Teleost fish osmoregulation: what have we learned since August Krogh, Homer Smith, and Ancel Keys

2008 ◽  
Vol 295 (2) ◽  
pp. R704-R713 ◽  
Author(s):  
David H. Evans
Keyword(s):  
Molecular Techniques ◽  
Control Mechanisms ◽  
Teleost Fishes ◽  
Transport Mechanisms ◽  
Endocrine Control ◽  
Transport Pathways ◽  
The Past ◽  
Ionic Uptake ◽  
Nacl Secretion ◽  
Freshwater Teleosts

In the 1930s, August Krogh, Homer Smith, and Ancel Keys knew that teleost fishes were hyperosmotic to fresh water and hyposmotic to seawater, and, therefore, they were potentially salt depleted and dehydrated, respectively. Their seminal studies demonstrated that freshwater teleosts extract NaCl from the environment, while marine teleosts ingest seawater, absorb intestinal water by absorbing NaCl, and excrete the excess salt via gill transport mechanisms. During the past 70 years, their research descendents have used chemical, radioisotopic, pharmacological, cellular, and molecular techniques to further characterize the gill transport mechanisms and begin to study the signaling molecules that modulate these processes. The cellular site for these transport pathways was first described by Keys and is now known as the mitochondrion-rich cell (MRC). The model for NaCl secretion by the marine MRC is well supported, but the model for NaCl uptake by freshwater MRC is more unsettled. Importantly, these ionic uptake mechanisms also appear to be expressed in the marine gill MRC, for acid-base regulation. A large suite of potential endocrine control mechanisms have been identified, and recent evidence suggests that paracrines such as endothelin, nitric oxide, and prostaglandins might also control MRC function.

scholarly journals Translating Molecular Profiling of Soft Tissue Sarcomas into Daily Clinical Practice

Diagnostics ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 512
Author(s):  
Celine Jacobs ◽  
Lore Lapeire
Keyword(s):  
Soft Tissue ◽  
Unmet Need ◽  
Soft Tissue Sarcomas ◽  
Molecular Profiling ◽  
Point Of View ◽  
Molecular Techniques ◽  
Mesenchymal Tumors ◽  
The Past ◽  
Cancer Types ◽  
Sarcoma Treatment

Soft tissue sarcomas are a group of rare mesenchymal tumors with more than 70 subtypes described. Treatment of these subtypes in an advanced setting is mainly according to a one-size-fits-all strategy indicating a high unmet need of new and more targeted therapeutic options in order to optimize survival. The introduction of advanced molecular techniques in cancer has led to better diagnostics and identification of new therapeutic targets, leading to more personalized treatment and improved prognosis for several cancer types. In sarcoma, a likewise evolution is seen, albeit at a slower pace. This manuscript describes how in the past years advanced molecular profiling in soft tissue sarcomas was able to identify specific and often pathognomonic aberrations, deferring standard sarcoma treatment in favor of more targeted treatment from an oncologist’s point of view.

scholarly journals Antagonistic Activity of Pseudomonas Fluorescens Against Fusarium Oxysporum f. sp. Nievum Isolated from Soil Samples in Palestine

2017 ◽  
Vol 6 (2) ◽  
pp. 1 ◽  
Author(s):  
Mazen Salman ◽  
Nabil Shahin ◽  
Nawaf Abu-Khalaf ◽  
Mohammad Jawabrih ◽  
Basima Abu Rumaileh ◽  
...  
Keyword(s):  
Fusarium Oxysporum ◽  
Pseudomonas Fluorescens ◽  
Field Experiments ◽  
Antagonistic Activity ◽  
Arab Countries ◽  
Local Market ◽  
Control Mechanisms ◽  
The Past ◽  
Normal Seedling ◽  
Severe Infections

Watermelon is an important summer crop in Palestine, for several decades filling the needs of local market and some Arab countries. The yield of watermelon decreased dramatically in recent years due to severe infections with the soil borne fungal pathogen Fusarium oxysporum f. sp. niveum (FON). Soil fumigation with methyl bromide was commonly applied by Palestinian farmers until it was recently legally banned. Different control mechanisms were not feasible to overcome problems caused by the disease resulting in decreased watermelon cultivation in Palestine for the past 30 years. In this work, we have experimentally shown that Pseudomonas fluorescens was efficient in controlling FON infection and allowing normal seedling growth of both the root and shoot systems. Field experiments are necessary to further confirm the efficacy of biocontrol application.

scholarly journals Monitoring and risk assessment for groundwater sources in rural communities of Romania (GROUNDWATERISK)

2019 ◽  
Vol 5 ◽  
Author(s):  
Oana Teodora Moldovan ◽  
Rannveig Øvrevik Skoglund ◽  
Horia Leonard Banciu ◽  
Alexandra Dinu Cucoș ◽  
Erika Andrea Levei ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Drinking Water ◽  
Rural Communities ◽  
Groundwater Resources ◽  
Molecular Techniques ◽  
The Past ◽  
Physico Chemical ◽  
Groundwater Ecosystems ◽  
Alternative Sources ◽  
Agricultural Areas

In the past 100 years, a decreasing rainfall trend has been recorded on Romanian territory, a trend that continues today. Therefore, realistic estimation of the groundwater resources is crucial, especially for the rural communities lacking the economic power to use alternative sources of drinking water. The groundwater sources used by rural communities in Romania generally originate directly from caves, wells or springs with no proper evaluation of the water quality. Groundwater is exposed to different pollutants, as bats' guano in caves, fertilizers in agricultural areas or livestock (cattle, sheep, goats, etc.) farms on the surface. On the other hand, the water extracted directly from inside the caves is affecting groundwater ecosystems, highly vulnerable to any human impact and neglected by European legislation so far. The project aims to monitor, during two consecutive years, groundwater sources with different degrees of above- and underground pollution, from different regions of Romania. To achieve the goals of the project, a multidisciplinary monitoring strategy that will include measurements of hydrological, physico-chemical and biological (microbiology and aquatic invertebrates’ assessment) parameters alongside the quantification of radon and stable isotopes, rainfall or possible inflows of water. The specific outcomes of this project are: i) to test, develop and validate a new, more rapid and efficient method for monitoring and risk assessment of groundwater sources – and not only – by using molecular techniques, and propose this method to the water agencies in Romania; ii) to propose for Romanian authorities to implement a harmonized coherent methodology to measure radon concentration in water, as a consequence of EURATOM Directive; and iii) to educate local communities that are using groundwater as source for drinking water and raise young people’s awareness on the benefits of ecosystem services provided by the groundwater.

Absence of a microbiome in the midgut trunk of six representative Crustacea

2019 ◽  
Vol 40 (1) ◽  
pp. 122-130
Author(s):  
Gary G Martin ◽  
Zain Natha ◽  
Nicola Henderson ◽  
Sabi Bang ◽  
Hope Hendry ◽  
...  
Keyword(s):  
Immune Responses ◽  
Molecular Techniques ◽  
Peritrophic Matrix ◽  
Immune Functions ◽  
Actual Surface ◽  
Bacterial Symbiosis ◽  
The Past ◽  
Transmission Electron ◽  
Accessory Molecules ◽  
A Site

Abstract It has become a common expectation for an animal’s guts to be a site for bacterial symbiosis, which may play a role in influencing various aspects of physiology including digestion and immune responses. The presence of a microbiome in the digestive tracts of crustaceans has been demonstrated in the past using molecular techniques and has encouraged manipulations including probiotics to enhance growth rates in cultured species. We suggest, however, that bacteria are restricted to the lumen of the gut and separated from the epithelium by the peritrophic matrix, which prevents their establishment as a permanent component of the gut. The peritrophic matrix, found in most arthropods, is a chitinous sheet containing accessory molecules, and is continuously formed by delamination from the epithelium of the midgut such that the actual surface is constantly being cleaned. The lifted layer then surrounds ingested materials, including microbes, in an impenetrable wrapper compartmentalizing digestive and immune functions. The ectoperitrophic space, lying between the peritrophic matrix and the epithelium, was examined in six species representatives of six groups of crustaceans (Branchiopoda, Amphipoda, Copepoda, and Decapoda) for the presence of microbes using light and transmission electron microscopy as well as fluorescent probes for bacteria. The results suggest that a microbiome is lacking in several common groups of crustaceans.

Molecular Studies On Foraminifers: Past, Present, and Future

2018 ◽  
Vol 48 (3) ◽  
pp. 193-209
Author(s):  
Karan A. Bhatt ◽  
Mrugesh H. Trivedi
Keyword(s):  
Molecular Genetics ◽  
Evolutionary Biology ◽  
Molecular Techniques ◽  
Biological Research ◽  
Taxonomic Identification ◽  
Environmental Assessments ◽  
Future Studies ◽  
The Past ◽  
Molecular Studies ◽  
The Way

Abstract Applications of molecular techniques have become integral to most fields of biological research, including evolutionary biology. Over the past two decades, studies of molecular genetics of foraminifers have emerged to enhance taxonomic identification with broad applications, including biodiversity, environmental assessments, and paleoceanographic studies. However, the results are widely scattered across the literature, thereby inhibiting advances in such research on foraminifers, especially regionally. In this review, we discuss the developments and contributions in the field of molecular genetics as applied to foraminifers, offering a guide to beginners in this area of research. Furthermore, this review highlights new opportunities for foraminiferal research that will pave the way for future studies in this field.

A molecular phylogeny of the subtribe Pterostylidinae (Orchidaceae): resolving the taxonomic confusion

2010 ◽  
Vol 23 (4) ◽  
pp. 248 ◽  
Author(s):  
Jasmine K. Janes ◽  
Dorothy A. Steane ◽  
René E. Vaillancourt ◽  
Marco F. Duretto
Keyword(s):  
Bayesian Methods ◽  
Phylogenetic Trees ◽  
Taxonomic Status ◽  
Its Region ◽  
Population Level ◽  
Molecular Techniques ◽  
The Past ◽  
Single Well ◽  
Single Genus ◽  
Taxonomic Confusion

In the past decade, two major classification schemes of the subtribe Pterostylidinae have resulted in taxonomic confusion because a single well known genus was split into a large number of new genera and subgenera, many of which are difficult to discriminate accurately. These classifications have not been accepted widely among systematists because of poor phylogenetic support for several genera. Analyses of the internal transcribed spacer (ITS) region of nuclear rDNA in a large number of species and samples facilitate further clarification of the relationships within the Pterostylidinae. The phylogenetic trees were reconstructed using parsimony and Bayesian methods. These phylogenetic trees indicate that subtribe Pterostylidinae is monophyletic, and support the concept of a single genus, Pterostylis R.Br. sensu lato within the Pterostylidinae. Two clades representing subgenera correlate with the morphology of the lateral sepals, whereas several of the previously erected genera consistently have poor support. The proposed subgenera are divided further into 10 sections. Several closely related taxa with identical ITS sequences require further scrutiny by population-level molecular techniques to determine their taxonomic status.

Single- to Few-Layered, Graphene-Based Separation Membranes

2018 ◽  
Vol 9 (1) ◽  
pp. 17-39 ◽  
Author(s):  
Fanglei Zhou ◽  
Mahdi Fathizadeh ◽  
Miao Yu
Keyword(s):  
Model Systems ◽  
Two Dimensional ◽  
Transport Mechanisms ◽  
Membrane Structures ◽  
Large Area ◽  
Material Synthesis ◽  
Science And Engineering ◽  
Separation Potential ◽  
Transport Pathways ◽  
Separation Membranes

Two-dimensional, graphene-based materials have attracted great attention as a new membrane building block, primarily owing to their potential to make the thinnest possible membranes and thus provide the highest permeance for effective sieving, assuming comparable porosity to conventional membranes and uniform molecular-sized pores. However, a great challenge exists to fabricate large-area, single-layered graphene or graphene oxide (GO) membranes that have negligible undesired transport pathways, such as grain boundaries, tears, and cracks. Therefore, model systems, such as a single flake or nanochannels between graphene or GO flakes, have been studied via both simulations and experiments to explore the transport mechanisms and separation potential of graphene-based membranes. This article critically reviews literature related to single- to few-layered graphene and GO membranes, from material synthesis and characteristics, fundamental membrane structures, and transport mechanisms to potential separation applications. Knowledge gaps between science and engineering in this new field and future opportunities for practical separation applications are also discussed.

Money, Morphology and Molecules. Some comments on Wortley, Bennett and Scotland (2002), Taxonomy and phylogeny reconstruction: two distinct research agendas in systematics. (see p. 335 of this issue)

2002 ◽  
Vol 59 (3) ◽  
pp. 451-457 ◽  
Author(s):  
P. F. STEVENS
Keyword(s):  
Molecular Systematics ◽  
Large Scale ◽  
Species Level ◽  
Molecular Techniques ◽  
Morphological Data ◽  
Phylogeny Reconstruction ◽  
Reasonable Time ◽  
The Past ◽  
Short Time ◽  
Made In

The state of systematics, for convenience here divided into taxonomy (the delimitation, description and inventory of species) and phylogeny reconstruction, is evaluated. Molecular systematics may seem overemphasized, but the resulting gains made in our understanding of relationships in a relatively short time are very considerable. Although morphological data currently play only a limited role in detecting large-scale phylogenetic pattern, the analysis by Wortley et al. of the role morphology has played in the past is not easily interpreted. At species level, it is unclear what effect molecular techniques will have on our understanding of species limits, but it is likely to be considerable. Although taxonomy is both essential and underfunded, there seems little point in asking for more money until we can justify the limits of the species we describe more clearly and until we have cleared up the impediments that so much slow the practice of taxonomy. Business cannot remain as usual if any of the grand inventory projects we have started are to be finished within a reasonable time, or even to be of much use when they are.

Diverse mechanisms for body fluid regulation in teleost fishes

2014 ◽  
Vol 307 (7) ◽  
pp. R778-R792 ◽  
Author(s):  
Yoshio Takei ◽  
Junya Hiroi ◽  
Hideya Takahashi ◽  
Tatsuya Sakamoto
Keyword(s):  
Body Fluid ◽  
Plasma Osmolality ◽  
The Body ◽  
Fluid Composition ◽  
Teleost Fishes ◽  
Endocrine Control ◽  
Ion Regulation ◽  
Teleost Species ◽  
Fluid Regulation ◽  
Body Fluid Regulation

Teleost fishes are the major group of ray-finned fishes and represent more than one-half of the total number of vertebrate species. They have experienced in their evolution an additional third-round whole genome duplication just after the divergence of their lineage, which endowed them with an extra adaptability to invade various aquatic habitats. Thus their physiology is also extremely diverse compared with other vertebrate groups as exemplified by the many patterns of body fluid regulation or osmoregulation. The key osmoregulatory organ for teleosts, whose body fluid composition is similar to mammals, is the gill, where ions are absorbed from or excreted into surrounding waters of various salinities against concentration gradients. It has been shown that the underlying molecular physiology of gill ionocytes responsible for ion regulation is highly variable among species. This variability is also seen in the endocrine control of osmoregulation where some hormones have distinct effects on body fluid regulation in different teleost species. A typical example is atrial natriuretic peptide (ANP); ANP is secreted in response to increased blood volume and acts on various osmoregulatory organs to restore volume in rainbow trout as it does in mammals, but it is secreted in response to increased plasma osmolality, and specifically decreases NaCl, and not water, in the body of eels. The distinct actions of other osmoregulatory hormones such as growth hormone, prolactin, angiotensin II, and vasotocin among teleost species are also evident. We hypothesized that such diversity of ionocytes and hormone actions among species stems from their intrinsic differences in body fluid regulation that originated from their native habitats, either fresh water or seawater. In this review, we summarized remarkable differences in body fluid regulation and its endocrine control among teleost species, although the number of species is still limited to substantiate the hypothesis.

Geochemistry and pollution

1979 ◽  
Vol 288 (1026) ◽  
pp. 179-184
Keyword(s):  
Trace Metals ◽  
Pollution Control ◽  
National Science Foundation ◽  
State Agencies ◽  
Transport Pathways ◽  
The Past ◽  
Pollution Research ◽  
National Science ◽  
National Science Foundation Research ◽  
Research Findings

During the past 7 years, the National Science Foundation-Research Applied to National Needs (R. A. N. N.) programme has supported extensive interdisciplinary research concerned with Pb, Cd and other hazardous trace metals. Various aspects of geochemistry and pollution research at the universities of Missouri, Illinois, Colorado State and Purdue are presented and summarized. The transport, pathways and distribution of Pb, Cd and other trace metals are discussed and the utilization of research findings by government and state agencies for the development of standards and by industries for pollution control are presented.

Sign in / Sign up

Export Citation Format

Share Document