2006 Fiscal Year Final Research Report Summary
Studies on the genetic effect in termite caste determination
| Project/Area Number |
17570013
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Ecology/Environment
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| Research Institution | Ibaraki University |
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Principal Investigator |
KITADE Osamu Ibaraki University, College of Science, Associate Professor, 理学部, 助教授 (80302321)
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| Co-Investigator(Kenkyū-buntansha) |
KOJIMA Jun'ichi Ibaraki University, College of Science, Professor, 理学部, 教授 (00192576)
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| Project Period (FY) |
2005 – 2006
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| Keywords | termite / caste determination mechanism / gene / parthenogenesis |
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| Research Abstract |
1. Parthenogenetic ability of termites and caste ratio of the parthenogens:
Six species of termites (four Reticulitermes spp., Z. nevadensis, N. koshunensis) and regional populations of R. speratus were investigated on their parthenogenetic ability. The former sex species could not reproduce by parthenogenesis, but individuals from every local population of R. speratus could. All the parthenogens developed into female nymphs. The phylogeny of the local populations of R. speratus was inferred by molecular phylogenetic analysis of mitochondrial genes.
2. Test of genetic caste determination model:
Using R. kanmonensis and R. okinawanus, the genetic caste getermination model was tested. We carried out four types of crossing experiments using male and female nymphoid and ergatoid neotenic reproductives. Eggs were reared by male workers. In the former species the realized caste/sex ratios of the offspring did not differ from the expected values of the genetic model. The almost the same results were obtained in R. okinawanus, suggesting that a common mechanism regulate the caste ratio in the genus Reticulitermes.
3. Search for the caste-and sex-lined genetic markers:
We carried out AFLP analysis to find caste or sex specific genetic markers. Using 21 selective primer pairs, we found 316 polymorphic AFLP loci, but could not find caste specific bands. However, one male specific AFLP locus was found, which probably on the Y-chromosome. We also set up the experimental conditions of pulsed-field gel electrophoresis to separate sex chromosomes.
4. Genetic structure and caste ratio in the field colony:
We investigated of the genetic structures of R. speratus in Tokai, Ibaraki pref. using microsatellite and mt-DSCP markers. We estimated colony boundaries and examined caste compositions of the field colonies.
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Research Products
(14 results)
