@article{DennisBallesterosRobinetal.2020, author = {Dennis, Alice B. and Ballesteros, Gabriel I. and Robin, St{\´e}phanie and Schrader, Lukas and Bast, Jens and Bergh{\"o}fer, Jan and Beukeboom, Leo W. and Belghazi, Maya and Bretaudeau, Anthony and Buellesbach, Jan and Cash, Elizabeth and Colinet, Dominique and Dumas, Zo{\´e} and Errbii, Mohammed and Falabella, Patrizia and Gatti, Jean-Luc and Geuverink, Elzemiek and Gibson, Joshua D. and Hertaeg, Corinne and Hartmann, Stefanie and Jacquin-Joly, Emmanuelle and Lammers, Mark and Lavandero, Blas I. and Lindenbaum, Ina and Massardier-Galata, Lauriane and Meslin, Camille and Montagn{\´e}, Nicolas and Pak, Nina and Poiri{\´e}, Maryl{\`e}ne and Salvia, Rosanna and Smith, Chris R. and Tagu, Denis and Tares, Sophie and Vogel, Heiko and Schwander, Tanja and Simon, Jean-Christophe and Figueroa, Christian C. and Vorburger, Christoph and Legeai, Fabrice and Gadau, J{\"u}rgen}, title = {Functional insights from the GC-poor genomes of two aphid parasitoids, Aphidius ervi and Lysiphlebus fabarum}, series = {BMC Genomics}, volume = {21}, journal = {BMC Genomics}, publisher = {BioMed Central}, address = {London}, issn = {1471-2164}, doi = {10.1186/s12864-020-6764-0}, pages = {27}, year = {2020}, abstract = {Background Parasitoid wasps have fascinating life cycles and play an important role in trophic networks, yet little is known about their genome content and function. Parasitoids that infect aphids are an important group with the potential for biological control. Their success depends on adapting to develop inside aphids and overcoming both host aphid defenses and their protective endosymbionts. Results We present the de novo genome assemblies, detailed annotation, and comparative analysis of two closely related parasitoid wasps that target pest aphids: Aphidius ervi and Lysiphlebus fabarum (Hymenoptera: Braconidae: Aphidiinae). The genomes are small (139 and 141 Mbp) and the most AT-rich reported thus far for any arthropod (GC content: 25.8 and 23.8\%). This nucleotide bias is accompanied by skewed codon usage and is stronger in genes with adult-biased expression. AT-richness may be the consequence of reduced genome size, a near absence of DNA methylation, and energy efficiency. We identify missing desaturase genes, whose absence may underlie mimicry in the cuticular hydrocarbon profile of L. fabarum. We highlight key gene groups including those underlying venom composition, chemosensory perception, and sex determination, as well as potential losses in immune pathway genes. Conclusions These findings are of fundamental interest for insect evolution and biological control applications. They provide a strong foundation for further functional studies into coevolution between parasitoids and their hosts. Both genomes are available at https://bipaa.genouest.org.}, language = {en} } @article{MattheyDoretvanderKooiJeffriesetal.2019, author = {Matthey-Doret, Cyril and van der Kooi, Casper J. and Jeffries, Daniel L. and Bast, Jens and Dennis, Alice B. and Vorburger, Christoph and Schwander, Tanja}, title = {Mapping of Multiple Complementary Sex Determination Loci in a Parasitoid Wasp}, series = {Genome biology and evolution}, volume = {11}, journal = {Genome biology and evolution}, number = {10}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {1759-6653}, doi = {10.1093/gbe/evz219}, pages = {2954 -- 2962}, year = {2019}, abstract = {Sex determination has evolved in a variety of ways and can depend on environmental and genetic signals. A widespread form of genetic sex determination is haplodiploidy, where unfertilized, haploid eggs develop into males and fertilized diploid eggs into females. One of the molecular mechanisms underlying haplodiploidy in Hymenoptera, the large insect order comprising ants, bees, and wasps, is complementary sex determination (CSD). In species with CSD, heterozygosity at one or several loci induces female development. Here, we identify the genomic regions putatively underlying multilocus CSD in the parasitoid wasp Lysiphlebus fabarum using restriction -site associated DNA sequencing. By analyzing segregation patterns at polymorphic sites among 331 diploid males and females, we identify up to four CSD candidate regions, all on different chromosomes. None of the candidate regions feature evidence for homology with the csd gene from the honey bee, the only species in which CSD has been characterized, suggesting that CSD in L. fabarum is regulated via a novel molecular mechanism. Moreover, no homology is shared between the candidate loci, in contrast to the idea that multilocus CSD should emerge from duplications of an ancestral single -locus system. Taken together, our results suggest that the molecular mechanisms underlying CSD in Hymenoptera are not conserved between species, raising the question as to whether CSD may have evolved multiple times independently in the group.}, language = {en} }