Spiders have a diverse spectrum of morphologies, behaviors & physiologies. Attempts to understand the genomic basis of this diversity are often hindered by their large, heterozygous, and AT-rich genomes with high repeat content resulting in highly fragmented, poor-quality assemblies. Our findings reveal that spider genomes are highly variable and that genomic novelty may have been driven by the burst of ancient whole-genome duplication, followed by gene family and transposable element expansion.
"The Tetragnatha kauaiensis genome sheds light on the origins of genomic novelty in spiders" is published on Genome Biology and Evolution https://academic.oup.com/gbe/advance-article/doi/10.1093/gbe/evab262/6443144
We confirmed a high variation in terms of genome assembly size and found that it is likely associated with different transposable element annotation (image above). We also found some cool signatures of gene family expansions linked to metabolism, immune response, and sensory perception! The problem is: few genomes are available and some of them are highly fragmented and missing tons of data, not allowing for very deep inferences. However, adding more genomes should give a clearer picture and be a very productive endeavor.
We also explored chemosensory gene families, spidroins (silk genes), and venoms. We found/confirmed some really big expansions private to some genomes (definitely worth exploring - image above) and that most venoms were present by the time scorpions and spiders diverged.