Evidence for Selection on Sensory Structures in a Cave Population of Gammarus minus (Amphipoda)

Evolution ◽  
1989 ◽  
Vol 43 (3) ◽  
pp. 688 ◽  
Author(s):  
Ross Jones ◽  
David C. Culver
Keyword(s):  
Gammarus Minus ◽  
Cave Population ◽  
Sensory Structures

Comparative Study of the Fine Morphology of Sensory Receptors in Aspidogaster conchicola and Cotylaspis insignis

1972 ◽  
Vol 30 ◽  
pp. 150-151
Author(s):  
Venita F. Allison ◽  
J. E. Ubelaker ◽  
J. H. Martin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Nervous System ◽  
Osmic Acid ◽  
Sensory Receptors ◽  
Transmission Electron ◽  
Sensory Structures ◽  
Fine Morphology ◽  
Scanning Electron

It has been suggested that parasitism results in a reduction of sensory structures which concomitantly reflects a reduction in the complexity of the nervous system. The present study tests this hypothesis by examining the fine morphology and the distribution of sensory receptors for two species of aspidogastrid trematodes by transmission and scanning electron microscopy. The species chosen are an ectoparasite, Cotylaspis insignis and an endoparasite, Aspidogaster conchicola.Aspidogaster conchicola and Cotylaspis insignis were obtained from natural infections of clams, Anodonta corpulenta and Proptera purpurata. The specimens were fixed for transmission electron microscopy in phosphate buffered paraformaldehyde followed by osmic acid in the same buffer, dehydrated in an ascending series of ethanol solutions and embedded in Epon 812.

MANAGEMENT OF ELECTROPHYSICAL CHARACTERISTICS OF THE POLYSILICON SENSORY STRUCTURES OF MICROELECTRONIC SENSORS

2019 ◽  
Author(s):  
P. G. Mikhailov ◽  
◽  
T. A. Glebova ◽  
A. V. Sokolov ◽  
A. U. Analieva ◽  
...  
Keyword(s):  
Sensory Structures

scholarly journals When SEM becomes a deceptive tool of analysis: the unexpected discovery of epidermal glands with stalked ducts on the ultimate legs of geophilomorph centipedes

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Andy Sombke ◽  
Carsten H. G. Müller
Keyword(s):  
Sensory Function ◽  
Sexually Dimorphic ◽  
Non Invasive ◽  
Defensive Role ◽  
Transmission Electron ◽  
Sensory Structures ◽  
Taxonomic Studies ◽  
Invasive Techniques ◽  
Epidermal Glands ◽  
Intrinsic Musculature

Abstract Background The jointed appendage is a key novelty in arthropod evolution and arthropod legs are known to vary enormously in relation to function. Among centipedes, the ultimate legs always are distinctly different from locomotory legs, and different centipede taxa evolved different structural and functional modifications. In Geophilomorpha (soil centipedes), ultimate legs do not participate in locomotion and were interpret to serve a sensory function. They can be sexually dimorphic and in some species, male ultimate legs notably appear “hairy”. It can be assumed that the high abundance of sensilla indicates a pronounced sensory function. This study seeks for assessing the sensory diversity, however, documents the surprising and unique case of an extensive glandular epithelium in the ultimate legs of three phylogenetically distant species. Results The tightly aggregated epidermal glands with stalked ducts – mistakenly thought to be sensilla – were scrutinized using a multimodal microscopic approach comprising histology as well as scanning and transmission electron microscopy in Haplophilus subterraneus. Hence, this is the first detailed account on centipede ultimate legs demonstrating an evolutionary transformation into a “secretory leg”. Additionally, we investigated sensory structures as well as anatomical features using microCT analysis. Contrary to its nomination as a tarsus, tarsus 1 possesses intrinsic musculature, which is an indication that this podomere might be a derivate of the tibia. Discussion The presence and identity of ultimate leg associated epidermal glands with stalked ducts is a new discovery for myriapods. A pronounced secretory as well as moderate sensory function in Haplophilus subterraneus can be concluded. The set of characters will improve future taxonomic studies, to test the hypotheses whether the presence of these specialized glands is a common feature in Geophilomorpha, and that tarsus 1 may be a derivate of the tibia. As the number of epidermal glands with stalked ducts is sexually dimorphic, their function might be connected to reproduction or a sex-specific defensive role. Our results, in particular the unexpected discovery of ‘glandular hairs’, may account for a striking example for how deceptive morphological descriptions of epidermal organs may be, if based on non-invasive techniques alone.

scholarly journals Fine Morphology of Antennal and Ovipositor Sensory Structures of the Gall Chestnut Wasp, Dryocosmus kuriphilus

Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 231
Author(s):  
Milos Sevarika ◽  
Marco Valerio Rossi Stacconi ◽  
Roberto Romani
Keyword(s):  
Ultrastructural Organization ◽  
Antennal Sensilla ◽  
Dryocosmus Kuriphilus ◽  
Transmission Electron ◽  
Significant Damage ◽  
Sensory Structures ◽  
Host Plant Location ◽  
Oviposition Sites ◽  
Fine Morphology

Dryocosmus kuriphilus is a gall-inducing insect, which can cause significant damage on plants of the genus Castanea Mill., 1754. Antennae and ovipositor are the main sensory organs involved in the location of suitable oviposition sites. Antennal sensilla are involved in the host plant location, while ovipositor sensilla assess the suitability of the ovipositional bud. On both organs, diverse sensillar organs are present. Here, the distribution and ultrastructural organization of the sensilla were investigated by scanning and transmission electron microscopy. The antennae of D. kuriphilus are filiform and composed of 14 antennomeres, with the distal flagellomere bearing the highest number of sensilla. On the antennae, 6 sensilla types were found; sensilla chaetica, campaniformia, coeloconica-I, coeloconica-II, trichoidea and placoidea. The sensilla placoidea and trichoidea were the most abundant types. On the external walls of the ovipositor, gustatory and mechanoreceptive sensilla were observed. Internally, the egg channel hosted two additional sensory structures. The putative functional role of each sensilla in the context of insect’s ecology is discussed as well as the ovipositional mechanism used by this insect.

scholarly journals Sensory processing and corollary discharge effects in posterior caudal lobe Purkinje cells in a weakly electric mormyrid fish

2014 ◽  
Vol 112 (2) ◽  
pp. 328-339 ◽  
Author(s):  
Karina Alviña ◽  
Nathaniel B. Sawtell
Keyword(s):  
Purkinje Cells ◽  
Mossy Fiber ◽  
Corollary Discharge ◽  
Electrophysiological Response ◽  
Caudal Lobe ◽  
Mormyrid Fish ◽  
Sensory Structures ◽  
Proprioceptive Inputs ◽  
Weakly Electric ◽  
Complete Account

Although it has been suggested that the cerebellum functions to predict the sensory consequences of motor commands, how such predictions are implemented in cerebellar circuitry remains largely unknown. A detailed and relatively complete account of predictive mechanisms has emerged from studies of cerebellum-like sensory structures in fish, suggesting that comparisons of the cerebellum and cerebellum-like structures may be useful. Here we characterize electrophysiological response properties of Purkinje cells in a region of the cerebellum proper of weakly electric mormyrid fish, the posterior caudal lobe (LCp), which receives the same mossy fiber inputs and projects to the same target structures as the electrosensory lobe (ELL), a well-studied cerebellum-like structure. We describe patterns of simple spike and climbing fiber activation in LCp Purkinje cells in response to motor corollary discharge, electrosensory, and proprioceptive inputs and provide evidence for two functionally distinct Purkinje cell subtypes within LCp. Protocols that induce rapid associative plasticity in ELL fail to induce plasticity in LCp, suggesting differences in the adaptive functions of the two structures. Similarities and differences between LCp and ELL are discussed in light of these results.

Multiple products from the shavenbaby-ovo gene region of Drosophila melanogaster: relationship to genetic complexity

1994 ◽  
Vol 14 (10) ◽  
pp. 6809-6818
Author(s):  
M D Garfinkel ◽  
J Wang ◽  
Y Liang ◽  
A P Mahowald
Keyword(s):  
Drosophila Melanogaster ◽  
Germ Line ◽  
Gene Region ◽  
Multiple Products ◽  
Zinc Finger Motifs ◽  
Genetic Complexity ◽  
Complex Locus ◽  
Female Germ Line ◽  
Sensory Structures ◽  
Pole Cells

The Drosophila melanogaster shavenbaby (svb)-ovo gene region is a complex locus, containing two distinct but comutable genetic functions. ovo is required for survival and differentiation of female germ line cells and plays a role in germ line sex determination. In contrast, svb is required in both male and female embryos for the production of epidermal locomotor and sensory structures. Sequences required for the two genetic functions are partially overlapping. ovo corresponds to a previously described germ line-dependent 5.0-kb poly(A)+ mRNA that first appears in the germarium and accumulates in nurse cells during oogenesis. The 5.0-kb mRNA is stored in the egg, but it is rapidly lost in the embryos except for its continued presence in the germ line precursor pole cells. The ovo mRNA predicts a 1,028-amino-acid 110.6-kDa protein homologous with transcription factors. We have identified an embryonic mRNA, 7.1 kb in length, that contains exons partially overlapping those of the 5.0-kb poly(A)+ mRNA. The spatial distribution of this newly discovered transcript during midembryogenesis suggests that it corresponds to the svb function. The arrangement of exons common to the 5.0- and 7.1-kb mRNAs suggests that the Ovo and Svb proteins share DNA-binding specificity conferred by four Cys2-His2 zinc finger motifs but differ functionally in their capacity to interact with other components of the transcription machinery.

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