Micro-Computed Tomography Reveals a Remarkable Twin Intromittent Organ in Spiders – A Novelty for Arachnids With Direct Sperm Transfer

The modification of male pedipalps into secondary sexual intromittent organs is one of the hallmark characteristics of spiders, yet understanding the development and evolution of male genitalia across the order remains a challenging prospect. The embolus – the sclerite bearing the efferent spermatic duct or spermophor, and used to deliver sperm directly to the female genitalia during copulation – has always been considered the single unambiguously homologous palpal sclerite shared by all spider species, fundamental to the bauplan of the order and to the evolution and functional morphology of spider reproductive systems. Indeed, after two centuries of comparative research on spider reproduction, the presence of a single spermophor and embolus on each of a male spider’s two pedipalps remains a central tenet of evolutionary arachnology. Our findings challenge this premise, and reveal a remarkable twin intromittent organ sperm transfer system in a lineage of Australian palpimanoid spiders, characterized by a bifurcate spermophor and the presence of two efferent ducts leading to a pair of embolic sclerites on each pedipalp. This is the first time such a remarkable conformation has been observed in any group of arachnids with direct sperm transfer, complicating our understanding of palpal sclerite homologies, and challenging ideas about the evolution of spider genitalia.

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A unique mating pattern of Panorpodes kuandianensis (Mecoptera: Panorpodidae)

Contributions to Zoology ◽

10.1163/18759866-08603003 ◽

2017 ◽

Vol 86 (3) ◽

pp. 229-237 ◽

Cited By ~ 4

Author(s):

Xin Tong ◽

Lu Jiang ◽

Bao-Zhen Hua

Keyword(s):

Mating Behavior ◽

Sexual Conflict ◽

Sperm Transfer ◽

Nuptial Gift ◽

Mating Pattern ◽

End To End ◽

Mating Behaviors ◽

First Time

Sexually reproductive insects exhibit diverse mating behaviors. However, the mating pattern remains unknown for Panorpodes of Panorpodidae to date. In this study, we investigated the mating behavior and copulatory mechanism of the short-faced scorpionfly Panorpodes kuandianensis Zhong, Zhang and Hua, 2011 for the first time. The results show that the male provides a salivary mass as a nuptial gift to the female and starts to copulate with the female in a V-shaped position, then changes to an end-to-end position by temporarily twisting the female abdominal segments VII−IX by 180°. During mating the basal processes and the basal teeth of the gonostyli and the hypandrium are used to obtain copulation and sustain the coupling of genitalia to secure successful sperm transfer. This unique mating pattern is greatly different from that of other Mecoptera reported and is likely evolved as an adaptation in the context of sexual conflict.

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Functional morphology of immature mating in a widow spider

Frontiers in Zoology ◽

10.1186/s12983-021-00404-1 ◽

2021 ◽

Vol 18 (1) ◽

Author(s):

Lenka Sentenská ◽

Aileen Neumann ◽

Yael Lubin ◽

Gabriele Uhl

Keyword(s):

Sperm Competition ◽

Storage Conditions ◽

Sperm Storage ◽

Sperm Transfer ◽

Costs And Benefits ◽

Micro Computed Tomography ◽

Mating Tactics ◽

Adult Females ◽

Storage Organs ◽

Widow Spider

Abstract Background Mating generally occurs after individuals reach adulthood. In many arthropods including spiders, the adult stage is marked by a final moult after which the genitalia are fully developed and functional. In several widow spider species (genus Latrodectus), however, immature females may mate a few days before they moult to adulthood, i.e. in their late-subadult stage. While the “adult” mating typically results in cannibalism, males survive the “immature” mating. During both “immature” and “adult” matings, males leave parts of their paired copulatory organs within female genitalia, which may act as mating plugs. To study potential costs and benefits of the two mating tactics, we investigated female genital morphology of the brown widow spider, L. geometricus. Light microscopy, histology and micro-computed tomography of early-subadult, late-subadult and adult females were conducted to determine the overall pattern of genital maturation. We compared genitalia of mated late-subadult and adult females to reveal potential differences in the genitalic details that might indicate differential success in sperm transfer and different environments for sperm storage and sperm competition. Results We found that the paired sperm storage organs (spermathecae) and copulatory ducts are developed already in late-subadult females and host sperm after immature mating. However, the thickness of the spermathecal cuticle and the staining of the secretions inside differ significantly between the late-subadult and adult females. In late-subadult females mating plugs were found with higher probability in both spermathecae compared to adult females. Conclusions Sperm transfer in matings with late-subadult females follows the same route as in matings with adult females. The observed differences in the secretions inside the spermathecae of adult and late-subadult females likely reflect different storage conditions for the transferred sperm which may lead to a disadvantage under sperm competition if the subadult female later re-mates with another male. However, since males mating with late-subadult females typically transfer sperm to both spermathecae they might benefit from numerical sperm competition as well as from monopolizing access to the female sperm storage organs. The assessment of re-mating probability and relative paternity will clarify the costs and benefits of the two mating tactics in light of these findings.

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A fresh look at Cladarosymblema narrienense, a tetrapodomorph fish (Sarcopterygii: Megalichthyidae) from the Carboniferous of Australia, illuminated via X-ray tomography

PeerJ ◽

10.7717/peerj.12597 ◽

2021 ◽

Vol 9 ◽

pp. e12597

Author(s):

Alice M. Clement ◽

Richard Cloutier ◽

Jing Lu ◽

Egon Perilli ◽

Anton Maksimenko ◽

...

Keyword(s):

Original Description ◽

Sister Group ◽

Axial Skeleton ◽

Phylogenetic Position ◽

Micro Computed Tomography ◽

Holotype Specimen ◽

Freshwater Swamp ◽

The Family ◽

First Time ◽

Detailed Work

Background The megalichthyids are one of several clades of extinct tetrapodomorph fish that lived throughout the Devonian–Permian periods. They are advanced “osteolepidid-grade” fishes that lived in freshwater swamp and lake environments, with some taxa growing to very large sizes. They bear cosmine-covered bones and a large premaxillary tusk that lies lingually to a row of small teeth. Diagnosis of the family remains controversial with various authors revising it several times in recent works. There are fewer than 10 genera known globally, and only one member definitively identified from Gondwana. Cladarosymblema narrienense Fox et al. 1995 was described from the Lower Carboniferous Raymond Formation in Queensland, Australia, on the basis of several well-preserved specimens. Despite this detailed work, several aspects of its anatomy remain undescribed. Methods Two especially well-preserved 3D fossils of Cladarosymblema narrienense, including the holotype specimen, are scanned using synchrotron or micro-computed tomography (µCT), and 3D modelled using specialist segmentation and visualisation software. New anatomical detail, in particular internal anatomy, is revealed for the first time in this taxon. A novel phylogenetic matrix, adapted from other recent work on tetrapodomorphs, is used to clarify the interrelationships of the megalichthyids and confirm the phylogenetic position of C. narrienense. Results Never before seen morphological details of the palate, hyoid arch, basibranchial skeleton, pectoral girdle and axial skeleton are revealed and described. Several additional features are confirmed or updated from the original description. Moreover, the first full, virtual cranial endocast of any tetrapodomorph fish is presented and described, giving insight into the early neural adaptations in this group. Phylogenetic analysis confirms the monophyly of the Megalichthyidae with seven genera included (Askerichthys, Cladarosymblema, Ectosteorhachis, Mahalalepis, Megalichthys, Palatinichthys, and Sengoerichthys). The position of the megalichthyids as sister group to canowindrids, crownward of “osteolepidids” (e.g.,Osteolepis and Gogonasus), but below “tristichopterids” such as Eusthenopteron is confirmed, but our findings suggest further work is required to resolve megalichthyid interrelationships.

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RGS12 Drives Macrophage Activation and Osteoclastogenesis in Periodontitis

Journal of Dental Research ◽

10.1177/00220345211045303 ◽

2021 ◽

pp. 002203452110453

Author(s):

G. Yuan ◽

C. Fu ◽

S.T. Yang ◽

D.Y. Yuh ◽

G. Hajishengallis ◽

...

Keyword(s):

Inflammatory Cytokines ◽

Alveolar Bone ◽

Osteoclast Formation ◽

Protein Signaling ◽

Micro Computed Tomography ◽

Promising Therapeutic Target ◽

Rgs Protein ◽

And Migration ◽

First Time

Periodontitis is a complex inflammatory disease affecting the supporting structures of teeth and is associated with systemic inflammatory disorders. Regulator of G-protein signaling 12 (RGS12), the largest protein in the RGS protein family, plays a crucial role in the development of inflammation and bone remodeling. However, the role and mechanism(s) by which RGS12 may regulate periodontitis have not been elucidated. Here, we showed that ablation of RGS12 in Mx1+ hematopoietic cells blocked bone loss in the ligature-induced periodontitis model, as evidenced morphometrically and by micro–computed tomography analysis of the alveolar bone. Moreover, hematopoietic cell-specific deletion of RGS12 inhibited osteoclast formation and activity as well as the production of inflammatory cytokines such as IL1β, IL6, and TNFα in the diseased periodontal tissue. In the in vitro experiments, we found that the overexpression of RGS12 promoted the reprogramming of macrophages to the proinflammatory M1 type, but not the anti-inflammatory M2 type, and enhanced the ability of macrophages for migration. Conversely, knockdown of RGS12 in macrophages inhibited the production of inflammatory cytokines and migration of macrophages in response to lipopolysaccharide stimulation. Our results demonstrate for the first time that inhibition of RGS12 in macrophages is a promising therapeutic target for the treatment of periodontitis.

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Autocatalytic amplified detection of DNA based on a CdSe quantum dot/folic acid electrochemiluminescence energy transfer system

The Analyst ◽

10.1039/c4an01465k ◽

2015 ◽

Vol 140 (1) ◽

pp. 79-82 ◽

Cited By ~ 25

Author(s):

Guifen Jie ◽

Yingqiang Qin ◽

Qingmin Meng ◽

Jialin Wang

Keyword(s):

Energy Transfer ◽

Folic Acid ◽

Quantum Dot ◽

Transfer System ◽

Cdse Qds ◽

System P ◽

Cdse Quantum Dot ◽

Autocatalytic System ◽

First Time

Electrochemiluminescence energy transfer from CdSe QDs to folic acid was applied for the first time for amplified detection of DNA by a DNAzyme autocatalytic system.

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A new fossil Eurypinae genus and sexual dimorphism in the representatives of Omineus (Coleoptera: Mycteridae) from Tertiary amber of Europe

Zootaxa ◽

10.11646/zootaxa.4820.3.8 ◽

2020 ◽

Vol 4820 (3) ◽

pp. 551-562

Author(s):

VITALII IGOREVICH ALEKSEEV ◽

ANDRIS BUKEJS ◽

DARREN ANDREW POLLOCK

Keyword(s):

Computed Tomography ◽

Sexual Dimorphism ◽

Baltic Amber ◽

Micro Computed Tomography ◽

Fossil Species ◽

X Ray ◽

Secondary Sexual Characters ◽

Kaliningrad Region ◽

First Time ◽

Secondary Sexual

Europoeurypus inglaeso gen. et sp. nov. is described from Eocene Baltic amber found on the Sambian Peninsula, Kaliningrad Region, Russia. Four additional specimens of mycterid beetles from collections of Baltic amber are reported. The secondary sexual characters and sexual dimorphism in the Eocene representatives of the genus Omineus Lewis, 1895 are documented for the first time and examined using X-ray micro-computed tomography (μCT). The studied Omineus male specimens were attributed to the fossil species Omineus febribilis Alekseev, Pollock & Bukejs, 2019. A key to fossil species of Eurypinae from Eocene ambers is provided and several aspects of the biogeography of the subfamily Eurypinae are discussed.

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New information on the braincase and inner ear of Euparkeria capensis Broom: implications for diapsid and archosaur evolution

Royal Society Open Science ◽

10.1098/rsos.160072 ◽

2016 ◽

Vol 3 (7) ◽

pp. 160072 ◽

Cited By ~ 33

Author(s):

Gabriela Sobral ◽

Roland B. Sookias ◽

Bhart-Anjan S. Bhullar ◽

Roger Smith ◽

Richard J. Butler ◽

...

Keyword(s):

Lateral View ◽

Micro Computed Tomography ◽

Active Lifestyle ◽

Pressure Relief ◽

New Information ◽

Computed Tomography Scanning ◽

Anterior Semicircular Canal ◽

First Time ◽

Tomography Scanning ◽

Hearing System

Since its discovery, Euparkeria capensis has been a key taxon for understanding the early evolution of archosaurs. The braincase of Euparkeria was described based on a single specimen, but much uncertainty remained. For the first time, all available braincase material of Euparkeria is re-examined using micro-computed tomography scanning. Contrary to previous work, the parabasisphenoid does not form the posterior border of the fenestra ovalis in lateral view, but it does bear a dorsal projection that forms the anteroventral half of the fenestra. No bone pneumatization was found, but the lateral depression of the parabasisphenoid may have been pneumatic. We propose that the lateral depression likely corresponds to the anterior tympanic recess present in crown archosaurs. The presence of a laterosphenoid is confirmed for Euparkeria . It largely conforms to the crocodilian condition, but shows some features which make it more similar to the avemetatarsalian laterosphenoid. The cochlea of Euparkeria is elongated, forming a deep cochlear recess. In comparison with other basal archosauromorphs, the metotic foramen is much enlarged and regionalized into vagus and recessus scalae tympani areas, indicating an increase in its pressure-relief mechanism. The anterior semicircular canal is extended and corresponds to an enlarged floccular fossa. These aspects of the braincase morphology may be related to the development of a more upright posture and active lifestyle. They also indicate further adaptations of the hearing system of Euparkeria to terrestriality.

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Transformation of internal head structures during the metamorphosis of Chrysopa pallens (Neuroptera: Chrysopidae)

10.21203/rs.2.15700/v1 ◽

2019 ◽

Author(s):

Chenjing Zhao ◽

Yuchen Ang ◽

Mengqing Wang ◽

Caixia Gao ◽

Kuiyan Zhang ◽

...

Keyword(s):

Developmental Stages ◽

Pupal Stage ◽

Model Organisms ◽

Micro Computed Tomography ◽

Muscular System ◽

Dynamic Transformation ◽

Morphological Differences ◽

First Time ◽

The Brain ◽

Head Muscles

Abstract Background The metamorphosis is a complicated but very interesting process because of the highly dynamic transformation in sheath. Very few studies had coverage on the head muscles of larvae, pupae, and adults. Most of these studies were focusing on the model organisms about the rough changes of the external and internal tissues or the time of metamorphosis based on the traditional methods. In our study,the skeleto-muscular system of head, as well as the brain of Chrysopa pallens (Rambur, 1838) from larvae to adults are described in detail for the first time by the technology of micro computed tomography (µ-CT). The transformations of these systems during pupal stage are studied for the first time.Results The morphological differences and functional adaptations between the stages are assessed. Muscles are distinctly slender in larvae than in adults with a significantly larger quantity. A larger brain with improved sensory perception is suggested to be essential for dispersal, mating and flying for adults. For the pupae, the results show that the histolysis of the muscles happens in first third of the pupal period and their reconstruction happens in the following days. The brain exists all along.Conclusion We suggest the transformations of the skeleton occur earlier than the musculature. Most of the transformations are related to tasks they play in the developmental stages.

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Using micro-CT techniques to explore the role of sex and hair in the functional morphology of bumblebee (Bombus terrestris) ocelli

10.1101/433979 ◽

2018 ◽

Author(s):

David Wilby ◽

Tobio Aarts ◽

Pierre Tichit ◽

Andrew Bodey ◽

Christoph Rau ◽

...

Keyword(s):

Bombus Terrestris ◽

Visual Fields ◽

Mating Strategies ◽

Micro Ct ◽

Micro Computed Tomography ◽

3D Data ◽

Computed Tomography Scans ◽

The Difference ◽

First Time

AbstractMany insects have triplets of camera type eyes, called ocelli, whose function remains unclear for most species. Here, we investigate the ocelli of the bumblebee, Bombus terrestris, using reconstructed 3D data from X-ray micro computed-tomography scans combined with computational ray-tracing simulations. This method enables us, not only to predict the visual fields of the ocelli, but to explore for the first time the effect that hair has on them as well as the difference between worker female and male ocelli.We find that bumblebee ocellar fields of view are directed forward and dorsally, incorporating the horizon as well as the sky. There is substantial binocular overlap between the median and lateral ocelli, but no overlap between the two lateral ocelli. Hairs in both workers and males occlude the ocellar field of view, mostly laterally in the worker median ocellus and dorsally in the lateral ocelli. There is little to no sexual dimorphism in the ocellar visual field, suggesting that in B. terrestris they confer no advantage to mating strategies.We compare our results with published observations for the visual fields of compound eyes in the same species as well as with the ocellar vision of other bee and insect species.

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An atlas of seven zebrafish hox cluster mutants provides insights into sub/neofunctionalization of vertebrate Hox clusters

Development ◽

10.1242/dev.198325 ◽

2021 ◽

Vol 148 (11) ◽

Author(s):

Kazuya Yamada ◽

Akiteru Maeno ◽

Soh Araki ◽

Morimichi Kikuchi ◽

Masato Suzuki ◽

...

Keyword(s):

Hox Genes ◽

Main Body ◽

Loss Of Function ◽

Micro Computed Tomography ◽

Genetic Studies ◽

Hox Cluster ◽

Species Specific ◽

First Time ◽

Hox Clusters ◽

Tomography Scan

ABSTRACT Vertebrate Hox clusters are comprised of multiple Hox genes that control morphology and developmental timing along multiple body axes. Although results of genetic analyses using Hox-knockout mice have been accumulating, genetic studies in other vertebrates have not been sufficient for functional comparisons of vertebrate Hox genes. In this study, we isolated all of the seven hox cluster loss-of-function alleles in zebrafish using the CRISPR-Cas9 system. Comprehensive analysis of the embryonic phenotype and X-ray micro-computed tomography scan analysis of adult fish revealed several species-specific functional contributions of homologous Hox clusters along the appendicular axis, whereas important shared general principles were also confirmed, as exemplified by serial anterior vertebral transformations along the main body axis, observed in fish for the first time. Our results provide insights into discrete sub/neofunctionalization of vertebrate Hox clusters after quadruplication of the ancient Hox cluster. This set of seven complete hox cluster loss-of-function alleles provide a formidable resource for future developmental genetic analysis of the Hox patterning system in zebrafish.

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