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The embryonic development of the central American wandering spider Cupiennius salei.

Wolff C, Hilbrant M - Front. Zool. (2011)

Bottom Line: The imaging procedure also elucidates the encircling border between the cell-dense embryo hemisphere and the hemisphere with much lower cell density (a structure termed 'equator' in earlier studies).Our improved staging system of development in C. salei development should be of considerable value to future comparative studies of animal development.A dense germ disc is not evident during development in C. salei, but we show that the gastrulation process is similar to that in spider species that do have a dense germ disc.

View Article: PubMed Central - HTML - PubMed

Affiliation: Humboldt-Universität zu Berlin Institut für Biologie/Vergleichende Zoologie Philippstraße 13, 10115 Berlin, Germany. carsten.wolff@rz.hu-berlin.de.

ABSTRACT

Background: The spider Cupiennius salei (Keyserling 1877) has become an important study organism in evolutionary and developmental biology. However, the available staging system for its embryonic development is difficult to apply to modern studies, with strong bias towards the earliest developmental stages. Furthermore, important embryonic events are poorly understood. We address these problems, providing a new description of the embryonic development of C. salei. The paper also discusses various observations that will improve our understanding of spider development.

Results: Conspicuous developmental events were used to define numbered stages 1 to 21. Stages 1 to 9 follow the existing staging system for the spider Achaearanea tepidariorum, and stages 10 to 21 provide a high-resolution description of later development. Live-embryo imaging shows cell movements during the earliest formation of embryonic tissue in C. salei. The imaging procedure also elucidates the encircling border between the cell-dense embryo hemisphere and the hemisphere with much lower cell density (a structure termed 'equator' in earlier studies). This border results from subsurface migration of primordial mesendodermal cells from their invagination site at the blastopore. Furthermore, our detailed successive sequence shows: 1) early differentiation of the precheliceral neuroectoderm; 2) the morphogenetic process of inversion and 3) initial invaginations of the opisthosomal epithelium for the respiratory system.

Conclusions: Our improved staging system of development in C. salei development should be of considerable value to future comparative studies of animal development. A dense germ disc is not evident during development in C. salei, but we show that the gastrulation process is similar to that in spider species that do have a dense germ disc. In the opisthosoma, the order of appearance of precursor epithelial invaginations provides evidence for the non-homology of the tracheal and book lung respiratory systems.

No MeSH data available.


Related in: MedlinePlus

Overview of development of the embryo, postembryo and first and second instar of C. salei. Nuclear stained embryos illustrate the 21 embryonic stages. The postembryo and the first and second instar are illustrated by images of live animals. Additional file 1 provides a comparison between this revised staging system and the system used in earlier publications.
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Figure 1: Overview of development of the embryo, postembryo and first and second instar of C. salei. Nuclear stained embryos illustrate the 21 embryonic stages. The postembryo and the first and second instar are illustrated by images of live animals. Additional file 1 provides a comparison between this revised staging system and the system used in earlier publications.

Mentions: The numbered stages into which we divide development in C. salei are intended to replace the existing hAEL staging system by Seitz [26]. Besides a number, each stage is also given a colloquial name for practical use. Figure 1 gives a general overview of our new system, and additional file 1 provides a detailed comparison between the old and new systems. The number of stages allocated to early development (up to stage 6) is higher in the Seitz system, where the early stages are separated into numerous time (hour) intervals after egg laying (hAEL). The resolution we chose for the early stages reflects the degree of detail we were able to observe using our methods, and follows the staging nomenclature of A. tepidariorum [25] until stage 9 (prosomal limb buds). From stage 6 to 10, the staging resolution of the two systems is similar, and after stage 10 our new system is more detailed (additional file 1).


The embryonic development of the central American wandering spider Cupiennius salei.

Wolff C, Hilbrant M - Front. Zool. (2011)

Overview of development of the embryo, postembryo and first and second instar of C. salei. Nuclear stained embryos illustrate the 21 embryonic stages. The postembryo and the first and second instar are illustrated by images of live animals. Additional file 1 provides a comparison between this revised staging system and the system used in earlier publications.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3141654&req=5

Figure 1: Overview of development of the embryo, postembryo and first and second instar of C. salei. Nuclear stained embryos illustrate the 21 embryonic stages. The postembryo and the first and second instar are illustrated by images of live animals. Additional file 1 provides a comparison between this revised staging system and the system used in earlier publications.
Mentions: The numbered stages into which we divide development in C. salei are intended to replace the existing hAEL staging system by Seitz [26]. Besides a number, each stage is also given a colloquial name for practical use. Figure 1 gives a general overview of our new system, and additional file 1 provides a detailed comparison between the old and new systems. The number of stages allocated to early development (up to stage 6) is higher in the Seitz system, where the early stages are separated into numerous time (hour) intervals after egg laying (hAEL). The resolution we chose for the early stages reflects the degree of detail we were able to observe using our methods, and follows the staging nomenclature of A. tepidariorum [25] until stage 9 (prosomal limb buds). From stage 6 to 10, the staging resolution of the two systems is similar, and after stage 10 our new system is more detailed (additional file 1).

Bottom Line: The imaging procedure also elucidates the encircling border between the cell-dense embryo hemisphere and the hemisphere with much lower cell density (a structure termed 'equator' in earlier studies).Our improved staging system of development in C. salei development should be of considerable value to future comparative studies of animal development.A dense germ disc is not evident during development in C. salei, but we show that the gastrulation process is similar to that in spider species that do have a dense germ disc.

View Article: PubMed Central - HTML - PubMed

Affiliation: Humboldt-Universität zu Berlin Institut für Biologie/Vergleichende Zoologie Philippstraße 13, 10115 Berlin, Germany. carsten.wolff@rz.hu-berlin.de.

ABSTRACT

Background: The spider Cupiennius salei (Keyserling 1877) has become an important study organism in evolutionary and developmental biology. However, the available staging system for its embryonic development is difficult to apply to modern studies, with strong bias towards the earliest developmental stages. Furthermore, important embryonic events are poorly understood. We address these problems, providing a new description of the embryonic development of C. salei. The paper also discusses various observations that will improve our understanding of spider development.

Results: Conspicuous developmental events were used to define numbered stages 1 to 21. Stages 1 to 9 follow the existing staging system for the spider Achaearanea tepidariorum, and stages 10 to 21 provide a high-resolution description of later development. Live-embryo imaging shows cell movements during the earliest formation of embryonic tissue in C. salei. The imaging procedure also elucidates the encircling border between the cell-dense embryo hemisphere and the hemisphere with much lower cell density (a structure termed 'equator' in earlier studies). This border results from subsurface migration of primordial mesendodermal cells from their invagination site at the blastopore. Furthermore, our detailed successive sequence shows: 1) early differentiation of the precheliceral neuroectoderm; 2) the morphogenetic process of inversion and 3) initial invaginations of the opisthosomal epithelium for the respiratory system.

Conclusions: Our improved staging system of development in C. salei development should be of considerable value to future comparative studies of animal development. A dense germ disc is not evident during development in C. salei, but we show that the gastrulation process is similar to that in spider species that do have a dense germ disc. In the opisthosoma, the order of appearance of precursor epithelial invaginations provides evidence for the non-homology of the tracheal and book lung respiratory systems.

No MeSH data available.


Related in: MedlinePlus