Zoological Letters最新文献

{"title":"Structure and development of the complex helmet of treehoppers (Insecta: Hemiptera: Membracidae).","authors":"Haruhiko Adachi,&nbsp;Keisuke Matsuda,&nbsp;Kenji Nishida,&nbsp;Paul Hanson,&nbsp;Shigeru Kondo,&nbsp;Hiroki Gotoh","doi":"10.1186/s40851-020-00155-7","DOIUrl":"https://doi.org/10.1186/s40851-020-00155-7","url":null,"abstract":"<p><p>Some insects possess complex three-dimensional (3D) structures that develop under the old cuticle prior to the last imaginal molt. Adult treehoppers (Insecta: Hemiptera: Auchenorrhyncha: Membracidae) have one such complex 3D structure, known as a helmet, on their dorsal side. The adult helmet likely forms inside the nymphal pronotum during the final instar nymphal stage. Previous morphological studies have reported that the adult helmet is a large, bi-layered, plywood-like structure, whereas the nymphal pronotum is a monolayer, sheath-like structure. The adult helmet is much larger than nymphal helmet. Thus, the emergence of the adult helmet involves two structural transitions: a transition from a monolayer, sheath-like pronotum to a bi-layer, plywood-like helmet, and a transition in size from small to large. However, when, how, and in what order these transitions occur within the nymphal cuticle is largely unknown. To determine how adult helmet development occurs under the nymphal cuticle, in the present study we describe the morphology of the final adult helmet and investigate developmental trajectories of the helmet during the final instar nymphal stage. We used micro-CT, scanning electron microscope and paraffin sections for morphological observations, and used <i>Antianthe expansa</i> as a model species. We found that the structural transition (from monolayer, sheath-like structure to bi-layer, roof-like structure) occurs through the formation of a \"miniature\" of the adult helmet during the middle stage of development and that subsequently, extensive folding and furrows form, which account for the increase in size. We suggest that the making of a \"miniature\" is the key developmental step for the formation of various 3D structures of treehopper helmets.</p>","PeriodicalId":54280,"journal":{"name":"Zoological Letters","volume":"6 ","pages":"3"},"PeriodicalIF":2.7,"publicationDate":"2020-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s40851-020-00155-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37699048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new redescription of <i>Richtersius coronifer</i>, supported by transcriptome, provides resources for describing concealed species diversity within the monotypic genus <i>Richtersius</i> (Eutardigrada).","authors":"Daniel Stec, Łukasz Krzywański, Kazuharu Arakawa, Łukasz Michalczyk","doi":"10.1186/s40851-020-0154-y","DOIUrl":"10.1186/s40851-020-0154-y","url":null,"abstract":"<p><p><i>Richtersius coronifer</i>, the nominal species for the family Richtersiidae and a popular laboratory model, exemplifies a common problem in modern tardigrade taxonomy. Despite undeniable progress in the field, many old and incomplete descriptions of taxa hinder both species delimitation and the estimation of species diversity and distribution. Although for over a century this species has been recorded throughout the world, recent research indicates that records to date are likely to represent a species complex rather than a single cosmopolitan species. However, in order to recognise and name species diversity within the complex, an integrative redescription of the nominal species is first needed. Here, we describe an <i>R. coronifer</i> population collected from Spitsbergen, i.e., one of the two localities mentioned in the original description, with detailed morphological and morphometric data associated with standard DNA sequences of four standard genetic markers (18S rRNA, 28S rRNA, ITS-2, and COI) and supported by transcriptome sequencing. We propose replacement of the neotype designated in 1981 by Maucci and Ramazzotti, as it is impossible to verify whether the existing neotype is conspecific with specimens studied by Richters in 1903 and 1904. Finally, using newly obtained cytochrome c oxidase subunit I (COI) sequences of populations from Spitsbergen, Italy, Poland, and Greece together with sequences deposited in GenBank (China, Greenland, Italy, Mongolia), we performed genetic species delimitation, which indicated seven distinct potential species within the genus <i>Richtersius</i>, in addition to the nominal taxon. This study marks a starting point for further research on the taxonomy of and species diversity within the genus. Moreover, this work has the potential to be the first tardigrade redescription to provide both genetic barcodes and a transcriptome of the species in question.</p>","PeriodicalId":54280,"journal":{"name":"Zoological Letters","volume":"6 ","pages":"2"},"PeriodicalIF":2.7,"publicationDate":"2020-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7003491/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37635313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Long-term monitoring reveals invariant clutch size and unequal reproductive costs between sexes in a subtropical lacertid lizard.","authors":"Jhan-Wei Lin,&nbsp;Ying-Rong Chen,&nbsp;Tsui-Wen Li,&nbsp;Pei-Jen L Shaner,&nbsp;Si-Min Lin","doi":"10.1186/s40851-019-0152-0","DOIUrl":"https://doi.org/10.1186/s40851-019-0152-0","url":null,"abstract":"<p><p>Based on 20,000 records representing <i>c</i>. 11,000 individuals from an 8-year capture-mark-recapture (CMR) study, we tested and confirmed a new case of invariant clutch size (ICS) in a sexually dichromatic lacertid lizard, <i>Takydromus viridipunctatus</i>. In the grassland habitat of the early succession stage, females showed strictly low and invariant clutch size, multiple clutches in a breeding season, high reproductive potential, and annual breeding cycles that correspond to the emergence of male courtship coloration. The hatchlings mature quickly, and join the adult cohort for breeding within a few months, whereas adults show low survival rates and a short lifespan, such that most die within one year. Mortality increased in both sexes during the breeding season, especially in females, indicating an unequal cost of reproduction in survival. These life history characters may be explained by two non-exclusive hypotheses of ICS-arboreal hypothesis and predation hypothesis-within the ecological context of their habitat. Our study highlights a confirmed case of ICS, which adapts well to this <i>r</i>-selected grassland habitat that experiences seasonal fluctuation and frequent disturbance.</p>","PeriodicalId":54280,"journal":{"name":"Zoological Letters","volume":"6 ","pages":"1"},"PeriodicalIF":2.7,"publicationDate":"2020-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s40851-019-0152-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37529815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A right whale (Mysticeti, Balaenidae) from the Pleistocene of Taiwan.","authors":"Cheng-Hsiu Tsai,&nbsp;Chun-Hsiang Chang","doi":"10.1186/s40851-019-0153-z","DOIUrl":"https://doi.org/10.1186/s40851-019-0153-z","url":null,"abstract":"<p><p>Current patterns of biological distribution result from the deep past. Of particular interest, some closely related species appear at high latitudes of both hemispheres, but not in between, a pattern known as antitropical distribution. However, the timing, pathway, and drivers of antitropical distributions remain mostly unknown. Here we describe a new fossil, a left tympanic bulla (part of the ear bones), from the Middle/Late Pleistocene (0.78-0.01 mya, but not excluding the possibility of Holocene in age, as the specimen was dredged from the sea bottom and the geological horizon remains uncertain) of Taiwan. The tympanic bulla is diagnostic in baleen whales, and this specimen shows morphological features that are identical to extant <i>Eubalaena</i>, including: relatively large size (the anteroposterior length is 117 mm); rectangular outline in medial view; short anterior lobe, judging from the remaining of the lateral furrow; squared anterior margin; prominent transverse crease on the involucrum; transversely compressed in anterior view; well-developed and rounded outer lip; and parallel involucral and main ridges. Although incomplete, the morphological characters and overall similarity to extant <i>Eubalaena</i> allow a reliable taxonomic assignment to <i>Eubalaena</i> sp. The occurrence of a Pleistocene <i>Eubalaena</i> on the southern margin of the western North Pacific is the first balaenid fossil evidence indicative of the biotic interchange between two hemispheres leading to the origin of antitropical distribution in the Pleistocene; alternatively, this specimen might merely represent an extra-limital record of the North Pacific <i>Eubalaena</i>. Furthermore, this find suggests that the <i>Eubalaena</i> interchange, being one of the largest species displaying antitropical distribution pairs in the history of life, likely took place along the western Pacific. Notably, this does not preclude the <i>Eubalaena</i> interchange from other routes, such as the eastern Pacific or the Atlantic Ocean, and future finds should test the scenario for the biotic interchange between Northern and Southern Hemispheres of <i>Eubalaena</i>.</p>","PeriodicalId":54280,"journal":{"name":"Zoological Letters","volume":"5 ","pages":"37"},"PeriodicalIF":2.7,"publicationDate":"2019-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s40851-019-0153-z","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37502535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Histaminergic interneurons in the ventral nerve cord: assessment of their value for Euarthropod phylogeny.","authors":"Maite Maurer,&nbsp;Janina Hladik,&nbsp;Thomas M Iliffe,&nbsp;Torben Stemme","doi":"10.1186/s40851-019-0151-1","DOIUrl":"https://doi.org/10.1186/s40851-019-0151-1","url":null,"abstract":"<p><p>Despite numerous approaches to the resolution of euarthropod phylogeny, mainly based on modern sequence information and traditional external morphology, the resulting hypotheses are often contradictory and leave many questions about euarthropod evolution unanswered. The comparison of developmental and structural aspects of the nervous system has shown to be a valuable contribution to the assessment of current phylogenetic hypotheses. One promising approach for the generation of new character sets is the morphology of transmitter systems and the discovery of individually identifiable neurons, which allow phylogenetic comparisons on the single cell level. In this context, the serotonin transmitter system has been investigated to a considerable degree. Studies to date have yielded important stimuli to our understanding of euarthropod relationships and the evolution of their nervous systems. However, data on other transmitter systems remain fragmented, and their value with respect to phylogenetic questions remains speculative. The biogenic amine histamine is a promising transmitter; a substantial amount of data has been reported in the literature and the homology of some histaminergic neurons has been suggested. Here, we present a comprehensive review of histaminergic neurons in the ventral nerve cord of Euarthropoda. Using immunocytochemical labeling of histamine combined with confocal laser-scanning microscopy, we investigated the transmitter system in phylogenetically relevant taxa, such as Zygentoma, Remipedia, Diplopoda, and Arachnida. By reconstructing ground patterns, we evaluated the significance of this specific character set for euarthropod phylogeny. With this approach, we identified a set of neurons, which can be considered homologous within the respective major taxon. In conclusion, the histaminergic system contains useful information for our understanding of euarthropod phylogeny, supporting the proposed clades Tetraconata and Mandibulata. Furthermore, this character set has considerable potential to help resolve relationships within the major clades at a deeper level of taxonomy, due to the considerable variability in neurite morphology.</p>","PeriodicalId":54280,"journal":{"name":"Zoological Letters","volume":"5 ","pages":"36"},"PeriodicalIF":2.7,"publicationDate":"2019-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s40851-019-0151-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37502534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A self-marker-like protein governs hemocyte allorecognition in <i>Halocynthia roretzi</i>.","authors":"Masaki Ema, Taizo Okada, Miki Takahashi, Masato Uchiyama, Hideo Kubo, Hideaki Moriyama, Hitoshi Miyakawa, Midori Matsumoto","doi":"10.1186/s40851-019-0149-8","DOIUrl":"10.1186/s40851-019-0149-8","url":null,"abstract":"<p><strong>Background: </strong>Self-incompatibility, fusion/non-fusion reactions, and contact reactions (CRs) have all been identified as allorecognition phenomena in ascidians. CR is a reaction characteristic of the hemocytes of <i>Halocynthia roretzi</i>, whereby they release phenol oxidase (PO) upon contact with non-self hemocytes. Thus, these cells may represent a primitive form of the vertebrate immune system. In the present study, we focused on the CR of <i>H. roretzi</i> hemocytes and sought to identify self-marker proteins that distinguish between self and non-self cells.</p><p><strong>Results: </strong>We initially generated a CR-inducing monoclonal antibody against the complete hemocyte membrane-protein complement (mAb11B16B10). This antibody was identified based on the differential induction of PO activity in individual organisms. The level of PO activity induced by this antibody in individual ascidians was consistent with the observed CR-induced PO activity. mAb11B16B10 recognized a series of 12 spots corresponding to a 100-kDa protein, with differing isoelectric points (pIs). A comparison of the 2D electrophoresis gels of samples from CR-reactive/non-reactive individuals revealed that some spots in this series in hemocytes were common to the CR-non-inducible individuals, but not to CR-inducible individuals. We cloned the corresponding gene and named it <i>Halocynthia roretzi</i> self-marker-like protein-1 (HrSMLP1). This gene is similar to the glycoprotein DD3-3 found in <i>Dictyostelium,</i> and is conserved in invertebrates.</p><p><strong>Conclusion: </strong>We generated a CR-inducing monoclonal antibody (mAb11B16B10) that recognized a series of novel membrane proteins (HrSMLP1) in the hemocytes of <i>H. roretzi</i>. The combination of expressed spots of HrSMLP1 distinguishes non-self cells from self cells with respect to CR inducibility. Given that the HrSMLP1 gene is a single gene, it may represent a novel type of self-marker protein with a role in CR.</p>","PeriodicalId":54280,"journal":{"name":"Zoological Letters","volume":"5 ","pages":"34"},"PeriodicalIF":1.7,"publicationDate":"2019-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6916515/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37502532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spectral tuning mediated by helix III in butterfly long wavelength-sensitive visual opsins revealed by heterologous action spectroscopy.","authors":"Tomoka Saito,&nbsp;Mitsumasa Koyanagi,&nbsp;Tomohiro Sugihara,&nbsp;Takashi Nagata,&nbsp;Kentaro Arikawa,&nbsp;Akihisa Terakita","doi":"10.1186/s40851-019-0150-2","DOIUrl":"https://doi.org/10.1186/s40851-019-0150-2","url":null,"abstract":"<p><p>Absorption spectra of opsin-based pigments are tuned from the UV to the red regions by interactions of the chromophore with surrounding amino acid residues. Both vertebrates and invertebrates possess long-wavelength-sensitive (LWS) opsins, which underlie color vision involving \"red\" sensing. The LWS opsins have independently evolved in each lineage, which suggests the existence of diverse mechanisms in spectral tuning. In vertebrate LWS opsins, the mechanisms underlying spectral tuning have been well characterized by spectroscopic analyses with recombinant pigments of wild type (WT) and mutant opsins. However in invertebrate LWS opsins including insect ones, the mechanisms are largely unknown due to the difficulty in obtaining recombinant pigments. Here we have overcome the problem by analyzing heterologous action spectra based on light-dependent changes in the second messenger in opsin-expressing cultured cells. We found that WTs of two LWS opsins of the butterfly, <i>Papilio xuthus</i>, PxRh3 and PxRh1 have the wavelengths of the absorption maxima at around 570 nm and 540 nm, respectively. Analysis of a series of chimeric mutants showed that helix III is crucial to generating a difference of about 15 nm in the wavelength of absorption maxima of these LWS opsins. Further site-directed mutations in helix III revealed that amino acid residues at position 116 and 120 (bovine rhodopsin numbering system) are involved in the spectral tuning of PxRh1 and PxRh3, suggesting a different spectral tuning mechanism from that of primate LWS opsins.</p>","PeriodicalId":54280,"journal":{"name":"Zoological Letters","volume":"5 ","pages":"35"},"PeriodicalIF":2.7,"publicationDate":"2019-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s40851-019-0150-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37502533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recapitulation-like developmental transitions of chromatin accessibility in vertebrates","authors":"Masahiro Uesaka, S. Kuratani, H. Takeda, Naoki Irie","doi":"10.1186/s40851-019-0148-9","DOIUrl":"https://doi.org/10.1186/s40851-019-0148-9","url":null,"abstract":"","PeriodicalId":54280,"journal":{"name":"Zoological Letters","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2019-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s40851-019-0148-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47475606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gene expression profiles of dicyemid life-cycle stages may explain how dispersing larvae locate new hosts","authors":"Tsai-Ming Lu, H. Furuya, N. Satoh","doi":"10.1186/s40851-019-0146-y","DOIUrl":"https://doi.org/10.1186/s40851-019-0146-y","url":null,"abstract":"","PeriodicalId":54280,"journal":{"name":"Zoological Letters","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2019-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s40851-019-0146-y","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42068180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Calcium ions in the aquatic environment drive planarians to food","authors":"M. Mori, Maria Narahashi, Tetsutaro Hayashi, Miyuki Ishida, Nobuyoshi Kumagai, Yuki Sato, R. Bagherzadeh, K. Agata, Takeshi Inoue","doi":"10.1186/s40851-019-0147-x","DOIUrl":"https://doi.org/10.1186/s40851-019-0147-x","url":null,"abstract":"","PeriodicalId":54280,"journal":{"name":"Zoological Letters","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2019-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s40851-019-0147-x","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48088984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}