scholarly journals Aquatic silk proteins in Chironomus: A review

2018 ◽  
Author(s):  
Leena J. Thorat ◽  
Bimalendu B. Nath
Keyword(s):  
Environmental Factors ◽  
Salivary Glands ◽  
Significant Role ◽  
Balbiani Ring ◽  
Silk Proteins ◽  
Pilot Studies ◽  
Chironomid Midges ◽  
Balbiani Rings ◽  
Literature Database

Silk proteins secreted by salivary glands in the dipteran insect, Chironomus play a significant role as proteinaceous adhesives for construction of underwater housing nests by larvae. To date, only three Chironomus species, C. tentans Fabricius, C. pallidivittatus Malloch and C. riparius Meigen have been explored for characterization of their aquatic silk protein. Genes coding for silk proteins are located on specific chromosomal ‘puffs’ called Balbiani rings as well as non-Balbiani ring regions.  Expression of these genes is closely regulated by developmental and hormonal alterations and environmental factors. Furthermore, pilot studies have postulated that silk proteins probably occur in diverse size classes grouped into large (~1000 kDa), intermediate (100-200 kDa) and small (≤100 kDa). Barring few preliminary reports that date back to the 1990s, the physical and bioproperties of silk from chironomid midges remain largely unknown, leading to paucity of updated information. This review was therefore aimed to compile existing literature database and to highlight the wide possibilities for commercialization of midge larval silk as a novel biopolymer.

scholarly journals Large-sized polysomes in Chironomus tentans salivary glands and their relation to Balbiani ring 75S RNA.

1977 ◽  
Vol 73 (1) ◽  
pp. 149-160 ◽  
Author(s):  
B Daneholt ◽  
K Anderson ◽  
M Fagerlind
Keyword(s):  
Salivary Glands ◽  
Messenger Rna ◽  
High Yield ◽  
Chironomus Tentans ◽  
Balbiani Ring ◽  
Rna Molecules ◽  
Large Size ◽  
Present Information ◽  
Balbiani Rings ◽  
Available Information

Polysomes from the salivary glands of Chironomus tentans were investigated to determine whether Balbiani ring 75S RNA is incorporated into polysomal structures, and thus probably acts as messenger RNA. A new extraction technique for obtaining ribonucleoproteins was applied that gives a high yield of polysomes with only moderate degradation of the cytoplasmic, high molecular weight RNA. The polysomes sedimented in a broad region (200-2,000S) with a peak value of about 700S, which suggested that they were partly of very large sizes. This was confirmed by visualization of the polysomes in the electron microscope: 400S polysomes contained mainly 11-16 ribosomes, and 1,500S polysomes about 60 ribosomes per polysome. However, polysomes containing 100 or more ribosomes were also observed. It was further established that most of the cytoplasmic 75S RNA was located in polysomes, preferentially in the most rapidly sedimenting ones. From the available information on Balbiani ring RNA in cytoplasm and the present demonstration of 75S RNA molecules in polysomes, it was concluded that at least some Balbiani ring RNA, generated as 75S RNA within the Balbiani rings, eventually enters polysomes without being measurably changed in size. The present information on the potential amino acid coding sequences in 75S RNA is discussed in relation to the large size of the polysomes observed.

scholarly journals 31.B. Workshop: Public health and urban design: an interdisciplinary approach to promote autism friendly environments

2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
◽  
Keyword(s):  
Public Health ◽  
Risk Factors ◽  
Environmental Factors ◽  
Built Environment ◽  
Urban Design ◽  
Significant Role ◽  
Prevalence Rates ◽  
Environmental Characteristics ◽  
The Relationship

Abstract Autism is a set of heterogeneous neurodevelopmental conditions, characterised by early-onset difficulties in social communication and restricted, repetitive behaviour and interests. The worldwide population prevalence is about 1% with an increasing incidence and prevalence rates. Autism affects more male than female individuals, and comorbidity is common (>70% have concurrent conditions). Determinants of these changes in incidence and prevalence rates may also be related to exposure to environmental factors and to modifications in diagnostic concepts and criteria. In spite of the uncertainty in determinants of incidence of autisms, there is evidence that environmental characteristics play a significant role both as autism risk factors and as potential obstacles that influence the capabilities of autonomously and fully “using” everyday spaces. The workshop aims to provide a framework on risk factors of autism and explore the relationship with the built environment, focusing on the quality of the everyday spaces and projecting the effects that it could have in the long term on achieving a desirable level of quality of life. The 11th Sustainable Development Goals of United Nations “Make cities inclusive, safe, resilient and sustainable” underlines the necessity of designing policies and projects acting to enhance and promote healthy cities and communities by addressing the needs of the most vulnerable groups of inhabitants. Herewith we bring together the discipline of Public Health and Urban Design to promote an interdisciplinary debate on a little explored topic investigating how the approaches adopted during childhood to promote the wellbeing of people with ASD can be related or strengthen by focusing also on built environment design intervention to pursue and reach the same objectives even during adulthood. The workshop will consist of four presentations. The first focuses on giving an overview on current knowledge of intervention for people with autism, presenting also criteria for evidence-based interventions. The second explores the relationship between autism and built environment by providing an exhaustive framework of the available research literature in order to identify a first set of spatial requirements for autism friendly cities. The third examines the impact of built environment on ASD users with the aim of developing a specific evaluation tool for healthcare spaces and best practices formulation according to the specific sensorial hypo- or hyper-activation of people with autism. Finally, the fourth reports the results of a two years Research & Development project called “GAP REDUCE” finalized at developing an Assistive Technology tool to support people with ASD, adult and high-functioning, to plan urban itineraries towards daily destinations. Key messages World's incidence of autism is about 1% with an increasing incidence whose determining rates may also be related to environmental factors and to modifications in diagnostic concepts and criteria. Environmental characteristics play a significant role also as potential obstacles that influence the capabilities of people with autism of autonomously and fully “using” everyday spaces.

Morphological and functional characterization of the thoracic portion of blowfly salivary glands

2008 ◽  
Vol 37 (5) ◽  
pp. 372-382 ◽  
Author(s):  
Cathleen Rotte ◽  
Bernd Walz ◽  
Otto Baumann
Keyword(s):  
Salivary Glands ◽  
Functional Characterization

scholarly journals A novel giant secretion polypeptide in Chironomus salivary glands: implications for another Balbiani ring gene.

1985 ◽  
Vol 101 (3) ◽  
pp. 1044-1051 ◽  
Author(s):  
W Y Kao ◽  
S T Case
Keyword(s):  
Amino Acid ◽  
Nucleotide Sequence ◽  
Salivary Glands ◽  
Cyanogen Bromide ◽  
Tryptic Peptide ◽  
Amino Acid Sequences ◽  
The Other ◽  
Balbiani Ring ◽  
Sequence Organization ◽  
Peptide Maps

Chironomus salivary glands contain a family of high Mr (approximately 1,000 X 10(3)) secretion polypeptides thought to consist of three components: sp-Ia, sp-Ib, and sp-Ic. The use of a new extraction protocol revealed a novel high Mr component, sp-Id. Results of a survey of individual salivary glands indicated that sp-Id was widespread in more than a dozen strains of C. tentans and C. pallidivittatus. Sp-Id was phosphorylated at Ser residues, and a comparison of cyanogen bromide and tryptic peptide maps of 32P-labeled polypeptides suggested that sp-Ia, sp-Ib, and sp-Id are comprised of similar but nonidentical tandemly repeated amino acid sequences. We concluded that sp-Id is encoded by an mRNA whose size and nucleotide sequence organization are similar to Balbiani ring (BR) mRNAs that code for the other sp-I components. Furthermore, parallel repression of sp-Ib and sp-Id synthesis by galactose led us to hypothesize that both of their genes exist within Balbiani ring 2.

Transcriptional characterization of the salivary glands of Ornithodoros brasiliensis (Acari: Argasidae)

2012 ◽  
Vol 29 ◽  
pp. S111
Author(s):  
Darci Moraes Barrosd Battesti ◽  
Ana Carolina Carmo Viegas ◽  
Leila A.B. Proenca ◽  
Luisa Viana Pevidor ◽  
Paulo Lee Ho ◽  
...  
Keyword(s):  
Salivary Glands

scholarly journals Microscopical characterization of the salivary glands of the carnivorous cephalaspidean Philinopsis depicta (Mollusca, Opisthobranchia)

2009 ◽  
Vol 15 (S3) ◽  
pp. 39-40
Author(s):  
A. Lobo-da-Cunha ◽  
I. Ferreira ◽  
G. Calado
Keyword(s):  
Salivary Glands ◽  
Secretory Cells ◽  
Apical Region ◽  
Ciliated Cells ◽  
Transmission Electron ◽  
Herbivorous Species ◽  
Small Clusters ◽  
The Relationship ◽  
Apical Vacuole

AbstractCephalaspideans are a group of opisthobranch gastropods comprising carnivorous and herbivorous species, allowing an investigation of the relationship between these diets and the morphofunctional features of the salivary glands.In this study, the salivary glands of the carnivorous cephalaspidean Philinopsis depicta were observed by light microscopy using semithin sections and by transmission electron microscopy. A central duct runs along the length of these thin ribbon-shaped glands dividing them in two halves, each formed by a single row of tubules perpendicularly attached to the central duct. The simple epithelium of the central duct and lateral tubes contains ciliated cells and two types of secretory cells, named granular cells and cells with apical vacuole (Fig. 1). A very thin outer layer of connective tissue covers the epithelium (Fig. 1). The ciliated cells are numerous but very thin, forming small clusters between secretory cells. The nucleus, several mitochondria and a few lysosomes are located in the apical region were the cells are wider. A very thin cytoplasmic stalk reaches the base of the epithelium and contains bundles of filaments in addition to some mitochondria.

Sign in / Sign up

Export Citation Format

Share Document