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Semen quality of stallions involved in breeding
VOKROUHLÍKOVÁ, Jana
The main objective of the study was to determine the seminal characteristics of warmblooded stallions, to assess a relationship between motility parameters of spermatozoa and sperm head dimensions (Experiment 1) and to compare the ability of three milk-based extenders to preserve the motility and viability of cooled shipped semen (Experiment 2) using Sperm Class Analyzer (SCA, MICROPTIC SL). In Experiment 1, 32 and 36 ejaculates were collected during breeding seasons 2016 and 2017 from 10 clinically healthy and fertile warmblooded stallions (age 3- 22 years). The volume of ejaculate (mL), sperm concentration (M/mL), motility of sperm with kinematic parameters, viability of sperm (%) and sperm morphometry with morphometric parameters were evaluated. In Experiment 2, 21 ejaculates from 11 stallions were collected before the beginning of the breeding season 2018 and diluted with Kenney, EquiPlus and INRA 96. Spermatozoa viability (VIT, %), total motility (MOT, %), progressive motility (PMOT, %) and selected kinematic parameters were evaluated for 63 semen samples. These parameters were determined 2 hours after semen processing and then in 24, 48 and 72-hour intervals of storage at 5 °C. The following average values were found in the obtained ejaculate samples for the observed periods of the breeding seasons 2016 and 2017 - volume of ejaculate 49.22 and 56.77 ml, sperm concentration 208.20 and 222.19 M/ml, MOT 82.44 and 81.38 %, PMOT 37.34 and 35.46 %, VIT 60.71 and 42.91 %, morphologically normal sperm 75.00 and 64.50 %, curvilinear velocity (VCL) 62.67 and 60.26 ?m/s, straight-line velocity (VSL) 32.10 and 27.55 ?m/s, average path velocity (VAP) 48.14 and 44.35 ?m/s, linearity coeficient (LIN) 50.64 and 44.89 %, straightness coeficient (STR) 66.56 and 62.01 %, wobble coeficient (WOB) 75.74 and 72.12 %, amplitude of lateral head displacement (ALH) 2.59 and 2.90 ?m, beat- cross frequency (BCF) 7.32 and 7.49 Hz, head length (L) 6.33 and 6,41 ?m, head maximum width (W) 3.01 and 3.11 ?m, head area (A) 15.65 and 16.37 ?m2, head perimeter (P) 16.26 and 16.55 ?m, elongation (Elong ) 0.36 and 0.35, ellipticity (Ellip) 2.11 and 2.07, roughness (Rugo) 0.74 and 0.75 and regularity (Regu) 0.96. There where significant differences among stallions in all evaluated parameters of sperm (P < 0.05). Furthermore, the influence of age and fertility of stallions was also demonstrated for the observed parameters. MOT, PMOT, VCL, VSL, VAP, LIN and WOB were positively correlated with area, width, length and perimeter of the head and negatively correlated with elongation and ellipticity of the sperm head. Sperms with larger head dimensions thus had larger MOT, PMOT, VCL, VSL, VAP, LIN, WOB, STR and smaller ALH and BCF. In contrast, sperms with greater elongation and ellipticity had lower motility and kinematic parameters. The effect of the extender (P < 0.05) and the storage time (P < 0.001) was highly significant for evaluated parameters. The ejaculates extended with INRA 96 reached significantly higher values (P < 0.01) for all evaluated parameters compared to Kenney extender. The INRA 96 extender significantly increased the values of PMOT, VCL and VAP compared to EquiPlus (P < 0.05). The results obtained from using INRA 96 showed that quality of cooled semen can be sufficiently maintained during at least 24 hours of storage.
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Sperm motility and postmating prezygotic isolation in two nightingale species
Baránková, Lucie ; Reifová, Radka (advisor) ; Frolíková, Michaela (referee)
The motility of male gametes (sperm) is one of the important factors influencing the reproductive success of males. Because sperms are often subjected to strong postmating sexual selection and even closely related species often differ in sperm morphology, sperm motility could also differ between species, which may contribute to reproductive isolation between species. As part of my diploma thesis, I studied sperm motility in two closely related species of songbirds, the common nightingale (Luscinia megarhynchos) and the thrush nightingale (Luscinia luscinia). These two species of nightingales are an ideal model system because the areas of these two species overlap in the secondary contact zone across Central and Eastern Europe, where they occasionally hybridize and thus allow the study of speciation mechanisms in the natural environment. Both species also differ greatly in total sperm length. As part of my diploma thesis, I studied the possible influence of different sperm morphology on their motility. I further tested whether the motility of nightingale sperm differs in the fluid from the cloaca of a female of the same species and a different species, which would demonstrate the presence of postmating prezygotic reproductive isolation between species. The results of my work showed that despite the...
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Postcopulatory sexual selection on phenotypic traits in European barn swallows
Míčková, Kristýna ; Albrecht, Tomáš (advisor) ; Svobodová, Jana (referee)
Sperm phenotype is an essential indicator of the male ejaculate quality and may have a significant impact on male reproductive success. Sperm phenotypes are considerably variable across species but variation is also found among males within species. This thesis examines (1) variation in sperm phenotypes among males in barn swallows (Hirundo rustica), (2) changes in male ejaculate quality with age, (3) relationships between sperm morphology and motility, (4) effects of sperm phenotypes (morphology and motility) on male fertilization success, using a large dataset of 174 observation for 130 males, and (5) the influence of female reproductive environment on sperm motility. From the tested variables, only midpiece length correlated with male age. Older males had shorter midpiece but no relationship between male age and reproductive success was found. Sperm length negatively affected sperm motility and, simultaneosly, relative midpiece length posively correlated with sperm motility. No correlation was found between the male reproductive success and sperm motility, presence of abnormalities, length of outermost tail feathers or age. Males with shorter relative midpiece were more successful in within-pair paternity, and males with shorter sperms but longer relative midpiece were more successful in...
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Obsah metabolitů ve spermiích ryb za různých fyziologických podmínek
FEDOROV, Pavlo
Investigation of creatine- and adenylate phosphates involvement in fish spermatozoa metabolism is of high interest for fish spermatology. These compounds are necessary to support normal physiological state and motility of spermatozoa. The simultaneous changes in content of creatine- and adenylate phosphates in fish spermatozoa prior and during their motility are quite unclear. Therefore, studying and development of new methods for the quantification of creatine- and adenylate phosphates in spermatozoa of different fish species under such physiological conditions as maturation and in vitro manipulation are of high importance. One of the study outputs is the developed LC/HRPS (liquid chromatography coupled with high resolution product scan) method for the analysis of creatine- and adenylate phosphates content in fish spermatozoa (Chapter 2). Its main advantage is the possibility to detect and quantify several compounds (creatine, creatine phosphate (CP), AMP, ADP, ATP, and cAMP) simultaneously to obtain maximum information with minimum analytical effort. The method was validated taking into account such key parameters as limit of quantification, selectivity, recovery and repeatability. It represented an excellent performance allowing determination of target compounds in highly diluted fish sperm samples. Consequently, the method was applied for the quantification of aforementioned substances during sterlet (Acipenser ruthenus) spermatozoa maturation and in vitro manipulation with sperm of whitefish (Coregonus lavaretus maraena) and European eel (Anguilla Anguilla). The present study showed that immature sterlet spermatozoa are not able to initiate motility. Significant decrease of CP and stable levels of ATP and ADP content during their maturation were found. The critical importance of ATP regeneration system and oxidative phosphorilation for the maturation process of sterlet sperm as a prerequisite for successful fertilization was assumed (Chapter 3). Further experiments revealed that European eel spermatozoa were not able to initiate motility by activation medium (AM) at the start of the induced spermiation. They acquired the ability to be activated after the dilution with AM at the end of hormonal treatment. This accompanied by the increase of CP and cAMP levels in spermatozoa after activation. That allowed us to assume the involvement of ATP regenerating system and cAMP-dependent regulatory pathways in the process of hormonally induced spermiation (Chapter 4). Current study represents a first successful estimation of cAMP in fish spermatozoa during the motility period using the LC/HRPS. Important issues concerning the short-term storage of European eel sperm were rised. Storage at 4 °C was accompanied by higher marcoergic phosphates content and higher motility in comparison to the storage at 20 °C. It suggests the involvement of macroergic phosphates metabolism in short-term storage. (Chapter 4). Obtained results could contribute to the development of new effective methods for improving of spermiation and short-term sperm storage in European eel aquaculture. Various degrees of energy consumption in response to environment composition were found in whitefish spermatozoa. Energy consumption was significantly higher in motility activating conditions. No effect of osmolality was found on this process. The content of CP and ATP was significantly higher when cells were in motility inhibiting medium comparing to activation medium. No relationship between content of CP, ADP, and ATP and spermatozoa motility parameters in AM of different osmolality was found. Isotonic conditions favor the spermatozoa with longer motility period, higher linearity, and fast velocity without increase in ATP content (Chapter 5). This suggests that whitefish sperm energy management is more efficient after activation in isotonic conditions. Obtained results are of high interest for elaboration of new sperm motility activating media for fisheries practice.
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