| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2006: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 2005: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Research Abstract |
To date, we have obtained specimens (mostly dried, but some in ethanol) and extracted DNA from 70 colonies (genetic individuals) of 15 described species of Cauloramphus and several additional unidentified and/or undescribed species. We saved part of each colony selected for DNA extraction as a voucher specimen for morphological analysis. Universal 16S primers (l6Sar/br) quite unexpectedly did not work to amplify the Cauloramphus 16S gene. We therefore switched to the mitochondrial cytochrome oxidase c subunit 1 (COI) gene, which like 16S has successfully been employed with bryozoans. With universal COI primers (LCO1490, HCO2198) we have amplified, cloned, and sequenced an approximately 650 bp COI fragment from nine colonies of seven species. In this limited sample, within-population variation ranged from 0.28 to 0.70%, whereas between-species variation ranged from 10.2 to 22.3%. The COI gene is evolving faster than 16S in bryozoans; however, since COI is a coding gene, third-position bases can be eliminated from the phylogenetic analysis if there are indications that they have reached saturation. The COI primer set amplifies about 200 bp more sequence than the universal 16S primers, so even after removal of third positions, there will be sufficient sequence data for analysis. Work is underway to clone and sequence additional COI amplification products. During the course of this study, we described in detail the general morphology of seven species of Cauloramphus, including five new species. In addition, we completed a detailed comparative study of one key but previously poorly understood morphological character in Cauloramphus, the ooecium, which is reduced because species of Cauloramphus brood internally. We documented the morphology of this structure in eight species and are thus in a good position to map this structure onto a phylogeny.
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