Project description:MicroRNAs (miRNAs) are involved in post-transcriptional regulation of gene expression. Since several miRNAs are known to affect the stability or translation of developmental regulatory genes, the origin of novel miRNAs may have contributed to the evolution of developmental processes and morphology. Lepidoptera (butterflies and moths) is a species-rich clade with a well-established phylogeny and abundant genomic resources, thereby representing an ideal system in which to study miRNA evolution. We sequenced small RNA libraries from developmental stages of two divergent lepidopterans, Cameraria ohridella (Horse chestnut Leafminer) and Pararge aegeria (Speckled Wood butterfly), discovering 90 and 81 conserved miRNAs respectively, and many species-specific miRNA sequences. Mapping miRNAs onto the lepidopteran phylogeny reveals rapid miRNA turnover and an episode of miRNA fixation early in lepidopteran evolution, implying that miRNA acquisition accompanied the early radiation of the Lepidoptera. One lepidopteran-specific miRNA gene, miR-2768, is located within an intron of the homeobox gene invected, involved in insect segmental and wing patterning. We identified cubitus interruptus (ci) as a likely direct target of miR-2768, and validated this suppression using a luciferase assay system. We propose a model by which miR-2768 modulates expression of ci in the segmentation pathway and in patterning of lepidopteran wing primordia. Examination of the small RNA complements pooled across life cycle stages in each of Cameraria ohridella and Pararge aegeria.
Project description:MicroRNAs (miRNAs) are involved in post-transcriptional regulation of gene expression. Since several miRNAs are known to affect the stability or translation of developmental regulatory genes, the origin of novel miRNAs may have contributed to the evolution of developmental processes and morphology. Lepidoptera (butterflies and moths) is a species-rich clade with a well-established phylogeny and abundant genomic resources, thereby representing an ideal system in which to study miRNA evolution. We sequenced small RNA libraries from developmental stages of two divergent lepidopterans, Cameraria ohridella (Horse chestnut Leafminer) and Pararge aegeria (Speckled Wood butterfly), discovering 90 and 81 conserved miRNAs respectively, and many species-specific miRNA sequences. Mapping miRNAs onto the lepidopteran phylogeny reveals rapid miRNA turnover and an episode of miRNA fixation early in lepidopteran evolution, implying that miRNA acquisition accompanied the early radiation of the Lepidoptera. One lepidopteran-specific miRNA gene, miR-2768, is located within an intron of the homeobox gene invected, involved in insect segmental and wing patterning. We identified cubitus interruptus (ci) as a likely direct target of miR-2768, and validated this suppression using a luciferase assay system. We propose a model by which miR-2768 modulates expression of ci in the segmentation pathway and in patterning of lepidopteran wing primordia.
Project description:Streptococcus pneumoniae of serotype 3 possess a mucoid capsule and cause disease associated with high mortality rates relative to other pneumococci. Phylogenetic analysis of a complete reference genome and 81 draft sequences from clonal complex 180, the predominant serotype 3 clone in much of the world, found most sampled isolates belonged to a clade affected by few diversifying recombinations. However, other isolates indicate significant genetic variation has accumulated over the clonal complex's entire history. Two closely related genomes, one from the blood and another from the cerebrospinal fluid, were obtained from a patient with meningitis. The pair differed in their behaviour in a mouse model of disease and in their susceptibility to antimicrobials, with at least some of these changes attributable to a mutation that up-regulated the patAB efflux pump. This indicates clinically important phenotypic variation can accumulate rapidly through small alterations to the genotype. [Data is also available from http://bugs.sgul.ac.uk/E-BUGS-144]
Project description:A new phase of the COVID-19 pandemic has started as SARS-CoV-2 variants with increased transmissibility are emerging globally, calling for the development of reliable platforms to rapidly phenotype viruses. Currently, no rapid phenotyping system exists that both accurately models human biology and can be standardized properly. Organoids accurately model viral target cells in vivo, can be established from many tissues, passaged indefinitely, biobanked and shared. We found that the British variant (clade B.1.1.7), compared to an ancestral 614G-containing clade B virus, produced higher levels of infectious virus late in infection and had a higher replicative fitness in human airway, alveolar and intestinal organoid models. Our findings unveil extended shedding as a correlate of fitness for SARS-CoV-2, possibly explaining the rapid emergence of SARS-CoV-2 B.1.1.7. Combined with genomic surveillance systems, virus phenotyping using standardized organoid models may be implemented into public health decision making.
Project description:We characterized sperm from the seminal vesicles of male monarch butterflies (Danaus plexippus), in triplicate, identifying 548 high confidence proteins. As with all but the most basal lepidopteran species male monarch butterflies are sperm heteromorphic, producing fertilization competent and anucleate fertilization incompetent sperm morphs. Comparing this data to the sperm proteomes of the Carolina sphinx moth (Manduca sexta) and the fruit fly (Drosophila melanogaster) demonstrated high levels of functional coherence across proteomes, and conservation at the level of protein abundance and post-translational modification within Lepidoptera. Comparative genomic analyses revealed a significant reduction in orthology among Monarch sperm genes relative to the remainder of the genome in non-Lepidopteran insects. A substantial number of sperm proteins were found to be specific to Lepidoptera, lacking detectable homology outside this taxa. These findings are consistent with a burst of genetic novelty in the sperm proteome concurrent with the origin of heteromorphic spermatogenesis early in Lepidoptera evolution.
Project description:Lipomyces genome scale model based on the Lipomyces starkeyi NRRL-11557 genome.
Published in:
Genome-Scale Model Development and Genomic Sequencing of the Oleaginous Clade Lipomyces
Frontiers in Bioengineering and Biotechnology
Industrial Biotechnology
Volume 12 - 2024 | doi: 10.3389/fbioe.2024.1356551
Project description:Background Coral reefs belong to the most ecologically and economically important ecosystems on our planet. Yet, they are under steady decline worldwide due to rising sea surface temperatures, disease, and pollution. Understanding the molecular impact of these stressors on different coral species is imperative in order to predict how coral populations will respond to this continued disturbance. The use of molecular tools such as microarrays has provided deep insight into the molecular stress response of corals. Here, we have performed comparative genomic hybridizations (CGH) with different coral species to an Acropora palmata microarray platform containing 13,546 cDNA clones in order to identify potentially rapidly evolving genes and to determine the suitability of existing microarray platforms for use in gene expression studies (via heterologous hybridization). Results Our results showed that the current microarray platform for A. palmata is able to provide biological relevant information for a wide variety of coral species covering both the complex clade as well the robust clade. Analysis of the fraction of highly diverged genes showed a significantly higher amount of genes without annotation corroborating previous findings that point towards a higher rate of divergence for taxonomically restricted genes. Among the genes with annotation, we found many mitochondrial genes to be highly diverged in M. faveolata when compared to A. palmata, while the majority of nuclear encoded genes maintained an average divergence rate. Conclusions The use of present microarray platforms for transcriptional analyses in different coral species will greatly enhance the understanding of the molecular basis of stress and health and highlight evolutionary differences between scleractinian coral species. On a genomic basis, we show that cDNA arrays can be used to identify patterns of divergence. Mitochondrion-encoded genes seem to have diverged faster than nuclear encoded genes in robust corals. Accordingly, this needs to be taken into account when using mitochondrial markers for scleractinian phylogenies.
Project description:Picocyanobacteria from the genus Synechococcus are ubiquitous in ocean waters. Their phylogenetic and genomic diversity suggests ecological niche differentiation, but the selective forces influencing this are not well defined. Marine picocyanobacteria are sensitive to Cu toxicity, so adaptations to this stress could represent a selective force within, and between, “species” also known as clades. We compared Cu stress responses in cultures and natural populations of marine Synechococcus from two co-occurring major mesotrophic clades (I and IV). Using custom microarrays and proteomics to characterize expression responses to Cu in the lab and field, we found evidence for a general stress regulon in marine Synechococcus. However, the two clades also exhibited distinct responses to copper. The Clade I representative induced expression of genomic island genes in cultures and Southern California Bight populations, while the Clade IV representative downregulated Fe-limitation proteins. Copper incubation experiments suggest that Clade IV populations may harbor stress-tolerant subgroups, and thus fitness tradeoffs may govern Cu-tolerant strain distributions. This work demonstrates that Synechococcus has distinct adaptive strategies to deal with Cu toxicity at both the clade and subclade level, implying that metal toxicity and stress response adaptations represent an important selective force for influencing diversity within marine Synechococcus populations.