Reproductive context of extremely short sperm in the parasitic wasp Cotesia congregata (Hymenoptera: Braconidae)

2020 ◽  
Vol 131 (2) ◽  
pp. 384-395
Author(s):  
Justin P Bredlau ◽  
Ahmed M El-Sabrout ◽  
Christophe Bressac
Keyword(s):  
Parasitic Wasp ◽  
Sperm Concentration ◽  
Pupal Stage ◽  
Interspecific Variation ◽  
Reproductive Organs ◽  
Sperm Length ◽  
Small Female ◽  
Cotesia Congregata ◽  
Sperm Counts ◽  
Reproductive Life

Abstract Among adaptive traits under sexual selection, the length of spermatozoa shows high interspecific variation. In insects, extremes exist for both short and long sperm. The spermatozoa of the endoparasitic wasp Cotesia congregata (Say) are the shortest flagellated sperm described in animals, 6.6 µm in length. By comparison, the sperm of Drosophila bifurca are almost 6000 times longer. Thus, C. congregata has the potential to shed light on the selection pressures that drive variation in sperm length in relation to their production and use. The reproductive organs, sperm counts, controlled oviposition and sex ratios were investigated. The testes showed stratified differentiation stages of spermatogenesis, and sperm counts revealed continuous spermatogenesis in the late pupal stage. The small female spermatheca stored ~1000 sperm, resulting in an extremely high sperm concentration. The number of progeny per brood decreased over time until depletion of eggs. Females produced up to 370 daughters, corresponding to the effective use of 34% of the average sperm stock. Haploid males made up a greater proportion of broods in later parasitisms. Sperm miniaturization may be an adaptation to transfer increased quantities for the entire reproductive life of females in the absence of sperm competition but in the reduced space offered by the spermatheca.

scholarly journals Patterns of sperm damage in Chernobyl passerine birds suggest a trade-off between sperm length and integrity

2013 ◽  
Vol 9 (5) ◽  
pp. 20130530 ◽  
Author(s):  
Ignacio G. Hermosell ◽  
Terje Laskemoen ◽  
Melissah Rowe ◽  
Anders P. Møller ◽  
Timothy A. Mousseau ◽  
...  
Keyword(s):  
Sperm Competition ◽  
Acrosome Reaction ◽  
Interspecific Variation ◽  
Passerine Bird ◽  
Sperm Length ◽  
Passerine Birds ◽  
Trade Off ◽  
Sperm Abnormalities ◽  
Trade Offs ◽  
Sperm Competition Risk

Interspecific variation in sperm size is enigmatic, but generally assumed to reflect species-specific trade-offs in selection pressures. Among passerine birds, sperm length varies sevenfold, and sperm competition risk seems to drive the evolution of longer sperm. However, little is known about factors favouring short sperm or constraining the evolution of longer sperm. Here, we report a comparative analysis of sperm head abnormalities among 11 species of passerine bird in Chernobyl, presumably resulting from chronic irradiation following the 1986 accident. Frequencies of sperm abnormalities varied between 15.7 and 77.3% among species, more than fourfold higher than in uncontaminated areas. Nonetheless, species ranked similarly in sperm abnormalities in unpolluted areas as in Chernobyl, pointing to intrinsic factors underlying variation in sperm damage among species. Scanning electron microscopy of abnormal spermatozoa revealed patterns of acrosome damage consistent with premature acrosome reaction. Sperm length, but not sperm competition risk explained variation in sperm damage among species. This suggests that longer spermatozoa are more susceptible to premature acrosome reaction. Therefore, we hypothesize a trade-off between sperm length and sperm integrity affecting sperm evolution in passerine birds.

scholarly journals Semen quality in patients with pituitary disease and adult-onset hypogonadotropic hypogonadism

2018 ◽  
Vol 7 (4) ◽  
pp. 523-533 ◽  
Author(s):  
Mikkel Andreassen ◽  
Anders Juul ◽  
Ulla Feldt-Rasmussen ◽  
Niels Jørgensen
Keyword(s):  
Semen Quality ◽  
Hypogonadotropic Hypogonadism ◽  
Sperm Concentration ◽  
Serum Testosterone ◽  
Free Testosterone ◽  
Pituitary Insufficiency ◽  
Adult Onset ◽  
Pituitary Disease ◽  
Sperm Counts ◽  
The Individual

Objective Gonadotropins (luteinizing hormone (LH) and follicle-stimulating hormone (FSH)) are released from the pituitary gland and stimulate Leydig cells to produce testosterone and initiates spermatogenesis. Little is known about how and when the deterioration of semen quality occurs in patients with adult-onset gonadotropin insufficiency. Design and methods A retrospective study comprising 20 testosterone-deficient men (median age, 29 years) with acquired pituitary disease who delivered semen for cryopreservation before initiation of testosterone therapy. Semen variables and hormone concentrations were compared to those of young healthy men (n = 340). Results Thirteen of 20 patients (65%) and 82% of controls had total sperm counts above 39 million and progressive motile spermatozoa above 32% (P = 0.05). For the individual semen variables, there were no significant differences in semen volume (median (intraquartile range) 3.0 (1.3–6.8) vs 3.2 (2.3–4.3) mL, P = 0.47), sperm concentration 41 (11–71) vs 43 (22–73) mill/mL (P = 0.56) or total sperm counts (P = 0.66). One patient had azoospermia. Patients vs controls had lower serum testosterone 5.4 (2.2–7.6) vs 19.7 (15.5–24.5) nmol/L (P = 0.001), calculated free testosterone (cfT) 145 (56–183) vs 464 (359–574) pmol/L (P < 0.001), LH 1.5 (1.1–2.1) vs 3.1 (2.3–4.0) U/L (P = 0.002) and inhibin b (P < 0.001). Levels of FSH were similar (P = 0.63). Testosterone/LH ratio and cfT/LH ratio were reduced in patients (both P < 0.001). Conclusions Despite Leydig cell insufficiency in patients with acquired pituitary insufficiency, the majority presented with normal semen quality based on the determination of the number of progressively motile spermatozoa. In addition, the data suggest reduced LH bioactivity in patients with pituitary insufficiency.

scholarly journals The effect of treatment by L-carnitine for infertile men on semen parameters

2019 ◽  
Vol 24 (2) ◽  
pp. 30
Author(s):  
Abdul Rahman Jihad Manssor1 ◽  
Zaid Mohammed Mubarak Al–Mahdawi1 ◽  
Azzawi Mustafa Hadi2
Keyword(s):  
Male Infertility ◽  
Semen Quality ◽  
Antioxidant Properties ◽  
Sperm Concentration ◽  
Multiple Roles ◽  
Male Reproduction ◽  
Semen Parameters ◽  
Beneficial Effects ◽  
Sperm Counts ◽  
Effect Of Treatment

L-Carnitine (LC) is highly concentrated in the epididymis and plays a crucial role in sperm metabolism and maturation. They are related to sperm motility and have antioxidant properties. The objective of this review is to summarize the multiple roles played by LC in male reproduction, and to highlight their limitations as well as their benefits in the treatment of male infertility. A variety of studies support the conclusion that LC at total daily amounts of at least 500mg  per day can significantly improve both sperm concentration and total sperm counts among men with astheno – or oligoasthenozoospermia. Although many clinical trials have demonstrated the beneficial effects of LC in selected cases of male infertility. Additional, a well – designed study is necessary to further validate the use of carnitines in the treatment of patients  with male infertility, specifically in men with poor semen  quality .    http://dx.doi.org/10.25130/tjps.24.2019.027   

scholarly journals Effect of Exogenous Proteases on the Spermiogram and Microscopic and Macroscopic Characteristics of Boar Ejaculate

2013 ◽  
Vol 57 (2) ◽  
pp. 275-279
Author(s):  
Łukasz Zielonka ◽  
Włodzimierz Przewoski ◽  
Magdalena Gajęcka ◽  
Ewa Jakimiuk ◽  
Maciej Gajęcki
Keyword(s):  
Sperm Count ◽  
Sperm Concentration ◽  
Growth Promoters ◽  
Streptomyces Fradiae ◽  
Sperm Counts ◽  
Enzymatic Complex

Abstract A growing interest in enzymatic growth promoters prompted the authors of the study to investigate the effects of a stimulating enzymatic complex on ejaculate characteristics of boars. The enzymatic complex comprising five proteases (proteinases - endopeptidases) and two peptidases (exopeptidases) was obtained by fermentation from Streptomyces fradiae. This complex was added to boar diets for 3 months at the initial doses of 90 (group E1) and 120 (group E2) g/ton of feed in the first week, followed by 40 and 60 g/ton, respectively, in the following weeks. Evaluation was based on the assessment of key ejaculate characteristics (volume, sperm concentration, total sperm count, primary and secondary sperm defects). The enzymatic complex improved the microscopic and macroscopic characteristics of boar ejaculate by increasing sperm concentrations and total sperm counts, and decreasing the volume of the analysed ejaculates without significant changes in the spermiograms of primary and secondary defects.

P–018 Observational study on the behaviour of the seminal sample in donors: seasonal variation according to parameters

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
B Amoroch. Llanos ◽  
R Hernánde. Jornet ◽  
E Sellé. Soriano ◽  
E Martíne. Díaz-Jiménez ◽  
I.Pére Cano ◽  
...  
Keyword(s):  
Semen Quality ◽  
Sperm Quality ◽  
Sperm Concentration ◽  
Male Factor ◽  
Spanish Law ◽  
Sperm Donors ◽  
Reproductive Life ◽  
Registration Number ◽  
Full Capacity ◽  
Autumn And Winter

Abstract Study question What is causing the decline in semen quality worldwide? Summary answer Our results indicated significant differences, finding a decrease in sperm concentration/mobility in summer compared to the other seasons, with greater differences being observed in spring. What is known already Infertility is an increasing global problem and it is estimated that approximately 15 to 20% of all couples experience it at some point in their reproductive life. Among all causes, the male factor is becoming increasingly important as seminal quality is steadily declining globally. Knowing that the spermatogenesis process is very sensible to temperature fluctuations we could focus on the ambient temperature as one of the causes. Study design, size, duration Taking into account that donors are selected for having an optimal seminal quality, a retrospective study (January 2006 /February 2020) was proposed at IVI Alicante from 160 seminal samples to determine whether environment actually affects spermatogenesis and semen quality. It was evaluated whether there is variation in donors in mobility/volume / concentration depending on the season and quarter of the year in which the sample was obtained; and relation to the age of the donor. Participants/materials, setting, methods The inclusion criteria were sperm donors between 18 and 35 years old, anonymously, with good physical health, full capacity to act, and with seminal samples with characteristics to survive sperm thawing, complying with the requirements according to Spanish law on ART 2006. Exclusion criteria were based mainly on poor sperm survival after thawing. The statistical analysis was performed with the R statistical software, version 4.0, linear and multiple regression, establishing significant differences when p &lt; 0.05. Main results and the role of chance The results indicated significant differences, finding in summer a decrease in concentration and sperm motility (p &lt; 0.05) compared to autumn and winter and obtaining the best quality in spring. The concentration and mobility decrease from 63.4 million sperm / ml and 49.6% in spring to 44.4 million (p = 0.009) and 39.9% mobility in summer (p = 0.0075). We found the same results comparing them by quarters, having 62.7 million / ml and 49.3% between April-June, up to 44.9 million (p = 0.003) and 39.3% mobility between July-September (p = 0.03), showing that July and September there is a decrease in both concentration and mobility. This association has not been significantly affected by age. Thus, we conclude that high temperatures affect seminal concentration and mobility. Limitations, reasons for caution More studies can be done to increase the number of donors and confirm our findings. Wider implications of the findings: According to other studies, carried out in Denmark, Israel and China, with different latitudes and temperature-humidity, the same trend has been observed in sperm quality, decreasing the quality in summer and being optimal in spring-winter, so the temperature could be a variable to take into account when studying semen. Trial registration number Not applicable for non clinical-trials

Effect of water sprinkling during the hot-dry summer season on semen quality of Holstein bulls in Saudi Arabia

1992 ◽  
Vol 55 (1) ◽  
pp. 59-63
Author(s):  
M. S. Salah ◽  
F. D. El-Nouty ◽  
M. R. Al-Hajri
Keyword(s):  
Saudi Arabia ◽  
Semen Quality ◽  
Sperm Concentration ◽  
Experimental Period ◽  
Summer Season ◽  
Cooling Period ◽  
Sperm Counts ◽  
Sperm Abnormality ◽  
Blood Haemoglobin ◽  
Holstein Bulls

AbstractTen Holstein bulls, 4 to 5 years old were used to study the effect of cooling the bulls on their semen quality. Five bulls were sprinkled with water for 15 min five times a day throughout a 6-week period of the summer season (hot-dry) in Saudi Arabia, and the other five bulls acted as the control and were not sprinkled with water. Semen quality was improved significantly during the cooling period. This improvement was evident from the significant increase in sperm motility (P < 0·01) and decrease in the percentage of both dead and morphologically abnormal (primary and secondary) spermatozoa per ejaculate of cooled bulls (P < 0·01). The effect of cooling was more marked through the last 3 weeks than during the first 3 weeks of the experimental period. Ejaculate volume, sperm concentration and hence total sperm counts did not differ significantly between the cooled and the non-cooled bulls. Concerning the type of abnormal spermatozoa, the overall secondary abnormality was higher than the primary in both the cooled and the control groups, with higher values for the control (P < 0·01). Only the mid piece showed higher primary defects than the secondary. The pyriform heads, the coiled mid pieces and tails and the bent tails were the main sources of variations (P < 0·01) in the incidence of sperm abnormality between the cooled and the non-cooled bulls. Cooling the bulls during the heat stress period also lowered their rectal temperature and increased blood haemoglobin level without affecting the packed cell volume

scholarly journals Association of Ejaculate Sperm Counts with their Morphological and Morphometric Characteristics in Hypor Boars

2017 ◽  
Vol 17 (4) ◽  
pp. 1043-1052 ◽  
Author(s):  
Krzysztof Górski ◽  
Stanisław Kondracki ◽  
Karolina Strachocka ◽  
Anna Wysokińska
Keyword(s):  
Sperm Count ◽  
Tail Length ◽  
Reproductive Efficiency ◽  
Sperm Length ◽  
Morphometric Characteristics ◽  
Progressive Motility ◽  
Sperm Counts ◽  
Small Head ◽  
Fertilization Capacity ◽  
High Fertilization

AbstractReproductive efficiency in pigs is largely dependent on the fertility of the boar. Boars used at insemination stations should produce a large amount of semen with high fertilization capacity. The sperm count influences the conception rate and the number of insemination doses produced. The aim of this study was to evaluate the morphological and morphometric characteristics of boars of the Hypor breed in relation to the total sperm count in the ejaculate. An analysis was performed of 120 ejaculates collected from 12 Hypor boars used at three insemination stations. The ejaculate sperm count was found to affect the morphometric characteristics of spermatozoa from boars. In the ejaculates with the lowest sperm count the spermatozoa heads were significantly shorter and narrower and had a smaller surface area. The sperm from ejaculates with the lowest sperm count had relatively small head dimensions in relation to the tail length and total sperm length. In the ejaculates with the most sperm cells, the proportion of spermatozoa with major defects was significantly greater than in the ejaculates from other groups. In the ejaculates with the lowest sperm count the frequency of sperm with progressive motility was significantly lower. The fewest insemination doses can be prepared from these ejaculates.

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