Scanning electron microscopical studies of some cephalopod radulae

1971 ◽  
Vol 49 (12) ◽  
pp. 1589-1594 ◽  
Author(s):  
Margueritte M. Aldrich ◽  
Vernon C. Barber ◽  
Carolyn J. Emerson

In an attempt to evaluate the possible uses of scanning electron microscopical (SEM) studies of cephalopod radulae, we examined the radulae of 58 specimens (representing 22 species of nine genera), the majority being from the genera Loligo, Rossia, and Illex. Octopod and decapod radulae have considerable differences and were easily distinguished, as were decapod radulae down to the family level. However, considerable differences in radular tooth form between individuals of a species, not related to size or sex of the animals, were found. Also, similarities between species in a genus, and genera in a family were noted. The advantages of the scanning electron microscopical method of examining radulae are discussed.

2019 ◽  
Vol 152 (2) ◽  
pp. 142-149
Author(s):  
Richard W. Jordan ◽  
Matt P. Ashworth ◽  
Yuki Uezato ◽  
Schonna R. Manning

Background and aims – Traditionally, extant rhizosolenioid diatom genera have been placed in a single family, the Rhizosoleniaceae. However, preliminary molecular data suggested that the family might be polyphyletic. Therefore, a literature review of the morphological, ultrastructural and molecular data of the rhizosolenioid genera was undertaken. Methods – In addition to the literature survey, the location of the rimoportula in a number of rhizosolenioid genera was investigated by breaking the valves and observing the fragments in the scanning electron microscope. Key results – The data provides strong support for the previous separation of Proboscia and Rhizosolenia at the family level (Probosciaceae vs. Rhizosoleniaceae), with the rimoportula being located at the tip of the proboscis in Proboscia, or with an internal labia at the base of the hollow tubular rimoportula (= spine or process) in Rhizosolenia and Pseudosolenia. Conclusions – The data suggests that a number of rhizosolenioid genera should be transferred to other families, and that gene sequences of two genera (Dactyliosolen and Neocalyptrella) are needed as their morphological features differ markedly from those of the Rhizosoleniceae s. str. (Rhizosolenia, Guinardia, Pseudosolenia).


1985 ◽  
Vol 17 (3) ◽  
pp. 239-245 ◽  
Author(s):  
T. Wadsten ◽  
R. Moberg

AbstractThe examination of the surface deposit of various lichens with X-ray diffraction methods, correlated with scanning electron microscopical (SEM) studies, have shown that calcium oxalate is present as two different hydrates; weddellite (CaC2O4-(2 + x)H2O), in three slightly different morphologies, and whewellite (CaC2O4H2O). The reason for the formation of calcium oxalate is not known and the presence of the various crystal forms is yet to be explained. However, the various hydrates may have some role in the water balance as they are different in dry and humid sites.


Author(s):  
J. A. Traquair ◽  
E. G. Kokko

With the advent of improved dehydration techniques, scanning electron microscopy has become routine in anatomical studies of fungi. Fine structure of hyphae and spore surfaces has been illustrated for many hyphomycetes, and yet, the ultrastructure of the ubiquitous soil fungus, Geomyces pannorus (Link) Sigler & Carmichael has been neglected. This presentation shows that scanning and transmission electron microscopical data must be correlated in resolving septal structure and conidial release in G. pannorus.Although it is reported to be cellulolytic but not keratinolytic, G. pannorus is found on human skin, animals, birds, mushrooms, dung, roots, and frozen meat in addition to various organic soils. In fact, it readily adapts to growth at low temperatures.


Author(s):  
A.D. Hyatt

Bluetongue virus (BTV) is the type species os the genus orbivirus in the family Reoviridae. The virus has a fibrillar outer coat containing two major structural proteins VP2 and VP5 which surround an icosahedral core. The core contains two major proteins VP3 and VP7 and three minor proteins VP1, VP4 and VP6. Recent evidence has indicated that the core comprises a neucleoprotein center which is surrounded by two protein layers; VP7, a major constituent of capsomeres comprises the outer and VP3 the inner layer of the core . Antibodies to VP7 are currently used in enzyme-linked immunosorbant assays and immuno-electron microscopical (JEM) tests for the detection of BTV. The tests involve the antibody recognition of VP7 on virus particles. In an attempt to understand how complete viruses can interact with antibodies to VP7 various antibody types and methodologies were utilized to determine the physical accessibility of the core to the external environment.


Author(s):  
Jianhua Wang ◽  
Guan-Zhu Han

Abstract LTR retrotransposons comprise a major component of the genomes of eukaryotes. On occasion, retrotransposon genes can be recruited by their hosts for diverse functions, a process formally referred to as co-option. However, a comprehensive picture of LTR retrotransposon gag gene co-option in eukaryotes is still lacking, with several documented cases exclusively involving Ty3/Gypsy retrotransposons in animals. Here we use a phylogenomic approach to systemically unearth co-option of retrotransposon gag genes above the family level of taxonomy in 2,011 eukaryotes, namely co-option occurring during the deep evolution of eukaryotes. We identify a total of 14 independent gag gene co-option events across more than 740 eukaryote families, eight of which have not been reported previously. Among these retrotransposon gag gene co-option events, nine, four, and one involve gag genes of Ty3/Gypsy, Ty1/Copia, and Bel-Pao retrotransposons, respectively. Seven, four, and three co-option events occurred in animals, plants, and fungi, respectively. Interestingly, two co-option events took place in the early evolution of angiosperms. Both selective pressure and gene expression analyses further support that these co-opted gag genes might perform diverse cellular functions in their hosts, and several co-opted gag genes might be subject to positive selection. Taken together, our results provide a comprehensive picture of LTR retrotransposon gag gene co-option events that occurred during the deep evolution of eukaryotes, and suggest paucity of LTR retrotransposon gag gene co-option during the deep evolution of eukaryotes.


Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 163
Author(s):  
Airy Gras ◽  
Oriane Hidalgo ◽  
Ugo D’Ambrosio ◽  
Montse Parada ◽  
Teresa Garnatje ◽  
...  

Studies suggesting that medicinal plants are not chosen at random are becoming more common. The goal of this work is to shed light on the role of botanical families in ethnobotany, depicting in a molecular phylogenetic frame the relationships between families and medicinal uses of vascular plants in several Catalan-speaking territories. The simple quantitative analyses for ailments categories and the construction of families and disorders matrix were carried out in this study. A Bayesian approach was used to estimate the over- and underused families in the medicinal flora. Phylogenetically informed analyses were carried out to identify lineages in which there is an overrepresentation of families in a given category of use, i.e., hot nodes. The ethnobotanicity index, at a specific level, was calculated and also adapted to the family level. Two diversity indices to measure the richness of reported taxa within each family were calculated. A total of 47,630 use reports were analysed. These uses are grouped in 120 botanical families. The ethnobotanicity index for this area is 14.44% and the ethnobotanicity index at the family level is 68.21%. The most-reported families are Lamiaceae and Asteraceae and the most reported troubles are disorders of the digestive and nutritional system. Based on the meta-analytic results, indicating hot nodes of useful plants at the phylogenetic level, specific ethnopharmacological research may be suggested, including a phytochemical approach of particularly interesting taxa.


Botany ◽  
2019 ◽  
Vol 97 (5) ◽  
pp. 271-282
Author(s):  
Alain Cuerrier ◽  
Courtenay Clark ◽  
Christian H. Norton

Plants are important in traditional Inuit life. They are used for food, tea, medicine, etc. Based on semi-structured interviews with 35 informants, we documented and compared plant names and uses in Kangiqsualujjuaq, Nunavik, and in Nain, Nunatsiavut. Plant names and uses were expected to be similar between communities owing to common boreal–subarctic environments and cultural ties. Both communities reported the same number of taxa, with equivalent proportions of vascular and nonvascular plants, growth forms, use categories, and medicinal uses. Forty-three species were used in each community, for a total of 78 species from 39 families. Despite a high overlap in species distributions, only 35% of nonvascular and 56% of vascular species were used in both communities. Correspondence was higher at the family level (64% of nonvascular and 75% of vascular families shared). The Ericaceae family was the most used, followed by Rosaceae. Thirteen of 30 medicinal species were shared between communities. There was a low correspondence regarding the conditions for which the medicinal species were used. Edible taxa were shared the most (52%). Plant uses unique to either Nain or Kangiqsualujjuaq may reveal separate bodies of traditional knowledge, or may reflect an overall loss of ethnobotanical knowledge in the Subarctic due to recent lifestyle changes.


1978 ◽  
Vol 115 (1) ◽  
pp. 1-19 ◽  
Author(s):  
Minoo Hojjatzadeh

SummaryTwenty-three species of the Family Discoasteraceae Vekshina, 1959 recovered from 18 samples of the Blue Clay at Fort Chambray, Gozo, and 31 samples from Fomm-Ir-Rih Bay, Malta, have been studied under light and scanning electron microscopes. Fourteen Middle Miocene species are reviewed, their stratigraphical ranges and importance as marker species discussed. Nine species are described as new. On the basis of the discoaster species present, a Middle Miocene age (NN.6 Discoaster exilis Zone – NN.7 Discoaster kugleri Zone) for the Blue Clay in Malta and Gozo is suggested.


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