Biology subjects

Turetzek, N.

Publications and source records attributed to Turetzek, N..

4 recordsLinked to original sources

bioRxiv2026

Lost and found: beer belly is a novel, ancient regulator of animal development

Single-cell RNA sequencing (scRNA-seq) can provide new insights into the regulation of developmental processes by revealing unknown or overlooked genes. We identified a novel gene called beer belly (bebe) as a marker of a segment addition zone (SAZ) associated cell cluster in a single-cell atlas of the spider Parasteatoda tepidariorum. Here we show that bebe is an ancient toolkit gene encoding a previously uncharacterised protein predicted to be secreted, which likely plays an important role in the development of most animal phyla. However, we could not identify a bebe ortholog in any mammal or holometabolous insect, suggesting it has been lost in these lineages and explaining why it has been overlooked to date. Knock-down of bebe expression in P. tepidariorum demonstrates that it regulates SAZ size and consequently segment size by interacting with Wnt8. Our findings also suggest that bebe may regulate segmentation in other invertebrates and play additional developmental roles in bilaterian and non-bilaterian animals, likely ancestrally, through modulation of Wnt signalling. This study emphasises the promise of applying single-cell sequencing across a diverse range of species to better understand the regulation of development beyond candidate genes from traditional models, allowing us to better characterise the animal developmental toolkit and its evolution.

developmental biology↗

bioRxiv2022

An atlas of spider development at single-cell resolution provides new insights into arthropod embryogenesis

Spiders are a diverse order of chelicerates that diverged from other arthropods over 500 million years ago. Research on spider embryogenesis, particular studies using the common house spider Parasteatoda tepidariorum, has made important contributions to understanding the evolution of animal development, including axis formation, segmentation, and patterning. However, we lack knowledge about the cells that build spider embryos, their gene expression profiles and fate. Single-cell transcriptomic analyses have been revolutionary in describing these complex landscapes of cellular genetics in a range of animals. Therefore, we carried out single-cell RNA sequencing of P. tepidariorum embryos at stages 7, 8 and 9, which encompass the establishment and patterning of the body plan, and initial differentiation of many tissues and organs. We identified 20 cell clusters, from 18.5k cells, which were marked by many developmental toolkit genes, as well as a plethora of genes not previously investigated. There were differences in the cell cycle transcriptional signatures, suggestive of different proliferation dynamics, which related to distinctions between endodermal and some mesodermal clusters, compared with ectodermal clusters. We found many Hox genes were markers of cell clusters, and Hox gene ohnologs often were present in different clusters. This provided additional evidence of sub- and/or neo-functionalisation of these important developmental genes after the whole genome duplication in the arachnopulmonate ancestor (spiders, scorpions, and allies). We also examined the spatial expression of marker genes for each cluster to generate a comprehensive cell atlas of these embryonic stages. This revealed new insights into the cellular basis and genetic regulation of head patterning, hematopoiesis, limb development, gut development, and posterior segmentation. This atlas will serve as a platform for future analysis of spider cell specification and fate, and studying the evolution of these processes among animals at cellular resolution.

developmental biology↗

bioRxiv2022

The mating system of the common house spider Parasteatoda tepidariorum

Mating systems, with varying female mating rates occurring with the same partner (monogamy) or with multiple mates (polyandry), can have far reaching consequences for population viability and the rate of gene flow. Here, we investigate the mating system of the common house spider Parasteatoda tepidariorum (Theridiidae), an emerging model for genetic studies, with yet undescribed reproductive behavior. It is hypothesized that spiders belonging to this family have low re-mating rates. We paired females twice with the same male (monogamy) or with different males (polyandry), scored behaviors and mating success and fitness resulting from single- and double-matings, either monogamous or polyandrous. Despite the study being explorative in nature, we predict successful matings to be more frequent during first encounters, to reduce the risk of remaining unmated. For re-mating to be adaptive, we expect higher fitness of double-mated females, and polyandrous females to experience highest mating success and fitness if reproductive gains are achieved by mating with multiple partners. We show that the majority of the females mated once, not necessarily on their first encounter, and the likelihood of re-mating did not differ between monogamous and polyandrous encounters. The number of matings did not affect fitness, indicated by similar offspring production in females. Female twanging of the web, a behavior that likely advertises female receptivity, lead successful matings, suggesting female control. We discuss how the species ecology, with high mating costs for males and potentially limited female receptivity, may shape a mating system with low mating rates.

animal behavior and cognition↗

bioRxiv2017

The house spider genome reveals an ancient whole-genome duplication during arachnid evolution

The duplication of genes can occur through various mechanisms and is thought to make a major contribution to the evolutionary diversification of organisms. There is increasing evidence for a large-scale duplication of genes in some chelicerate lineages including two rounds of whole genome duplication (WGD) in horseshoe crabs. To investigate this further we sequenced and analyzed the genome of the common house spider Parasteatoda tepidariorum. We found pervasive duplication of both coding and non-coding genes in this spider, including two clusters of Hox genes. Analysis of synteny conservation across the P. tepidariorum genome suggests that there has been an ancient WGD in spiders. Comparison with the genomes of other chelicerates, including that of the newly sequenced bark scorpion Centruroides sculpturatus, suggests that this event occurred in the common ancestor of spiders and scorpions and is probably independent of the WGDs in horseshoe crabs. Furthermore, characterization of the sequence and expression of the Hox paralogs in P. tepidariorum suggests that many have been subject to neofunctionalization and/or subfunctionalization since their duplication, and therefore may have contributed to the diversification of spiders and other pulmonate arachnids.

genomics↗