Development, genomic, and regeneration studies of a crinoid, Oxycomanthus japonicus Mariko Kondo Misaki Marine Biological Station and Center for Marine Biology, The University of Tokyo Among the echinoderms, sea urchins and sea stars have been studied as model organisms. Crinoids (sea lilies and feather stars) seem to be the least familiar group of the echinoderms, since most of them occur in the deep sea. Nevertheless, crinoids are potentially important model organisms for research, since they are considered the group of animals that have diverged the earliest from the other extant echinoderms. The feather star, Oxycomanthus japonicus, can be collected in shallower waters and maintained in cages hung in the cove of our station. This enables us to use the feather star for research, namely, on evolution and development of the echinoderm body plan and on regeneration. Given the very unique body plan of echinoderms, expression and genomic organization of Hox genes in echinoderms has been of great interest. To see whether Hox genes reflect the individual unique body plans observed in echinoderms, we are using the feather star for comparative and evolutionary studies. It has been reported that, unlike the well-known Hox gene clusters of vertebrates, the sea urchin Hox cluster lacks several Hox gene members and other modifications are present. Several of the sea urchin Hox genes are expressed along the oral-aboral axis during a certain period of early embryogenesis. From the feather star, our group has so far identified nine Hox genes and analyzed their expression during embryogenesis. To elucidate the genomic characteristics of the feather star Hox cluste, we are working on genomic BAC and fosmid clones to show the alignment and orientation of these genes. Our data indicate the presence of a single Hox cluster. Echinoderms, with the exception of sea urchins, exhibit a strong capacity for regeneration. Feather stars also are reported to regenerate most of its body parts. In natural conditions, their arms autotomize quite frequently, and this is followed by regeneration. There have been morphological or histological studies on crinoid regeneration, but only few have dealt with the molecular basis of regeneration. We have isolated several genes from the feather star. We are currently analyzing the expression of these genes during regeneration to test their involvement.

Development, genomic, and regeneration studies of a crinoid, Oxycomanthus japonicus

Mariko Kondo

Misaki Marine Biological Station and Center for Marine Biology, The University of Tokyo

Among the echinoderms, sea urchins and sea stars have been studied as model organisms. Crinoids (sea lilies and feather stars) seem to be the least familiar group of the echinoderms, since most of them occur in the deep sea. Nevertheless, crinoids are potentially important model organisms for research, since they are considered the group of animals that have diverged the earliest from the other extant echinoderms.

The feather star, Oxycomanthus japonicus, can be collected in shallower waters and maintained in cages hung in the cove of our station. This enables us to use the feather star for research, namely, on evolution and development of the echinoderm body plan and on regeneration.

Given the very unique body plan of echinoderms, expression and genomic organization of Hox genes in echinoderms has been of great interest. To see whether Hox genes reflect the individual unique body plans observed in echinoderms, we are using the feather star for comparative and evolutionary studies. It has been reported that, unlike the well-known Hox gene clusters of vertebrates, the sea urchin Hox cluster lacks several Hox gene members and other modifications are present. Several of the sea urchin Hox genes are expressed along the oral-aboral axis during a certain period of early embryogenesis. From the feather star, our group has so far identified nine Hox genes and analyzed their expression during embryogenesis. To elucidate the genomic characteristics of the feather star Hox cluste, we are working on genomic BAC and fosmid clones to show the alignment and orientation of these genes. Our data indicate the presence of a single Hox cluster.

Echinoderms, with the exception of sea urchins, exhibit a strong capacity for regeneration. Feather stars also are reported to regenerate most of its body parts. In natural conditions, their arms autotomize quite frequently, and this is followed by regeneration. There have been morphological or histological studies on crinoid regeneration, but only few have dealt with the molecular basis of regeneration. We have isolated several genes from the feather star. We are currently analyzing the expression of these genes during regeneration to test their involvement.