Sperm Velocity Research Articles

Rapid evolution of pollen and pistil traits as a response to sexual selection in the post-pollination phase of mating

Sexual selection is the basis of some of the most striking phenotypic variation in nature.1,2 In animals, sexual selection in males can act on traits that improve access to mates prior to copulation,3-8 but also on sperm traits filtered by sperm competition,9-14 or female choice expressed simply by the morphology and physiology of genital tracts.14-16 Although long overlooked as a mode of selection on plant traits, sexual selection should act on land plants too because they are anisogamous: males produce more, and smaller, gametes than females.17-19 Numerical asymmetry in gamete production is thought to play a central role in selection on traits that affect pollen transfer to mates,20,21 but very little is known about how pollen competition or cryptic female choice might affect the evolution of traits expressed after pollination.22,23 Here, we report the divergence of pollen and pistil traits of the dioecious wind-pollinated annual herb Mercurialis annua during evolution over three generations between populations at low versus high plant density, corresponding to low versus higher levels of polyandry;24 we expected selection under higher polyandry to strengthen competition among pollen donors for fertilizing ovules. We found that populations at high density evolved faster-growing pollen tubes (an equivalent of greater sperm velocity), greater expression of pollen proteins involved in pollen growth, and larger stigmas (a trait likely enhancing the number of pollen donors and thus competition for ovules). Our results identify the post-pollination phase of plant mating as an important arena for the action of sexual selection.

New insights into sperm rheotaxis, agglutination and bundle formation in Sharkasi chickens based on an in vitro study

Fertility in birds is dependent on their ability to store adequate populations of viable sperm for extended durations in sperm storage tubules (SSTs). The exact mechanisms by which sperm enter, reside, and egress from the SSTs are still controversial. Sharkasi chicken sperm showed a high tendency to agglutinate, forming motile thread-like bundles comprising many cells. Since it is difficult to observe sperm motility and behavior inside the opaque oviduct, we employed a microfluidic device with a microchannel cross-section resembling close to that of sperm glands allowing for the study of sperm agglutination and motility behavior. This study discusses how sperm bundles are formed, how they move, and what role they may have in extending sperm residency inside the SSTs. We investigated sperm velocity and rheotaxis behavior when a fluid flow was generated inside a microfluidic channel by hydrostatic pressure (flow velocity = 33 µm/s). Spermatozoa tended to swim against the flow (positive rheotaxis) and sperm bundles had significantly lower velocity compared to lonesome sperm. Sperm bundles were observed to swim in a spiral-like motion and to grow in length and thickness as more lonesome sperm are recruited. Sperm bundles were observed approaching and adhering to the sidewalls of the microfluidic channels to avoid being swept with fluid flow velocity > 33 µm/s. Scanning and transmission electron microscopy revealed that sperm bundles were supported by a copious dense substance. The findings show the distinct motility of Sharkasi chicken sperm, as well as sperm's capacity to agglutinate and form motile bundles, which provides a better understanding of long-term sperm storage in the SSTs.

Computer aided semen analysis (CASA) to determine the quality and fertility of frozen thawed sumba ongole sperm supplemented with amino acids

<p><strong>Objective</strong>: The objective of this research was to investigate the quality and reproductive potential of frozen-thawed Sumba Ongole (SO) bull spermatozoa supplemented with specified amino acids using computer-assisted semen analysis (CASA).</p><p><strong>Methods</strong>: A total of 18 ejaculates were collected once a week from three Sumba Ongole bulls and diluted in tris-citric-fructose-egg yolk (TCFY) extender and various concentrations of selected amino acids. The post-thaw spermatozoa were examined for motility, head behavior, and swimming pattern using CASA technique. Data were analysis using SPSS 24 ebvaluated by ANOVA.</p><p><strong>Results</strong>: Total motility (72.56%±3.20) and progressive motility (71.11%±3.31) the addition of Glutamine 5% significantly different (p<0.05) than other treatments. The addition of 7mM cysteine resulted in significantly (p<0.05) in velocity average path (VAP), velocity curve line (VCL), velocity straight line(VSL) parameters also have higher in distance average path (DAP), distance curve line (DCL), dan distance straight line (DSL) parameters significantly (p<0,05). </p><p><strong>Conclusion</strong>: In conclusion, the introduction of CASA systems enabled quantification of individual spermatozoa motility patterns and CASA colud be used to estimate the fertilizing capacity of sperm based on the characteristics of sperm velocity.</p>

The Effect of Copper and Copper Oxide Nanoparticles on Rainbow Trout (Oncorhynchus mykiss W.) Spermatozoa Motility after Incubation with Contaminants.

The study aimed to analyse the effect of copper nanoparticles of similar particle size of Cu and CuO and copper ions (CuSO4) on the motility parameters of rainbow trout spermatozoa after long-term exposure and compare its harmful effect. Nanoproducts of Cu and CuO (Cu NPs, CuO NPs) of primary particle size around 50 nm and ionic solution of CuSO4 were used for the study. Suspension of concentrations 0, 1, 5, 10, 25, and 50 mg Cu·L−1 of Cu NPs, CuO NPs, and CuSO4 was dissolved in an artificial seminal plasma. Milt was mixed with the prepared solution and stored in a fridge, at 6 °C, for 96 h. At the defined incubation time, spermatozoa were activated for movement, and six motility parameters were evaluated using an automated system (CASA). Increasing concentrations of Cu NPs, CuO NPs, and CuSO4 in an incubation medium in parallel decreased the percentage of motile sperm (MOT). The effect of Cu NPs and ionic copper on MOT was more deleterious than that of CuO NPs. Copper products slightly increased the velocity (VCL) compared to the control, particularly up to 24 h of storage. Linearity (LIN) was improved by three tested products, particularly CuO NPs. Generally, the motility duration was prolonged when the sperm was incubated with copper products compared to the control. Nanoproducts made from different compounds of the same elements of similar particle size have a different effect on cells. Cu NPs were more harmful than CuO NPs. The effect of Cu NPs was similar to an ionic form of CuSO4. When incubated, the copper nanoproducts and ionic form exert a slightly positive effect on spermatozoa velocity, linearity, and motility duration, particularly up to 24 h of storage.

Seasonal effects on the semen production of Bali bulls (Bos javanicus) in West Nusa Tenggara's Lelede regional artificial insemination center

<p class="MDPI17abstract"><strong>Objective: </strong>The purpose of this research is to determine the effect of the rainy and dry seasons on the sperm qualities and frozen sperm production of Bali bulls at the Lelede Regional Artificial Insemination Center (RAIC) in West Nusa Tenggara.</p><p class="MDPI17abstract"><strong>Methods: </strong>A total of 1226 ejaculates were examined from five Bali bulls during a 24-month period (November 2018–October 2019), which was classified into rainy (November–April, 658 ejaculates) and dry (May–October, 568 ejaculates) seasons. Semen volume (mL), sperm velocity (1-4), motility (%), concentration (x106 cell/ml), pre-freezing motility (%), post-freezing motility (%), recovery rate (%), and total frozen semen production were examined as sperm quality measures.<strong></strong></p><p class="MDPI17abstract"><strong>Results: </strong>The results indicated that during the rainy season, ejaculates and processed sperm were more abundant than during the dry season. Additionally, the features of discarded fresh semen in the volume parameter were significantly (P<0.05) larger during the dry season than during the rainy season. The pattern in semen output rises during the dry season and decreasing during the rainy season.<strong></strong></p><p><strong>Conclusions: </strong>It was concluded that the rainy season results in a higher number of ejaculates and total sperm production than the dry season. Meanwhile, no differences in sperm characteristics exist between the two seasons.</p>

Determining the Optimal Dosage of Lecithin Nanoliposome in Rooster Semen Freezing Medium and Fertility Potential.

Introduction: Lecithin nanoliposome (nano-LPO), with its cryoprotective properties, is considered to enhance the performance of a traditional semen cryoprotectant. Objective: To determine the optimal dose of lecithin nano-LPO added to the rooster semen extender. Materials and Methods: Semen samples collected weekly from eight broiler breeder roosters were mixed and aliquoted into five equal subsamples, during the five successive weeks. The subsamples were then diluted with a semen extender containing 0%, 0.5%, 1%, 1.5%, or 2% of lecithin nano-LPO. Post-thawed semen quality attributes, including sperm motility and velocity parameters, plasma membrane functionality, mitochondrial membrane potential (MMP), apoptosis-like changes, and fertility potential, were evaluated. Results: Total motility and velocity parameters, including curvilinear velocity (VCL), straight-line velocity (VSL), average path velocity μm/s (VAP), straightness (STR), linearity (LIN), lateral head displacement (ALH), and wobble (WOB) were quadratically (p < 0.01) influenced by graded levels of lecithin nano-LPO, such that the highest values were obtained when 1% of lecithin nano-LPO was used. Treatments had no significant effect on plasma membrane functionality; however, MMP (p < 0.08) and percentages of live and dead spermatozoa (p < 0.05) quadratically responded to increasing levels of lecithin nano-LPO, where the best outcome was found when about 1% of lecithin nano-LPO was used in the semen extender. The percentage of apoptotic spermatozoa cubically responded to increasing levels of lecithin nano-LPO (p ≤ 0.07). No significant trend of fertility rate was found in response to addition of lecithin nano-LPO levels. Conclusions: Supplementing an extender with 1.10% of lecithin nano-LPO is shown to be the optimal dose associated with the most improvement in post-thawed rooster sperm velocity measurements.

Molecular, behavioural and morphological comparisons of sperm adaptations in a fish with alternative reproductive tactics.

In species with alternative reproductive tactics, there is much empirical support that parasitically spawning males have larger testes and greater sperm numbers as an evolved response to a higher degree of sperm competition, but support for higher sperm performance (motility, longevity and speed) by such males is inconsistent. We used the sand goby (Pomatoschistus minutus) to test whether sperm performance differed between breeding-coloured males (small testes, large mucus-filled sperm-duct glands; build nests lined with sperm-containing mucus, provide care) and parasitic sneaker-morph males (no breeding colouration, large testes, rudimentary sperm-duct glands; no nest, no care). We compared motility (per cent motile sperm), velocity, longevity of sperm, gene expression of testes and sperm morphometrics between the two morphs. We also tested if sperm-duct gland contents affected sperm performance. We found a clear difference in gene expression of testes between the male morphs with 109 transcripts differentially expressed between the morphs. Notably, several mucin genes were upregulated in breeding-coloured males and two ATP-related genes were upregulated in sneaker-morph males. There was a partial evidence of higher sperm velocity in sneaker-morph males, but no difference in sperm motility. Presence of sperm-duct gland contents significantly increased sperm velocity, and nonsignificantly tended to increase sperm motility, but equally so for the two morphs. The sand goby has remarkably long-lived sperm, with only small or no decline in motility and velocity over time (5 min vs. 22 h), but again, this was equally true for both morphs. Sperm length (head, flagella, total and flagella-to-head ratio) did not differ between morphs and did not correlate with sperm velocity for either morph. Thus, other than a clear difference in testes gene expression, we found only modest differences between the two male morphs, confirming previous findings that increased sperm performance as an adaptation to sperm competition is not a primary target of evolution.

Transgenerational effects and phenotypic plasticity in sperm and larvae of the sea urchin Paracentrotus lividus under ocean acidification.

In marine organisms, differing degree of sensitivity to ocean acidification (OA) is expected for each life stage, and disturbance at one stage can carry over into the following stage or following generation. In this study we investigated phenotypic changes of sperm and larvae of the sea urchin Paracentrotus lividus in response to different pH conditions (8.0, 7.7, 7.4) experienced by the parents during gametogenesis. In sperm from two-months exposed males, sperm motility, velocity, ATP content, ATP consumption and respiration rate were evaluated at three pH values of the activating medium (8.0, 7.7 and 7.4). Moreover, larvae from each parental group were reared at pH 8.0 and 7.7 for 20 days and larval mortality and growth were then assessed. Sperm motility and respiration rate were not affected either by exposure of males to low pH or by the post-activation pH. Sperm velocity did not differ among post-activation pH values in all sperm groups, but it decreased slower in sperm developed under acidified conditions, suggesting the presence of positive carryover effect on sperm longevity. This positive carryover effect of exposure of males to low pH values was highlighted also for the sperm ATP content, which was higher in these groups of sperm. ATP consumption rate was affected by post-activation pH with higher values at pH 8.0 in sperm from males maintained at control condition and pH 7.7 while the energy consumption appeared to be differently modulated at different experimental conditions. A negative carry over effect of OA was observed on survival of larvae from parents acclimated at pH 7.4 and additive negative effects of both parental and larval exposure to low pH can be suggested. In all groups of larvae, decreased somatic growth was observed at low rearing pH, thus larvae from parents maintained at low pH did not show an increased capability to cope with OA.

Freezing chicken semen: Influence of base medium osmolality, cryoprotectants, cryoprotectant concentration, and cooling rate on post-thaw sperm survival

A classical chicken semen diluent (Lake's 7.1 diluent) was modified to have lowered osmolalities (ranging from 290 to 410 mOsm/kg). The modified medium with physiological osmolality of 325 mOsm/kg allowed cold storage of fresh semen for several days with very little loss of membrane integrity and motility, while high osmolalities inhibited motility. This modified medium was then used as base for freezing medium to test effects of the type and concentration of cryoprotective agent (CPA), and the cooling rate (CR). A number of CPAs (methylformamide, methylacetamide, dimethylformamide (DMF), dimethylacetamide (DMA), diethylformamide, and propylene glycol) were first compared by freezing semen with 0.6 mol/l of the respective CPA at a cooling rate of 250 °C/min. Post-thaw motility and membrane integrity were highest with DMA and DMF. Finally, in more detailed factorial experiments, semen from individual cocks or pooled semen was frozen using CRs of 4, 50, 250, and 440 °C/min and DMA concentrations ([DMA]) of 0.4, 0.6, 1.0, and 1.5 mol/l. Straws from each semen sample x treatment combination were divided for semen assessment at three different research groups for sperm motility, membrane integrity, kinked tails, and DNA fragmentation, using microscopy, computer assisted motility analysis, and flow cytometry. There were clear effects of both CR and [DMA] and their interaction. CRs 50 and 250 °C/min gave best post-thaw sperm performance. Higher DMA concentrations gave better post-thaw membrane integrity, but concentrations above 1.0 mol/l can decrease sperm velocity or even inhibit sperm motility. Therefore [DMA] may best be 0.6–1.0 mol/l at a CR of 50–250 °C/min.

Linseed oil in boar’s diet during high temperature humidity index (THI) period improves sperm quality characteristics, antioxidant status and fatty acid composition of sperm under hot humid sub-tropical climate

Environmental heat stress in sub-tropical climates negatively impacts boar semen production and its quality. The present study aimed to examine the heat stress alleviating effects of dietary linseed oil on semen quality and antioxidant status of boar, in the summer and winter seasons in sub-tropical climate. Six Hampshire crossbreed boars were fed with 90 mL linseed oil (treatment) whereas six boars of the same breed were fed 90 mL vegetable oil (control) for sixteen weeks during both season. Sperm quality was assessed for motility, viability, abnormality, acrosomal integrity, and Hypo-osmotic swelling test (HOST). Sperm velocity attributes were assessed by computer-assisted semen analysis (CASA). Antioxidants (glutathione peroxidase; GPx, catalase; CAT, total antioxidant capacity; TAC and nitric oxide; NO) and lipid peroxidation (malondialdehyde; MDA) were measured in seminal plasma and serum. Gas chromatography-mass spectrometry (GC-MS) was used for the estimation of fatty acid composition of seminal plasma and spermatozoa. Feeding linseed oil to the boars significantly (p < 0.05) improved sperm quality at the fresh stage and after 72 h of liquid storage in both season. There was a significant (p < 0.01) effect of treatment and season on semen quality parameters. Significant boar (p < 0.05) effect was recorded on reaction time, semen volume, sperm abnormality, acrosomal integrity and HOST reactive sperm. There was a significant (p < 0.01) effect of treatment and season on the velocity attributes viz. VAP, VSL, VCL, ALH, BCF and STR%. Linseed oil supplementation significantly (p < 0.01) enhanced antioxidant and lowered MDA levels in serum as well as seminal plasma. The concentration of alpha-linolenic (ALA), arachidonic and docosahexaenoic (DHA) fatty acids were significantly (p < 0.01) increased in seminal plasma and sperm after linseed oil supplementation. In conclusion, linseed oil supplementation to boar during high THI months improved the semen quality parameters viz. semen volume, sperm concentration, and progressive motile sperm, along with enhanced antioxidant capacity.

A new fluorescent method to determine honey bee sperm motility parameters with computer-aided sperm analysis

Honey bees are a keystone species, playing an important role in the food cycle. Improving honey bee reproduction will aid in the replacement of lost colonies. Fertility potential and reproductive health are dependent on semen and sperm quality. Current data on drone semen parameters are limited to semen volume, sperm concentration, sperm viability, and the assignment of sperm motility grade scores. The assessment of drone sperm motility is of importance to determine fertility potential and colony health. This study aimed to establish a quantitative and a qualitative method to measure drone sperm quality, and the fertility potential of Apis mellifera capensis subspecies of South Africa. Firstly, an improved five-point semi-quantitative manual motility index score was used to classify drone sperm motility. Secondly, it was possible to accurately analyse drone sperm motility qualitatively using a fluorescent technique in conjunction with a computer-aided sperm analysis (CASA) system. Manual motility index scores corresponded with total motility percentages as determined by using a CASA system. Furthermore, low values for motility kinematic parameters, particularly velocity parameters, were obtained in samples with both low motility index scores and low total motility percentages. Additionally, total sperm motility percentage and velocity parameters positively correlated with sperm total progressivity. This study provides in-depth data on honey bee drone sperm motility and motility kinematic parameters, which can serve as a reference for future studies on honey bee sperm and possibly related species.

Common carp (Cyprinus carpio) sperm reduction during short-term in vitro storage at 4 °C

This study was designed to optimize a short-term storage protocol for common carp sperm at 4 °C under aerobic condition. Sperm from individual males were collected directly with or without extenders. The results demonstrated that in general, it was similar effect to collect sperm directly in extenders and keeping sperm for 0.5 h after collection without extenders. Sperm was diluted with eight selected extenders (sperm: extender = 2:1, 1:1 and 1:9) and undiluted sperm was used as a control. Sperm and seminal plasma parameters (sperm motility, velocity, membrane integrity, sperm concentration, osmolality and pH in seminal plasma) were evaluated in sperm stored on ice under aerobic conditions at 0, 2, 4, 6 and 8 days post stripping (DPS) using the computer- assisted sperm analysis system. Results showed that 1:1 and 2:1 dilution maintained higher sperm function and more sperm for a longer period. After 8 DPS, the best sperm quality and quantity was recorded in the common carp seminal plasma supplemented with 50 mM NaCl, Cejko extender (2 mM CaCl2, 1 mM MgSO4, 20 mM Tris, 110 mM NaCl, 40 mM KCl, pH 7.5 and 310 mOsm/kg) supplemented with/without 25 mM KCl/NaCl. The reduction of spermatozoa number with time during short-term storage but varied according to different dilution ratios and extenders. At 8 DPS, sperm count has dropped by 22.9 % in a dilution of 1:1 compared to 50.3 % in sperm without dilution. Extenders with diluted 1:1, especially Cejko solution, largely postponed sperm reduction, 21.3 % compared to 55.5 % for sperm stored without extenders.

Personality, sperm traits and a test for their combined dependence on male condition in guppies.

There is evidence that animal personality can affect sexual selection, with studies reporting that male behavioural types are associated with success during pre- and post-copulatory sexual selection. Given these links between personality and sexual traits, and the accumulating evidence that their expression can depend on an individual's dietary status (i.e. condition), a novel prediction is that changes in a male's diet should alter both the average expression of personality and sexual traits, and their covariance. We tested these predictions using the guppy Poecilia reticulata, a species previously shown to exhibit strong condition dependence in ejaculate traits and a positive correlation between sperm production and individual variation in boldness. Contrary to expectation, we found that dietary restriction—when administered in mature adult males—did not affect the expression of either behavioural (boldness and activity) or ejaculate traits, although we did find that males subjected to dietary stress exhibited a positive association between sperm velocity and boldness that was not apparent in the unrestricted diet group. This latter finding points to possible context-dependent patterns of covariance between sexually selected traits and personalities, which may have implications for patterns of selection and evolutionary processes under fluctuating environmental conditions.

Effects of post-freezing addition of relaxin on the fertility parameters of equine semen

The cryopreservation of equine semen, although advantageous, has critical points: the spermatozoa undergo structural and physico-chemical changes which cause alterations of flagellum, plasma membrane and cellular organelles, compromising the fertilizing potential (Freitas et al. J Equine Vet Sci. 2016; 46: 1–6). The aim of the work was to evaluate whether the post-thawing addition of relaxin, a pleiotropic hormone, had positive effects on motility, velocity, viability, membrane and DNA integrity, mitochondrial activity and apoptosis rate of the equine semen. The data were compared with a previous work, in which relaxin had been added before cryopreservation to the same semen batches (Elkhawagah et al. Anim Reprod Sci. 2020; 106351). The semen of 3 stallions of proven fertility was collected, pooled, and frozen using standard procedures, with relaxin supplementation (0, 12.5, 25, 50, 100 ng/ml). In this work, relaxin was added after thawing to the row semen at the same concentrations. Immediately after the addition of relaxin and after 15’, 30′, 60′, 90′ and 120′ of incubation (37°C, CO2 5%), sperm motility and velocity were evaluated with CASA system, viability was assessed through Hancok test and membrane integrity with Hypoosmotic Swelling test. DNA integrity, mitochondrial activity and apoptosis rate were assessed by acridine orange staining, JC-1 and annexin V-PI (flow cytometricanalyses). Viability, mitochondrial activity, DNA integrity and percentage of apoptotic spermatozoa were not significantly improved after post-thawing addition of relaxin, but it seemed to exert a positive effect on the mitochondrial membrane potential and on the prevention of apoptosis, in accordance with Ferlin et al. (J Androl. 2012; 33: 474–482). The percentage of spermatozoa with intact membrane significantly increased in the samples with the post-thawing addition of 12.5, 25 and 50 ng/ml relaxin, but not in those supplemented with relaxin before freezing. The post-thawing addition of 50 ng/ml relaxin implemented and maintained sperm motility and velocity over time, particularly after 90 min of incubation, and the same results were obtained after 30 minutes of pre-freeze relaxin supplementation at 12.5 ng/ml. It was concluded that one protocol was no better than the other, but the pre-freeze addition of relaxin is more suitable for classical AI, while the post-freeze supplementation is better for deep AI, endoscopic AI or ICSI, as it also seems to activate capacitation. In the future, establishing the metabolic pathways through which relaxin acts on the male gamete will be essential to fully exploit the potential of a hormone that, only recently, has been found to be extremely important for male fertility.

Microbiota in Goat Buck Ejaculates Differs Between Breeding and Non-breeding Seasons.

Changes in semen microbiota are associated with alterations to sperm quality and fertility. However, the microbiota from most livestock species has not yet been studied. Goats are seasonal breeders, but semen microbiota has never been described in this species, and it is unknown how seasonality affects it. Our study objective is 2-fold: to describe the microbiota in goat buck ejaculates and to determine if it differs between breeding and non-breeding seasons. Semen from six males of the Murciano-Granadina breed was collected during both seasons. Two replicates were performed per male and season on different days. The microbiota was characterized by genomic sequencing technology. Sperm quality was also evaluated. Repetition was not significant for the studied variables. Sperm velocities were higher for the breeding than for the non-breeding season. The ejaculates from both seasons also differed in the proportion of apoptotic spermatozoa. The five dominant phyla were Firmicutes, Proteobacteria, Fusobacteria, Actinobacteria, and Bacteroidetes during the breeding season and Firmicutes, Proteobacteria, Actinobacteria, Bacteroidetes, and Cyanobacteria during the non-breeding season. The dominant genus during both seasons was Ureaplasma. Differences in microbial community structure (the beta diversity) were found. A decrease in the relative abundance of the genus Faecalibacterium and an increase in the genera Sphingomonas and Halomonas were observed in the ejaculates collected during the breeding season. Sphingomonas and Faecalibacterium abundance favorably and unfavorably correlated with sperm quality, respectively. In conclusion, the semen microbiota from goat bucks varies between breeding and non-breeding seasons, and the microbiota remains stable for 7 days within a season. In addition, the genera Sphingomonas and Faecalibacterium could be possible biomarkers of semen quality in goat bucks. These results contribute to an in-depth understanding of the effects of reproductive seasonality on goat buck ejaculates.

Practical use of extender and activation solutions for short-term storage of common carp (Cyprinus carpio) milt in a hatchery

The purpose of this study was to investigate the effect of an activation solution (AS) (hatchery water (pH 7.9 and 4 mOsm/kg), Perchec solution (5 mM KCl, 45 mM NaCl, 30 mM Tris-HCl; pH 8.0 and 130 mOsm/kg) and Cheng solution (40 mM NaCl, 20 mM Tris; pH 8.0 and 100 mOsm/kg) on aging sperm of common carp ( Cyprinus carpio ) after storage in a carp artificial seminal plasma (carp ASP: 2 mM CaCl 2 , 1 mM MgSO 4 , 40 mM KCl, 110 mM NaCl, 20 mM Tris; pH 7.5 and 310 mOsm/kg) for 7 days without antibiotics at 4 °C. Fresh milt and undiluted aging milt were used as the control groups. Milt (5 ml) was collected and diluted 1:1 in a carp ASP in 50 ml containers and stored at 4 °C under aerobic conditions. The highest sperm motility was found 45% and 36% at 15 s and 45 s post sperm activation (PSA) in hatchery water. Additionally, the curvilinear velocity (VCL, μm/s) and straight-line velocity (VSL, µm/s) of sperm were the highest in hatchery water and the solution with 5 mM KCl, 45 mM NaCl, 30 mM Tris and pH 8.0, which were above 122 µm/s and 87 µm/s at 15 PSA. Sperm concentration in aging sperm of common carp is known to decrease rapidly, so prior to fertilization, sperm concentration was determined and accurately set to 200,000 sperm per egg. The fertilization of eggs and hatching rate after 7 days of sperm storage in carp ASP were 85–87% and 78–81% in both ASs of hatchery water and Perchec solution. Less than 1% sperm motility, fertilization and hatching rate were observed in undiluted sperm (control). In conclusion, the fertilization ability of aging common carp sperm in carp ASP within different ASs was confirmed for practical use in aquaculture. • Fertilization and hatching rate were 85–87% and 78–81% after 7 days of sperm storage in a carp artificial seminal plasma. • Less than 1% sperm motility, fertilization and hatchery rate were observed in undiluted sperm with a carp artificial seminal plasma. • The fertilization success of old sperm confirmed that the sperm may have good prospect to use in common carp aquaculture.

Supplementation effect of dietary flaxseed and coconut oil on antioxidant enzyme activities, LPO seminal plasma protein profiling in adult ram

Energy based diet supplementation is responsible for body growth and plays a significant role to improve spermatogenesis, semen quality, fertility and influence livestock production. The aim of the present study was to evaluate the effect of dietary flaxseed and coconut oil supplementation on semen profile, hormone level, testicular biometry, antioxidant enzyme activity and seminal plasma protein in adult rams. A total number of nine rams (Bannur crossbred rams, aged 20–23 months) were divided into three groups and each group consisted of three rams. The sheep of the control were fed a diet consisting of concentrate mixture and ragi straw in a ratio of 50:50, respectively as per ICAR 2013 standard. The sheep of the coconut oil supplemented group were fed the same basal diet as that of the control group; additionally they were supplemented with coconut oil @ 5 g/100 g concentrate mixture. The sheep of flaxseed oil supplemented group were fed the same basal diet as that of the control group, additionally they were supplemented with flaxseed oil @ 5 g/100 g concentrate mixture. A total of 45 semen samples (5 collections from each ram), were collected through electro-ejaculator method (twice in a week and in 3 days interval). The volume, initial motility, mass motility, live and dead percentage, concentration, acrosome intactness and functional membrane integrity were assessed in fresh semen. Sperm velocity and motility parameters were assessed using CASA. Antioxidant enzyme activities, LPO and seminal plasma protein profiling were estimated in seminal plasma. The results indicated that rams fed with oils (treatment groups) produced semen with higher volume, sperm concentrations, with improved membrane and acrosome integrities. The antioxidant enzyme activities were increased and the oxidative stress reduced as indicated by lowered MDA level in the treatment groups. However, the motility and velocity of spermatozoa did not improve although testosterone increased. Testicular biometric measurements did not differ between control and treatment groups. Marked changes were observed in the seminal plasma protein profile due to feeding of oils. The MALDI-TOF/TOF analysis revealed that the differentially expressed protein spots in the coconut oil group were Interleukin-2, Endothelin-1, Secreted phosphoprotein 24, Caveoilin-I, Interferon gamma and in flaxseed oil group were SRY protein. This study indicated that supplementation of flaxseed and coconut oil at 5% level to the rams improved the protective role against oxidative stress and induced over expression of certain seminal plasma proteins depending upon the oil fed.

Motility and oxidative stress of common carp Cyprinus carpio sperm during short-term storage

Short-term storage of semen is a simple and inexpensive procedure to deal with logistics of large-scale hatchery operations but can lead to oxidative stress and a significant decrease in sperm motility and velocity. To better understand the mechanisms responsible for the association of poor sperm quality with oxidative stress, in the present study we investigated the effect of refrigerated storage for 0, 24, 48, 72, and 144 h on sperm motility and curvilinear velocity and oxidant/antioxidant balance of common carp Cyprinus carpio. Percentage of motile sperm was significantly (p < 0.05) reduced stored for 72 h storage compared to that of fresh sperm. Sperm stored 144 h showed < 40% motility with an average velocity of 91.12 ± 10.4 µm s−1. A time-dependent increase in the level of the oxidative stress indices lipid peroxidation and carbonyl derivatives of proteins was observed. Increase (p > 0.05) in total superoxide dismutase was detected after 48 h, and glutathione reductase and glutathione peroxidase activity demonstrated a significant increase after 72 h. These results provide an additional tool for the development and improvement of short-term sperm preservation procedures commonly applied in aquaculture.

The impact of diet quality on the velocity, morphology and normality of sperm in the zebra finch Taeniopygia guttata

ABSTRACTSperm traits can influence fertilisation success, but there is still much we do not understand about sperm condition dependence, that is, how much sperm traits depend on the male's energy acquisition and allocation. This is especially pronounced in avian taxa, despite extensive observational studies and sampling in wild populations. In this study, we collected sperm samples before and after experimentally reducing diet quality of wild-derived captive zebra finches in small mixed-sex groups, which we compared with individuals on a control diet. We measured the length of sperm components (head, midpiece, flagellum and total sperm length), the proportion of sperm with normal morphology, the proportion of sperm that were progressively motile and sperm swimming velocity (curvilinear velocity; VCL). The only sperm trait we found to be impacted by reduced diet quality was a significant decrease in sperm midpiece length. This is consistent with emerging evidence in other non-model systems, as well the fact that diet can alter mitochondrial density and structure in other tissue types. There was also a significant decrease in sperm velocity and the proportion of motile sperm over the course of the experiment for both experimental groups (i.e. unrelated to diet). This decrease in sperm velocity with largely unchanged sperm morphology emphasizes that there are other important determinants of sperm velocity, likely including seminal fluid composition.

When Older Males Sire More Offspring—Increased Attractiveness or Higher Fertility?

In birds with extrapair mating, older males usually have higher fertilization success than younger males. Two hypotheses can potentially explain this pattern: 1) females prefer older, and often more ornamented males, or 2) older males invest more in reproduction and fertility than younger males. Here we studied factors associated with age-related male fertilization success in a population of barn swallows Hirundo rustica in Canada. We document that male fertilization success increased gradually up to a minimum age of four-year old. The age effect was especially strong for the number of extrapair offspring obtained and the occurrence of a second brood. The higher fertilization success of older males was also associated with an early start of breeding in spring. The length of the elongated outermost tail feathers, a postulated male ornament preferred by females, also increased with age (in both sexes), but it was not a significant predictor of male fertilization success within age classes. Male fertility traits, especially testis size, but also sperm motility and sperm velocity, increased significantly across age groups. Our results suggest that the higher fertilization success by older males is due to their higher reproductive investments and that their longer tails are an adaptation to early arrival on the breeding grounds.Significance statementThe barn swallow is a socially monogamous passerine with extensive extrapair mating. We found that males become more successful in siring both withinpair and extrapair offspring as they become older. Their increased fertilization success was associated with a higher reproductive effort as indicated by larger testes, more motile sperm, and an earlier start of breeding in spring. The length of the outer tail feathers increased with age in both sexes, but long tails did not enhance male fertilization success among males of the same age. Long tails are probably an adaptation to rapid migration and earlier arrival on the breeding grounds. Our findings suggest that the commonly observed age-related increase in male fertilization success in passerine birds is better explained by life history theory than by sexual selection theory.