Biology subjects

Horak, P.

Publications and source records attributed to Horak, P..

3 recordsLinked to original sources

bioRxiv2021

Differential proteomic analysis of laser-microdissected penetration glands of avian schistosome cercariae with a focus on proteins involved in host invasion

Schistosome invasive stages, cercariae, leave intermediate snail hosts, penetrate the skin of definitive hosts, and transform to schistosomula migrating to final localization. During invasion, cercariae employ histolytic and other bioactive products of specialized holocrine secretory cells - postacetabular (PA) and circumacetabular (CA) penetration glands. Although several studies attempted to characterize protein composition of the in vitro induced gland secretions in Schistosoma mansoni and Schistosoma japonicum, the results were inconsistent and dependent on the method of sample collection and processing. Products of both gland types mixed during their secretion did not allow localization of identified proteins to a particular gland. Here we compared proteomes of separately isolated cercarial gland cells of the avian schistosome Trichobilharzia szidati employing laser-assisted microdissection and shotgun LC-MS/MS, thus obtaining the largest dataset so far concerning the representation and localization of cercarial penetration gland proteins. We optimized the methods of sample processing with cercarial bodies (heads) first. Alizarin-pre-stained, chemically non-fixed samples provided optimal results of MS analyses, and enabled distinguishing PA and CA glands for microdissection. Using 7.5 x 106 m3 sample volume per gland replicate, we identified 3347 peptides assigned to 792 proteins, from which 461 occurred in at least 2 of 3 replicates in either gland type (PA = 455, 40 exclusives; CA = 421, 6 exclusives; 60 proteins differed significantly in their abundance between the glands). Peptidases of 5 catalytic types accounted for ca. 8 % and 6 % of reliably identified proteins in PA and CA glands, respectively. Invadolysin, nardilysin, cathepsins B2 and L3, and elastase 2b orthologs were the major gland endopeptidases. Two cystatins and a serpin were highly abundant peptidase inhibitors in the glands. CA glands were rich in venom allergen-like proteins. The assembled total cercarial body proteome included 1631 identified proteins and revealed additional interesting factors possibly related to tissue invasion. HighlightsO_LIProteomes of two penetration gland types in schistosome cercariae greatly differ C_LIO_LIPostacetabular glands possess 40 unique proteins and are abundant in hydrolases C_LIO_LICircumacetabular glands posses 6 unique proteins and are rich in VAL proteins C_LIO_LIPeptidases make up 8 % of postacetabular and 6 % of circumacetabular gland proteins C_LIO_LICercarial elastase is unique to circumacetabular glands of Trichobilharzia szidati C_LI Note: Supplementary data associated with this article All supplementary data files can be accessed from the following link: http://www.helminthology.cz/supplementary_files.html

bioinformatics↗

bioRxiv2021

Evolution of the open-access CIViC knowledgebase is driven by the needsof the cancer variant interpretation community

CIViC (Clinical Interpretation of Variants in Cancer; civicdb.org) is a crowd-sourced, public domain knowledgebase composed of literature-derived evidence characterizing the clinical utility of cancer variants. As clinical sequencing becomes more prevalent in cancer management, the need for cancer variant interpretation has grown beyond the capability of any single institution. With nearly 300 contributors, CIViC contains peer-reviewed, published literature curated and expert-moderated into structured data units (Evidence Items) that can be accessed globally and in real time, reducing barriers to clinical variant knowledge sharing. We have extended CIViCs functionality to support emergent variant interpretation guidelines, increase interoperability with other variant resources, and promote widespread dissemination of structured curated data. To support the full breadth of variant interpretation from basic to translational, including integration of somatic and germline variant knowledge and inference of drug response, we have enabled curation of three new evidence types (predisposing, oncogenic and functional). The growing CIViC knowledgebase distributes clinically-relevant cancer variant data currently representing >2500 variants in >400 genes from >2800 publications.

genomics↗

bioRxiv2021

Antibiotic treatment increases yellowness of carotenoid feather coloration in greenfinches (Chloris chloris)

Carotenoid plumage coloration is an important signal of quality, and plays an important role in mate choice in many bird species. However, it remains unclear what mechanism makes carotenoids an honest signal. Here, we test the hypothesis that carotenoid plumage coloration might indicate gut health. Parasitic and microbial infections can affect nutrient absorption due to decreased gut surface or by altered gut microbiome. We took an advantage of a naturally occurring coinfection of parasites inhabiting the upper and lower portions of the digestive track to distinguish between the direct and indirect effects of parasites on carotenoid acquisition. Protozoan coccidian intestinal parasites are widespread in greenfinches (Chloris chloris) and the majority of greenfinches are infected in nature. Trichomonosis is an emerging disease of the upper digestive track that causes high mortality among greenfinches. We captured wild greenfinches (N=71) and administered anticoccidial medication toltrazuril (TOLTRA) to one group, antibiotic metronidazole (METRO) that is also effective for treating Trichomonas gallinea, to the second group, and third group received no medication. In the METRO group, feathers grown during the experiment had significantly higher chroma of yellow parts, but there was no effect of TOLTRA on feather chroma. These results suggest that METRO increased the efficiency of carotenoid modification or deposition to the feathers rather than nutrient acquisition, and/or freed energy resources that could be invested in coloration. Alternatively, in accordance with shared pathway hypothesis, increase in efficiency of vital cellular processes might have occurred, as many microbial metabolites can modulate mitochondrial and immune function.

ecology↗