The fall armyworm (S. frugiperda) has developed resistance to numerous insecticides and is currently considered one of the most destructive pests threatening global crop production. Consequently, the development of environmentally sustainable pest management strategies has become increasingly important. Insect-associated pathogenic bacteria represent a promising source of bioactive metabolites with potential insecticidal properties. In the present study, pathogenic bacteria associated with S. frugiperda were isolated and molecularly identified as Serratia marcescens strain INS420 based on 16 S rRNA gene sequencing. The secondary metabolites produced by this bacterium demonstrated significant insecticidal activity under both laboratory and field conditions. Metabolic profiling of the extracted compounds was performed using liquid chromatography–mass spectrometry (LC–MS) and gas chromatography–mass spectrometry (GC–MS), revealing the presence of several bioactive compounds, including diketopiperazines, fatty acids and their esters, squalene, phthalate derivatives, and a cardenolide. To gain insights into the potential mechanism of action, molecular docking simulations were conducted to evaluate the binding affinity of the identified metabolites with S. frugiperda acetylcholinesterase (AChE). Among the detected compounds, squalene and several fatty acid derivatives exhibited stable interactions within the active site of the enzyme, suggesting a possible inhibitory effect on AChE activity. Collectively, these findings demonstrate that S. marcescens associated with S. frugiperda produces metabolites with notable insecticidal potential and highlight insect-associated pathogenic bacteria as a valuable source of bioactive compounds for the sustainable management of fall armyworm.
Kreema A. El-Lebody, Ramy E. El-Ansary, Shaimaa A. Nour et al.· Scientific Reports· 0 citations
This research provides the first extensive breed‑pool whole‑genome sequencing (WGS) analysis across five Egyptian sheep populations: Barki (BAR), Rahmani (RAH), their crossbred offspring (CRS), Ossimi (OSI) and Awassi (AWI). To establish a genomic atlas of the genetic architecture of production and adaptation in Egyptian sheep, providing a baseline for future candidate gene discovery and conservation strategies. Through Illumina sequencing of 120 samples, we compiled a dataset exceeding 470 Gb, with mean coverage depths spanning 24.2x to 41.3x. Variant profiling, functional annotation, KEGG pathway analysis, and independent structural variant analysis were conducted. Phenotypic data were collected and validated through qRT-PCR gene expression analysis. Variant profiling revealed between 11.9 and 17.4 million SNPs per breed after stringent filtering. Heterozygosity patterns (population‑level estimates) differed substantially between groups, recorded at 60.41% in the CRS crossbred versus 74.92–85.01% in the purebred lines. Functional annotation identified conserved enrichment related to xenobiotic detoxification and lipid metabolism. KEGG pathway analysis prioritized the PPAR signalling pathway (map03320) and fatty acid metabolism (map01212) as highly significant (p < 0.0001). Independent structural variant analysis identified distinct genomic hotspots on chromosomes 2, 6 and 18, overlapping candidate genes; FABP4, KAP cluster and MSTN implicated in the regulation of fat deposition and muscle development. Phenotypic data confirmed a high degree of breed divergence (p < 0.001). RAH and CRS individuals reached higher body condition scores (BCS 4.31‑ 4.53) and increased fat deposition, whereas BAR was significantly leaner (BCS 2.53). The highest trimmed meat yields were observed in CRS (23.95 kg) and RAH (18.40 kg) (p < 0.001), with RAH also displaying the highest intramuscular fat content at 4.20%. qRT‑PCR validation showed elevated expression of lipogenic genes (ACACA, FASN and FABP4) in fat‑tailed breeds and differential expression of myogenic regulators (MSTN and IGF‑1) correlating with muscularity variations. The current findings establish a genomic atlas for the genetic architecture of production and adaptation in Egyptian sheep, providing a baseline for future genetic and conservation strategies. Formal selection signature analyses, such as XP‑EHH and iHS are recommended for subsequent studies.
Nada N A M Hassanine, Ali H. Amin, E. Hafez et al.· BMC Biotechnology· 0 citations