The ancient and helical architecture of Elasmobranchii’s spermatozoa enables progressive motility in viscous environments

PLoS ONE, Journal Year: 2025, Volume and Issue: 20(2), P. e0319354 - e0319354

Published: Feb. 25, 2025

Subclass Elasmobranchii belongs to an old evolutionary class of Chondrichthyes that diverged 450 mya, presenting a wide diversity reproductive strategies while preserving the ancient mode internal fertilization. Despite such success, many species in this group are at serious risk extinction. Understanding principles sperm progressive motility and physiology vertebrates is crucial for advancing future assisted techniques safeguard deepening our understanding evolution reproduction. possess big spermatozoa (compared bony fishes) with elongated helical head tail similar one currently existing (but later diverged) birds, reptiles, amphibians, which can be considered ancient. These structures may associated necessity penetrate viscous ovarian fluid or jelly layer eggs, suggesting environmental viscosity as driving pressure shaping large-sized heads into shapes through evolution. We observed high-speed video microscopy capture flagellar motion three species: freshwater ray Potamotrygon motoro , marine skate Raja asterias shark Scyliorhinus canicula . investigated effect on parameters its ability break free from spermatozeugmata, move progressively, perform directional changes. After 20 min observation, spermatozeugmata conserved their structure low media 1000 mOsm/kg osmolality. In comparison, no remaining could found high-viscosity 2% methylcellulose (MC) all due motion. find spermatozoa’s unique head-to-flagellum architecture specific promote locomotion fluid; they cannot progressively viscosity. The highest velocity was 0.75% MC 1% sperm. Viscosity stabilizes propagation, producing rotational forces allowing “screw” media. Our observations suggest surrounding critical enabling control direction via newly buckling high As such, key element controlling regulating performance navigation during fertilization species.

Language: Английский

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Label-free metabolic fingerprinting of motile mammalian spermatozoa with subcellular resolution

BMC Biology, Journal Year: 2025, Volume and Issue: 23(1)

Published: March 24, 2025

Sperm metabolic pathways that generate energy for motility are compartmentalized within the flagellum. Dysfunctions in compartments, namely mitochondrial respiration and glycolysis, can compromise male fertility. Studying these compartments is thus required fertility treatment. However, it very challenging to capture images of motile spermatozoa because fast beating flagellum introduces motion blur. Therefore, most approaches immobilize prior imaging. Our findings indicate immobilizing sperm alters their profile, highlighting necessity measuring metabolism during movement. We achieved this by encapsulating mouse epididymis a hydrogel followed two-photon fluorescence lifetime imaging microscopy situ. The autofluorescence endogenous metabolites—FAD, NADH, NADPH—enabled us visualize without staining. trained machine learning automated image segmentation generated fingerprints using object-based phasor analysis. show compartment (1) distinguish individual males genetic background, age, or fecundity status, (2) correlate with fertility, (3) change age likely due increased oxidative metabolism. approach eliminates need immobilization labeling captures native state This technique could be adapted metabolism-based selection assisted reproduction.

Language: Английский

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Evolutionary Aspects of Sperm Physiology and Its Assessment

Methods in molecular biology, Journal Year: 2025, Volume and Issue: unknown, P. 29 - 41

Published: Jan. 1, 2025

Language: Английский

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The evolution of testis architecture and sperm size in Anolis lizards

Biological Journal of the Linnean Society, Journal Year: 2025, Volume and Issue: 144(4)

Published: April 1, 2025

Abstract The major function of the testes is production sperm cells. Across species there are dramatic differences in morphology, and this variation may result from internal structure testis. Yet, extent to which testis anatomy associated with size remains unclear. In study, we used 20 Anolis lizards examine interspecific relationships between architecture component lengths, as well a proxy for copulation rate (hemipenis muscle damage), using both phylogenetic regular linear models. Results our evolutionary analysis indicate that components have high signal. Further, length, variance these traits, not one another models, although non-phylogenetic analyses suggest larger produce longer flagella. Our interpretation conflicting models strong signal traits mask significant functional developmental reveal. This suggests experiencing selection would cause covary different pattern than their relationships; instead, group they likely evolving together neutrally.

Language: Английский

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Comparing novel sperm extenders for the internally-fertilizing tiger salamander (Ambystoma tigrinum)

Frontiers in Amphibian and Reptile Science, Journal Year: 2024, Volume and Issue: 1

Published: Jan. 19, 2024

Due to the concentrated nature and small volume of spermic milt that is typically produced from internally-fertilizing salamanders, an extender needed analyze sperm for quality quantity metrics. Techniques diluting salamander analysis have thus far utilized low osmolality media, which are likely physiologically distinct female reproductive tract. Application mammalian extenders could maintain motility morphology in storage longer due similar internal fertilization both taxa. Several were tested including: Multipurpose Handling Medium, Sperm Washing Modified Ham’s F-10 Basal Medium (HAM’s), Refrigeration 10% Holtfreter’s solution as a control. The experimental treatments divided into two groups: diluted (90 mOsm, approximate sperm) undiluted (280-320 mOsm). Milt samples collected male tiger salamanders (N=11) 1:50 with each measured progressive motility, total normal every 10 minutes one hour. When comparing versus same extender, there was no difference (p>0.05) any response variables. In addition, we found best maintaining while HAM’s retaining over time. Overall, not key driver influencing but rather other factors such ionic composition or pH be affecting form function.

Language: Английский

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Coevolution between eggs and sperm of insects

Proceedings of the Royal Society B Biological Sciences, Journal Year: 2024, Volume and Issue: 291(2026)

Published: July 1, 2024

Sexual selection is known to play a major role in the evolution of insect sperm size, whereas natural thought be driver egg size. Despite these differing forms operating, it possible coevolution between male and female gametes can occur owing their vital interactions during fertilization. We tested egg–sperm insects found that longer correlated wider eggs. Moreover, size entry point into eggs (micropyles), was positively related diameter sperm, on average being approximately three times sperm. This suggests function reducing channelling entry, but potentially still leaving space for movement. Our work greater attention needs paid prior fertilization as they may influence gametes.

Language: Английский

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Tetrapod sperm length evolution in relation to body mass is shaped by multiple trade-offs

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: July 22, 2024

Abstract Sperm length is highly variable across species and many questions about its variation remain open. Although in body mass may affect sperm evolution through influence on multiple factors, the extent to which linked remains elusive. Here, we use Pareto multi-task framework investigate relationship between tetrapods. We find that tetrapods occupy a triangular front, indicating trade-offs shape of relation mass. By exploring factors predicted evolution, mainly driven by competition clutch size, rather than genome size. Moreover, front maintained within endotherms, internal fertilizers, mammals birds, suggesting similar evolutionary Finally, demonstrate robust phylogenetic dependencies finite sampling bias. Our findings provide insights into mechanisms driving interspecific highlight importance considering optimizing reproductive traits.

Language: Английский

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Characterization of sperm and implications for male fertility in the last of the Rhynchocephalians

Conservation Physiology, Journal Year: 2023, Volume and Issue: 11(1)

Published: Jan. 1, 2023

Abstract Managing a species of conservation concern can be best achieved when there is information on the reproductive physiology both sexes available; however, many lack this critical, baseline information. One such species, tuatara (Sphenodon punctatus), last surviving member one four reptile orders (Rhynchocephalia) and only known to male intromittent organ. Culturally evolutionarily significant, global priority for maintenance biodiversity. In light this, we characterized morphology, viability swim speed mature sperm first time. We found that are filiform bear remarkably conserved three-part structure seen across animal kingdom. Tuatara long (mean total length 166 μm), with an approximate head:midpiece:tail ratio 15:1:17. While capable high levels within-mating (94.53%), mean all samples was 58.80%. Finally, had curvilinear velocity (μ × s − 1) 82.28. At population level, were no differences in or between collected from male’s mating season repeat matings; maximum increased observed repeated matings relative matings. Interestingly, faster shorter midpieces, but greater longer head tail sections. This work expands our understanding characteristics their variation new order, provides wild references assessment captive individuals, lays groundwork potential assisted techniques highlights as important factor consideration future programs unique species.

Language: Английский

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Impact of Z chromosome inversions on gene expression in testis and liver tissues in the zebra finch

Molecular Ecology, Journal Year: 2023, Volume and Issue: 33(24)

Published: Dec. 21, 2023

Chromosomal inversions have been identified in many natural populations and can be responsible for novel traits rapid adaptation. In zebra finch, a large region on the Z chromosome has subject to multiple inversions, which pleiotropic effects but especially sperm phenotypes, such as midpiece flagellum length. To understand effect, inversion these traits, we examined testis liver transcriptomes of young males at different maturation times. We compared gene expression differences among three karyotypes: AA, B*B* AB*, where B* denotes inverted regions with respect A. testis, 794 differentially expressed genes were found most them located Z. They functionally enriched sperm-related traits. also clusters co-expressed that matched inversion-related phenotypes. liver, there some functions overrepresentation similar location testis. both tissues, overrepresented near distal end middle chromosome. For heterokaryotype, observed several one allele being dominantly expressed, patterns or other homokaryotype. This was confirmed SNPs genes, interestingly gene, DMGDH, had allele-specific originating mainly from haplotype yet haplotypes equally liver. karyotype-specific difference tissue-specific suggests effect thus mechanism divergent phenotypic resulting an inversion.

Language: Английский

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Intra-specific correlations between ejaculate traits and competitive fertilization success: a meta-analysis across species and fertilization modes

Evolution, Journal Year: 2023, Volume and Issue: 78(3), P. 497 - 510

Published: Dec. 26, 2023

Abstract Understanding of how selection can act on traits that improve competitiveness and subsequent paternity has advanced, including the idea internal external fertilization presents different environments may select differentially ejaculate traits. However, no studies have quantitatively synthesized intra-specific relationships between these paternity. Therefore, we conducted a meta-analysis across 52 papers to determine which positively correlate with share correlations vary mode. Overall, most were associated paternity, notable exception sperm length. Sub-analyses number, length, velocity revealed statistical differences modes in relationship when all effect sizes species combined. sub-analysis fish only, found evidence be more important fertilizers. We also observed importance phylogenetic relatedness some species-specific differences. Our results suggest while should under positive directional both fertilizers, length subject nuanced pressures. highlight patterns competitive success.

Language: Английский

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