Find research datasets worth reusing

opencc-by-4.0Apr 2020View details →

Dataset for "Metabolic rate and oxygen radical levels increase but radical generation rate decreases with male age in Drosophila melanogaster sperm"

Metabolic rate, H2O2 level, and ROS production data for D. melanogaster sperm and gut tissue

FIGURES 13–18 in A new species and new records of Malagasy Megalopinus Eichelbaum (Coleoptera Staphylinidae, Megalopsidiinae), with notes on the sperm pump in rove beetles

FIGURES 13–18. Megalopinus heissi Puthz, male. Dorsal habitus (13); head, pronotum and elytra in dorsal (14) and lateral (15) views; aedeagus in dorsal (16) and lateral (17) views; close-up of endophallic structures (18).

FIGURES 7–12 in A new species and new records of Malagasy Megalopinus Eichelbaum (Coleoptera Staphylinidae, Megalopsidiinae), with notes on the sperm pump in rove beetles

FIGURES 7–12. Megalopinus lemur Puthz, male. Dorsal habitus (7); head, pronotum and elytra in dorsal (8) and lateral (9) views; aedeagus in dorsal (10) and lateral (11) views; close-up of endophallic structures (12).

FIGURES 19–27 in A new species and new records of Malagasy Megalopinus Eichelbaum (Coleoptera Staphylinidae, Megalopsidiinae), with notes on the sperm pump in rove beetles

FIGURES 19–27. Examples of sperm pumps in Staphylinidae. Euaesthetinae: Edaphus sp. (19); Euaesthetinae: Euaesthetus ruficapillus (Lacordaire) (20); Steninae: Stenus ludyi Fauvel (21); Solieriinae: Solierius obscurus (Solier) (22); Scydmaeninae: Leptochromus laselva Lord et al. (23); Scydmaeninae: Ablepton treforti Frivaldszky (24); Scydmaeninae: Taurablepton sp. (25); Scydmaeninae: Clidicus assymetricus Jałoszyński (26); Scydmaeninae: Stenomastigus longicornis (Boheman), histological cross-section through middle region of sperm pump (27). Abbreviations: aed, aedeagus; de, ductus ejaculatorius; fn, funnel; ms, muscle; spp, sperm pump.

FIGURES 1–6 in A new species and new records of Malagasy Megalopinus Eichelbaum (Coleoptera Staphylinidae, Megalopsidiinae), with notes on the sperm pump in rove beetles

FIGURES 1–6. Megalopinus puthzi sp. n., male. Dorsal habitus (1); head, pronotum and elytra in dorsal (2) and lateral (3) views; aedeagus in dorsal (4) and lateral (5) views; close-up of endophallic structures (6). Abbreviations: dsr, dorsal row; spp, sperm pump; shr, subhumeral row; slr, sublateral row.

opencc-zeroJun 2020View details →

Data from: Sperm quality, aggressiveness and generation turnover can facilitate unidirectional Y chromosome introgression across the European house mouse hybrid zone

The widespread and locally massive introgression of Y chromosomes of the eastern house mouse (Mus musculus musculus) into the range of the western subspecies (M. m. domesticus) in Central Europe calls for an explanation of its underlying mechanisms. Given the paternal inheritance pattern, obvious candidates for traits mediating the introgression are characters associated with sperm quantity and quality. We can also expect traits such as size, aggression, or the length of generation cycles to facilitate the spread. We have created two consomic strains carrying the non-recombining region of the Y chromosome of the opposite subspecies, allowing us to study introgression in both directions, something impossible in nature due to the unidirectionality of introgression. We analysed several traits potentially related to male fitness. Transmission of the domesticus Y onto the musculus background had negative effects on all studied traits. Likewise , domesticus males possessing the musculus Y had, on average, smaller body and testes and lower sperm count than the parental strain. However, the same consomic males tended to produce less dissociated sperm heads, to win more dyadic encounters, and to have shorter generation cycles than pure domesticus males. These data suggest the domesticus Y is disadvantageous on the musculus background while introgression in the opposite direction can confer a recognizable, though not always significant, selective advantage. Our results are thus congruent with the unidirectional musculus→domesticus Y chromosome introgression in Central Europe. In addition to some previous studies, they show this to be a multifaceted phenomenon demanding a multidisciplinary approach.

opencc-zeroJul 2020View details →

Data from: Female sperm storage mediates postcopulatory costs and benefits of ejaculate anticipatory plasticity in the guppy

Males of many species evolved the capability of adjusting their ejaculate phenotype in response to social cues to match the expected mating conditions. When females store sperm for prolonged time, the expected fitness return of plastic adjustments of ejaculate phenotype may depend on the interval between mating and fertilization. While, prolonged female sperm storage (FSS) increases the opportunity for sperm competition, as a consequence of the longer temporal overlapping of ejaculates from several males, it may also create variable selective forces on ejaculate phenotype, for example by exposing trade-offs between sperm velocity and sperm survival. We evaluated the relationship between the plasticity of ejaculate quality and FSS in the guppy, Poecilia reticulata, a polyandrous livebearing fish in which females store sperm for several months and where stored sperm contribute significantly to a male's lifelong reproductive success. In this species, males respond to the perception of future mating opportunities by increasing the quantity (number) and quality (swimming velocity) of ready-to-use sperm (an anticipatory response called 'sperm priming'). Here we investigated 1) the effect of sperm priming on in-vitro sperm viability at stripping and its temporal decline (as estimate of sperm survival), and, 2) the in-vitro competitive fertilization success in relation to female sperm storage using artificial insemination. As expected, sperm-primed males produced more numerous and faster sperm, but with a reduced in-vitro sperm viability at stripping and after 4 hours, compared to their counterparts. Artificial insemination revealed that the small (non-significant) advantage of primed sperm when fertilization immediately follows insemination, is reversed when eggs are fertilized by female-stored sperm, weeks after insemination. By suggesting a plastic trade-off between sperm velocity and viability, these results demonstrate that prolonged female sperm storage generates divergent selection pressures on ejaculate phenotype.

opencc-zeroAug 2020View details →

The long-range echo scene of the sperm whale biosonar

Sperm whales use their gigantic nose to produce the most powerful sounds in the animal kingdom, presumably to echolocate deep-sea prey at long ranges and possibly to debilitate prey. To test these hypotheses, we deployed sound recording tags (DTAG-4) on the tip of the nose of three sperm whales. One of these recordings yielded over 6000 echo streams from organisms detected up to 144 m ahead of the whale, supporting a long-range prey detection function of the sperm whale biosonar. The whale navigated this complex acoustic scene by maintaining a stable, long-range acoustic gaze suggesting continual resource evaluation. Less than 10% of the echoic organisms recorded by the tag were targeted for capture and only 18% of the buzzes were emitted within the 50 m depth interval of maximum organism encounter rate, demonstrating echo guided prey selection. Buzzes were initiated >20 m from the prey, showing that sperm whales do not debilitate their prey with sound, but trade echo levels for reduced forward masking and rapid updates on prey location in keeping with the lower manoeuvrability of these large predators. We conclude that the powerful biosonar of sperm whales enables long-range echolocation and selection of prey, but not acoustic debilitation.

opencc-zeroSep 2020View details →

Data from: Post-ejaculation thermal stress causes changes to the RNA profile of sperm in an external fertiliser

Sperm cells experience considerable post-ejaculation environmental variation. However, little is known about whether this affects their molecular composition, likely due to the assumption that sperm are transcriptionally quiescent. Nevertheless, recent evidence shows sperm have distinct RNA profiles that affect fertilisation and embryo viability. Moreover, RNAs are expected to be highly sensitive to extracellular changes. One such group of RNAs are heat shock protein (hsp) transcripts, which function in stress responses and are enriched in sperm. Here, we exploit the tractability of the mussel Mytilus galloprovincialis to exposed paired samples of ejaculated sperm to ambient (19 °C) and increased (25 °C) temperatures, then measure (a) sperm motility phenotypes, and (b) mRNA levels of two target genes (hsp70 and hsp90) and several putative reference genes. We find no phenotypic changes in motility, but reduced mRNA levels for hsp90 and the putative reference gene gapdh at 25 °C. This could reflect either decay of specific RNAs, or changes in translation and degradation rates of transcripts to maintain sperm function under stress. These findings represent the first evidence for changes in sperm RNA profiles due to post-ejaculation environments, and suggest that sperm may be more vulnerable to stress from rising temperatures than currently thought.

opencc-zeroSep 2020View details →

Combined effects of rearing and testing temperatures on sperm traits

Temperature experienced during early development can affect a range of adult life history traits. Animals often show seemingly adaptive developmental plasticity – with animals reared at certain temperatures performing better as adults at those temperatures. The extent to which this type of adaptive response occurs in gonadal tissue that affect sperm traits is, however, poorly studied. We initially reared male mosquitofish (Gambusia holbrooki) at either 18oC or 30oC, and then measured their sperm reserves as adults. We also looked at the velocity of their sperm, at both the matched and mismatched temperature. Although males reared at 30oC were larger than those initially reared at 18oC, there was no detectable effect of rearing temperature on absolute sperm number. Sperm swam faster at 30oC than 18oC regardless of the male's rearing temperature. Therefore, we found no evidence of adaptive developmental plasticity. Rearing temperature did, however, significantly influence the relationship between male body size and sperm velocity. Larger males had faster sperm when reared at the warmer temperature, and slower sperm when reared at the cooler temperature. This suggests that rearing temperature could alter the relationship between pre- and post-copulatory sexual selection as male size affects mating success. Finally, there was a positive correlation between velocity at the two test temperatures, suggesting that temperature experienced during sperm competition is unlikely to affect a male's relative fertilisation success.

opencc-zeroSep 2020View details →

Data from: Costs and benefits of giant sperm and sperm storage organs in Drosophila melanogaster

In Drosophila, long sperm are favoured in sperm competition based on the length of the female's primary sperm storage organ, the seminal receptacle (SR). This sperm-SR interaction, together with a genetic correlation between the traits, suggests that the coevolution of exaggerated sperm and SR lengths may be driven by Fisherian runaway selection. Here, we explore the costs and benefits of long sperm and SR genotypes, both in the sex that carries them and in the sex that does not. We measured male and female fitness in inbred lines of D. melanogaster derived from four populations previously selected for long sperm, short sperm, long SRs, or short SRs. We specifically asked: what are the costs and benefits of long sperm in males and long SRs in females? Furthermore, do genotypes that generate long sperm in males or long SRs in females impose a fitness cost on the opposite sex? Answers to these questions will address whether long sperm are an honest indicator of male fitness, if male post-copulatory success is associated with male pre-copulatory success, if female choice benefits females or is costly, and whether intra-genomic conflict could influence evolution of these traits. We found that both sexes have increased longevity in long sperm and long SR genotypes. Males, but not females, from long SR lines had higher fecundity. Our results suggest that sperm-SR coevolution is facilitated by both increased viability and indirect benefits of long sperm and SRs in both sexes.

opencc-zeroOct 2020View details →

Data from: Temporal dynamics of competitive fertilization in social groups of red junglefowl (Gallus gallus) shed new light on avian sperm competition

Studies of birds have made a fundamental contribution to elucidating sperm competition processes, experimentally demonstrating the role of individual mechanisms in competitive fertilisation. However, the relative importance of these mechanisms and the way in which they interact under natural conditions remain largely unexplored. Here, we conduct a detailed behavioural study of freely-mating replicate groups of red junglefowl, Gallus gallus, to predict the probability that competing males fertilise individual eggs over the course of 10-day trials. Remating frequently with a female and mating last increased a male's probability of fertilisation, but only for eggs ovulated in the last days of a trial. Conversely, older males, and those mating with more polyandrous females, had consistently lower fertilisation success. Similarly, resistance to a male's mating attempts, particularly by younger females, reduced fertilisation probability. After considering these factors, male social status, partner relatedness and the estimated state of a male extragonadal sperm reserves did not predict sperm competition outcomes. These results shed new light on sperm competition dynamics in taxa such as birds, with prolonged female sperm storage and staggered fertilisations.

opencc-zeroDec 2020View details →

Data from: Nasal compartmentalization in Kogiidae (Cetacea, Physeteroidea): Insights from a new late Miocene dwarf sperm whale from the Pisco Formation

Facial compartmentalization in the skull of extant pygmy whales (Kogiidae) is a unique feature among cetaceans that allows the housing of a wide array of organs responsible for echolocation. Recent fossil findings depict a remarkable disparity of the facial bone organization in Miocene kogiids, but the significance of such a rearrangement for the evolution of the clade has been barely explored. Here we describe Kogia danomurai sp. nov., a late Miocene (ca. 5.8 Ma) taxon from the Pisco Formation (Peru), based on a partially preserved skull with a new facial bone pattern. Our phylogenetic analysis recovers K. danomurai as the most basal representative of the extant genus Kogia, displaying a combination of derived (incipiently developed and excavated sagittal facial crest) and plesiomorphic features (high position of the temporal fossa and antorbital notch not transformed into a narrow slit). Furthermore, when compared with the extant Kogia, the facial patterning found in K. danomurai indicates differential development among the facial organs, implying different capabilities of sound production relative to extant Kogia spp. Different facial bone patterns are particularly notable within the multi-species kogiid assemblage of the Pisco Formation, which suggests causal connections between different patterns and feeding ecologies (e.g., nekton piscivory and benthic foraging). At about 5.8 Ma, K. danomurai was part of a cetacean community composed by clades typical of the late Miocene as well as other early representatives of extant taxa, a mixture probably depicting the initial faunal change toward the coastal ecosystem dynamics of the present-day Southeastern Pacific.

opencc-zeroJan 2021View details →

Data from: Kin relationships in cultural species of the marine realm: case study of a matrilineal social group of sperm whales off Mauritius Island, Indian Ocean

Understanding the organization and dynamics of social groups of marine mammals through the study of kin relationships is particularly challenging. Here we studied a stable social group of sperm whales off Mauritius, using underwater observations, individual-specific identification, non-invasive sampling, and genetic analyses based on mitochondrial sequencing and microsatellite profiling. Twenty-four sperm whales were sampled between 2017 and 2019. All individuals except one adult female shared the same mtDNA haplotype—one that is rare in the Western Indian Ocean—thus confirming with near certainty the matrilineality of the group. All probable first- and second-degree kin relationships were depicted in a sperm whale social group: 13 first-degree and 34 second-degree relationships were identified. Notably, we highlight the likely case of an unrelated female having been integrated into a social unit, in that she presented a distinct mtDNA haplotype and no close relationships with any members of the group. Investigating the possible matrilineality of sperm whale cultural units (i.e., vocal clans) is the next step in our research program to elucidate and better apprehend the complex organization of sperm whale social groups.

opencc-zeroSep 2019View details →

Data from: Sperm cryopreservation reduces offspring growth

Sperm cryopreservation is routinely used in reproductive medicine, livestock production, and wildlife management. Its effect on offspring performance is often assumed negligible, but this still remains to be confirmed in well controlled within-subject experiments. We use a vertebrate model that allows to experimentally separate parental and environmental effects to test whether sperm cryopreservation influences offspring phenotype under stress and non-stress conditions, and whether such effects are male-specific. Wild brown trout (Salmo trutta) were stripped for their gametes, and a portion of each male's milt was cryopreserved. Then, 960 eggs were simultaneously fertilized with either non-cryopreserved or frozen-thawed semen and raised singly in the presence or absence of a pathogen. We found no significant effects of cryopreservation on fertilization rates, and no effects on growth, survival, nor pathogen resistance during the embryo stage. However, fertilization by cryopreserved sperm lead to significantly reduced larval growth after hatching. Males varied in genetic quality as determined from offspring performance, but effects of cryopreservation on larval growth were not male specific. We conclude that cryopreservation causes a reduction of offspring growth that is easily overlooked because it only manifests itself at later developmental stages when many other factors affect growth and survival, too.

opencc-zeroDec 2015View details →

Data from: Using sperm morphometry and multivariate analysis to differentiate species of gray Mazama

There is genetic evidence that the two species of Brazilian gray Mazama, Mazama gouazoubira and Mazama nemorivaga, belong to different genera. This study identified significant differences that separated them into distinct groups, based on characteristics of the spermatozoa and ejaculate of both species. The characteristics that most clearly differentiated between the species were ejaculate colour, white for M. gouazoubira and reddish for M. nemorivaga, and sperm head dimensions. Multivariate analysis of sperm head dimension and format data accurately discriminated three groups for species with total percentage of misclassified of 0.71. The individual analysis, by animal, and the multivariate analysis have also discriminated correctly all five animals (total percentage of misclassified of 13.95%), and the canonical plot has shown three different clusters: Cluster 1, including individuals of M. nemorivaga; Cluster 2, including two individuals of M. gouazoubira; and Cluster 3, including a single individual of M. gouazoubira. The results obtained in this work corroborate the hypothesis of the formation of new genera and species for gray Mazama. Moreover, the easily applied method described herein can be used as an auxiliary tool to identify sibling species of other taxonomic groups.