Dengue Fever: A Viral Hemorrhagic Fever of Global Concern
Jagriti Narang, Manika Khanuja in Small Bite, Big Threat, 2020
Tissues such as muscle, diverticula, hindgut, and Malpighian tubules are not infected by DENV, which shows selective tissue tropism in insects as it has been reported in humans (Linthicum et al., 1996; Sriurairatna and Bhamarapravati, 1997). The well known mechanism of DENV entry is not clear yet due to the diversity in DENV cellular tropism both in vitro and in vivo. However there may be possibility that DENV enters inside the host cells by using receptor present at the surface of affected host cell class (Acosta et al., 2008). In 1989, Hase and his coworkers reported that DENV virions can penetrate the plasma membrane of the mosquito cells by interrupting the membrane formed at the adsorption sites. According to a study by Salas-Benito and del Angel, DENV-4 binds to two glycoproteins having MWs of 40,000 and 45,000 Da located at C6/C36 cell surface (Salas-Benito and del Angel, 1997). Angel and Joshi (2008) and Angel et al. (2014) explained the mechanism of association of 200 kDa protein found in the ovarian tissues of Aedes mosquito with the DENV Presence of this ovarian protein inhibits virus multiplication and circulates through the TOT route (Angel and Joshi, 2008; Angel et al., 2014). Transmission of DENV is on C6/C36 cells, and titer of particles of virus has been investigated by infectious center plaque titration or infectious center assays on BHK-15 cells (Diamond et al., 2000; Lambeth et al., 2005; Roche et al., 2000). In genus Aedes, it has been demonstrated that DENV and its receptors are present in different tissues of mosquito in diverse stages of its life cycle (Angel, 2012; Frier and Grimstad, 1983; Khin and Than, 1983; Rosen et al., 1983, 1987; Sriurairatna and Bhamarapravati, 1977).
Electro-Osmosis Surmounts High Water Potential Differences in Insects
Gheorghe Benga in Water Transport in Biological Membranes, 1989
Anatomy and ultrastructure of the recta differ considerably between various groups, and are often very intricate (cf. to the comprehensive review of Edney2). In Tenebrionidae, the “cryptonephridial complex”, an association of rectal tissue and the distal parts of the Malpighian tubules, dehydrates the feces and absorbs water vapor from the air. In Thysanura and flea larvae, water-vapor resorption is obviously the main function, if not the only one, of the anal sac or rectal sac respectively, because feces pass these segments quickly so that their lumen is usually filled with air.
The Anopheles vector
David A Warrell, Herbert M Gilles in Essential Malariology, 2017
In the mosquito, the initial phase of diuresis and nitrogen excretion occurs in the five malpighian tubules. The resultant fluid is discharged into the hind-gut, being modified in the rectum before being discharged from the anus as urine. The dog heart-worm, Dirofilaria, which occasionally infects humans, undergoes part of its development in the malpighian tubules of mosquitoes.
Pleiotropy of the Drosophila melanogaster foraging gene on larval feeding-related traits
Published in Journal of Neurogenetics, 2018
A. M. Allen, I. Anreiter, A. Vesterberg, S. J. Douglas, M. B. Sokolowski
Overall, this work represents a significant advance in how the foraging gene elicits its phenotypic effects in the larva. The expression patterns reported here can be used to generate new hypotheses about where foraging is required for other of its pleiotropic phenotypes. For example, foraging has previously been implicated in nutrient absorption in larvae (Kaun, Chakaborty-Chatterjee, & Sokolowski, 2008) and gut function in adults (Urquhart-Cronish & Sokolowski, 2014). The enterocytes and enteroendocrine cells reported here are important for absorption and digestion of ingested nutrients and visceral muscle may affect peristalsis of nutrients through the gut. foraging’s orthologue in mice is known to function in smooth muscle (Hofmann, Feil, Kleppisch, & Schlossmann, 2006; Hofmann et al., 2009; Lohmann, Vaandrager, Smolenski, Walter, & De Jonge, 1997) and it also affects gut passage time (Weber et al., 2007). The forpr3-Gal4 also drove expression in the Malpighian tubules. The tubules are vital for ion balance in the hemolymph, and foraging has been previously characterized for influencing adult Malpighian tubule secretion rate (MacPherson et al., 2004a, 2004b).
Simple techniques to study multifaceted diabesity in the fly model
Published in Toxicology Mechanisms and Methods, 2019
Nibedita Nayak, Monalisa Mishra
Drosophila fat body is a multifunctional tissue which shares similarity with the mammalian adipose tissue in the function of the nutritional sensor, response to immune, and storage of energy (Zhang and Xi 2015). It is found in both larvae and adult Drosophila body (Bharucha 2009). The dietary food taken up by the body is converted to triglycerides and is then stored as lipid droplet in the fat body, but when there is an energy deficit, this stored fat can be mobilized to target tissues through lipolysis (Athenstaedt and Daum 2006; Brasaemle 2007; Kühnlein 2011). When there is an energy demand, Drosophila triglycerol lipase, bummer (bmm) catalyze triglyceride to fatty acid, and this bmm has functional similarity with the human lipase (Zimmermann et al. 2004; Zechner et al. 2005). Other than the fat body, lipid droplets can be displayed in Drosophila gut, Malpighian tubules, and even larval imaginal discs (Kühnlein 2011; Palm et al. 2012).
How relevant are in vitro culture models for study of tick-pathogen interactions?
Published in Pathogens and Global Health, 2021
Cristiano Salata, Sara Moutailler, Houssam Attoui, Erich Zweygarth, Lygia Decker, Lesley Bell-Sakyi
Isolated organs from adult, and occasionally nymphal, ticks have been used in a variety of short- and long-term studies focusing on tick physiology, pathogen propagation and/or development, and tick-pathogen interactions. The earliest studies, carried out on fed nymphal and adult female organs (ovaries, salivary glands, midguts, and Malpighian tubules) from ticks of the genera Hyalomma and Rhipicephalus, demonstrated survival, determined by observation of peristalsis and examination of histological preparations, for 13–58 days in vitro [66]. Subsequent studies focussed on salivary glands; short-term organ cultures were used to unravel the mechanisms of salivation [67,68], and an elegant technique was developed for collection of saliva secreted by individually excised glands for up to 14 days in vitro [69]. Excised salivary glands, and occasionally other tissues, such as midgut, synganglion, ovaries, and Malpighian tubules, subsequently used in studies on pathogen metabolism, development, and interaction with host tissues [58,70–73], were reported to survive for, at most, 9–12 days. However, when co-cultivated with tick cell lines, adult organs from some tick species may maintain viability as shown by midgut peristalsis for up to four months (Bell-Sakyi, unpublished observations of unfed adult Dermacentor reticulatus organs co-cultivated with BME/CTVM23 cells).
Related Knowledge Centers
- Actin
- Calcium Oxalate
- Excretion
- Gastrointestinal Tract
- Hemolymph
- Microvillus
- Osmoregulation
- Tubule
- Solution
- Fat Body