Biology subjects

Hurtado, O.

Publications and source records attributed to Hurtado, O..

3 recordsLinked to original sources

bioRxiv2023

Coordination of host and endosymbiont gene expression governs endosymbiont growth and elimination in the cereal weevil Sitophilus spp.

BackgroundInsects living in nutritionally poor environments often establish long-term relationships with intracellular bacteria that supplement their diets and improve their adaptive and invasive powers. Even though these symbiotic associations have been extensively studied on physiological, ecological and evolutionary levels, few studies have focused on the molecular dialogue between host and endosymbionts to identify genes and pathways involved in endosymbiosis control and dynamics throughout host development. ResultsWe simultaneously analyzed host and endosymbiont gene expression during the life cycle of the cereal weevil Sitophilus oryzae, from larval stages to adults, with a particular emphasis on emerging adults where the endosymbiont Sodalis pierantonius experiences a contrasted growth-climax-elimination dynamics. We unraveled a constant arms race in which different biological functions are intertwined and coregulated across both partners. These include immunity, metabolism, metal control, apoptosis, and bacterial stress response. ConclusionsThe study of these tightly regulated functions, which are at the center of symbiotic regulations, provides evidence on how hosts and bacteria finely tune their gene expression and respond to different physiological challenges constrained by insect development in a nutritionally limited ecological niche. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=143 HEIGHT=200 SRC="FIGDIR/small/535335v2_ufig1.gif" ALT="Figure 1"> View larger version (42K): org.highwire.dtl.DTLVardef@800121org.highwire.dtl.DTLVardef@1ca2c25org.highwire.dtl.DTLVardef@183d56org.highwire.dtl.DTLVardef@163074f_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioinformatics↗

bioRxiv2023

Transcriptomic-based selection of reference genes for quantitative real-time PCR in an insect endosymbiotic model

Reference genes are a fundamental tool for analyses of gene expression by real-time quantitative PCR (qRT-PCR), in that they ensure the correct comparison between conditions, stages, or treatments. Because of this, selection of appropriate genes to use as references is crucial for proper application of the technique. Nevertheless, efforts to find appropriate, stably expressed transcripts are still lacking, in particular in the field of insect science. Here, we took advantage of a massive transcriptomic high-throughput analysis of various developmental stages of the gut and associated-bacteriomes of the cereal weevil Sitophilus oryzae and identified a subset of stably expressed genes with the potential to be used as housekeeping genes from the larva to the adult stage. We employed several normalization techniques to select the most suitable genes among our subset. Our final selection includes three genes - TAO, YTH3 and PP12A - which can also be used to compare transcript abundance at various developmental stages in symbiotic insects, and in insects devoid of endosymbionts (aposymbiotic). Since they are well conserved, these genes have the potential to be useful for many other insect species. This work confirms the interest in using large-scale, unbiased methods for reference gene selection.

molecular biology↗

bioRxiv2022

IPSILESIONAL HIPPOCAMPAL GABA CORRELATES WITH COGNITIVE IMPAIRMENT AND MALADAPTIVE NEUROGENESIS AFTER STROKE IN MICE

BackgroundCognitive dysfunction is a frequent stroke sequela but its pathogenesis and treatment remain unresolved. Involvement of aberrant hippocampal neurogenesis and maladaptive circuitry remodelling has been proposed but their mechanisms are unknown. Our aim was to evaluate potential underlying molecular/cellular events implicated. MethodsStroke was induced by permanent occlusion of the middle cerebral artery (MCAO) in 2-month-old C57BL/6 male mice. Hippocampal metabolites/neurotransmitters were analysed longitudinally by in vivo magnetic resonance spectroscopy (MRS). Cognitive function was evaluated with the contextual fear conditioning test. Microglia, astrocytes, neuroblasts and interneurons were analysed by immunofluorescence. ResultsApproximately 50% of mice exhibited progressive post-MCAO cognitive impairment. Notably, immature hippocampal neurons in the impaired group displayed more severe aberrant phenotypes than those from the non-impaired group. Using MRS, significant bilateral changes in hippocampal metabolites such as myo-Inositol (mIns) or N-acetylaspartic acid (NAA) were found that correlated, respectively, with numbers of glia and immature neuroblasts in the ischemic group. Importantly, some metabolites were specifically altered in the ipsilateral hippocampus suggesting its involvement in aberrant neurogenesis and remodelling processes. Specifically, MCAO animals with higher hippocampal GABA levels displayed worse cognitive outcome. Implication of GABA in this setting was supported by the amelioration of ischemia-induced memory deficits and aberrant hippocampal neurogenesis after blocking pharmacologically GABAergic neurotransmission. These data suggest that GABA exerts its detrimental effect, at least partly, by affecting morphology and integration of newborn neurons into the hippocampal circuits. ConclusionsHippocampal GABAergic neurotransmission could be considered a novel diagnostic and therapeutic target for post-stroke cognitive impairment.

animal behavior and cognition↗