Project description:Species classified in Penicillium sect. Chrysogena are primary soil-borne and the most well-known members are P. chrysogenum and P. nalgiovense. Penicillium chrysogenum has received much attention because of its role in the production on penicillin and as a contaminant of indoor environments and various food and feedstuffs. Another biotechnologically important species is P. nalgiovense, which is used as a fungal starter culture for the production of fermented meat products. Previous taxonomic studies often had conflicting species circumscriptions. Here, we present a multigene analysis, combined with phenotypic characters and extrolite data, demonstrating that sect. Chrysogena consists of 18 species. Six of these are newly described here (P. allii-sativi, P. desertorum, P. goetzii, P. halotolerans, P. tardochrysogenum, P. vanluykii) and P. lanoscoeruleum was found to be an older name for P. aethiopicum. Each species produces a unique extrolite profile. The species share phenotypic characters, such as good growth on CYA supplemented with 5 % NaCl, ter- or quarterverticillate branched conidiophores and short, ampulliform phialides (< 9 ?m). Conidial colours, production of ascomata and ascospores, shape and ornamentation of conidia and growth rates on other agar media are valuable for species identification. Eight species (P. allii-sativi, P. chrysogenum, P. dipodomyis, P. flavigenum, P. nalgiovense, P. rubens, P. tardochrysogenum and P. vanluykii) produce penicillin in culture.
Project description:Seven cyclic depsipeptides were isolated from Hapsidospora irregularis and structurally characterized as the calcium channel blocker leualacin and six new analogues based on the NMR and HRESIMS data. These new compounds were named leualacins B-G. The absolute configurations of the amino acids and 2-hydroxyisocaproic acids were determined by recording the optical rotation values. Biological studies showed that calcium influx elicited by leualacin F in primary human lobar bronchial epithelial cells involves the TRPA1 channel. Through genome sequencing and targeted gene disruption, a noniterative nonribosomal peptide synthetase was found to be involved in the biosynthesis of leualacin. A comparison of the structures of leualacin and its analogues indicated that the A2 and A4 domains of the leualacin synthetase are substrate specific, while A1, A3, and A5 can accept alternative precursors to yield new molecules.
Project description:BmN4 cells are cultured cells derived from Bombyx mori ovaries and widely used to study transposon silencing by PIWI-interacting RNAs (piRNAs). A high-accurate genome sequence of BmN4 cells is required to analyze the piRNA pathway using RNA-seq. The genome sequence of BmN4 cells was assembled using Pacific Biosciences (PacBio) HiFi and Oxford Nanopore technology Ultralong (ONT-UL) reads. Microscopic observation and image analysis showed that BmN4 cells were octoploid on average, and the number of chromosomes per cell was highly variable. We concluded the haplotype-resolved assembly of such a complex genome would be difficult; therefore, we assembled a consensus genome sequence. RNA-seq analysis of Siwi knockdown cells also revealed that Siwi-piRISC may target Countdown (Cd), an LTR retrotransposon. By comparing the consensus genome sequence with the reads, we identified differences between haplotypes, particulary structural variants, suggesting that some transposons, including Countdown, increased their copy number in BmN4 cells.