy and confocal microscopy with the pH-sensitive dye seminaphthorhodafluor (SNARF-1). Freshly ejaculated spermatozoa had a high adenylate energy charge (AEC=0.8), which decreased to 0.6 under aerobic conditions and to 0.2 under anaerobic conditions. Correspondingly, no ATP resonances but high AMP resonance were visible in (31)P-NMR-spectra of the spermatozoa. When an artificial oxygen buffer (Fluosol) and a purpose-built air supply system were used during (31)P-NMR data acquisition, ATP resonances reappeared whereas the AMP resonance disappeared. Boar spermato…
Microtubule organization and distribution of gamma-tubulin in male meiosis of lepidoptera
1996
Meiotic spindles in males of higher Lepidotera are unusual in that the bulk of the spindle micro-tubules (MTs) ends about halfway between the equatorial plate and the centrosomes in metaphase. It appears worthwhile to determine how the MTs are nucleated, while their pole proximal ends are distant from the centrosomes. To this end, spermatocytes of Phragmatobia fuliginosa (Arctiidae), collected in the field, were double-labeled with antibodies to beta- and gamma-tubulin. The former antibody reveals the entire microtubular cytoskeleton, and the latter is directed against a newly-discovered tublin isoform that is prevalent in microtubule-organizing centers (MTOCs). The immunocytochemical work …
The role of Doppler ultrasonography in determining the proper surgical approach to the management of varicocele in children and adolescents
2006
In a study from Italy, colour-Doppler ultrasonography was a reliable diagnostic tool in the preoperative assessment of patients with varicocele. The authors also found that it helped to distinguish those who could be treated laparoscopically from those who should be treated by microsurgical subinguinal ligature. OBJECTIVE To investigate whether colour Doppler ultrasonography (CDUS) is a reliable diagnostic tool for selecting patients with varicocele to undergo either laparoscopy or open microsurgical subinguinal ligation. PATIENTS AND METHODS In a 3-year period, 42 boys affected by left varicocele were evaluated before surgery by inguinal and scrotal CDUS. Using this method it was possible …
Safety and efficacy of intensity-modulated radiotherapy in the management of spermatic cord sarcoma.
2017
International audience; Purpose. - Spermatic cord sarcoma is a rare disease, which management remains controversial due to the lack of guidelines. The standard therapeutic approach is surgical: wide soft-tissue resection with radical inguinal orchidectomy, The diagnosis is made during the analysis of the specimen. The high rate of local recurrence indicates adjuvant radiotherapy of the tumor bed. The aim of this series is to determine the efficacy and safety of postoperative intensity-modulated radiotherapy for spermatic cord sarcomas. Patients and methods. - Our series included five consecutive cases of spermatic cord sarcoma treated between 2011 and 2014. The indications for radiotherapy …
Differential expression of estrogen receptors (ER?/ER?) in testis of mature and immature pigs
2004
High affinity estrogen receptors (ERs) mediate estrogen action in male reproductive tissues. The objective of the present study was the immunolocalization of estrogen receptor alpha and estrogen receptor beta in immature and mature testes of pig, a species in which the role of estrogens on gonadal function is scarcely known. Testes from 3 and 18 month-old pigs were investigated. Immunohistochemistry was performed on paraffin embedded-tissues using both mouse anti-human monoclonal IgG ERalpha and IgG ERbeta 1 isoform. Western blot analysis demonstrated antibody specificity. ERalpha staining was not observed in immature testes, but it was detected in spermatogonia, spermatocytes and in the mo…
No evidence for prezygotic postcopulatory avoidance of kin despite high inbreeding depression.
2018
11 pages; International audience; Offspring resulting from mating among close relatives can suffer from impaired fitness through the expression of recessive alleles with deleterious effects. Postcopulatory sperm selection (a prezygotic mechanism of cryptic female choice) has been suggested to be an effective way to avoid inbreeding. To investigate whether postcopulatory female choice allows the avoidance of fertilization by close kin, we performed artificial inseminations in a promiscuous bird, the houbara bustard (Chlamydotis undulata undulata). Females were inseminated with a mix of sperm from triads of males, each constituted of a male genetically unrelated to the female, a first cousin …
Evolution of male and female choice in polyandrous systems
2017
We study the evolution of male and female mating strategies and mate choice for female fecundity and male fertilization ability in a system where both sexes can mate with multiple partners, and where there is variation in individual quality (i.e. in the availability of resources individuals can allocate to matings, mate choice and production of gametes). We find that when the cost of mating differs between sexes, the sex with higher cost of mating is reluctant to accept matings and is often also choosy, while the other sex accepts all matings. With equal mating costs, the evolution of mating strategies depends on the strength of female sperm limitation, so that when sperm limitation is stro…
The sperm of aging male bustards retards their offspring's development.
2015
Understanding whether the sperm of older males has a diminished capacity to produce successful offspring is a key challenge in evolutionary biology. We investigate this issue using 10 years of reproductive data on captive long-lived houbara bustards (Chlamydotis undulata), where the use of artificial insemination techniques means parents can only influence offspring quality via their gametes. Here we show that paternal aging reduces both the likelihood that eggs hatch and the rate at which chicks grow, with older males producing the lightest offspring after the first month. Surprisingly, this cost of paternal aging on offspring development is of a similar scale to that associated with mater…
Genetic and potential non-genetic benefits increase offspring fitness of polyandrous females in non-resource based mating system
2010
Abstract Background The adaptive significance of female polyandry is currently under considerable debate. In non-resource based mating systems, indirect, i.e. genetic benefits have been proposed to be responsible for the fitness gain from polyandry. We studied the benefits of polyandry in the Arctic charr (Salvelinus alpinus) using an experimental design in which the material investments by the sires and maternal environmental effects were controlled. Results Embryonic mortality showed a strong paternal genetic component, and it was lower in polyandrously fertilized offspring (sperm competition of two males) than in monandrous fertilizations. We also found that high sperm velocity was assoc…
Sperm competition accentuates selection on ejaculate attributes.
2019
Ejaculate attributes are important factors driving the probability of fertilizing eggs. When females mate with several males, competition between sperm to fertilize eggs should accentuate selection on ejaculate attributes. We tested this hypothesis in the North African houbara bustard ( Chlamydotis undulata undulata ) by comparing the strength of selection acting on two ejaculate attributes when sperm from single males or sperm from different males were used for insemination. In agreement with the prediction, we found that selection on ejaculate attributes was stronger when sperm of different males competed for egg fertilization. These findings provide the first direct comparison of the st…