71 research outputs found
Ischnura praematura sp. nov. (Odonata: Zygoptera: Coenagrionidae): a species from Yunnan (China) whose females mate in the teneral state
Ischnura praematura sp. nov. (Holotype ♂, China, Yunnan, Lijiang, 26º31´03.54”N, 100º13’38.89”E, 2396 m, 04 xii 2015, I. Sanmartín-Villar & H. Zhang leg.) is morphologically described, illustrated and compared with close species of the genus. Ischnura praematura can be mainly distinguished from its congeners I. aurora, I. rubilio and I. asiatica by its abdominal and thoracic morphology and colouration. The posterior lobe of the prothorax is elevated in I. praematura and the mesostigmal plates possess dorsal triangular protuberances. Ischnura praematura shows pointed paraprocts, internalised wide cerci and lacks a dorsal tuberculum in the tenth abdominal segment. The blue abdominal colouration is present in the last three segments (incomplete for segment eight and ten in some individuals). No female polychromatism was detected and all females observed possessed different colouration than male (gynochrome). Morphological distinctiveness of the species is supported by genetic analyses, which show that I. praematura forms a well-supported, monophyletic clade, with I. asiatica, I. ezoin and I. pumilio as the most closely related species. In the field, mature females show strong reluctance to mate, and males were observed mating with newly emerged females.
Ministerio de Economía y Competitividad | Ref. BES-2012-052005Ministerio de Economía y Competitividad | Ref. EEBB-I-15- 09382Ministerio de Ciencia e Innovación | Ref. CGL2014-53140-PMinisterio de Ciencia e Innovación | Ref. PGC2018-096656-B-I0
The evolution and diversity of intra-male sperm translocation in Odonata: a unique behaviour in animals
Behavioural diversity is a basic component of biodiversity, with implications in ecological interactions at the intra- and interspecific levels. The reproductive behaviour of Odonata (dragonflies and damselflies) is unique among insects and conditioned by the anatomical separation between the male’s reproductive organs and the intromittent organ. Prior to mating, males must translocate sperm from the genital pore in the ninth abdominal segment to the seminal vesicle located ventrally in the second abdominal segment. This behaviour, exclusive to odonates, is known as intra-male sperm translocation (ST). Here, we review the literature on ST and use phylogenetic comparative analyses to investigate the evolution of ST within the Odonata. Information on ST was compiled for 176 species, with the commonest variant being ST once per mating, after tandem formation (66%). Other variants found were ST involving precopulatory genital touching (10%), ST by the male alone before tandem (16%) or after copulation (5%), and repetition of ST during the same copulation (3%). The precopulatory genital touching might have evolved to detect female receptivity. ST before tandem formation might be favoured when mating opportunities are scarce and copulations are brief. ST after mating might be favoured if males need to be ready to copulate fast. Finally, repeated ST could have evolved through postcopulatory sexual selection in males with limited sperm removal ability, as a means to improve their sperm competition. The most plausible scenario for the evolution of ST is that the ancestors of the Odonata produced a spermatophore and attached it to the body, leading towards the evolution of the secondary genitalia in males. Our study emphasises the role of behavioural diversity to understand behavioural evolution.Ministerio de Economía y Competitividad | Ref. BES-2015-071965Ministerio de Economía y Competitividad | Ref. CGL2014-53140-
Sexual conflict and the evolution of monandry: the case of the damselfly Ischnura hastata (Odonata: Coenagrionidae) in the Galápagos Islands
Financiado para publicación en acceso aberto: Universidade de Vigo/CISUG1. Sexual selection favours the evolution and maintenance of polygamy, which is the dominant reproductive strategy in insects. Monogamy can evolve in very short-lived species due to time constraints. Here we study adult activity and mating behaviour of a population of the damselfly Ischnura hastata, a species rarely seen mating, and which has been suggested to be monandric, in wetlands of Isabela Island, Galápagos.
2. By means of mark-recapture methods we estimated that the daily survival rate was low, ranging from 0.385 to 0.876, yielding average life expectancies of mature individuals of only 1.2-3.2 days. Adults showed very low activity before 7:00, indicating that mating does not occur early. The number of male-female interactions and mating attempts was extremely low, with only 44 copulations recorded on over 230 h of observations. 3. Copulations were brief, with a mean duration of 11 minutes (but only two observed from the start). Males showed clear preference to attempt to grasp in tandem females of intermediate age (in 94.3% of cases), rather than young (31.3%) or mature females (24.0%). Males were very persistent once a tandem was achieved, retaining females for up to 139 min, but most females resisted and did not copulate.
4. We conclude that females of I. hastata show a very short time window to mate, exactly when they change colour from juvenile to mature, and live only enough to mate once. Short lifespan has selected for female monandry in I. hastata, creating an intense sexual conflict over mating rates.Ministerio de Economía y Competitividad | Ref. CGL2014-53140-PAgencia Estatal de Investigación | Ref. PGC2018-096656-B-I0
Variation in intraspecific sperm translocation behaviour in a damselfly and its consequences for sperm viability
Sperm quality and viability affect both male and female fitness. Most dragonfly and damselfly males translocate sperm from the testis to the seminal vesicle before each copulation, a behaviour known as intramale sperm translocation (ST). However, some published observations indicate that odonate males can occasionally skip ST prior to copulation. Our aim was to determine the circumstances under which males skip ST and how this might affect sperm viability. We allowed males of the damselfly Ischnura graellsii to perform ST (interrupting the copulation at this stage) and we studied ST behaviour during subsequent copulation. Males were randomly assigned to four treatments, which consisted of allowing the experimental male to copulate again 15 min or 1–3 days after his last ST. Fertility of females mated with the experimental males was analysed as a proxy for sperm viability. All males used the sperm that they translocated previously when the second mating took place 15 min after the manipulation, while the proportion of males that repeated ST increased steadily over time. Both treatment (time elapsed since last ST) and the interaction between treatment and ST (yes/no) had a significant effect on fertility, which decreased only in males that did not perform ST immediately before copulation. Additional experiments with damselflies of the genus Calopteryx showed also that males did not repeat ST when the time to the next copulation was less than a day. Our results suggest that sperm quality decays over time in odonates, and that males can choose whether to keep and reuse the sperm in the seminal vesicle or to discard it. We conclude that the special anatomical disposition of odonate males might increase selective pressures to maximize sperm viability and/or repeated intramale ST behaviour.Ministerio de Economía y Competitividad | Ref. BES-2015-071965Ministerio de Economía y Competitividad | Ref. CGL2014-53140-
The complete mitochondrial genome of the broad-winged damselfly <i>Mnais costalis</i> Selys (Odonata: Calopterygidae) obtained by next-generation sequencing
<p>We used next-generation sequencing to characterise the complete mitochondrial genome of the damselfly <i>Mnais costalis</i> (Odonata, Calopterygidae). Illumina paired end reads were mapped against COI and 16S sequences from <i>M. costalis</i> and then extended using an iterative <i>de novo</i> map procedure. The final assembly was a contiguous sequence of 15,487 bp, which contained all standard mitochondrial coding regions and the putative A+T rich region. The gene configuration of the <i>M. costalis</i> mitogenome is similar to that of other odonates, comprising 13 protein-coding genes, large and small rRNA genes, and 22 tRNA genes. We found three intergenic spacers that are also present in all available whole odonate mitogenomes. Base composition of the <i>M. costalis</i> mitogenome is 40% (A), 20% (C), 14% (G) and 26% (T), with a high A+T content (66%). The characterisation of the complete mitochondrial genome of <i>M. costalis</i> adds to the growing list of mitogenomes currently available for odonates, and will help to improve primer design for future population genetic studies. A phylogenetic analysis including the currently available mitochondrial genome sequences of odonates suggests that <i>Epiophlebia superstes</i> is more closely related to the Zygoptera than to the Anisoptera.</p
Influence of Microcystis sp. and freshwater algae on pH: changes in their growth associated with sediment
Samples from two reservoirs with eutrophication problems, located in Pontevedra and Ourense (Northwestern Spain), were cultured, along with a third crop from a reservoir with no problems detected in Ourense (Northwestern Spain). The samples were grown under the same conditions (with an average temperature of 21 ± 2 °C, and a 3000 lux light intensity) in triplicate, and their growth, absorbance and pH were studied. High correlation values were obtained for pH and cellular growth (R2 ≥ 95%). The water from Salas showed the greatest microalgal growth (0.15 × 106 cells/ml to 31.70 × 106 cells/ml of "Microcystis sp." for the last day of culturing) and the greatest increase in pH (5.72–9.02). In all the cultures studied here, the main species that reproduced was "Microcystis sp.", which can produce neurotoxins and hepatotoxins. In addition, water samples were cultured with sediments of their own reservoir and with others to observe their evolution. The sediments studied in this case were rich in biotites, which can lead phosphate to be a limiting factor for phytoplankton due to the formation and sedimentation of insoluble salts of ferric phosphate. In crops grown with sediments from the Salas reservoir, actinobacteria developed which can inhibit microalgal growth. The study of the growth of cyanobacteria and possible methods of inhibiting them directly concerns the quality of water and its ecosystems, avoiding pollution and impact on ecosystems
Acylcarnitine profile in neonatal hypoxic-ischemic encephalopathy: The value of butyrylcarnitine as a prognostic marker
Optimal prognostic markers evaluating early neuroprotective interventions in neonatal hypoxic-ischemic encephalopathy (HIE) are lacking. This study was designed to assess the prognostic value of acylcarnitines in neonatal HIE.An observational cohort study was conducted over 10 years in 67 HIE. Variables analyzed included sex, blood cord pH, Apgar score, hypothermia treatment (yes/no), neuron-specific enolase (NSE) levels, and clinical outcome (neurological examination, brain magnetic resonance imaging [MRI], and electroencephalogram) before discharge and at 6 months. Acylcarnitine profiles were analyzed by tandem-mass spectrometry on dried-blood spots collected on day 3 for newborn screening. A cohort of healthy newborns was used as control group.HIE patients had significantly increased C4, C5, C5:1, C6, C6-OH, C8 levels (all P < .01) and decreased long-chain acylcarnitine levels (P < .03). Hypothermia treatment was associated with a decrease in C4 levels (p = 0.005) and an increase in most long-chain acylcarnitine levels (P < .01). A significant association was found between C4 levels and NSE on day 1 of hypothermia treatment (P = .002) and abnormal brain magnetic resonance imaging (MRI) at discharge (P = .037). In the hypothermia group, C4 levels decreased in patients with favorable outcomes but remained high in those who progressed unfavorably.C4 appears to be a good prognostic marker in HIE, as blood levels correlated with NSE levels and abnormal MRI findings. Furthermore, hypothermia did not lead to decreased levels in patients with adverse outcomes
Newborn screening for Fabry disease in the north-west of Spain
Fabry disease is an X-linked lysosomal storage disorder caused by the impairment of α-galactosidase A. Enzyme replacement therapy is available to treat patients, who often experience delayed diagnosis. A newborn screening for Fabry disease was performed to study the prevalence of the pathology and to evaluate the possibility to implement the test in systematic screenings. We collected 14,600 dried blood spot samples (7575 males and 7025 females) and carried out a diagnostic study by fluorometric measurement of α-galactosidase A enzymatic activity and GLA gene sequencing. We detected one patient with a mutation in GLA associated with classical Fabry Disease (M290I), ten subjects carrying genetic variants of uncertain diagnosis (S126G, R118C, A143T), and a girl with the non-characterized variant F18Y, which was not previously described. Additional 25 samples presented nucleotide substitutions described as polymorphisms (D313Y, rs2071225, and rs2071397). The estimated prevalence for Fabry disease in north-western Spanish males is of 0.013%.
Conclusion: These results confirm that the prevalence of Fabry disease is underestimated and systematic screening is feasible; however, further characterization of variants of uncertain clinical significance is necessary to establish protocols of patients’ managementThis studied was founded by the Spanish National Institute of Health-Instituto Carlos III/EU-FEDER, grant no. PI11-00842, to Ortolano S. and FEEL Foundation to Cristobal ColónS
Water toxicity in reservoirs after freshwater algae harvest
Blooms of microalgae and cyanobacteria increase every year, presenting great problems for the environment. Finding a way of harvesting these microalgae could be useful for water governance. Furthermore, the method should not cause cell lysis and should thus avoiding discharging toxins into the water. Three reservoirs were studied, two of them with eutrophication problems (As Conchas and A Baxe) and another (Salas) with no such problems. Three different harvesting methods were studied; electroflocculation (EF) with the application time being varied; centrifugation, with application times and speeds being varied; and finally, natural sedimentation. The highest efficiency was obtained in the culture from A Baxe, which had a higher initial absorbance value (1.664), using EF (90.64% for an application time of 2 min and 30 s) and centrifugation at 4000 rpm (92.25% for2 minutes, 92.73% for 5 min). Electrofloculation can obtain up to 84% more biomass than natural sedimentation alone. Sample toxicity was studied before and after harvesting using Microcystest and found to be higher after harvesting. It was observed that for the same sample, the higher the yield was the greater the toxicity was. For the A Baxe culture with an application time of 2 min, a speed of 2000 rpm and a yield of 87.02%, a toxicity figure of 0.94 μg/L was obtained, while for a speed of 4000 rpm the yield was 92.25% and the toxicity was 1.05 μg/L. The toxicity limit set by the World Health Organization (WHO) is 1 μg/L, and this small difference seems to be key. With these results, this study concludes that chlorophyll levels may interfere with the test used. Future tests or analyses should be developed so as to avoid such interference, which may alter the toxin values. Electroflocculation seems to be a promising method since it does not cause the lysis of "Microcystis aeruginosa", whereas the centrifugation method could give problems. Finally, it is worth highlighting the importance of performing toxin measurements after harvesting the microalgae to check that the method is viable in natural ecosystems
Recent advances in the application of pulsed light processing for improving food safety and increasing shelf life
peer-reviewedBackground
New technologies of non-thermal disinfection such as pulsed light (PL) have emerged lately as an alternative to traditional (thermal and chemical) disinfection and preservation methods. PL can be used to decontaminate a great variety of foods as well as to decontaminate contact surfaces, thus improving safety in foods and extending their shelf life. Moreover, this technology can prevent or reduce some of the detrimental effects of traditional methods on nutrients and bioactive compounds of food products.
Scope and approach
The combination of PL with other techniques such as ultraviolet light (UV), thermosonication (TS), pulsed electric fields (PEF), manothermosonication (MTS), etc., can improve the effectiveness of the decontamination process. Therefore, in this review, some of the most relevant studies evaluating the potential application of PL treatments to decontaminate food samples, and its impact of nutritional and physicochemical quality parameters will be discussed.
Key findings and conclusions
PL treatments are suitable for microbial decontamination in transparent drinks and for surface contaminated foods without complex microstructures. They also can be used for meat, fish and their by-products However, it is still necessary to evaluate the appropriate treatment conditions (number of light flashed, voltage, distance between sample and flash light, spectral range of light flashes and contamination) for each food and microorganism separately to improve the effectiveness and minimize the appearance of negative attributes reducing the quality of product as, in some cases, PL can have a negative effect on the photosensitive compounds and sensory characteristics of food products
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