Ultrastructure of feathered triancres in the Thaumastodermatidae and the description of a new species of Tetranchyroderma (Gastrotricha: Macrodasyida) from Australia

Author(s):  
Rick Hochberg

Tetranchyroderma adeleae sp. nov. is described from North Stradbroke Island, eastern Australia, where it is present in low abundance in the clean, coarse sediments of Cylinder beach. The species is characterized by the presence of epidermal glands on the oral hood and three pairs of dorsolateral cirrata. This is also the first described species of Tetranchyroderma with mixed ancre types that consist of both ordinary triancres and feathered triancres. Ordinary triancres are present on the ventrolateral margins of the body while feathered triancres adorn the dorsal side. Details of the ultrastructure of the cuticle in T. adeleae sp. nov. and a species of Pseudostomella are compared to each other and the cuticle of additional species of Thaumastodermatidae. At the ultrastructural level, feathered triancres are composed of a thickened endocuticular base with three tines (shafts) that give rise to pointed, feather-shaped scales. The structure of the base, tines and scales reveals a finely granular construction without noticeable substructure. The ultrastructure of feathered triancres is similar to that of ordinary triancres and broadly similar to feathered triancres in other species. However, differences are noted in the contour of the feathered scales that are not detected with light microscopy. Future studies of the thaumastodermatid cuticle using scanning electron microscopy are warranted to provide enhanced three-dimensional resolution and insight into their evolution.

2021 ◽  
Vol 28 ◽  
Author(s):  
Syed Mohammad Zakariya ◽  
Aiman Zehr ◽  
Rizwan Hasan Khan

: The failure of protein to correctly fold into its functional and unique three dimensional form leads to misfolded or partially folded protein. When these rogue proteins and polypeptides escape the quality control mechanism within the body, they result in aberrant aggregation of proteins into characteristic amyloid fibrils. This is the main cause for the number of neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s and Huntington’s diseases. This review aims to summarise the underlying mechanisms of protein folding, misfolding and aggregation. It also highlights the recent technologies for the structural characterisation and detection of amyloid fibrils in addition to the various factors responsible for the aggregate formation and the strategies to combat the aggregation process. Besides, the journey from origin to the current scenario of protein aggregation is also concisely discussed.


2012 ◽  
Vol 712 ◽  
pp. 598-613 ◽  
Author(s):  
Gao-Jin Li ◽  
Xi-Yun Lu

AbstractThe force and power of flapping plates are studied by vortex dynamic analysis. Based on the dynamic analysis of the numerical results of viscous flow past three-dimensional flapping plates, it is found that the force and power are strongly dominated by the vortical structures close to the body. Further, the dynamics of the flapping plate is investigated in terms of viscous vortex-ring model. It is revealed that the model can reasonably reflect the essential properties of the ring-like vortical structure in the wake, and the energy of the plate transferred to the flow for the formation of each vortical structure possesses a certain relation. Moreover, simplified formulae for the thrust and efficiency are proposed and verified to be reliable by the numerical solutions and experimental measurements of animal locomotion. The results obtained in this study provide physical insight into the understanding of the dynamic mechanisms relevant to flapping locomotion.


Zootaxa ◽  
2007 ◽  
Vol 1626 (1) ◽  
pp. 59-67 ◽  
Author(s):  
HANPING WANG ◽  
LIZHI WANG ◽  
XIAOCHEN LI

Seventeen species of tardigrades were found in this study. All species are new records for Guizhou Province, including two new records for China (Echiniscus perviridis and Doryphoribius zappalai) and one (Doryphoribius huangguoshuensis sp. nov.) new for science. The new species differs from the most similar species of the genus Doryphoribius mainly by different configuration of gibbosities on dorsal side of the body (configuration 4, 4, 4, 4, 4, 4, 4, 2, 2 in the new species; 2, 2, 2, 2, 2, 2, 2 in D. dupliglobulatus; 4, 4, 4, 4, 4, 4, 4, 2, 2, 3 in D. gibber; 6, 4, 6, 4, 6,4, 4, 2 in D. zyxiglobus).


F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 291
Author(s):  
Tingliang Wang ◽  
Lian Zhu ◽  
Ming Pei

For decades, researchers have been fascinated by the strategy of using cell therapy for bone defects; some progress in the field has been made. Owing to its ample supply and easy access, skin, the largest organ in the body, has gained attention as a potential source of stem cells. Despite extensive applications in skin and nerve regeneration, an increasing number of reports indicate its potential use in bone tissue engineering and regeneration. Unfortunately, few review articles are available to outline current research efforts in skin-based osteogenesis. This review first summarizes the latest findings on stem cells or progenitors in skin and their niches and then discusses the strategies of skin cell-based osteogenesis. We hope this article elucidates this topic and generates new ideas for future studies.


2020 ◽  
Vol 190 (2) ◽  
pp. 448-459 ◽  
Author(s):  
Sergey Sokolov ◽  
Ekaterina Voropaeva ◽  
Dmitry Atopkin

Abstract A new species, Skrjabinopsolus nudidorsalis sp. nov. is described from the sterlet Acipenser ruthenus, caught in the River Volga basin (Russia). This species differs from previously described congeners by the absence of vitelline follicles on the dorsal side of the body. The complete 18S rRNA and partial 28S rRNA gene sequences obtained for S. nudidorsalis are the first molecular data for the family Deropristidae. The results of phylogenetic analysis indicate that Deropristidae is sister to the Monorchiidae + Lissorchiidae group. The results of the phylogenetic study contradict the current taxonomic hypothesis that Deropristidae belongs to the superfamily Lepocreadioidea and allow inclusion of this family in Monorchioidea. The morphological similarity of deropristids to other monorchioids is recognizable from the presence of a bipartite internal seminal vesicle, spinous cirrus and a voluminous, armed metraterm.


Zootaxa ◽  
2009 ◽  
Vol 2271 (1) ◽  
pp. 57-63 ◽  
Author(s):  
HISASHI IMAMURA ◽  
LESLIE W. KNAPP

A new plataycephalid, Platycephalus orbitalis, is described on the basis of specimens collected in the Indian Ocean off the coast of Western Australia at depths of 50–144 m. The new species had been mistakenly identified as P. marmoratus, which is now known to be restricted to eastern Australia. Several morphological characters (e.g, 65–68 pored scales in lateral line, snout and interorbit naked, and caudal fin blackish with white posterior margin) can separate Platycephalus orbitalis sp. nov. and P. marmoratus from the other 14 congeners. In addition, Platycephalus orbitalis sp. nov. differs from P. marmoratus in having the margin of the interopercle scalloped, skinny sensory tubes on the infraorbitals, the preopercle well developed and mostly covering the cheek region, and the body and head lacking distinct large spots and bands dorsally.


2021 ◽  
Vol 22 (13) ◽  
pp. 6773
Author(s):  
Yuze Wu ◽  
Guojun Wei ◽  
Ningning Zhao

As a newly identified manganese transport protein, ZIP14 is highly expressed in the small intestine and liver, which are the two principal organs involved in regulating systemic manganese homeostasis. Loss of ZIP14 function leads to manganese overload in both humans and mice. Excess manganese in the body primarily affects the central nervous system, resulting in irreversible neurological disorders. Therefore, to prevent the onset of brain manganese accumulation becomes critical. In this study, we used Zip14−/− mice as a model for ZIP14 deficiency and discovered that these mice were born without manganese loading in the brain, but started to hyper-accumulate manganese within 3 weeks after birth. We demonstrated that decreasing manganese intake in Zip14−/− mice was effective in preventing manganese overload that typically occurs in these animals. Our results provide important insight into future studies that are targeted to reduce the onset of manganese accumulation associated with ZIP14 dysfunction in humans.


Author(s):  
Bahja I. Behbehani ◽  
Ramesh K. Nayak ◽  
Randall E. McCoy

Nematodes are elongate, unsegmented worms with an elastic cuticle made of protein. Few published references concerning scanning electron microscopy of nematode are available and there is paucity of information at the ultrastructural level on cuticle forming male reproductive structures. The species of the genus Physaloptera (tetradelphynema) commonly live as parasites in the adult form in the stomach of the desert rodent Gerbillus cheesmani. To date, the three-dimensional surface features of this spiruroid nematode have not been described. The main purpose of this investigation was to elucidate the surface features of the male nematode utilizing the current techniques of scanning electron microscopy.Adult worms were collected in the laboratory from the stomach of the gerbil, Gerbillus cheesmani. They were washed in PO4 buffer solution and subsequently fixed overnight in 2.5% glutaraldehyde in 0.1 M cacodylate buffer. Following fixation, the specimens were washed 3 times in buffer and sonically cleaned for 30 seconds to remove debris adhering on the body wall of the nematode.


2020 ◽  
Vol 18 (2) ◽  
Author(s):  
Elizabeth Kathleen de Queiroz Rodrigues ◽  
Andre L. Netto-Ferreira

ABSTRACT A new species of Odontocharacidium is described from the upper Río Orinoco basin, in Venezuela. The new species is distinguished from its only congener, Odontocharacidium aphanes, by the presence of: the antorbital, the parietal branch of the supraorbital laterosensory canal, the postcleithrum 1, the conspicuous bars extending ventrally below the middle portion of the body posteriorly, and two dark round blotches at the tip of the caudal peduncle. With the recognition of an additional species of Odontocharacidium the diagnostic characters of the genus and the variability in the number of maxillary teeth in specimens are discussed.


Zootaxa ◽  
2019 ◽  
Vol 4603 (1) ◽  
pp. 125 ◽  
Author(s):  
XU LI ◽  
WEI ZHOU ◽  
XING-JIN CHE

After comparing specimens of Vanmanenia collected from the Lancang-jiang (the upper Mekong River), Yuan-jiang (the upper Red River), Lixian-jiang (first branch of the Red River), and Jinsha-jiang (the upper Yangtze River) drainages in Yunnan, China, we considered the specimens of Vanmanenia from Shunbi Township, Yangbi County, Yunnan (a branch of the Lancang-jiang drainage basin, the upper Mekong River) a new species, herein named V. microcephala sp. nov. Our investigation also suggested that V. striata should be restored as a valid species. On the basis of the systematic comparison of morphological characteristics of the genus Vanmanenia and based on the combination of the characteristics of the rostral fold, rostral barbels, the bars/marks on the flank, the rows of spots on the paired fins, and the markings on the caudal-fin base, the loaches of Vanmanenia should be divided into three groups: 1) the barred group, characterized by bars on the flank, 2), the cusped rostral fold group, characterized by the rostral fold lobes forming a cusp process, and 3) the barbeled rostral fold group, characterized by the rostral fold lobes specialized as secondary barbels. The barred group differs from congeners in Vanmanenia by the following combination of characters: three rostral lobes with a smooth and arcuate outer edge, a pattern of bars on the flank, and spotless paired fins. This group includes six species: V. crassicauda, V. microcephala sp. nov., V. serrilineata, V. striata, V. tetraloba, and Vanmanenia pseudostriata. The new species, V. microcephala, differs from the other species in the barred group by the following combination of characters: the lateral side of the body with 14–22 vermiculations with widths smaller than the diameter of the eye; the dorsal side of the head covered with a large black blotch; the gill opening smaller and its upper angle aligned with the lower edge of the eye; and the head smaller, head depth 45.2–47.1% head length. The characteristic evolutionary trends, origin, and taxonomic status of the barred group in the genus Vanmanenia are also discussed.


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