1. The Wnt and Delta-Notch signalling pathways interact to direct pair-rule gene expression via caudal during segment addition in the spider Parasteatoda tepidariorum.

    Development 143(13):2455 (2016) PMID 27287802

    In short-germ arthropods, posterior segments are added sequentially from a segment addition zone (SAZ) during embryogenesis. Studies in spiders such as Parasteatoda tepidariorum have provided insights into the gene regulatory network (GRN) underlying segment addition, and revealed that Wnt8 is r...
  2. The embryonic origin of the ampullate silk glands of the spider Cupiennius salei.

    Arthropod Structure & Development 44(3):280 (2015) PMID 25882741

    Silk production in spiders is considered a key innovation, and to have been vital for the diversification of the clade. The evolutionary origin of the organs involved in spider silk production, however, and in particular of the silk glands, is poorly understood. Homologies have been proposed bet...
  3. A comprehensive reference transcriptome resource for the common house spider Parasteatoda tepidariorum.

    PLoS ONE 9(8):e104885 (2014) PMID 25118601 PMCID PMC4132015

    Parasteatoda tepidariorum is an increasingly popular model for the study of spider development and the evolution of development more broadly. However, fully understanding the regulation and evolution of P. tepidariorum development in comparison to other animals requires a genomic perspective. Al...
  4. Evolutionary crossroads in developmental biology: the spider Parasteatoda tepidariorum.

    Development 139(15):2655 (2012) PMID 22782720

    Spiders belong to the chelicerates, which is an arthropod group that branches basally from myriapods, crustaceans and insects. Spiders are thus useful models with which to investigate whether aspects of development are ancestral or derived with respect to the arthropod common ancestor. Moreover,...
  5. Divergent role of the Hox gene Antennapedia in spiders is responsible for the convergent evolution of abdominal limb repression.

    PNAS 109(13):4921 (2012) PMID 22421434 PMCID PMC3323954

    Evolution often results in morphologically similar solutions in different organisms, a phenomenon known as convergence. However, there is little knowledge of the processes that lead to convergence at the genetic level. The genes of the Hox cluster control morphology in animals. They may also be ...
  6. Expression of pair rule gene orthologs in the blastoderm of a myriapod: evidence for pair rule-like mechanisms?

    BMC Developmental Biology 12:15 (2012) PMID 22595029 PMCID PMC3477074

    A hallmark of Drosophila segmentation is the stepwise subdivision of the body into smaller and smaller units, and finally into the segments. This is achieved by the function of the well-understood segmentation gene cascade. The first molecular sign of a segmented body appears with the action of ...
  7. Novel function of Distal-less as a gap gene during spider segmentation.

    PLoS Genetics 7(10):e1002342 (2011) PMID 22028676 PMCID PMC3197691

    Despite many aspects of the regulation of segmentation being conserved among arthropods, the evolution of novel gene functions has played an important role in the evolution of developmental regulation and the emergence of new segmental structures. Moreover the study of such novel gene functions ...
  8. Gene expression suggests conserved mechanisms patterning the heads of insects and myriapods.

    Developmental Biology 357(1):64 (2011) PMID 21658375

    Segmentation, i.e. the subdivision of the body into serially homologous units, is one of the hallmarks of the arthropods. Arthropod segmentation is best understood in the fly Drosophila melanogaster. But different from the situation in most arthropods in this species all segments are formed from...
  9. Evolutionary plasticity of collier function in head development of diverse arthropods.

    Developmental Biology 344(1):363 (2010) PMID 20457148

    The insect intercalary segment represents a small and appendage-less head segment that is homologous to the second antennal segment of Crustacea and the pedipalpal segment in Chelicerata, which are generally referred to as "tritocerebral segment." In Drosophila, the gene collier (col) has an imp...
  10. Hox genes and the body plans of chelicerates and pycnogonids.

    Advances in Experimental Medicine and Biology 689:125 (2010) PMID 20795327

    Hox genes are found in all metazoan phyla and are involved in specifying identity along the anterior-posterior body axis. In arthropods, ten different classes of Hox genes can be distinguished, which are expressed in a typical staggered array along the anterior-posterior axis of the embryo in ch...
  11. Conservation, loss, and redeployment of Wnt ligands in protostomes: implications for understanding the evolution of segment formation.

    BMC Evolutionary Biology 10:374 (2010) PMID 21122121 PMCID PMC3003278

    The Wnt genes encode secreted glycoprotein ligands that regulate a wide range of developmental processes, including axis elongation and segmentation. There are thirteen subfamilies of Wnt genes in metazoans and this gene diversity appeared early in animal evolution. The loss of Wnt subfamilies a...
  12. Probing the Drosophila retinal determination gene network in Tribolium (II): The Pax6 genes eyeless and twin of eyeless.

    Developmental Biology 333(1):215 (2009) PMID 19527703

    The Pax6 genes eyeless (ey) and twin of eyeless (toy) are upstream regulators in the retinal determination gene network (RDGN), which instructs the formation of the adult eye primordium in Drosophila. Most animals possess a singleton Pax6 ortholog, but the dependence of eye development on Pax6 i...
  13. hunchback functions as a segmentation gene in the spider Achaearanea tepidariorum.

    Current Biology 19(16):1333 (2009) PMID 19631543

    In insects, the gap gene hunchback (hb) is required for the formation of a set of adjacent segments through the regulation of downstream target genes of the pair rule and segment-polarity classes. In addition, hb is a major regulator of Hox genes and it has been suggested that this is the ancest...
  14. Dynamic gene expression is required for anterior regionalization in a spider.

    PNAS 106(5):1468 (2009) PMID 19147844 PMCID PMC2635816

    Patterning of a multicellular embryo requires precise spatiotemporal control of gene expression during development. The gradient of the morphogen bicoid regulates anterior regionalization in the syncytial blastoderm of Drosophila. However many arthropod embryos develop from a cellular blastoderm...
  15. Wnt8 is required for growth-zone establishment and development of opisthosomal segments in a spider.

    Current Biology 18(20):1619 (2008) PMID 18926703

    The Wnt genes encode secreted glycoprotein ligands that regulate many developmental processes from axis formation to tissue regeneration [1]. In bilaterians, there are at least 12 subfamilies of Wnt genes [2]. Wnt3 and Wnt8 are required for somitogenesis in vertebrates [3-7] and are thought to b...
  16. Evidence for Wg-independent tergite boundary formation in the millipede Glomeris marginata.

    Development Genes and Evolution 218(7):361 (2008) PMID 18592266

    The correlation between dorsal and ventral segmental units in diplopod myriapods is complex and disputed. Recent results with engrailed (en), hedgehog (hh), wingless (wg), and cubitus-interruptus (ci) have shown that the dorsal segments are patterned differently from the ventral segments. Ventra...
  17. Cupiennius salei and Achaearanea tepidariorum: Spider models for investigating evolution and development.

    Bioessays 30(5):487 (2008) PMID 18404731

    The spiders Cupiennius salei and Achaearanea tepidariorum are firmly established laboratory models that have already contributed greatly to answering evolutionary developmental questions. Here we appraise why these animals are such useful models from phylogeny, natural history and embryogenesis ...
  18. Whole-mount in situ hybridization of spider embryos.

    PMID 21356699

    INTRODUCTIONThe spider Cupiennius salei, commonly known as the American wandering spider, is a particularly useful laboratory model for embryological studies because of the availability of tools to study and manipulate its embryonic development. Cupiennius is used to study axis formation, segmen...
  19. Detection of Cell Death in Spider Embryos Using TUNEL.

    PMID 21356700

    INTRODUCTIONThe spider Cupiennius salei, commonly known as the American Wandering Spider, is a particularly useful laboratory model for embryological studies because of the availability of tools to study and manipulate its embryonic development. Cupiennius is used to study axis formation, segmen...
  20. The American Wandering Spider Cupiennius salei.

    PMID 21356686

    INTRODUCTIONThe spider Cupiennius salei is a useful laboratory model for embryological and physiological studies. Its highly developed sensory organs also make it an excellent model for behavioral studies. Furthermore, Cupiennius has contributed greatly to the study of evolutionary developmental...