Ecological regulation of development: induction of marine invertebrate metamorphosis.
In the marine environment a wide range of invertebrates have a pelagobenthic lifecycle that includes planktonic larval and benthic adult phases. Transition between these morphologically and ecologically distinct phases typically occurs when the developmentally competent larva comes into contact with a species-specific environmental cue. This cue acts as a morphogenetic signal that induces the completion of the postlarval/juvenile/adult developmental program at metamorphosis. The development of competence often occurs hours to days after the larva is morphologically mature. In the non-feeding--lecithotrophic--larvae of the ascidian Herdmania curvata and the gastropod mollusc Haliotis asinina, gene expression patterns in pre-competent and competent stages are markedly different, reflecting the different developmental states of these larval stages. For example, the expression of Hemps, an EGF-like signalling peptide required for the induction of Herdmania metamorphosis, increases in competent larvae. Induction of settlement and metamorphosis results in further changes in developmental gene expression, which apparently is necessary for the complete transformation of the larval body plan into the adult form.
Department of Zoology and Entomology, University of Queensland, Brisbane, Australia.
Daniel
D
Jackson
Sally P
SP
Leys
Veronica F
VF
Hinman
Rick
R
Woods
Martin F
MF
Lavin
Bernard M
BM
Degnan
D000818:Animals; D004463:Ecology; D004815:Epidermal Growth Factor / Q000378:metabolism; D005260:Female; D005775:Gastrula / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D008297:Male; D008675:Metamorphosis, Biological; D008954:Models, Biological; D008974:Mollusca; D011161:Porifera; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D013997:Time Factors
D004815:Epidermal Growth Factor