Biology subjects

Zurovec, M.

Publications and source records attributed to Zurovec, M..

4 recordsLinked to original sources

bioRxiv2024

Dominant suppressor genes of p53-induced apoptosis in Drosophila melanogaster

Apoptosis, the programmed cell death, is responsible for the removal of cells seriously damaged or unwanted in development. A major function of apoptosis is the removal of cells which suffered oncogenic mutations, thereby preventing cancerous transformation. By making use of the DEP transposon, a P element derivative made in our laboratory, we made an insertional mutagenesis screen in Drosophila melanogaster to identify genes which, when overexpressed, suppress the p53-activated apoptosis. The DEP element has Gal4-activatable, outward-directed UAS-promoters at both ends which can be deleted separately in vivo. In the DEP insertion mutants, we used the GMR-Gal4 driver to induce transcription from both UAS-promoters and tested the suppression effect on the apoptotic rough eye phenotype generated by an activated UAS-p53 transgene. By DEP insertions, seven genes were identified which suppressed the p53-induced apoptosis. In four mutants, the suppression effect was resulted by single genes activated by one UAS-promoter (Pka-R2, Rga, crol, Spt5). In the other three (Orct2, Polr2M, stg), deleting either UAS-promoter eliminated the suppression effect. In qPCR experiments we found that the genes in the vicinity of the DEP insertion also showed an elevated expression level. This suggested an additive effect of the nearby genes on suppressing apoptosis. In the eucaryotic genomes there are co-expressed gene clusters. Three of the DEP insertion mutants are included and two are in close vicinity of separate co-expressed gene clusters. This raises the possibility that the activity of some of the genes in these clusters may help the suppression of the apoptotic cell death.

genetics↗

bioRxiv2023

Unravelling the complexity of silk sericins: P150/sericin 6 is a new silk gene in Bombyx mori

Sericins are a small family of highly divergent proteins that serve as adhesives and coatings for silk fibers and are produced in the middle part of the silk gland. So far, five genes encoding sericin proteins have been found in Bombyx mori. Sericins 1 and 3 are responsible for silk adhesion in the cocoon, while sericins 2, 4, and 5 are present in non-cocoon spun silk of younger larvae (including the early last instar). We found a new gene, which we named P150/sericin 6, which appears to be an ortholog of the sericin-like protein previously found in Galleria mellonella. The B. mori sequence of the P150/sericin 6 ORF was previously incorrectly predicted and assigned to two smaller, uncharacterized genes. We present a new P150/sericin 6 gene model and show that it encodes a large protein of 467 kDa. It is characterized by repeats with a high proportion of threonine residues and a short conserved region with a cysteine knot motif (CXCXCX) at the C-terminus. Expression analysis has shown that B. mori P150/ser6 has low transcriptional level in contrast to its G. mellonella homolog. We also discuss the synteny of homologous genes on corresponding chromosomes between moth species and possible phylogenetic relationships between P150/ser6 and cysteine knot mucins. Our results improve our understanding of the evolutionary relationships between adhesion proteins in different lepidopteran species.

molecular biology↗

bioRxiv2023

Ghost W chromosomes and unique genome architecture in ghost moths of the family Hepialidae

The classical model of sex chromosome evolution has been recently challenged in moths and butterflies (Lepidoptera). According to the current hypothesis, the adoption of a supernumerary chromosome may have driven the transition from the Z0 to the WZ sex chromosome system in females. However, the evolutionary history of the W chromosome remains enigmatic, especially in the early-diverging lepidopteran lineages. In ghost moths of the family Hepialidae, one of the most basal lepidopteran clades, there is conflicting evidence regarding their sex chromosomes. In this study, we aimed to clarify the status of the hepialid W chromosome. Using cytogenetics and genomics, we investigated the karyotype, sex chromosomes, genome size and repeatome of multiple ghost moth species and reconstructed basic phylogenetic relationships in the group. Our data show that Hepialidae have unusually large genomes (reaching up to 1C = 3 Gb) and are the oldest known lepidopteran clade with a W chromosome. However, the W does not form a typical heterochromatin body in polyploid nuclei, known as sex chromatin, previously employed to detect the presence of W chromosomes across Lepidoptera. Moreover, in some species, the W does not exhibit distinct repeat content and can escape detection via methods that rely on W-specific sequences. Analysis of the Z chromosome confirmed highly conserved gene content, arguing for a possible origin of the hepialid W chromosome from a B chromosome. We hypothesize that the mechanism underlying the formation of sex chromatin could be used in future research to study the origin of the W chromosome.

genomics↗

bioRxiv2019

Adenosine receptor and its downstream target mod(mdg4) modify the pathogenic effects of polyglutamine in a Drosophila model of Huntington's disease

Adenosine (Ado) is an important signaling molecule involved in stress responses. Studies in mammalian models have shown that Ado regulates signaling mechanisms involved in danger-sensing and tissue-protection. Yet, little is known about the role of Ado signaling in Drosophila. In the present study, we observed lower extracellular Ado concentration and suppressed expression of Ado transporters in flies expressing mutant huntingtin protein (mHTT). We altered Ado signaling using genetic tools and found that the overexpression of Ado metabolic enzymes, as well as the suppression of Ado receptor (AdoR) and transporters (ENTs), were able to minimize mHTT-induced mortality. We also identified the downstream targets of the AdoR pathway, the modifier of mdg4 (Mod(mdg4)) and heat-shock protein 70 (Hsp70), which carry out its function. Finally, we showed that a decrease in Ado signaling affect other Drosophila stress reactions, including paraquat and heat-shock treatments. Our study provides important insights into how Ado regulates stress responses in Drosophila.

genetics↗