|Id||Title||Authors▲||Abstract||Picture||Thematic fields||Recommender||Reviewers||Submission date|
27 Apr 2023
Climate of origin influences how a herbivorous mite responds to drought-stressed host plantsAlain Migeon, Philippe Auger, Odile Fossati-Gaschignard, Ruth A. Hufbauer, Maëva Miranda, Ghais Zriki, Maria Navajas https://doi.org/10.1101/2021.10.21.465244
Not all spider-mites respond in the same way to droughtRecommended by Inês Fragata and Raul Costa-Pereira based on reviews by Bastien Castagneyrol and 2 anonymous reviewers
Biotic interactions are often shaped by abiotic factors (Liu and Gaines 2022). Although this notion is not new in ecology and evolutionary biology, we are still far from a thorough understanding of how biotic interactions change along abiotic gradients in space and time. This is particularly challenging because abiotic factors can affect organisms and their interactions in multiple – direct or indirect – ways. For example, because abiotic conditions strongly determine how energy enters biological systems via producers, their effects can propagate through entire food webs, from the bottom to the top (O’Connor 2009, Gilbert et al 2019). Understanding how biological diversity - both within and across species - is shaped by the indirect effects of environmental conditions is a timely question as climate change and anthropogenic activities have been altering temperature and water availability across different ecosystems.
Motivated by the current water crisis and severe droughts predicted for the near future worldwide (du Plessis 2019), Migeon et al. (2023) investigated how water limitation on producers scales up to affect life-history patterns of a widespread crop pest, the spider mite Tetranychus urticae. The authors sampled spider mite populations (n = 12) along a striking gradient of climatic conditions (>16 degrees of latitude) in Europe. After letting mites acclimate to lab conditions for several generations, the authors performed a common garden experiment to quantify how the life-history traits of mite populations from different locations respond to drought stress in their host plants.
Curiously, the authors found that, when reared on drought-stressed plants, mites tended to develop faster, had higher fecundity and lower dispersion rates. This response was in line with some results obtained previously with Tetranychus species (e.g. Ximénez-Embun et al 2016). Importantly, despite some experimental caveats in the experimental design, which makes it difficult to completely disentangle the specific effects of location vs. environmental noise, results suggest the climate that populations originally experienced was also an important determinant of the plastic response in these herbivores. In fact, populations from wetter and colder regions showed a steeper change in drought response, while populations from arid climates showed a shallower response. This interesting result suggests the importance of intraspecific (between-populations) variation in the response to drought, which might be explained by the climatic heterogeneity in space throughout the evolutionary history of different populations. These results become even more important in our rapidly changing world, highlighting the importance of considering genetic variation (and conditions that generate it) when predicting plastic and evolutionary responses to stressful conditions.
du Plessis, A. (2019). Current and Future Water Scarcity and Stress. In: Water as an Inescapable Risk. Springer Water. Springer, Cham. https://doi.org/10.1007/978-3-030-03186-2
|Climate of origin influences how a herbivorous mite responds to drought-stressed host plants||Alain Migeon, Philippe Auger, Odile Fossati-Gaschignard, Ruth A. Hufbauer, Maëva Miranda, Ghais Zriki, Maria Navajas||<p style="text-align: justify;">Drought associated with climate change can stress plants, altering their interactions with phytophagous arthropods. Drought not only impacts cultivated plants but also their parasites, which in some cases are favore...||Acari, Ecology, Life histories||Inês Fragata||2021-10-22 14:56:03||View|
02 Nov 2021
Cuckoo male bumblebees perform slower and longer flower visits than free-living male and worker bumblebeesAlessandro Fisogni, Gherardo Bogo, François Massol, Laura Bortolotti, Marta Galloni https://doi.org/10.5281/zenodo.4489066
Cuckoo bumblebee males might reduce plant fitnessRecommended by Michael Lattorff based on reviews by Patrick Lhomme, Silvio Erler and 2 anonymous reviewers
In pollinator insects, especially bees, foraging is almost exclusively performed by females due to the close linkage with brood care. They collect pollen as a protein- and lipid-rich food to feed developing larvae in solitary and social species. Bees take carbohydrate-rich nectar in small quantities to fuel their flight and carry the pollen load. To optimise the foraging flight, they tend to be flower constant, reducing the flower handling time and time among individual inflorescences (Goulson, 1999). Males of pollinator species might be found on flowers as well. As they do not collect any pollen for brood care, their foraging flights and visits to flowers might not be shaped by the selective forces that optimise the foraging flights of females. They might stay longer in individual flowers, take up nectar if needed, but might unintentionally carry pollen on their body surface (Wolf & Moritz, 2014).
|Cuckoo male bumblebees perform slower and longer flower visits than free-living male and worker bumblebees||Alessandro Fisogni, Gherardo Bogo, François Massol, Laura Bortolotti, Marta Galloni||<p>Cuckoo bumblebees are a monophyletic group within the genus Bombus and social parasites of free-living bumblebees, upon which they rely to rear their offspring. Cuckoo bumblebees lack the worker caste and visit flowers primarily for their own s...||Behavior, Biology, Ecology, Insecta, Invertebrates, Terrestrial||Michael Lattorff||Patrick Lhomme, Silvio Erler, Denis Michez,||2021-02-02 01:41:35||View|
05 Jan 2021
Do substrate roughness and gap distance impact gap-bridging strategies in arboreal chameleons?Allison M. Luger, Vincent Vermeylen, Anthony Herrel, Dominique Adriaens https://doi.org/10.1101/2020.08.21.260596
Gap-bridging strategies in arboreal chameleonsRecommended by Ellen Decaestecker based on reviews by Simon Baeckens and 2 anonymous reviewers
Until now, very little is known about the tail use and functional performance in tail prehensile animals. Luger et al. (2020) are the first to provide explorative observations on trait related modulation of tail use, despite the lack of a sufficiently standardized data set to allow statistical testing. They described whether gap distance, perch diameter, and perch roughness influence tail use and overall locomotor behavior of the species Chamaeleo calyptratus.
Luger, A.M., Vermeylen, V., Herrel, A. and Adriaens, D. (2020) Do substrate roughness and gap distance impact gap-bridging strategies in arboreal chameleons? bioRxiv, 2020.08.21.260596, ver. 3 peer-reviewed and recommended by PCI Zoology. doi: https://doi.org/10.1101/2020.08.21.260596
|Do substrate roughness and gap distance impact gap-bridging strategies in arboreal chameleons?||Allison M. Luger, Vincent Vermeylen, Anthony Herrel, Dominique Adriaens||<p>Chameleons are well-equipped for an arboreal lifestyle, having ‘zygodactylous’ hands and feet as well as a fully prehensile tail. However, to what degree tail use is preferred over autopod prehension has been largely neglected. Using an indoor ...||Behavior, Biology, Herpetology, Reptiles, Vertebrates||Ellen Decaestecker||2020-08-25 10:06:42||View|
09 Feb 2023
A novel nematode species from the Siberian permafrost shares adaptive mechanisms for cryptobiotic survival with C. elegans dauer larvaAnastasia Shatilovich, Vamshidhar R. Gade, Martin Pippel, Tarja T. Hoffmeyer, Alexei V. Tchesunov, Lewis Stevens, Sylke Winkler, Graham M. Hughes, Sofia Traikov, Michael Hiller, Elizaveta Rivkina, Philipp H. Schiffer, Eugene W Myers, Teymuras V. Kurzchalia https://doi.org/10.1101/2022.01.28.478251
A novel nematode species from the Siberian permafrost shares adaptive mechanisms for cryptobiotic survival with C. elegans dauer larvaRecommended by Isa Schon based on reviews by 3 anonymous reviewers
This article  investigated two nematode genera, Panagrolaimus and Plectus, from the Siberian permafrost to unravel the adaptations allowing them to survive cryptobiosis; radio carbon dating showed that the individuals of Panagrolaimus had been in cryobiosis in Siberia for as long as 46,000 years!
I was impressed by the multidisciplinary approach of this study, including morphological as well as phylogenetic and -genomic analyses to describe a new species. In triploids as some of the species studied here, it is quite challenging to assemble a novel genome. The authors furthermore not only managed to successfully reanimate the Siberian specimens but could also expose them to repeated freezing and desiccation in the lab, not an easy task.
This study reports some amazing discoveries - comparing the molecular toolkits between C. elegans and Panagrolaimus and Plectus revealed that several components were orthologues. Likewise, some of the biochemical mechanisms for surviving freezing in the lab turned out to be similar for C. elegans and the Siberian nematodes. This study thus provides strong evidence that nematodes developed specific mechanisms allowing them to stay in cryobiosis over very long times.
A surprising additional experimental result concerns the well-studied C. elegans - dauer larvae of this species can stay viable much longer after periods of animated suspension than previously thought.
I highly recommend this article as it is an important contribution to the fields of evolution and molecular biology. This study greatly advanced our understanding of how nematodes could have adapted to cryobiosis. The applied techniques could also be useful for studying similar research questions in other organisms.
 Shatilovich A, Gade VR, Pippel M, Hoffmeyer TT, Tchesunov AV, Stevens L, Winkler S, Hughes GM, Traikov S, Hiller M, Rivkina E, Schiffer PH, Myers EW, Kurzchalia TV (2023) A novel nematode species from the Siberian permafrost shares adaptive mechanisms for cryptobiotic survival with C. elegans dauer larva. bioRxiv, 2022.01.28.478251, ver. 6 peer-reviewed and recommended by Peer Community in Zoology. https://doi.org/10.1101/2022.01.28.478251
|A novel nematode species from the Siberian permafrost shares adaptive mechanisms for cryptobiotic survival with C. elegans dauer larva||Anastasia Shatilovich, Vamshidhar R. Gade, Martin Pippel, Tarja T. Hoffmeyer, Alexei V. Tchesunov, Lewis Stevens, Sylke Winkler, Graham M. Hughes, Sofia Traikov, Michael Hiller, Elizaveta Rivkina, Philipp H. Schiffer, Eugene W Myers, Teymuras V. K...||<p style="text-align: justify;">Some organisms in nature have developed the ability to enter a state of suspended metabolism called cryptobiosis1 when environmental conditions are unfavorable. This state-transition requires the execution of comple...||Ecology, Evolution, Genetics/Genomics||Isa Schon||2022-05-20 14:32:02||View|
10 Jan 2020
Culex saltanensis and Culex interfor (Diptera: Culicidae) are susceptible and competent to transmit St. Louis encephalitis virus (Flavivirus: Flaviviridae) in central ArgentinaBeranek MD, Quaglia AI, Peralta GC, Flores FS, Stein M, Diaz LA, Almirón WR and Contigiani MS https://doi.org/10.1101/722579
Multiple vector species may be responsible for transmission of Saint Louis Encephalatis Virus in ArgentinaRecommended by Anna Cohuet based on reviews by 2 anonymous reviewers
Medical and veterinary entomology is a discipline that deals with the role of insects on human and animal health. A primary objective is the identification of vectors that transmit pathogens. This is the aim of Beranek and co-authors in their study . They focus on mosquito vector species responsible for transmission of St. Louis encephalitis virus (SLEV), an arbovirus that circulates in avian species but can incidentally occur in dead end mammal hosts such as humans, inducing symptoms and sometimes fatalities. Culex pipiens quinquefasciatus is known as the most common vector, but other species are suspected to also participate in transmission. Among them Culex saltanensis and Culex interfor have been found to be infected by the virus in the context of outbreaks. The fact that field collected mosquitoes carry virus particles is not evidence for their vector competence: indeed to be a competent vector, the mosquito must not only carry the virus, but also the virus must be able to replicate within the vector, overcome multiple barriers (until the salivary glands) and be present at sufficient titre within the saliva. This paper describes the experiments implemented to evaluate the vector competence of Cx. saltanensis and Cx. interfor from ingestion of SLEV to release within the saliva. Females emerged from field-collected eggs of Cx. pipiens quinquefasciatus, Cx. saltanensis and Cx. interfor were allowed to feed on SLEV infected chicks and viral development was measured by using (i) the infection rate (presence/absence of virus in the mosquito abdomen), (ii) the dissemination rate (presence/absence of virus in mosquito legs), and (iii) the transmission rate (presence/absence of virus in mosquito saliva). The sample size for each species is limited because of difficulties for collecting, feeding and maintaining large numbers of individuals from field populations, however the results are sufficient to show that this strain of SLEV is able to disseminate and be expelled in the saliva of mosquitoes of the three species at similar viral loads. This work therefore provides evidence that Cx saltanensis and Cx interfor are competent species for SLEV to complete its life-cycle. Vector competence does not directly correlate with the ability to transmit in real life as the actual vectorial capacity also depends on the contact between the infectious vertebrate hosts, the mosquito life expectancy and the extrinsic incubation period of the viruses. The present study does not deal with these characteristics, which remain to be investigated to complete the picture of the role of Cx saltanensis and Cx interfor in SLEV transmission. However, this study provides proof of principle that that SLEV can complete it’s life-cycle in Cx saltanensis and Cx interfor. Combined with previous knowledge on their feeding preference, this highlights their potential role as bridge vectors between birds and mammals. These results have important implications for epidemiological forecasting and disease management. Public health strategies should consider the diversity of vectors in surveillance and control of SLEV.
|Culex saltanensis and Culex interfor (Diptera: Culicidae) are susceptible and competent to transmit St. Louis encephalitis virus (Flavivirus: Flaviviridae) in central Argentina||Beranek MD, Quaglia AI, Peralta GC, Flores FS, Stein M, Diaz LA, Almirón WR and Contigiani MS||<p>Infectious diseases caused by mosquito-borne viruses constitute health and economic problems worldwide. St. Louis encephalitis virus (SLEV) is endemic and autochthonous in the American continent. Culex pipiens quinquefasciatus is the primary ur...||Medical entomology||Anna Cohuet||2019-08-03 00:56:38||View|
25 Aug 2021
Up and to the light: intra- and interspecific variability of photo- and geo-tactic oviposition preferences in genus TrichogrammaBurte, V., Perez, G., Ayed, F. , Groussier, G., Mailleret, L., van Oudenhove, L. and Calcagno, V. https://doi.org/10.1101/2021.03.30.437671
New insights into oviposition preference of 5 Trichogramma speciesRecommended by Joel Meunier based on reviews by Kévin Tougeron and Eveline C. Verhulst
Insects exhibit a great diversity of life-history traits that often vary not only between species but also between populations of the same species (Flatt and Heyland, 2011). A better understanding of the variation in these traits can be of paramount importance when it comes to species of economic and agricultural interest (Wilby and Thomas, 2002). In particular, the control of the development and expansion of agricultural pests generally requires a good understanding of the parameters that favour the reproduction of these pests and/or the reproduction of the species used to control them (Bianchi et al., 2013; Gäde and Goldsworthy, 2003).
Parasitoid wasps of the genus Trichogramma are a classic example of insects involved in pest control (Smith, 1996). This genus comprises over 200 species worldwide, which have been used to control populations of a wide range of lepidopteran pests since the 1900s (Flanders, 1930; Hassan, 1993). Despite its common use, the egg-laying preference of this genus is only partially known. For example, all Trichogramma species are often thought to have positive phototaxis (or negative geotaxis) (e.g. Brower & Cline, 1984; van Atta et al., 2015), but comprehensive studies simultaneously testing this (or other) parameter among Trichogramma species and populations remain rare.
This is exactly the aim of the present study (Burte et al., 2021). Using a new experimental approach based on automatic image analysis, the authors compared the photo- and geo-tactic oviposition preference among 5 Trichogramma species from 25 populations. Their results first confirm that most Trichogramma species and populations prefer light to shade, and higher to lower positions for oviposition. Interestingly, they also reveal that the levels of preference for light and gravity show inter- and intraspecific variation (probably due to local adaptation to different strata) and that both preferences tend to relax over time.
Overall, this study provides important information for improving the use of Trichogramma species as biological agents. For example, it may help to establish breeding lines adapted to the microhabitat and/or growing parts of plants on which agricultural pests lay eggs most. Similarly, it suggests that the use of multiple strains with different microhabitat selection preferences could lead to better coverage of host plants, as well as a reduction in intraspecific competition in the preferred parts. Finally, this study provides a new methodology to efficiently and automatically study oviposition preferences in Trichogramma, which could be used in other insects with a particularly small size.
Bianchi, F. J. J. A., Schellhorn, N. A. and Cunningham, S. A. (2013). Habitat functionality for the ecosystem service of pest control: reproduction and feeding sites of pests and natural enemies. Agricultural and Forest Entomology, 15, 12–23. https://doi.org/10.1111/j.1461-9563.2012.00586.x
Burte V., Perez G., Ayed F., Groussier G., Mailleret L, van Oudenhove L. and Calcagno V. (2021). Up and to the light: intra- and interspecific variability of photo-and geo-tactic oviposition preferences in genus Trichogramma. bioRxiv, 2021.03.30.437671, ver. 4 peer-reviewed and recommended by PCI Zoology. https://doi.org/10.1101/2021.03.30.437671
Brower, J. H. and Cline, L. D. (1984). Response of Trichogramma pretiosum and T. evanescens to Whitelight, Blacklight or NoLight Suction Traps. The Florida Entomologist, 67, 262–268. https://doi.org/10.2307/3493947
Flanders, S. E. (1930). Mass production of egg parasites of the genus Trichogramma. Hilgardia, 4, 465–501. https://doi.org/10.3733/hilg.v04n16p465
Flatt, T. and Heyland, A. (2011). Mechanisms of life history evolution: the genetics and physiology of life history traits and trade-offs. Oxford University Press. https://doi.org/10.1093/acprof:oso/9780199568765.001.0001
Gäde, G. and Goldsworthy, G. J. (2003). Insect peptide hormones: a selective review of their physiology and potential application for pest control. Pest Management Science, 59, 1063–1075. https://doi.org/10.1002/ps.755
Hassan, S. A. (1993). The mass rearing and utilization of Trichogramma to control lepidopterous pests: Achievements and outlook. Pesticide Science, 37, 387–391. https://doi.org/10.1002/ps.2780370412
Smith, S. M. (1996). Biological Control with Trichogramma : Advances, Successes, and Potential of Their Use. Annual Review of Entomology, 41, 375–406. https://doi.org/10.1146/annurev.en.41.010196.002111
van Atta, K. J., Potter, K. A. and Woods, H. A. (2015). Effects of UV-B on Environmental Preference and Egg Parasitization by Trichogramma Wasps (Hymenoptera: Trichogrammatidae). Journal of Entomological Science, 50, 318–325. https://doi.org/10.18474/JES15-09.1
Wilby, A. and Thomas, M. B. (2002). Natural enemy diversity and pest control: patterns of pest emergence with agricultural intensification. Ecology Letters, 5, 353–360. https://doi.org/10.1046/j.1461-0248.2002.00331.x
|Up and to the light: intra- and interspecific variability of photo- and geo-tactic oviposition preferences in genus Trichogramma||Burte, V., Perez, G., Ayed, F. , Groussier, G., Mailleret, L., van Oudenhove, L. and Calcagno, V.||<p>Trichogramma are parasitic microwasps much used as biological control agents. The genus is known to harbor tremendous diversity, at both inter- and intra-specific levels. The successful selection of Trichogramma strains for biocontrol depends o...||Behavior, Biocontrol, Biodiversity, Ecology, Insecta, Parasitology, Pest management, Systematics, Terrestrial||Joel Meunier||Kévin Tougeron, Eveline C. Verhulst||2021-04-02 16:10:28||View|
21 Jun 2023
Life-history traits, pace of life and dispersal among and within five species of Trichogramma wasps: a comparative analysisChloé Guicharnaud, Géraldine Groussier, Erwan Beranger, Laurent Lamy, Elodie Vercken, Maxime Dahirel https://doi.org/10.1101/2023.01.24.525360
The relationship between dispersal and pace-of-life at different scalesRecommended by Jacques Deere based on reviews by Mélanie Thierry and 1 anonymous reviewer
The sorting of organisms along a fast-slow continuum through correlations between life history traits is a long-standing framework (Stearns 1983) and corresponds to the pace-of-life axis. This axis represents the variation in a continuum of life-history strategies, from fast-reproducing short-lived species to slow-reproducing long-lived species. The pace-of-life axis has been the focus of much research largely in mammals, birds, reptiles and plants but less so in invertebrates (Salguero-Gómez et al. 2016; Araya-Ajoy et al. 2018; Healy et al. 2019; Bakewell et al. 2020). Outcomes from this research have highlighted variation across taxa on this axis and mixed support for, and against, patterns expected of the pace-of-life continuum. Given this, a greater understanding of the variation of the pace-of-life across-, and within, taxa are needed. Indeed, Guicharnard et al. (2023) highlight several points regarding our broader understanding of pace-of-life. In general, invertebrates are poorly represented, the variation of pace-of-life across taxonomic scales is less well understood and the relationship between pace-of-life and dispersal, a key life history, requires more attention. Here, Guicharnard et al. (2023) provide a first attempt at addressing the relationship between dispersal and pace-of-life at different scales.
The authors, under controlled conditions, investigated how life-history traits and effective dispersal covary for 28 lines from five species of endoparasitoid wasps from the genus Trichogramma. At the species level negative correlations were found between development time and fecundity, matching pace-of-life axis predictions. Although this correlation was not found to be significant among lines, within species, a similar pattern of a negative correlation was observed. This outcome matches previous findings that consistent pace-of-life axes become more difficult to find at lower taxonomic levels. Unlike the other life-history traits measured, effective dispersal showed no evidence of differences between species or between lines. The authors also found no correlation between effective dispersal and other-life history traits which suggests no dispersal/life-history syndromes in the species investigated. One aspect that was not assessed was the impact of density dependence on pace-of-life and effective dispersal, largely as this was a first step in assessing relationship of dispersal with pace-of-life at different scales. However, the authors do acknowledge the importance of future studies incorporating density dependence and that such studies could potentially lead to more generalizable understanding of pace-of-life and dispersal within Trichogramma.
A pleasant addition was the link to potential implications for biocontrol. This addition showed an awareness by the authors of how insights into pace-of-life can have an applied component. The results of the study highlighted that selecting for specific lines of a species, to maximise a trait of interest at the cost of another, may not be as effective as selecting different species when implementing biocontrol. This is especially important as often single, established species used in biocontrol are favoured without consideration of the potential of other species which can lead to more efficient biocontrol.
Araya-Ajoy, Y.G., Bolstad, G.H., Brommer, J., Careau, V., Dingemanse, N.J. & Wright, J. (2018). Demographic measures of an individual's "pace of life": fecundity rate, lifespan, generation time, or a composite variable? Behavioral Ecology and Sociobiology, 72, 75.
|Life-history traits, pace of life and dispersal among and within five species of *Trichogramma* wasps: a comparative analysis||Chloé Guicharnaud, Géraldine Groussier, Erwan Beranger, Laurent Lamy, Elodie Vercken, Maxime Dahirel||<p>Major traits defining the life history of organisms are often not independent from each other, with most of their variation aligning along key axes such as the pace-of-life axis. We can define a pace-of-life axis structuring reproduction and de...||Biology, Ecology, Insecta, Invertebrates, Life histories||Jacques Deere||2023-01-25 18:15:20||View|
22 Jul 2020
The open bar is closed: restructuration of a native parasitoid community following successful control of an invasive pest.David Muru, Nicolas Borowiec, Marcel Thaon, Nicolas Ris, Madalina Ionela Viciriuc, Sylvie Warot, Elodie Vercken https://doi.org/10.1101/2019.12.20.884908
Raise and fall of an invasive pest and consequences for native parasitoid communitiesRecommended by Stefaniya Kamenova based on reviews by Kévin Tougeron and Miguel González Ximénez de Embún
Host-parasitoid interactions have been the focus of extensive ecological research for decades. One the of the major reasons is the importance host-parasitoid interactions play for the biological control of crop pests. Parasitoids are the main natural regulators for a large number of economically important pest insects, and in many cases they could be the only viable crop protection strategy. Parasitoids are also integral part of complex food webs whose structure and diversity display large spatio-temporal variations [1-3]. With the increasing globalization of human activities, the generalized spread and establishment of invasive species is a major cause of disruption in local community and food web spatio-temporal dynamics. In particular, the deliberate introduction of non-native parasitoids as part of biological control programs, aiming the suppression of established, and also highly invasive crop pests, is a common practice with potentially significant, yet poorly understood effects on local food web dynamics (e.g. ).
 Eveleigh ES, McCann KS, McCarthy PC, Pollock SJ, Lucarotti CJ, Morin B, McDougall GA, Strongman DB, Huber JT, Umbanhowar J, Faria LDB (2007). Fluctuations in density of an outbreak species drive diversity cascades in food webs. Proc. Natl. Acad. Sci. USA 104, 16976-16981. doi: 10.1073/pnas.0704301104
|The open bar is closed: restructuration of a native parasitoid community following successful control of an invasive pest.||David Muru, Nicolas Borowiec, Marcel Thaon, Nicolas Ris, Madalina Ionela Viciriuc, Sylvie Warot, Elodie Vercken||<p>The rise of the Asian chestnut gall wasp *Dryocosmus kuriphilus* in France has benefited the native community of parasitoids originally associated with oak gall wasps by becoming an additional trophic subsidy and therefore perturbing population...||Biocontrol, Biological invasions, Ecology, Insecta||Stefaniya Kamenova||2019-12-31 09:08:49||View|
25 Aug 2022
Improving species conservation plans under IUCN's One Plan Approach using quantitative genetic methodsDrew Sauve, Jane Hudecki, Jessica Steiner, Hazel Wheeler, Colleen Lynch, Amy A. Chabot https://doi.org/10.32942/osf.io/n3zxp
Quantitative genetics for a more qualitative conservationRecommended by Peter Galbusera based on reviews by Timothée Bonnet and 1 anonymous reviewer
Genetic (bio)diversity is one of three recognised levels of biodiversity, besides species and ecosystem diversity. Its importance for species survival and adaptation is increasingly highlighted and its monitoring recommended (e.g. O’Brien et al 2022). Especially the management of ex-situ populations has a long history of taking into account genetic aspects (through pedigree analysis but increasingly also by applying molecular tools). As in-situ and ex-situ efforts are nowadays often aligned (in a One-Plan-Approach), genetic management is becoming more the standard (supported by quickly developing genomic techniques). However, rarely quantitative genetic aspects are raised in this issue, while its relevance cannot be underestimated. Hence, the current manuscript by Sauve et al (2022) is a welcome contribution, in order to improve conservation efforts. The authors give a clear overview on how quantitative genetic analysis can aid the measurement, monitoring, prediction and management of adaptive genetic variation. The main tools are pedigrees (mainly of ex-situ populations) and the Animal Model. The main goal is to prevent adaption to captivity and altered genetics in general (in reintroduction projects). The confounding factors to take into account (like inbreeding, population structure, differences between facilities, sample size and parental/social effects) are well described by the authors. As such, I fully recommend this manuscript for publication, hoping increased interest in quantitative analysis will benefit the quality of species conservation management.
O'Brien D, Laikre L, Hoban S, Bruford MW et al. (2022) Bringing together approaches to reporting on within species genetic diversity. Journal of Applied Ecology, 00, 1–7. https://doi/10.1111/1365-2664.14225
Sauve D., Spero J., Steiner J., Wheeler H., Lynch C., Chabot A.A. (2022) Improving species conservation plans under IUCN’s One Plan Approach using quantitative genetic methods. EcoEvoRxiv, ver. 9 peer-reviewed and recommended by Peer Community in Zoology. https://doi.org/10.32942/osf.io/n3zxp
|Improving species conservation plans under IUCN's One Plan Approach using quantitative genetic methods||Drew Sauve, Jane Hudecki, Jessica Steiner, Hazel Wheeler, Colleen Lynch, Amy A. Chabot||<p>Human activities are resulting in altered environmental conditions that are impacting the demography and evolution of species globally. If we wish to prevent anthropogenic extinction and extirpation, we need to improve our ability to restore wi...||Conservation biology, Ecology, Evolution, Genetics/Genomics||Peter Galbusera||2022-02-21 10:45:22||View|
24 Jun 2022
Dopamine pathway characterization during the reproductive mode switch in the pea aphidGaël Le Trionnaire, Sylvie Hudaverdian, Gautier Richard, Sylvie Tanguy, Florence Gleonnec, Nathalie Prunier-Leterme, Jean-Pierre Gauthier, Denis Tagu https://doi.org/10.1101/2020.03.10.984989
In search of the links between environmental signals and polyphenismRecommended by Mathieu Joron based on reviews by Antonia Monteiro and 2 anonymous reviewers
Polyphenisms offer an opportunity to study the links between phenotype, development, and environment in a controlled genomic context (Simpson, Sword, & Lo, 2011). In organisms with short generation times, individuals living and developing in different seasons encounter different environmental conditions. Adaptive plasticity allows them to express different phenotypes in response to seasonal cues, such as temperature or photoperiod. Such phenotypes can be morphological variants, for instance displaying different wing patterns as seen in butterflies (Brakefield & Larsen, 1984; Nijhout, 1991; Windig, 1999), or physiological variants, characterized for instance by direct development vs winter diapause in temperate insects (Dalin & Nylin, 2012; Lindestad, Wheat, Nylin, & Gotthard, 2019; Shearer et al., 2016).
Many aphids display cyclical parthenogenesis, a remarkable seasonal polyphenism for reproductive mode (Tagu, Sabater-Muñoz, & Simon, 2005), also sometimes coupled with wing polyphenism (Braendle, Friebe, Caillaud, & Stern, 2005), which allows them to switch between parthenogenesis during spring and summer to sexual reproduction and the production of diapausing eggs before winter. In the pea aphid Acyrthosiphon pisum, photoperiod shortening results in the production, by parthenogenetic females, of embryos developing into the parthenogenetic mothers of sexual individuals. The link between parthenogenetic reproduction and sexual reproduction, therefore, occurs over two generations, changing from a parthenogenetic form producing parthenogenetic females (virginoparae), to a parthenogenetic form producing sexual offspring (sexuparae), and finally sexual forms producing overwintering eggs (Le Trionnaire et al., 2022).
The molecular basis for the transduction of the environmental signal into reproductive changes is still unknown, but the dopamine pathway is an interesting candidate. Form-specific expression of certain genes in the dopamine pathway occurs downstream of the perception of the seasonal cue, notably with a marked decrease in the heads of embryos reared under short-day conditions and destined to become sexuparae. Dopamine has multiple roles during development, with one mode of action in cuticle melanization and sclerotization, and a neurological role as a synaptic neurotransmitter. Both modes of action might be envisioned to contribute functionally to the perception and transduction of environmental signals.
In this study, Le Trionnaire and colleagues aim at clarifying this role in the pea aphid (Le Trionnaire et al., 2022). Using quantitative RT-PCR, RNA-seq, and in situ hybridization of RNA probes, they surveyed the timing and spatial patterns of expression of dopamine pathway genes during the development of different stages of embryo to larvae reared under long and short-day conditions, and destined to become virginoparae or sexuparae females, respectively. The genes involved in the synaptic release of dopamine generally did not show differences in expression between photoperiodic treatments. By contrast, pale and ddc, two genes acting upstream of dopamine production, generally tended to show a downregulation in sexuparare embryo, as well as genes involved in cuticle development and interacting with the dopamine pathway. The downregulation of dopamine pathway genes observed in the heads of sexuparare juveniles is already detectable at the embryonic stage, suggesting embryos might be sensing environmental cues leading them to differentiate into sexuparae females.
The way pale and ddc expression differences could influence environmental sensitivity is still unclear. The results suggest that a cuticle phenotype specifically in the heads of larvae could be explored, perhaps in the form of a reduction in cuticle sclerotization and melanization which might allow photoperiod shortening to be perceived and act on development. Although its causality might be either way, such a link would be exciting to investigate, yet the existence of cuticle differences between the two reproductive types is still a hypothesis to be tested. The lack of differences in the expression of synaptic release genes for dopamine might seem to indicate that the plastic response to photoperiod is not mediated via neurological roles. Yet, this does not rule out the role of decreasing levels of dopamine in mediating this response in the central nervous system of embryos, even if the genes regulating synaptic release are equally expressed.
To test for a direct role of ddc in regulating the reproductive fate of embryos, the authors have generated CrispR-Cas9 knockout mutants. Those mutants displayed egg cuticle melanization, but with lethal effects, precluding testing the effect of ddc at later stages in development. Gene manipulation becomes feasible in the pea aphid, opening up certain avenues for understanding the roles of other genes during development.
This study adds nicely to our understanding of the intricate changes in gene expression involved in polyphenism. But it also shows the complexity of deciphering the links between environmental perception and changes in physiology, which mobilise multiple interacting gene networks. In the era of manipulative genetics, this study also stresses the importance of understanding the traits and phenotypes affected by individual genes, which now seems essential to piece the puzzle together.
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|Dopamine pathway characterization during the reproductive mode switch in the pea aphid||Gaël Le Trionnaire, Sylvie Hudaverdian, Gautier Richard, Sylvie Tanguy, Florence Gleonnec, Nathalie Prunier-Leterme, Jean-Pierre Gauthier, Denis Tagu||<p>Aphids are major pests of most of the crops worldwide. Such a success is largely explained by the remarkable plasticity of their reproductive mode. They reproduce efficiently by viviparous parthenogenesis during spring and summer generating imp...||Development, Genetics/Genomics, Insecta, Molecular biology||Mathieu Joron||2020-03-13 13:01:44||View|