A new species of Urupelma Kaderka et al. 2023 from Peru (Araneae, Theraphosidae, Theraphosinae), and a new proposal of homologous keels

Posted by
  A new species of Urupelma Kaderka et al. 2023 from Peru (Araneae, Theraphosidae, Theraphosinae), and a new proposal of homologous keels Abstract A new Peruvian tarantula, Urupelma lamarensis sp. nov., from the Ayacucho Department, in south-central Peru, is herein described, diagnosed and illustrated. Homologous keels of male bulbs in Urupelma Kaderka et al. 2023 are revised and newly established, the generic diagnosis is modified, including diagnoses of single species using these characters. The female genitalia of Urupelma pampas Kaderka et al. 2023 is figured for the first time. The variability of female genitalia of U. veronicae Kaderka et al. 2023 is also shown for the first time.  Kaderka, R. (2026). A new species of Urupelma Kaderka et al. 2023 from Peru (Araneae, Theraphosidae, Theraphosinae), and a new proposal of homologous keels. Revista Peruana De Biología , 33 (3), e32750. https://doi.org/10.15381/rpb.v33i3.32750

Phase response curve and RNA-sequencing demonstrate spiders’ sensitivity to light and pinpoint candidate light-responsive genes

Posted by

 


Phase response curve and RNA-sequencing demonstrate spiders’ sensitivity to light and pinpoint candidate light-responsive genes

Abstract

Spiders can maintain a wide range of free-running periods while still being entrained to a 24-hour day. To investigate the underlying mechanism of this entrainment, we constructed the phase-response curve (PRC) for the orb weaver, Metazygia wittfeldae, by subjecting the spiders to one-hour light pulses at various times throughout the circadian day. The resulting type 0 PRC showed high amplitude (> 6 hour) phase advance and delays when the light pulse was applied during circadian time (CT) 16–18, including a break point of delays to advances. We then investigated the genetic mechanism of response to light by splitting M. wittfeldae adult females entrained to 12 hours light:12 hours dark (LD 12:12) into two groups. One group received a 1-hour light pulse 5 hours after lights off (equivalent to CT17), and the other group did not. We then sacrificed spiders for RNA isolations 1 and 10 hours after the light pulse. We identified numerous genes that were downregulated by the light pulse 1 hour after the pulse relative to no pulse group. Intriguingly, many of these genes had a flipped pattern of expression 9 hours later – the pulse group had higher expression than the no pulse group. We also identified clock gene homologs in M. wittfeldae that had distinct expression patterns from other arthropods.

Citation: Toporikova N, Cheng W, Qian L, Mah A, Clarke T, Jones TC, et al. (2026) Phase response curve and RNA-sequencing demonstrate spiders’ sensitivity to light and pinpoint candidate light-responsive genes. PLoS One 21(9): e0344063. https://doi.org/10.1371/journal.pone.0344063