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Phylogeographical patterns of a generalist acorn weevil: insight into the biogeographical history of broadleaved deciduous and evergreen forests.

Aoki K, Kato M, Murakami N - BMC Evol. Biol. (2009)

Bottom Line: Its genetic structure was compared to that of another host-specific seed predator, C. hilgendorfi, inhabiting only evergreen forests.Our results suggest that geology and historical environment have contributed to shaping the present genetic structure of C. sikkimensis.The geographical patterns of genetic differentiation in the Chugoku-Shikoku region observed in the two types of Fagaceae-associated Curculio in this study have also been observed in several plant species growing in warm and cool temperate zones of Japan.

View Article: PubMed Central - HTML - PubMed

Affiliation: Graduate School of Human and Environmental Studies, Kyoto University, Sakyo-ku, Kyoto, Japan. aoki@sys.bot.kyoto-u.ac.jp

ABSTRACT

Background: Climatic changes during glacial periods have had a major influence on the recent evolutionary history of living organisms, even in temperate forests on islands, where the land was not covered with ice sheets. We investigated the phylogeographical patterns of the weevil Curculio sikkimensis (Curculionidae), a generalist seed predator of Fagaceae plants living in both deciduous oak and evergreen forests of Japan. Its genetic structure was compared to that of another host-specific seed predator, C. hilgendorfi, inhabiting only evergreen forests.

Results: We examined 921 bp of mitochondrial DNA for 115 individuals collected from 33 populations of C. sikkimensis from 11 plant species of three genera, Quercus, Lithocarpus, and Castanopsis. An analysis of molecular variance revealed that a large proportion (almost 50%, P < 0.001) of the total genetic variance could be explained by differences between two geographical regions, the southwestern and northeastern parts of the main islands of Japan. In contrast, no significant genetic differentiation of the weevil was observed among vegetation types of their utilized host plant species. The phylogeographical patterns of the generalist and the host-specific seed predator exhibited a congruent genetic boundary in the Chugoku-Shikoku region.

Conclusion: Our results suggest that geology and historical environment have contributed to shaping the present genetic structure of C. sikkimensis. The geographical patterns of genetic differentiation in the Chugoku-Shikoku region observed in the two types of Fagaceae-associated Curculio in this study have also been observed in several plant species growing in warm and cool temperate zones of Japan. The occurrence of this common pattern suggests that deciduous oak and evergreen forests of Japan survived together, or adjacent to each other, in small refugia during glacial ages, in the southwestern and northeastern parts of the main islands, although these two types of forests are presently distributed in cool and warm temperate zones of Japan, respectively.

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Geographic distribution of mtDNA haplotypes of Curculio hilgendorfi on the main islands of Japan (modified from [24]). (a) Geographic distribution of 102 mtDNA haplotypes found among 189 individuals of the host-specific seed parasitic weevil C. hilgendorfi on the main islands of Japan. (b) Relatedness among haplotypes detected in 2709 bp of mtDNA (COI, COII, and ND5) of C. hilgendorfi, represented in a statistical parsimony haplotype network. The values of haplotype diversity and nucleotide diversity of NE and SW clades are 0.964 and 0.00385, respectively.
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Figure 2: Geographic distribution of mtDNA haplotypes of Curculio hilgendorfi on the main islands of Japan (modified from [24]). (a) Geographic distribution of 102 mtDNA haplotypes found among 189 individuals of the host-specific seed parasitic weevil C. hilgendorfi on the main islands of Japan. (b) Relatedness among haplotypes detected in 2709 bp of mtDNA (COI, COII, and ND5) of C. hilgendorfi, represented in a statistical parsimony haplotype network. The values of haplotype diversity and nucleotide diversity of NE and SW clades are 0.964 and 0.00385, respectively.

Mentions: The haplotype and nucleotide diversities of the main islands of Japan showed similar values in C. sikkimensis (Table 2) and C. hilgendorfi (h = 0.964 and π = 0.00385, [24]). Congruent phylogeographical patterns were observed between C. sikkimensis (Fig. 1) and C. hilgendorfi (Fig. 2, [24]), with a deep gap between the SW and NE clades with respect to the mtDNA sequences. Two differences in the phylogeographical patterns were observed between C. sikkimensis and C. hilgendorfi. The first was the existence of CS clades in C. sikkimensis in the Chugoku and Shikoku regions, and the second was the lack of genetic differentiation in the SW clade of C. sikkimensis between the coasts of Pacific and the Sea of Japan.


Phylogeographical patterns of a generalist acorn weevil: insight into the biogeographical history of broadleaved deciduous and evergreen forests.

Aoki K, Kato M, Murakami N - BMC Evol. Biol. (2009)

Geographic distribution of mtDNA haplotypes of Curculio hilgendorfi on the main islands of Japan (modified from [24]). (a) Geographic distribution of 102 mtDNA haplotypes found among 189 individuals of the host-specific seed parasitic weevil C. hilgendorfi on the main islands of Japan. (b) Relatedness among haplotypes detected in 2709 bp of mtDNA (COI, COII, and ND5) of C. hilgendorfi, represented in a statistical parsimony haplotype network. The values of haplotype diversity and nucleotide diversity of NE and SW clades are 0.964 and 0.00385, respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2691738&req=5

Figure 2: Geographic distribution of mtDNA haplotypes of Curculio hilgendorfi on the main islands of Japan (modified from [24]). (a) Geographic distribution of 102 mtDNA haplotypes found among 189 individuals of the host-specific seed parasitic weevil C. hilgendorfi on the main islands of Japan. (b) Relatedness among haplotypes detected in 2709 bp of mtDNA (COI, COII, and ND5) of C. hilgendorfi, represented in a statistical parsimony haplotype network. The values of haplotype diversity and nucleotide diversity of NE and SW clades are 0.964 and 0.00385, respectively.
Mentions: The haplotype and nucleotide diversities of the main islands of Japan showed similar values in C. sikkimensis (Table 2) and C. hilgendorfi (h = 0.964 and π = 0.00385, [24]). Congruent phylogeographical patterns were observed between C. sikkimensis (Fig. 1) and C. hilgendorfi (Fig. 2, [24]), with a deep gap between the SW and NE clades with respect to the mtDNA sequences. Two differences in the phylogeographical patterns were observed between C. sikkimensis and C. hilgendorfi. The first was the existence of CS clades in C. sikkimensis in the Chugoku and Shikoku regions, and the second was the lack of genetic differentiation in the SW clade of C. sikkimensis between the coasts of Pacific and the Sea of Japan.

Bottom Line: Its genetic structure was compared to that of another host-specific seed predator, C. hilgendorfi, inhabiting only evergreen forests.Our results suggest that geology and historical environment have contributed to shaping the present genetic structure of C. sikkimensis.The geographical patterns of genetic differentiation in the Chugoku-Shikoku region observed in the two types of Fagaceae-associated Curculio in this study have also been observed in several plant species growing in warm and cool temperate zones of Japan.

View Article: PubMed Central - HTML - PubMed

Affiliation: Graduate School of Human and Environmental Studies, Kyoto University, Sakyo-ku, Kyoto, Japan. aoki@sys.bot.kyoto-u.ac.jp

ABSTRACT

Background: Climatic changes during glacial periods have had a major influence on the recent evolutionary history of living organisms, even in temperate forests on islands, where the land was not covered with ice sheets. We investigated the phylogeographical patterns of the weevil Curculio sikkimensis (Curculionidae), a generalist seed predator of Fagaceae plants living in both deciduous oak and evergreen forests of Japan. Its genetic structure was compared to that of another host-specific seed predator, C. hilgendorfi, inhabiting only evergreen forests.

Results: We examined 921 bp of mitochondrial DNA for 115 individuals collected from 33 populations of C. sikkimensis from 11 plant species of three genera, Quercus, Lithocarpus, and Castanopsis. An analysis of molecular variance revealed that a large proportion (almost 50%, P < 0.001) of the total genetic variance could be explained by differences between two geographical regions, the southwestern and northeastern parts of the main islands of Japan. In contrast, no significant genetic differentiation of the weevil was observed among vegetation types of their utilized host plant species. The phylogeographical patterns of the generalist and the host-specific seed predator exhibited a congruent genetic boundary in the Chugoku-Shikoku region.

Conclusion: Our results suggest that geology and historical environment have contributed to shaping the present genetic structure of C. sikkimensis. The geographical patterns of genetic differentiation in the Chugoku-Shikoku region observed in the two types of Fagaceae-associated Curculio in this study have also been observed in several plant species growing in warm and cool temperate zones of Japan. The occurrence of this common pattern suggests that deciduous oak and evergreen forests of Japan survived together, or adjacent to each other, in small refugia during glacial ages, in the southwestern and northeastern parts of the main islands, although these two types of forests are presently distributed in cool and warm temperate zones of Japan, respectively.

Show MeSH
Related in: MedlinePlus