Novel morphological traits in the early developmental stages of Temnopleurus toreumaticus.
We have re-observed in detail the development of the sea urchin species Temnopleurus toreumaticus, which is considered to be a typical indirect-developing species with a feeding larval stage. In this re-observation, we discovered two new morphological traits in the early embryonic stages of T. toreumaticus. The first trait is that, immediately after fertilization, the egg enters a stage in which wrinkles form on its surface as a result of actin polymerization. The second new trait is that the blastulae form wrinkles; in sea urchins, this has previously been known only in direct-developing species that have a nonfeeding larval stage and form wrinkles during the blastula stage, before hatching. These phenomena indicate that after fertilization, the egg of T. toreumaticus undergoes a surface transformation that is unprecedented in echinoderms, and that an indirect-developing sea urchin can form a wrinkled blastula.
Kitazawa
Chisato
C
Biological Institute, Faculty of Education, Yamaguchi University, Yamaguchi 753-8513, Japan. chisak@yamaguchi-u.ac.jp
Nishimura
Hajime
H
Yamaguchi
Tadashi
T
Nakano
Michihiro
M
Yamanaka
Akira
A
D000199:Actins / Q000378:metabolism; D000818:Animals; D036703:Blastula / Q000166:cytology*; D008853:Microscopy; D008856:Microscopy, Fluorescence; D012617:Sea Urchins / Q000166:cytology* / Q000254:growth & development*; D015053:Zygote / Q000166:cytology*
D000199:Actins