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Starfish Ap DOCK protein essentially functions in larval defense system operated by mesenchyme cells
Author(s) -
Furukawa Ryohei,
Funabashi Hiromi,
Matsumoto Midori,
Kaneko Hiroyuki
Publication year - 2012
Publication title -
immunology and cell biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.999
H-Index - 104
eISSN - 1440-1711
pISSN - 0818-9641
DOI - 10.1038/icb.2012.37
Subject(s) - mesenchyme , ingression , microbiology and biotechnology , biology , starfish , sponge , mesenchymal stem cell , gastrulation , embryo , embryogenesis , ecology , botany
In larvae of the starfish, Asterina pectinifera , mesenchyme cells operate in the defense system through various behaviors. We have investigated mesenchyme cell dynamics during the immune response by identifying Ap DOCK, a new member of the DOCK180 superfamily protein. In 4‐day‐old bipinnaria larvae processed for morpholino oligonucleotide‐mediated knockdown of Ap DOCK, injection of inorganic foreign substances revealed that (1) mesenchyme cells fail to undergo either directed migration toward a large oil‐droplet or persistent spreading on the oil‐droplet after contact; (2) neither uptake of micro‐beads nor cell‐to‐cell fusion on the large oil‐droplet differed from that of mesenchyme cells from control larvae. Similar behaviors were also recorded in experiments where bacteria were injected. Under culture conditions, the expression level of Ap DOCK mRNA was significantly associated with the immunological behavior of mesenchyme cells. Apparently, the mesenchyme cells from Ap DOCK loss‐of‐function larvae exhibited insufficient lamellipodium formation via lack of fibrous form of actin organization at the leading edge. These results suggest that the migratory congregation and persistence of encapsulation of larval mesenchyme cells are intracellularly regulated by Ap DOCK protein, and this regulation is associated with organization of cytoskeletal actin.