Characterization of Bottlenose Dolphin (Tursiops truncatus) Sperm Based on Morphometric Traits

Bottlenose dolphin (Tursiops truncatus) males follow many reproductive strategies to ensure their paternity. However, little is known about the sperm traits, including morphometric features, that contribute to their reproductive success. Our aim was to study dolphin sperm morphometry (a total of 13 parameters) in two adult males to evaluate (i) presumptive sperm subpopulations, (ii) the correlation of sperm morphometry with testosterone levels and (iii) the effect of refrigerated storage on the sperm morphometry. Sperm populations were classified into four principal components (PCs) based on morphometry (>94% of cumulative variance). The PCs clustered into two different sperm subpopulations, which differed between males. Furthermore, the levels of serum testosterone were positively correlated with the length of the midpiece but negatively correlated with head width and the principal piece, flagellum and total sperm lengths. Most of the sperm morphometric parameters changed during the storage period (day 1 vs. day 7), but only the principal piece length was affected by the storage temperature (5 °C vs. 15 °C). This is the first study to identify dolphin sperm subpopulations based on morphometry and the influence of serum testosterone and refrigeration on sperm morphometry.

Evaluation of the Morphometry of Sperm from the Epididymides of Dogs Using Different Staining Methods

Evaluation of sperm morphometry is an important criterion in the diagnosis of a male animal’s suitability for breeding. The aim of the study was to evaluate the morphometry of sperm from the epididymides of dogs subjected to routine castration using various staining methods. The study was carried out on semen collected from ten healthy dogs. Gonads were obtained from each dog during routine castration at a veterinary surgery. Then, the epididymides (caput, corpus, cauda) were isolated from the gonads, semen was collected from them and microscope slides were prepared. The slides for evaluation of sperm morphometry were prepared by four methods: DiffQuik, SpermBlue, eosin-nigrosin and eosin-gentian. A total of 2400 sperm were analyzed (240 sperm from the dog). The sperm collected from the caput and corpus of the epididymis were found to have larger heads and tails than those collected from the cauda of the epididymis. The staining method was shown to affect the morphometry of sperm taken from the epididymides of dogs. The staining methods differentiate the dimensions of the head of sperm in different parts of the epididymis but do not affect the length of the sperm tail. The occurrence of differences in the head dimensions of sperm may be linked to the use of different fixatives and chemical reagents in the staining procedure. Sperm stained by the EN method had the smallest head and tail dimensions. The greatest head area was noted in the sperm stained by the EG method. In the slides stained by the SB method, the sperm heads were relatively long but narrow. The methods used are suitable for the evaluation of sperm structure, and the possibility of using all four methods enables a full characterization of sperm collected from the caput, corpus and cauda of the epididymides of dogs.

Quantitative sperm characteristics of Tankwa goats with special reference to hyperactivated motility

Computer-assisted semen analysis (CASA) is an automated and objective method of evaluating structural (e.g. morphology) and functional sperm parameters (e.g. motility and hyperactivation). Sperm hyperactivation is essential for successful fertilization and is thus an important aspect in determining the fertility potential of a male. In the current study, CASA was used for standard semen analysis and for comparison of the ability of phosphate buffered saline (PBS), BO sperm wash (10 mM caffeine), 4% lignocaine, and 5 mM procaine hydrochloride to induce hyperactivation in Tankwa goat spermatozoa. Twenty-nine ejaculates were collected from randomly selected male goats by electroejaculation. Although none of the four media affected percentage total sperm motility, lignocaine caused a significant decrease (P >0.05) in percentage progressive motility. Exposure to procaine resulted in an increase in swimming speed (P ≤0.05) and star-spin motility tracks, which are typical of sperm hyperactivation. Using PBS and procaine motility data from individually selected spermatozoa, receiver operator characteristic curves were constructed to distinguish the kinematic parameters employed as cut-off values for sperm hyperactivation. PBS and BO sperm wash did not induce hyperactivation (0.1 + 0.2% and 0.04  0.2% respectively), while lignocaine induced little hyperactivation (3.4 + 3.0%) and procaine hydrochloride had the highest percentage hyperactivation (25.3 + 13.6%). The large variation in hyperactivation (0–54.5%) may reflect inter-individual differences in sperm quality among these males. This study indicated procaine hydrochloride was the most promising hyperactivation-inducing medium for Tankwa goat spermatozoa and should be considered for similar assessments in other animal species Keywords: computer-aided sperm analysis, procaine hydrochloride, sperm kinematics, sperm morphometry, sperm motility

The correlation between spermatozoa morphometry and the testosterone levels in the epididymis of aceh cow

The objective of this study was to determine the correlation between spermatozoa morphometry and testosterone concentration in the epididymal caput, corpus, and cauda of aceh cattle. The epididymal sperm swab slides were stained using Williams's staining to examined the morphology and morphometry of spermatozoa whereas the level of testosterone from epididymal caput, corpus, and cauda extract was measured using enzyme-linked immunosorbent assay (ELISA). The data of sperm morphology were presented descriptively whereas the data of sperm morphometry and testosterone concentration were analyzed using one way ANOVA. Pearson correlation test was conducted to know the correlation between the total length of spermatozoa (TLS) and testosterone concentration in three parts of epididymis. The result showed that the sperm morphology in caput, corpus, and cauda of epididymis was not different statistically. The TLS of aceh cattle at caput, corpus, and cauda epididymis were 69,70±0,8 µm, 70,90±0.39 µm, and 72,98±0.74 µm respectively and statistically different (p<0.05). In addition, the concentration of testosterone in caput, corpus, and cauda epididymis were 9,92±3,76 ng/g, 16.96±13,22 ng/g, and 15,63±11.80 ng/g respectively and also not different among three parts of epididymis (p>0.05). The positive correlation (r= 0.413, p= 0.416) was found between TLS and testosterone concentration at caput whereas in corpus and cauda those correlation were negative and not different (corpus: r= -0.638, p= 0.172 and cauda: r= -0.719, p= 0,108). In conclusion, the longest-sized spermatozoa found in the cauda epididymis are mature spermatozoa where the maturation process optimally takes place in caput epididymis. Testosterone found in the epididymis of aceh cow can be used as an alternative source of testosterone.

PSXIII-4 Species feature of morphometric parameters in poultry semen

The aim of the research was to study the specific features of morphometric parameters in rooster and guinea fowl spermatozoa. Thirty ejaculate samples from each species were investigated. A macroscopic assessment of the ejaculates obtained was carried out by volume, color and consistency. Microscopic parameters were studied using computerized sperm quality analysis systems. Diff-Quick set was used for staining sperm. Visualization of fixed preparations was performed using a Nikon Eclipse Ni-U microscope and a Nikon DS-Qi2 camera. Measurement of morphometric parameters was carried out in the program NIS-Elements BR 4.30. Evaluation of sperm morphometry was carried out according to the following indicators: total length of spermatozoa, length of head and tail, perimeter and area, head shape in indexes of ellipticity and elongation. The SPSS v.15.0 package was used for statistical analysis. To assess the statistical differences in the distributions of spermatozoa, the χ2-test was used. ANOVA was conducted to determine the effect of species. Roosters surpassed guinea fowls in ejaculate volume by 83.3% (P &lt; 0.001). Statistically significant differences were not established for sperm activity between species. The content of motile spermatozoa in the roosters ejaculate was 92.4 ± 5.3%, in guinea fowls - 88.7 ± 6.54%. The results of the morphometric parameters analysis showed that they have a specific feature. The total length of rooster spermatozoa was 90 ± 2.6 μm, which is 8 μm more than that in guinea fowl (P &lt; 0.05). The length of the sperm head in roosters was 2 μm longer than that in guinea fowls (P &lt; 0.05). The interspecific difference across the perimeters and width of the head was not statistically significant. Rooster ejaculates differed relative homogeneity compared to guinea fowl. The study results showed that morphometric parameters of poultry sperm have a specific feature. Supported by the RSF (16-16-04104).

Sperm Morphology in Neotropical Primates

The morphological and morphometric characterization of spermatozoa has been used as a taxonomic and phylogenetic tool for different species of mammals. We evaluated and compared the sperm morphometry of five neotropical primate species: Alouatta caraya, Ateles belzebuth and Ateles chamek of family Atelidae; and Cebus cay (=Sapajus cay) and Cebus nigritus (=Sapajus nigritus) of family Cebidae. After the collection of semen samples, the following parameters were measured on 100 spermatozoa from each specimen: Head Length, Head Width, Acrosome Length, Midpiece Length, Midpiece Width and Tail Length. Considering the available literature on sperm morphometry, we gathered data of 75 individuals, from 20 species, 8 genera and 2 families. These data were superimposed on a phylogeny to infer the possible direction of evolutionary changes. Narrower and shorter spermatozoa seem to be the ancestral form for Cebidae, with a trend toward wider and larger heads in derived groups. The spermatozoa of Atelidae may show an increase in total length and midpiece length. Sperm heads would have become narrower in the more derived groups of Ateles. Sperm length may increase in the more derived species in both families. Our results are discussed in the context of sperm competition and sexual selection.