Big Spider, Big Genome: Chromosome-level genome of a North American tarantula (Aphonopelma marxi) and comparative genomics across 300 million years of spider evolution

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  Image Credit: WikiCommons Big Spider, Big Genome: Chromosome-level genome of a North American tarantula (Aphonopelma marxi) and comparative genomics across 300 million years of spider evolution Abstract The comparison of chromosome-level genomes allows biologists to investigate new axes of organismal evolution. Spiders comprise a significant proportion of known arachnid diversity, with many complex morphologies and unique natural histories, yet comparative genomics in spiders has been limited due to the number of available genomes. We present a de novo chromosomal reference genome of a mature male tarantula, Aphonopelma marxi, and comparatively examine spider genome evolution across the Order Araneae. Using PacBio HiFi and Hi-C sequencing, the final 6.5 Gb assembly consists of 17 autosomes, 1 X chromosome, and 127 unplaced scaffolds, with an N50 of 370 Mb and Arachnida (odb10; 2934 genes) BUSCO of 96.7%. By comparing 20 additional spider genomes from 15 families, we find mygalomo...

Should snakes used in antivenom production be retired? An analysis of Bothrops moojeni venom at different ages

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By (Greg Hume) - Own work, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=12164448

Should snakes used in antivenom production be retired? An analysis of Bothrops moojeni venom at different ages

ABSTRACT

Accidents involving venomous snakes in Brazil are mostly caused by the Bothrops genus. Snake venoms, just like Bothrops moojeni venom, one of the snake species used to produce the antibotropic serum, may have variations in its venom due to many factors like age, which could be analyzed due to the excellent maintenance of the Butantan Institute's vivarium. Therefore, analyzing the influence of senility on the venom profile is important in order to understand and guarantee the efficacy of the antibotropic serum. To this end, pools of Bothrops moojeni were used to better understand this variation, with females and males, adults and seniles. The results showed a variation between the adult and senile groups, where the adult groups have a higher proteolytic activity, while the senile groups have a higher coagulant and hemolytic activity. In relation to the immuno-recognition tests carried out, the senile groups were less recognized than the adults, an important result to guide more assertive treatment if necessary. Consequently, the venom of Bothrops moojeni varies according to senility, highlighting the importance of this study not only for this species, but for others that may also have this variation.
Moitas, M., Reis, G., Lima, E., Tavares, M., Tasima, L., Silveira, G., Grego, K., & Tanaka-Azevedo, A. (2025). Should snakes used in antivenom production be retired? An analysis of Bothrops moojeni venom at different ages. Toxicon, 108624. https://doi.org/10.1016/j.toxicon.2025.108624