[
Dev Biol,
1981]
In the present investigation we have examined the titer of poly(A) in squashes prepared from oocytes and variously staged embryos of the nematode Caenorhabditis elegans var. Bristol (N2) by in situ hybridization with a [3H]poly(U) probe. As shown by control experiments in which squashes were treated with dilute alkali and RNase prior to in situ hybridization, this probe interacts specifically with poly(A) sequences which are presumably present in poly(A)+ RNA. Using this method and saturating concentrations of the probe, it was shown that isolated oocytes and embryos up to the 125-cell stage exhibited substantial levels of poly(A) in their cytoplasms but no detectable amounts of this sequence within their nuclei. Nuclear poly(A) was first detected at the 90-cell stage and afterward increased at a linear rate through the 550-cell stage. The titer of total embryonic poly(A) also increased at a linear rate up to larval hatching. The results suggest that the major transcriptional effort for poly(A)+ RNA begins at the 90- to 125-cell stage of C. elegans embryogenesis and that the poly(A)+ RNA present in the cytoplasm prior to this time is primarily of maternal origin.
[
Parasitol Res,
1997]
An electron microscopy study was performed to evaluate the feasibility of the use of the anterior nerve ring of male Onchocerca volvulus for the assessment of early drug effects. Worms were exposed to new and known compounds at reasonable concentrations of 1 microM and less for 6, 12, 18, and 36 h in an established in vitro system. The anterior end of the filariae up to a length of 1 mm was examined and the morphological findings were compared with motility and reduction of a tetrazolium sat to formazan by live but not dead worms. The nerve fibers were more susceptible to the chemotherapeutic intervention then the other tissues in the anteriormost part of the worms. The alterations depended on the duration of exposure and the chemical nature of the compounds used. Morphological changes in the nervous tissue and the inhibition of motility and formazan production corresponded well for the arsenical mel w, used as an active standard, two pyrimidinyl-guanidines (PD 105482 and PD 105666), and an imidazolinylhydrazone (WR 251993).
Varady M, Raisova Stuchlikova L, Vogel H, Dimunova D, Skalova L, Lamka J, Laing R, Matouskova P, Lecova L, Vokal I, Nguyen LT, Kellerova P, Szotakova B
[
Int J Parasitol Drugs Drug Resist,
2018]
UDP-glycosyltransferases (UGT), catalysing conjugation of UDP-activated sugar donors to small lipophilic chemicals, are widespread in living organisms from bacteria to fungi, plant, or animals. The progress of genome sequencing has enabled an assessment of the UGT multigene family in Haemonchus contortus (family Trichostrongylidae, Nematoda), a hematophagous gastrointestinal parasite of small ruminants. Here we report 32 putative UGT genes divided into 15 UGT families. Phylogenetic analysis in comparison with UGTs from Caenorhabditis elegans, a free-living model nematode, revealed several single member homologues, a lack of the dramatic gene expansion seen in C. elegans, but also several families (UGT365, UGT366, UGT368) expanded in H. contortus only. The assessment of constitutive UGT mRNA expression in H. contortus adults identified significant differences between females and males. In addition, we compared the expression of selected UGTs in the drug-sensitive ISE strain to two benzimidazole-resistant strains, IRE and WR, with different genetic backgrounds. Constitutive expression of UGT368B2 was significantly higher in both resistant strains than in the sensitive strain. As resistant strains were able to deactivate benzimidazole anthelmintics via glycosylation more effectively then the sensitive strain, UGT368B2 enhanced constitutive expression might contribute to drug resistance in H. contortus.
[
PLoS Comput Biol,
2015]
Separases are large proteins that mediate sister chromatid disjunction in all eukaryotes. They belong to clan CD of cysteine peptidases and contain a well-conserved C-terminal catalytic protease domain similar to caspases and gingipains. However, unlike other well-characterized groups of clan CD peptidases, there are no high-resolution structures of separases and the details of their regulation and substrate recognition are poorly understood. Here we undertook an in-depth bioinformatical analysis of separases from different species with respect to their similarity in amino acid sequence and protein fold in comparison to caspases, MALT-1 proteins (mucosa-associated lymphoidtissue lymphoma translocation protein 1) and gingipain-R. A comparative model of the single C-terminal caspase-like domain in separase from C. elegans suggests similar binding modes of substrate peptides between these protein subfamilies, and enables differences in substrate specificity of separase proteins to be rationalised. We also modelled a newly identified putative death domain, located N-terminal to the caspase-like domain. The surface features of this domain identify potential sites of protein-protein interactions. Notably, we identified a novel conserved region with the consensus sequence WWxxRxxLD predicted to be exposed on the surface of the death domain, which we termed the WR motif. We envisage that findings from our study will guide structural and functional studies of this important protein family.