Speaker
Description
Orthopterans, encompassing crickets, bush-crickets, and grasshoppers, are key invertebrate herbivores notable for their genome size (GS) variation and reproductive diversity (RD). Over evolutionary timescales, orthopterans show large-scale chromosome rearrangements. The persistence chromosomal polymorphisms, such as B chromosomes and sex chromosomes in certain lineages but not others, warrants detailed investigation. Orthopterans possess the largest and most variable genomes among insects, and variations in GS can influence cell size and overall developmental processes, impacting organism fitness. Sperm cells are often subject to sexual selection, particularly in species experiencing high levels of sperm competition. This selective pressure can drive diversification in reproductive organs and sperm characters (e.g. size, shape, and structure), thereby promoting divergence among populations. Evolutionary traits like karyotypes, GS, and sperm morphology (SM) are crucial for understanding speciation and biodiversity origins. Here, we aim to characterize karyotypes, GS, and SM across the European orthopteran fauna, providing insights into their evolutionary mechanisms and contributions to biodiversity. Karyotype analyses from more than 30 species revealed variation in both diploid number (2n) and chromosome size between Acrididae and Tettigonidae species. The 2n in Acrididae males ranged from 17 to 23, while in Tettigonidae this trait showed a more stable pattern, ranged from 29 to 31. We compiled the most comprehensive matrix of GS information encompassing over 150 species across Europe, with values ranging from 0.96 pg to 21.96 pg. The study of SM in 10 species of Acrididae, Tettigoniidae, Tetrigidae and Gryllidae, showed noticeable differences in tail length, head morphology, and spermatodesm structure. These data, combined with recent fieldwork, will enable us to reconstruct the evolutionary history of genomic and RD, correlate genomic and RD with species ecological traits, and relate genomic and RD to species richness. This comprehensive analysis will provide insights into the drivers of diversity in Orthoptera on a continent-wide scale.
| Status Group | Postdoctoral Researcher |
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