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1. Novel genome sequences and evolutionary dynamics of the North American anopheline species Anopheles freeborni , Anopheles crucians , Anopheles quadrimaculatus , and Anopheles albimanus

   https://doi.org/10.1093/g3journal/jkac284  

   Henderson, Cory ; Kemirembe, Karen ; McKeand, Sage ; Bergey, Christina ; Rasgon, Jason L. ; Kern, ed., A. ( November 2022 , G3)

   Anopheles mosquitoes are the principal vectors for malaria and lymphatic filariasis, and evidence for arboviral transmission under laboratory and natural contexts has been demonstrated. Vector management approaches require an understanding of the ecological, epidemiological, and biological contexts of the species in question, and increased interest in gene drive systems for vector control applications has resulted in an increased need for genome assemblies from understudied mosquito vector species. In this study, we present novel genome assemblies for Anopheles crucians, Anopheles freeborni, Anopheles albimanus, and Anopheles quadrimaculatus and examine the evolutionary relationship between these species. We identified 790 shared single-copy orthologs between the newly sequenced genomes and created a phylogeny using 673 of the orthologs, identifying 289 orthologs with evidence for positive selection on at least 1 branch of the phylogeny. Gene ontology terms such as calcium ion signaling, histone binding, and protein acetylation identified as being biased in the set of selected genes. These novel genome sequences will be useful in developing our understanding of the diverse biological traits that drive vectorial capacity in anophelines.

    

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2. Evolving doublesex expression correlates with the origin and diversification of male sexual ornaments in the Drosophila immigrans species group

   https://doi.org/10.1111/ede.12249  

   Rice, Gavin ; Barmina, Olga ; Hu, Kevin ; Kopp, Artyom ( January 2018 , Evolution & Development)

   Male ornaments and other sex‐specific traits present some of the most dramatic examples of evolutionary innovations. Comparative studies of similar but independently evolved traits are particularly important for identifying repeated patterns in the evolution of these traits. Male‐specific modifications of the front legs have evolved repeatedly in Drosophilidae and other Diptera. The best understood of these novel structures is the sex comb ofDrosophila melanogasterand its close relatives. Here, we examine the evolution of another male foreleg modification, the sex brush, found in the distantly relatedDrosophila immigransspecies group. Similar to the sex comb, we find that the origin of the sex brush correlates with novel, spatially restricted expression of thedoublesex(dsx) transcription factor, the primary effector of theDrosophilasex determination pathway. The diversity of Dsx expression patterns in theimmigransspecies group closely reflects the differences in the presence, position, and size of the sex brush. Together with previous work on sex comb evolution, these observations suggest that tissue‐specific activation ofdsxexpression may be a common mechanism responsible for the evolution of sexual dimorphism and particularly for the origin of novel male‐specific ornaments.

    

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3. Discovery of a dune‐building hybrid beachgrass ( Ammophila arenaria  ×  A. breviligulata ) in the U.S. Pacific Northwest

   https://doi.org/10.1002/ecs2.3501  

   Mostow, Rebecca S. ; Barreto, Felipe ; Biel, Reuben ; Meyer, Eli ; Hacker, Sally D. ( April 2021 , Ecosphere)

   The production of novel hybrid zones is an ecologically important consequence of globally increasing rates of species introductions and invasions. Interspecific hybridization can facilitate gene flow between parent species or produce novel taxa that may alter invasion dynamics or ecosystem services. The coastal sand dunes of the U.S. Pacific Northwest coast are densely populated by two non‐native, congeneric, dune‐building beachgrasses (Ammophila arenariaandA. breviligulata). Here, we present morphological, cytological, and genetic evidence that the two beachgrass species have hybridized in this globally unique range overlap. TheA. arenaria × A. breviligulatahybrid has been found at 12 coastal sites in Washington and Oregon. It is a first‐generation hybrid between the beachgrass species as evidenced by genome size comparisons and single nucleotide polymorphism genotyping. It is intermediate between the parent grasses in many morphological characters but exceeds both parents in shoot height, a trait associated with dune‐building potential. Understanding the ecological and population genetic consequences of this novel hybridization event is of the utmost importance in a system where any change in dominant beachgrass species can have large effects on both biodiversity management and coastal protection.

    

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4. Prior restraint stress inhibits habituation to novel objects in the European starlings ( Sturnus vulgaris )

   https://doi.org/10.1002/jez.2327  

   de Bruijn, Robert ; Romero, L. Michael ( October 2019 , Journal of Experimental Zoology Part A: Ecological and Integrative Physiology)

   Animals often avoid novel objects, a behavior known as neophobia. We examined behavioral responses of captive European starlings to novel objects placed at their food dishes. Exposure occurred concurrently to food reintroduction following overnight fasting. Behavior was analyzed for 10 min via video recording. We expected an increase in avoidance behavior compared with trials in which food was reintroduced without a novel object. Seven of 10 novel objects increased latency to approach the dish. In contrast to our expectations, neither prior restraint nor exogenous corticosterone changed the neophobic response to novel objects. While exposure to a novel object increased approach latency, there was no additional effect of restraining animals in a cloth bag for 15 min before food reintroduction. Furthermore, the subcutaneous injection of corticosterone did not affect approach latency by itself, nor did it affect the response to a novel object. Finally, we expected repeated exposure to the same object to extinguishing the neophobic response, and that restraint stress would prevent habituation. Our results show that European starlings habituate rapidly to exposure to a novel object, as approach latency returned to baseline within three repeated exposures to the same object. When the repeated presentation of the object was combined with prior restraint, however, the latency to approach never returned to baseline. These results reveal that neophobia in starlings is object‐specific and that, while neither acute stress nor corticosterone directly affects the behavioral response to a novel object, acute stress appears to have a permissive effect on neophobia by inhibiting habituation.

    

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5. Silica Nanoparticle Dissolution Rate Controls the Suppression of Fusarium Wilt of Watermelon ( Citrullus lanatus )

   https://doi.org/10.1021/acs.est.0c07126  

   Kang, Hyunho ; Elmer, Wade ; Shen, Yu ; Zuverza-Mena, Nubia ; Ma, Chuanxin ; Botella, Pablo ; White, Jason C. ; Haynes, Christy L. ( January 2021 , Environmental Science & Technology)

   null (Ed.)

   Projected population increases over the next 30 years have elevated the need to develop novel agricultural technologies to dramatically increase crop yield, particularly under conditions of high pathogen pressure. In this study, silica nanoparticles (NPs) with tunable dissolution rates were synthesized and applied to watermelon (Citrullus lanatus) to enhance plant growth while mitigating development of the Fusarium wilt disease caused by Fusarium oxysporum f. sp. niveum. The hydrolysis rates of the silica particles were controlled by the degree of condensation or the catalytic activity of aminosilane. The results demonstrate that the plants treated with fast dissolving NPs maintained or increased biomass whereas the particle-free plants had a 34% decrease in biomass. Further, higher silicon concentrations were measured in root parts when the plants were treated with fast dissolving NPs, indicating effective silicic acid delivery. In a follow-up field study over 2.5 months, the fast dissolving NP treatment enhanced fruit yield by 81.5% in comparison to untreated plants. These findings indicate that the colloidal behavior of designed nanoparticles can be critical to nanoparticle-plant interactions, leading to disease suppression and plant health as part of a novel strategy for nanoenabled agriculture. 

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