56 research outputs found
The role of C-type lectin-like domain genes in C. elegans immunity
No full textC-type lectin-like domain (CTLD) proteins are mainly known for their crucial roles in vertebrate immunity acting either as pattern recognition receptors or antimicrobial peptides. In invertebrates the exact immune function of CTLD proteins is less described despite of the abundance of their encoding genes in many metazoan genomes. Caenorhabditis elegans particularly stands out for its enormous set of diversified CTLD proteins. Surprisingly, their exact contribution to C. elegans immunity still remains elusive.
During my PhD I systematically screened the CTLD gene (clec) repertoire of C. elegans to identify genes that are involved in the defense against the two pathogens Pseudomonas aeruginosa and Bacillus thuringiensis (BT). Unexpectedly, in the tested mutants clec-knock-out led equally to susceptibility and resistance to infection, indicating that clec genes mediate both immune activation and suppression. Resistance of clec mutants on BT could partially be explained by enhanced pathogen avoidance behavior. We could confirm for the clec gene C54G4.4 that it negatively regulates behavioral immune responses and thus demonstrated that beside a potential contribution to the physiological, clec genes might also function in behavioral immunity.
In parallel we analyzed the expression of clec genes upon infection and stress. We identified clec-4 as another interesting candidate due to its highly up-regulated profile upon exposure to many pathogens and stresses. Surprisingly, the clec-4 mutant showed resistance towards BT infection, suggesting a function in negative regulation of the immune response. We further examined the role of a co-expressed clec-4 paralog, clec-41, which was required for defense against BT and suppressed the resistance phenotype of the clec 4 mutant. These findings give hint to a complex regulation network of interacting clec genes.
Taken together, our work is the first step towards a more detailed analysis of the exact clec function in immunity
Effector and regulator: Diverse functions of C. elegans C-type lectin-like domain proteins
No full textIn C. elegans, 283 clec genes encode a highly diverse family of C-type lectin-like domain (CTLD) proteins. Since vertebrate CTLD proteins have characterized functions in defense responses against pathogens and since expression of C. elegans clec genes is pathogen-dependent, it is generally assumed that clec genes function in C. elegans immune defenses. However, little is known about the relative contribution and exact function of CLEC proteins in C. elegans immunity. Here, we focused on the C. elegans clec gene clec-4, whose expression is highly upregulated by pathogen infection, and its paralogs clec-41 and clec-42. We found that, while mutation of clec-4 resulted in enhanced resistance to the Gram-positive pathogen Bacillus thuringiensis MYBt18247 (Bt247), inactivation of clec-41 and clec-42 by RNAi enhanced susceptibility to Bt247. Further analyses revealed that enhanced resistance of clec-4 mutants to Bt247 was due to an increase in feeding cessation on the pathogen and consequently a decrease in pathogen load. Moreover, clec-4 mutants exhibited feeding deficits also on non-pathogenic bacteria that were in part reflected in the clec-4 gene expression profile, which overlapped with gene sets affected by starvation or mutation in nutrient sensing pathways. However, loss of CLEC-4 function only mildly affected life-history traits such as fertility, indicating that clec-4 mutants are not subjected to dietary restriction. While CLEC-4 function appears to be associated with the regulation of feeding behavior, we show that CLEC-41 and CLEC-42 proteins likely function as bona fide immune effector proteins that have bacterial binding and antimicrobial capacities. Together, our results exemplify functional diversification within clec gene paralogs. © 2021 Pees et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Enhanced behavioral immune defenses in a C. elegans C-type lectin-like domain gene mutant
No full textKretania sephirus
No full textKretania sephirus (Frivaldsky, 1835) —There are no published records for this species in Montenegro, although it occurs in the neighbouring countries of Serbia (Jakšić et al. 2013) and Albania (Verovnik & Popović 2013). The author observed the species in the Kučka Krajina mountain range (Fig. 4.1 and 4.3), flying in meadows near Veruša on June 13th 2017, and in the company of Martin Gascoigne-Pees at Mt. Volušnica and on the Čakor pass (Fig. 4.2 and Fig. 5) in the Prokletije mountain range on July 10th and 13th 2017. The species was relatively common and males were seen mud puddling, while females remained near the host plant, Astragalus sp.Published as part of Franeta, Filip, 2018, Checklist of the butterflies (Lepidoptera: Papilionoidea) of Montenegro, pp. 128-148 in Zootaxa 4392 (1) on page 138, DOI: 10.11646/zootaxa.4392.1.6, http://zenodo.org/record/119549
Cupido alcetas
No full textCupido alcetas (Hoffmannsegg, 1804) —Only one published record for this species exists. Müting (1973) reported the species for the area around Budva, where the author has undertaken many surveys and has only observed Cupido argiades Pallas, a species that is not mentioned in Müting’s paper. This fact would suggest a questionable determination by Müting. However, several worn specimens of C. alcetas were observed by Franeta & Gascoigne-Pees in the Đalovića gorge on July 14th 2017. The species is probably very rare in Montenegro and most likely only inhabits the very north of the country.Published as part of Franeta, Filip, 2018, Checklist of the butterflies (Lepidoptera: Papilionoidea) of Montenegro, pp. 128-148 in Zootaxa 4392 (1) on page 138, DOI: 10.11646/zootaxa.4392.1.6, http://zenodo.org/record/119549
Erebia rhodopensis Nicholl 1900
No full textErebia rhodopensis Nicholl, 1900 —A Balkan endemic, present in Bulgaria (Abadjiev 2001), Macedonia (Melovski 2002), Serbia (Jakšić et al. 2013), Albania (Verovnik & Popović 2013) and Greece (Pamperis 2009). The species was recorded for Montenegro from the Čakor mountain pass, on the Prokletije mountains (Jakšić & Pešić 1995; Jakšić 2001, 2003b). The author in the company of Martin Gascoigne-Pees observed one male specimen on Mt. Bogićevica in the Prokletije mountain range on July 12th 2017.Published as part of Franeta, Filip, 2018, Checklist of the butterflies (Lepidoptera: Papilionoidea) of Montenegro, pp. 128-148 in Zootaxa 4392 (1) on page 143, DOI: 10.11646/zootaxa.4392.1.6, http://zenodo.org/record/119549
Women and genital cosmetic surgery
No full textThis Issues Paper critically explores female genital cosmetic surgery in the Victorian context: to better understand what it is, who is undertaking it, and their reasons for doing so. The incidence of female genital cosmetic surgery appears to be increasing. This trend has been the subject of substantial analysis and opinion, but there is a lack of rigorous evidence on risks, efficacy, complications, and patient satisfaction. This Issues Paper considers how both individual and sociocultural factors are likely to contribute to the emerging trend, and how professional bodies, health professionals, and advocates might respond. It is intended as a starting point for further conversation, evidence-gathering, and action
Table_2_Preconditioning With Natural Microbiota Strain Ochrobactrum vermis MYb71 Influences Caenorhabditis elegans Behavior.xlsx
No full textIn comparison with the standard monoxenic maintenance in the laboratory, rearing the nematode Caenorhabditis elegans on its natural microbiota improves its fitness and immunity against pathogens. Although C. elegans is known to exhibit choice behavior and pathogen avoidance behavior, little is known about whether C. elegans actively chooses its (beneficial) microbiota and whether the microbiota influences worm behavior. We examined eleven natural C. elegans isolates in a multiple-choice experiment for their choice behavior toward four natural microbiota bacteria and found that microbiota choice varied among C. elegans isolates. The natural C. elegans isolate MY2079 changed its choice behavior toward microbiota isolate Ochrobactrum vermis MYb71 in both multiple-choice and binary-choice experiments, in particular on proliferating bacteria: O. vermis MYb71 was chosen less than other microbiota bacteria or OP50, but only after preconditioning with MYb71. Examining escape behavior and worm fitness on MYb71, we ruled out pathogenicity of MYb71 and consequently learned pathogen avoidance behavior as the main driver of the behavioral change toward MYb71. The change in behavior of C. elegans MY2079 toward microbiota bacterium MYb71 demonstrates how the microbiota influences the worm’s choice. These results might give a baseline for future research on host–microbiota interaction in the C. elegans model.</p
DataSheet_1_Preconditioning With Natural Microbiota Strain Ochrobactrum vermis MYb71 Influences Caenorhabditis elegans Behavior.pdf
No full textIn comparison with the standard monoxenic maintenance in the laboratory, rearing the nematode Caenorhabditis elegans on its natural microbiota improves its fitness and immunity against pathogens. Although C. elegans is known to exhibit choice behavior and pathogen avoidance behavior, little is known about whether C. elegans actively chooses its (beneficial) microbiota and whether the microbiota influences worm behavior. We examined eleven natural C. elegans isolates in a multiple-choice experiment for their choice behavior toward four natural microbiota bacteria and found that microbiota choice varied among C. elegans isolates. The natural C. elegans isolate MY2079 changed its choice behavior toward microbiota isolate Ochrobactrum vermis MYb71 in both multiple-choice and binary-choice experiments, in particular on proliferating bacteria: O. vermis MYb71 was chosen less than other microbiota bacteria or OP50, but only after preconditioning with MYb71. Examining escape behavior and worm fitness on MYb71, we ruled out pathogenicity of MYb71 and consequently learned pathogen avoidance behavior as the main driver of the behavioral change toward MYb71. The change in behavior of C. elegans MY2079 toward microbiota bacterium MYb71 demonstrates how the microbiota influences the worm’s choice. These results might give a baseline for future research on host–microbiota interaction in the C. elegans model.</p
- …
