We found fuchi nashi, a lineage-specific, fast-evolving GATA-like gene that contributes to zygotic activation of genes involved in endoderm specification and pattern formation in the early spider embryo. Read our paper.

 

Our mathematical model mimicking embryonic cell dynamics can reproduce the spider embryo shaping in silico. Read our paper.

 

In this work, we applied single-cell and single-nucleus RNA sequencing to early embryos in the common house spider Parasteatoda tepidariorum. These techniques require cell dissociation prior to obtaining transcriptomic data, which leads to a loss of information about the position of individual cells in the embryo. It is usually difficult to overcome this demerit, but our experiments using spider embryos allowed us to reconstruct a correct axis of the spider embryo on the computer. Read our paper.

 

Classical cadherins constitute a family of Ca²⁺-dependent cell-cell adhesion molecules that contribute to the construction and maintenance of the multi-celllular animal body. Despite the fundamental importance of this molecular family, they exhibit a great diversity in the domain composition and organization of the ectodmain depending on the phylogeny. The fruit fly Drsoophila melanogaster has two classical cadherins, one of which is ancestral, known as DN-cadherin, the other is derived, known as DE-cadherin. These two cadherins provide good examples with which we can investiagte the strucutral and functional relationships between the ancestral and derived states of classical cadherin. In this work, we successfully purified DN- and DE-cadherin ectodomains and visualized their molecular morphologies using high-speed atomic force microscopy(HS-AFM). Read more.

 

We genome-widely identified 98 genes which transcriptionally responded to altered states of Hedgehog signaling. Our analyses focused on the msx1 gene, which is negatively regulated by Hedgehog signaling. We found that this msx1 is a key segmentation gene in the spider embryo. Its expression behaves as waves and its function is requied to generate repetitive units in the embryonic field.  Read more.

We have published a mini-review in the international academic journal EvoDevo that introduces the common house spider Parasteatoda tepidariorum as an emerging experimental system. You can know the characteristics of this spider species, what kind of research themes can be addressed, and what experimental techniques can be used with this spider. The sequence of the genome of P. tepidariorum has been read and published, and rich transcriptomic resources are available. As spiders of this species live close to us, we believe that you can easily start using them not only for research purposes but also for education purposes. If interested, please read this mini-review. Our databases site also may be useful for getting information on this spider (https://www.brh2.jp).

Hiroki Oda and Yasuko Akiyama-Oda
The common house spider Parasteatoda tepidariorum
EvoDevo (2020) 11:6
https://doi.org/10.1186/s13227-020-00152-z

We have published a review paper that describes twinning of spider embryos experimentally induced as well as provides a historical background on such twinning experiments in spiders. One of the conclusions of this review paper is "The two concepts of developmental biology, organizer and self-regulation, which were described in vertebrate embryology, are similarly applied in the development of spiders." Please see two movies showing body axes duplications following two different types of embryological manipulations (Movie1 and Movie2), as well as a movie showing delayed body axes formation following removal of cumulus by laser irradiation (Movie3).
 

Hiroki Oda, Sawa Iwasaki-Yokozawa, Toshiya Usui, and Yasuko Akiyama-Oda
Experimental duplication of bilaterian body axes in spider embryos: Holm’s organizer and self-regulation of embryonic fields
Development Genes and Evolution, 10 April 2019, First Online (Open Access)
DOI: 10.1007/s00427-019-00631-x
https://link.springer.com/article/10.1007/s00427-019-00631-x

Our paper, which describes a quantitative study of stripe-forming processes relevant to segmentation in a spider embryo, has been published in the journal Developmental Biology. Segmented body patterns along the body axis are shared morphological characters of arthropods. Experimental studies using various insect and other arthropod models, however, have suggested that developmental processes resulting in striped patterns considerably vary depending on the body region as well as on the species. But, such varied stripe-forming processes have not been documented in a common framework. In this work, using embryos of the spider Parasteatoda tepidariorum, we quantitatively characterized the diversity of stripe-forming processes in a dynamic cellular field. Cell behaviors were also examined to show wave-like features of gene expression. Our descriptions highlight contrasting pattern dynamics, splitting versus oscillation, in both terminal (head and abdominal) regions of the field. In the middle (thoracic) region, stripes appear to form by a third mechanism. Employment of a diversity of segmentation processes in an embryonic field, which are region-dependent, is common among arthropods.
 

Natsuki Hemmi, Yasuko Akiyama-Oda, Koichi Fujimoto, and Hiroki Oda（2018）
A quantitative study of the diversity of stripe-forming processes in an arthropod cell-based field undergoing axis formation and growth
Developmental Biology 437 (2) :84-104
DOI: 10.1016/j.ydbio.2018.03.001
https://www.sciencedirect.com/science/article/pii/S0012160617309089

Mizuki Sasaki, Yasuko Akiyama-Oda, and Hiroki Oda（2017）
Evolutionary origin of type IV classical cadherins in arthropods
BMC Evolutionary Biology, Volume 17, Issue 142, June
DOI: 10.1186/s12862-017-0991-2
https://bmcevolbiol.biomedcentral.com/articles/10.1186/s12862-017-0991-2

Shigetaka Nishiguchi, Akira Yagi, Nobuaki Sakai, Hiroki Oda（2016）
Divergence of structural strategies for homophilic E-cadherin binding among bilaterians
Journal of Cell Science DOI: 10.1242/jcs.189258
http://jcs.biologists.org/content/129/17/3309