Publications by authors named "J PERREAU"

The profession of firefighter working on the rescue and emergency care involves many skills and requirements. The Health Sub-Directorate's supervisory division oversees the activities of these agents in partnership with the Operations, Forecasting and Prevention Division. A firefighter nurse is present on the site and watches over the 250 to 350 daily interventions.

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Because aphids are global agricultural pests and models for bacterial endosymbiosis, there is a need for reliable methods to study and control their gene function. However, current methods available for aphid gene knockout and knockdown of gene expression are often unreliable and time consuming. Techniques like CRISPR-Cas genome editing can take several months to achieve a single gene knockout because they rely on aphids going through a cycle of sexual reproduction, and aphids often lack strong, consistent levels of knockdown when fed or injected with molecules that induce an RNA interference (RNAi) response.

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Pea aphids (Acyrthosiphon pisum) are insects containing genes of bacterial origin with putative functions in peptidoglycan (PGN) metabolism. Of these, rlpA1-5, amiD, and ldcA are highly expressed in bacteriocytes, specialized aphid cells that harbor the obligate bacterial symbiont Buchnera aphidicola, required for amino acid supplementation of the host's nutrient-poor diet. Despite genome reduction associated with endosymbiosis, pea aphid Buchnera retains genes for the synthesis of PGN while Buchnera of many other aphid species partially or completely lack these genes.

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Numerous animal lineages have maternally inherited symbionts that are required for host reproduction and growth. Endosymbionts also pose a risk to their hosts because of the mutational decay of their genomes through genetic drift or to selfish mutations that favor symbiont fitness over host fitness. One model for heritable endosymbiosis is the association of aphids with their obligate bacterial symbiont, We experimentally established heteroplasmic pea aphid matrilines containing pairs of closely related haplotypes and used deep sequencing of diagnostic markers to measure haplotype frequencies in successive host generations.

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Article Synopsis
  • Animal hosts have formed long-lasting symbiotic relationships with microorganisms, adapting to changes in their environment over millions of years.
  • The success of these relationships relies on genetic changes in both the hosts and their symbionts, influenced by the way symbionts are transmitted between hosts.
  • Advances in sequencing and experimentation are offering new insights into how these genetic innovations develop and support the symbiosis between hosts and microorganisms.
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