Biology subjects

Ferrelli, M. L.

Publications and source records attributed to Ferrelli, M. L..

5 recordsLinked to original sources

bioRxiv2026

Phagocytosis without mitochondria is a lineage trait of planctomycetal bacteria of prey

Phagocytosis is considered energetically out of reach for prokaryotes. Mitochondria-first models of eukaryogenesis therefore suggest a non-phagocytic archaeal host. Yet two recently described planctomycetes lack mitochondria and engulf entire bacteria. Whether this mode of predation is an oddity of two isolates or the hallmark of a bacterial lineage remained unresolved. Here, we report eight additional predatory Planctomycetota from three aquatic habitats. The ten cultured strains now span two classes of the phylum Planctomycetota,"Candidatus Uabimicrobiia" and one newly proposed class. Using engineered fluorescent prey, we show that nine strains internalize prey into fully sealed compartments whereas one digests its prey externally, a non-engulfing predator for comparison. The strains additionally divide by two distinct modes, however, not correlating with their feeding behavior. Sequence- and structure-based searches detect no eukaryotic phagocytosis protein conserved across the engulfing strains. The actin homologue previously proposed to mediate uptake occurs only in three engulfing strains. Routine engulfment by aerobic bacteria without mitochondria thus unsettles a premise of mitochondria-first models and reopens the question of which cell plans could have hosted the mitochondrial endosymbiont.

microbiology↗

bioRxiv2026

MicroRNAome of Spodoptera frugiperda in Response to SfMNPV Infection

Spodoptera frugiperda is one of the most important agronomical pests due to its migratory capacity and broad host range. Since it is resistant to several insecticides, novel control strategies are being explored to control it. In this way, Spodoptera frugiperda Multiple Nucleopolyhedrovirus, a natural pathogen, has been proposed for its biocontrol. In this work, we performed a small RNA-seq on uninfected larvae and larvae infected with SfMNPV to identify expressed miRNA, characterize them, and identify differentially expressed (DE) miRNA in the infected condition. We identified several known and putative novel miRNAs, some of which are encoded in multiple copies and may be expressed within miRNA clusters. We also found 13 DE miRNA, most of them previously reported, two of them are putative novel miRNAs identified in this work. We predicted miRNA targets and found that their putative biological role could be related with processes relevant to the infection such as proliferative and apoptotic pathways, cell cycle regulation, autophagy, DNA damage response (DDR), vesicle transport, cytoskeleton remodelling, JAK/STAT and Toll signaling pathway, and immune response activation, among others. Moreover, we observed that several of the putative targets were hub genes in a predicted protein - protein interaction network. Finally, we found DE miRNA putatively associated with the regulation of viral gene expression, suggesting they might have a role in modulating the infection. Our results contribute to better understanding the miRNA landscape in S. frugiperda, and their putative role upon SfMNPV infection.

molecular biology↗

bioRxiv2025

Proteomic Characterization of Spodoptera frugiperda Granulovirus Occlusion Bodies

Lepidopteran-infecting baculoviruses represent one of the most promising alternatives for pest biocontrol. In particular, Spodoptera frugiperda granulovirus (SfGV) infects the fall armyworm Spodoptera frugiperda, an increasingly important pest for maize and other crops around the world. SfGV has been investigated due to its capacity to enhance other baculovirus infectivity and as a biopesticide itself. Although the proteome of SfGV occlusion bodies (OB) is fundamental for their infectivity properties, we still lack a detailed understanding of its protein components and how they compare with other baculoviruses. To tackle this problem, we performed mass spectrometry-based proteomics analysis on SfGV OB obtained from infected larvae. We could detect 72 proteins included in SfGV OB and confirm the presence of two enhancins. EmPAI-based semi-quantification highlighted the presence of two granulovirus proteins, ORF101 and ORF141, shared with other GV proteomic studies. ORF101 was shown to form aggregates in insect cells. Bioinformatic analysis determined that ORF101 is an Ac5 family protein and at the same time shares striking similarities with AcMNPV P10. Prediction and comparison of OB protein structures allowed the detection of a common structural fold among 6 proteins PEP-1, PEP-2, Pep-P10, ORF007, ORF025, and Bro-f. Finally, comparison of four reported ODV proteomic studies of different GVs indicated that ORF040, ORF101, ORF141 and Bro-f are common components in GV OBs.

molecular biology↗

bioRxiv2020

Genomic Diversity in a Population of Spodoptera frugiperda Nucleopolyhedrovirus

Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV) represents a strong candidate to develop environmental-friendly pesticides against the fall armyworm (Spodoptera frugiperda), a widespread pest that poses a severe threat to different crops around the world. However, little is known regarding the genomic diversity present inside SfMNPV isolates and how it shapes the interactions between virus and host. Here, the genomic diversity present inside an isolate of SfMNPV was explored using high-throughput sequencing for the first time. We identified 704 intrahost single nucleotide variants, from which 184 are nonsynonymous mutations distributed among 82 different coding sequences. We detected several structural variants affecting SfMNPV genome, including two previously reported deletions inside the egt region. A comparative analysis between polymorphisms present in different SfMNPV isolates and our intraisolate diversity data suggests that coding regions with higher genetic diversity are associated with oral infectivity or unknown functions. In this context, through molecular evolution studies we provide evidence of diversifying selection acting on sf29, a putative collagenase which could contribute to the oral infectivity of SfMNPV. Overall, our results contribute to deepen our understanding of the coevolution between SfMNPV and the fall armyworm and will be useful to improve the applicability of this virus as a biological control agent. HighlightsO_LIWe characterized the genomic diversity within a population of SfMNPV. C_LIO_LICoding regions with higher genetics diversity are associated with oral infectivity or unknown functions. C_LIO_LISeveral structural variants contribute to the genomic diversity of SfMNPV. C_LIO_LISf29, a putative collagenase, shows signs of adaptive evolution. C_LI

microbiology↗

bioRxiv2018

\"Protein composition of the occlusion bodies of Epinotia aporema granulovirus\"

Within family Baculoviridae, members of the Betabaculovirus genus are employed as biocontrol agents against lepidopteran pests, either alone or in combination with selected members of the Alphabaculovirus genus. Epinotia aporema granulovirus (EpapGV) is a fast killing betabaculovirus that infects the bean shoot borer (E. aporema) and is a promising biopesticide. Because occlusion bodies (OBs) play a key role in baculovirus horizontal transmission, we investigated the composition of EpapGV OBs. Using mass spectrometry-based proteomics we could identify 56 proteins that are included in the OBs during the final stages of larval infection. Our data provides experimental validation of several annotated hypothetical coding sequences. Proteogenomic mapping against genomic sequence detected a previously unannotated ac110-like core gene and a putative translation fusion product of ORFs epap48 and epap49. Comparative studies of the proteomes available for the family Baculoviridae highlight the conservation of core gene products as parts of the occluded virion. Two proteins specific for betabaculoviruses (Epap48 and Epap95) are incorporated into OBs. Moreover, quantification based on emPAI values showed that Epap95 is one of the most abundant components of EpapGV OBs.

microbiology↗