Related Experiment Videos
Morphological consequences for multi-partner chimerism in Botrylloides, a colonial urochordate.
1Minerva Center for Marine Invertebrate Immunology and Developmental Biology, National Institute of Oceanography, Tel Shikmona, P.O. Box 8030, Haifa 31080, Israel.
Developmental and Comparative Immunology
|June 21, 2002
Summary
Multi-partner chimeras (MC) in Botrylloides leachi grow larger and faster than bi-partner chimeras (BC). These findings suggest evolutionary pressures favor group-level interactions in botryllid ascidians.
Area of Science:
- Marine biology
- Evolutionary biology
- Developmental biology
Background:
- Colonial urochordates, like Botryllus schlosseri, form multi-partner chimeras (MC).
- Previous studies indicated MC are more stable and vigorous than bi-partner chimeras (BC).
Purpose of the Study:
- To investigate the morphological consequences of chimerism in Botrylloides leachi.
- To compare the life span, size, and growth rates of BC, tri-chimeras (TC), and hexa-chimeras (HC).
- To analyze differences in chimerism between Botrylloides and Botryllus genera.
Main Methods:
- Established five genotypic combinations for BC, TC, and HC, with three replicates each.
- Observed chimeras for up to 10 months.
- Analyzed morphological traits, life span, size, and growth rates.
Main Results:
- Life spans of BC, TC, and HC were similar.
- HC achieved larger maximum sizes due to a significantly higher daily growth rate.
- BC and TC reached maximal size earlier than HC.
- Morphological resorptions differed between HC and BC.
Conclusions:
- Multi-partner chimerism (MC) is a common phenomenon in botryllid ascidians, shaped by group-level evolutionary pressures.
- MC results in modified entities where conflicting intraspecific interactions are mitigated.
- Botrylloides and Botryllus genera exhibit significant differences in chimerism characteristics, yet MC is a conserved strategy.