Wan-Ok Lee

Complete mitochondrial genome of the Korean bitterling Acheilognathus intermedia (Cypriniformes; Cyprinidae).

The complete mitochondrial genome was sequenced from the Korean bitterling Acheilognathus intermedia. The genome sequence was 16,610 bp in size, and the gene order and contents were identical with the congeneric Acheilognathus signifier and other previously reported fish mitochondrial genomes. Of 13 protein-coding genes (PCGs), three genes (CO2, CO3, and Cytochrome b) had incomplete stop codons. The base composition of A. intermedia showed anti-G bias (12.48%) on the third position of PCGs.

Genetic Distribution Pattern of Bluegill Sunfish Lepomis macrochirus in Freshwater Ecosystems across Korea

Lepomis macrochirus from the family Centrarchidae, commonly known as Bluegill sunfish, is an introduced freshwater fish in Korea that thrives in lakes, ponds, reservoirs and rivers. Since its introduction into Korea in 1969, Lepomis macrochirus has rapidly dispersed out and increased in number almost all over the freshwater ecosystems in Korea. Consequently this species causes a severe ecological problem, threatening native fishes due to its omnivorous foraging behaviors upon fish juveniles and many freshwater invertebrates. To address population genetic structure of L. macrochirus, 74 fish samples from 10 populations were collected and compared for their mitochondrial D-loop control region. As the result we found that the genetic diversity of L. macrochirus is extremely low such as resulting only four haplotypes with a few nucleotide differences among them. Analysis of molecular variance (AMOVA) revealed that the source of population genetic variation is largely retained in the comparisons among individuals within populations, while it is relatively low with slight significance at the highest hierachical group. This distribution pattern differs from what is expected when biogeography is under the influence of natural geographic barriers such as mountain ranges in Korea. Instead the result is accord with the influential role of random spreading events facilitated by local people for aquaculture and fishing, and subsequent dispersals since its single point of introduction ito Korea.

Complete mitochondrial genome of the freshwater fish, Acanthorhodeus macropterus (Cypriniformes, Cyprinidae).

Abstract The complete mitochondrial genome was sequenced from the freshwater cyprinid fish, Acanthorhodeus macropterus. The genome sequence was 16,774 bp in size, and the gene order and contents were identical with another cyprinid fish, Acheilognathus yamatsutae. Of 13 protein-coding genes (PGCs), 3 genes (CO2, CO3, Cytb) had an incomplete stop codon. The base composition of A. macropterus showed anti-G bias (13.58% and 8.98%) on the second and third positions of PCGs.

Complete mitochondrial genome of the freshwater fish, Rhodeus suigensis (Cypriniformes, Cyprinidae)

Abstract The complete mitochondrial genome was sequenced from the cyprinid freshwater fish, Rhodeus suigensis. The genome sequence was 16,733 bp in size, and the gene order and contents were identical with the congeneric species R. uyekii. Of 13 protein-coding genes (PGCs), 3 genes (CO2, CO3 and Cytb) had an incomplete stop codon as shown in R. uyekii. Fot the base composition, R. suigensis showed anti-G bias (13.66% and 12.37%) on the second and third positions of the PCGs.

Population Genetic Structure and Evidence of Demographic Expansion of the Ayu (Plecoglossus altivelis) in East Asia

Plecoglossus altivelis (ayu) is an amphidromous fish widely distributed in Northeastern Asia from the East China Sea to the northern Japanese coastal waters, encompassing the Korean Peninsula within its range. The shore lines of northeastern region in Asia have severely fluctuated following glaciations in the Quaternary. In the present study, we investigate the population genetic structure and historical demographic change of P. altivelis at a population level in East Asia. Analysis of molecular variance (AMOVA) based on 244 mitochondrial control region DNA sequences clearly showed that as the sampling scope extended to a larger geographic area, genetic differentiation began to become significant, particularly among Northeastern populations. A series of hierarchical AMOVA could detect the genetic relationship of three closely located islands between Korea and Japan that might have been tightly connected by the regional Tsushima current. Neutrality and mismatch distribution analyses revealed a strong signature of a recent population expansion of P. altivelis in East Asia, estimated at 126 to 391 thousand years ago during the late Pleistocene. Therefore it suggests that the present population of P. altivelis traces back to its approximate demographic change long before the last glacial maximum. This contrasts our a priori expectation that the most recent glacial event might have the most crucial effect on the present day demography of marine organisms through bottleneck and subsequent increase of effective population size in this region.

Complete mitochondrial genome of the striped bittering Acheilognathus yamatsutae (Cypriniformes; Cyprinidae)

The complete mitochondrial genome was sequenced from the striped bittering Acheilognathus yamatsutae. The genome sequence was 16,703 bp in size, and the gene order and contents were identical tot those of the congeneric species Acheilognathus signifer and other previously reported fish mitochondrial genomes. Of 13 protein-coding genes (PCGs), three genes (CO2, CO3, and Cytb) had incomplete stop codons. The base composition of A. yamatsutae showed anti-G bias (13.50% and 9.72%) on the 2nd and 3rd position of PCGs.

Complete mitochondrial genome of the Korean bitterlingAcheilognathus intermedia(Cypriniformes; Cyprinidae)

The complete mitochondrial genome was sequenced from the Korean bitterling Acheilognathus koreensis. The genome sequence was 16,563 bp in size, and the gene order and contents were identical with the same genera Acheilognathus signifier and other previously reported fish mitochondrial genomes. Of 13 protein-coding genes (PCGs), four genes (CO2, CO3, ND4, and Cytochrome b) had incomplete stop codons. The base composition of A. koreensis showed anti-G bias (13.69%) on the third position of PCGs.

Multi-locus phylogenetic analyses support the monophyly and the Miocene diversification of Iksookimia (Teleostei: Cypriniformes: Cobitidae)

The genus Iksookimia contains six species of primary freshwater fishes that are endemic to South Korea. Previous phylogenetic studies, based on DNA sequence data from three or fewer loci, have suggested non-monophyly of the genus, providing inconsistent resolutions of the relationships of Iksookimia. Our coalescent and concatenation-based phylogenetic analyses, utilizing seven unlinked nuclear-encoded genes, strongly supported Iksookimia as a monophyletic group, emphasizing the importance of multi-locus data in investigating complicated phylogenetic relationships. A relaxed molecular clock analysis using fossil calibrations, indicated that the origin of the major lineages of Iksookimia occurred between ∼12 to 5 Ma, which is consistent with the Miocene uplift of the Taebaek and Sobaek Mountains and the Miocene activation of the major south-eastern faults. These palaeogeographic events may have served as vicariant events in the diversification of Iksookimia.