The bumblebee, Bombus ignitus (Hymenoptera: Apidae), is a valuable natural resource that is one of the most notably utilized for greenhouse pollination in Korea. In order to understand the nature of genetic relationships, gene flow, and population structure of the species we sequenced a partial COI gene of mitochondrial DNA (mtDNA) corresponding to “animal barcode” region and the complete internal transcribed spacer 2 (ITS2) of the nuclear ribosomal DNA (nrDNA) collected from Korean localities. Although the 658-bp long mtDNA sequence provided only six haplotypes with the maximum sequence divergence of 0.61% (4 bp), the ITS sequences provided 84 sequence types with the maximum sequence divergence of 1.02% (21 sites), confirming better applicability of the ITS sequences to the study of intraspecific variation. The complete ITS2 sequences of B. ignitus were shown to be longest among known insects, ranging in size from 2,034 bp ~ 2,052 bp, harboring two duplicated repeats. Overall, a very high per generation migration ratio, a very low level of genetic fixation, and no discernable hierarchical population/ population group were noted to exist among populations of B. ignitus on the basis of both molecules, thus suggesting that the B. ignitus populations on the Korean peninsula are panmictic, which is consistent with our understanding of the dispersal capability of the species

In an effort to gain a better understanding of the nature of the population genetic structure of the pest insect, Spodoptera litura (Lepidoptera: Noctuidae), tobacco cutworms were collected from six Korean and five Chinese localities and their mitochondrial A+T-rich region and nuclear internal transcribed spacer 2 (ITS2) regions were cloned and sequenced. A total of 106 A+T-rich region haplotypes and 92 ITS2 sequence types were obtained from 158 individuals. Compared to the preliminary mitochondrial COI gene sequence data that provided all identical sequence types in all samples, the A+T-rich region and nuclear ITS2 are highly variable. Overall, a low level of genetic fixation in the A+T-rich region (FST = 0 ~ 0.02965) and nuclear ITS2 (FST = 0 ~ 0.34491), and no discernable isolated population was noted to exist among most S. litura populations. The presence of a majority of within-population variations, rather than variations among populations or between China and Korea, indicates that the S. litura populations are composed of heterogeneous individuals. The fixation index at hierarchical level of among regions shows no significance, suggesting that the S. litura populations in both Korea and China are profoundly interrelated with one another. This finding is in accord with the current knowledge that S. litura has sufficient flight capacity for dispersal.

In order to understand the nature of population genetic structure of the notorious pest insect, Spodoptera litura (Lepidoptera: Noctuidae), a total of 159 individuals of the tobacco cutworm collected from six Korean and five Chinese localities were cloned and sequenced their mitochondrial A+T-rich region. A total of 90 haplotypes ranged 324 bp ~ 372 bp in length and 0.30% ~ 4.85% in sequence divergence. Compared to the preliminary mitochondrial COI gene sequence data that provided nearly identical sequences in all samples, the A+T-rich region provided substantially high sequence variation, validating the applicability of this molecule to the study of intraspecific variation. Overall, a very high per generation migration ratio (Nm = 5.91 ~ infinite), a very low level of genetic fixation (FST = 0 ~ 0.077796), and no discernable isolated population were noted to exist among populations of S. litura, although some significant genetic differentiations were found between several pairs of populations. These results collectively suggest that the S. litura populations in both Korea and China are very well interrelated to each other. The structural analysis revealed that the S. litura A+T-rich region harbored two stretches of the [TA(A)]n sequence, the poly-A stretch, and a stem-and-loop structure that are well found in other lepidopteran A+T-rich region. Furthermore, the region harbors the 13 ~ 19-bp long T stretch and 5-bp long motif that have been suggested to function as a possible recognition site for the initiation of replication of the minor strand of mtDNA also were found.

The bumblebee, Bombus ignitus (Hymenoptera: Apidae), is a valuable natural resource that is one of the most notably utilized for greenhouse pollination in Korea. In order to understand the nature of genetic relationships, gene flow, and population structure of the species we sequenced a partial COI gene of mitochondrial DNA (mtDNA) corresponding to “animal barcode” region and the complete internal transcribed spacer 2 (ITS2) of the nuclear ribosomal DNA (nrDNA) with the individuals collected from Korean localities. Although the 658-bp long mtDNA sequence provided only six haplotypes with the maximum sequence divergence of 0.456% (3 bp, from 91 individuals), but the ITS sequences provided 33 sequence types with the maximum sequence divergence of 0.78% (16 bp, from 35 individuals), confirming better applicability of the ITS sequences to the study of intraspecific variation. The ITS2 sequences of B. ignitus were shown to be the longest among known insects, ranging in size from 2,034 bp ~ 2,045 bp and harbored two duplicated repeats, indicating unusual structure of B. ignitus ITS2 sequences compared with other insect ITS sequences. Overall, a very high per generation migration ratio, a very low level of genetic fixation, and no discernable hierarchical population/population group were noted to exist among populations of B. ignitus on the basis of both molecules, thus suggesting that the B. ignitus populations on the Korean peninsula are panmictic, which is consistent with our understanding of the dispersal capability.

The complete nucleotide sequences of the mitochondrial genome (mitogenome) from the white-spotted flower chafer, Protaetia brevitarsis (Coleoptera: Cetoniidae) was determined. The 20,319-bp long circular genome is the longest among the completely sequenced arthropods. This extraordinary length of the genome stemmed from 5,654-bp long A+T-rich region composed of twenty-eight 117-bp tandem repeats, seven 82-bp tandem repeats, and each two 19-bp and 38-bp tandem repeats. The P. brevitarsis contains a typical gene complement, order, and arrangement identical to most common type found in insects. The P. brevitarsis COI gene does not have typical ATN codon. Thus, we also designated it as AAC (asparagine), which is found in the start context of all sequenced Polyphaga within Coleoptera. All tRNAs showed stable canonical clover-leaf structure of other mt tRNAs, except for tRNASer (AGN), DHU arm of which could not form stable stem-loop structure. The 5bp-long motif sequence (TAGTA) that has been suggested to be the possible binding site for the transcription termination peptide for the major-strand also was found betweent RNASer (UCN) and ND1, as have been detected in all sequenced coleopteran insects.

The bumblebee, Bombus ardens, is a valuable natural resource, and is most notably utilized for greenhouse pollination. In order to gain a greater understanding of the population genetic structure and the genetic diversity of this species, we sequenced a portion of the mitochondrial COI gene corresponding to the “DNA Barcode” region (658 bp) from 160 individuals collected over 15 Korean localities. Uncorrected pairwise distances among the eight haplotypes suggested low intraspecific genetic diversity, with a maximum sequence divergence of 0.3%. Such a low level of intraspecific genetic diversity was further reflected in local populations, particularly to islet populations, such as those of Youngheungdo, Jakyakdo, and Ulleugdo, which had zero genetic diversity. Geographically, one haplotype (BARBA01) was widespread and dominant, with a frequency of 90.6% (145 among 160 individuals). Other haplotypes were restricted to one to three localities and had low frequency. Overall, a very high rate of per generation female migration ratio (Nm= 4.6 to infinite) and a very low level of genetic fixation (FST= 0 to 0.099) were detected between pairs of localities, suggesting that the B. ardens population sonthe Korean peninsula are panmictic, which is consistent with our understanding of their dispersal capability.

We analyzed a portion of mitochondrial COI gene sequences (658 bp) to investigate the genetic diversity and geographic variation of the swallowtail butterfly, Papilioxuthus L., and the cabbage butterfly, Pieris rapae (Lepidoptera: Papilionidae). P. xuthus showed a moderate level of sequence divergence (0.91% at maximum) in 15 haplotypes, whereas P. rapae showed a moderate to high level of sequence divergence (1.67% at maximum) in 30 haplotypes, compared with other relevant studies. Analyses of population genetic structure showed that most populations are not genetically differentiated in both species. The distribution pattern of both species appears to be consistent with category IV of the phylogeographic pattern sensu Avise (Avise et al. 1987): a phylogenetic continuity, an absence of regional isolation of mtDNA clones, and extensive distribution of close clones. The observed pattern of genetic diversity and geographic variation of the two butterfly species seems to reflect the abundant habitats, abundant host plants, and flying abilities in connection with the lack of historical biogeographic barriers.

The 15,338-bp long complete mitochondrial genome (mitogenome) of the Japanese oak silkmoth, Antheraeayamamai (Lepidoptera: Saturniidae) was determined. This genome has a gene arrangement identical to those of all other sequenced lepidopteran insects, but differs from the most common type, as the result of the movement of tRNAMet to a position 5’-upstream of tRNAIle. No typical start codon of the A. yamamai COI gene is available. Instead, a tetranucleotide, TTAG, which is found at the beginning context of all sequenced lepidopteran insects was tentatively designated as the start codon for A. yamamai COI gene. Three of the 13 protein-coding genes (PCGs) harbor the incomplete termination codon, T or TA. All tRNAs formed stable stem-and-loop structures, with the exception of tRNASer(AGN), the DHU arm of which formed a simple loop as has been observed in many other metazoan mt tRNASer(AGN). The 334-bp long A+T-rich region is noteworthy in that it harbors tRNA-likestructures, as has also been seen in the A+T-rich regions of other insect mitogenomes. Phylogenetic analyses of the available species of Bombycoidea, Pyraloidea, and Tortricidea bolstered the current morphology-based hypothesis that Bombycoidea and Pyraloidea are monophyletic (Obtectomera). As has been previously suggested, Bombycidae (Bombyxmori and B.mandarina) and Saturniidae (A.yamamai and Caligula boisduvalii) formed a reciprocal monophyletic group.

In this study, we determined the complete mitochondrial genome of the jewel beetle, Chrysochroa fulgidissima (Coleoptera: Buprestidae), from four overlapping fragments. The 15,592-bp long C. fulgidissima mitogenome exhibits a gene arrangement and content identical to the most common type in insects. The start codon of the C. fulgidissima COI gene is unusual, in that no typical ATN codon is available. The 875-bp A+T-rich region is the shortest among the coleopteran mitogenomes that have thus far been sequenced in their entirety. The most unusual feature of the genome is the presence of three tRNA-like sequences within the A+T-rich region: two tRNALeu(UUR)-like sequences and one tRNAAsnlike sequence. These sequence stretches evidence the proper anticodon sequence and the potential to form secondary structures, but also harbor many mismatches in the stems. Phylogenetic analysis using a concatenation of 13 amino acid sequences of protein-coding genes among the available sequenced species of coleopteran superfamilies (Buprestoidea and Elateroidea belonging to the infraorder Elateriformnia, and Chrysomeloidea and Tenebrioroidea belonging to the infraorder Cucujoiformia) by Bayesian inference, maximum-parsimony analyses, and maximum-likelihood analysis unexpectedly revealed a lack of support for monophyletic Elateriformia.

The objective of this study was to determine the potential hazardous effects of sorting process by flowcytometry on the quality of boar spermatozoa by flowcytometer. Freshly collected boar semen was diluted and divided into two groups; control none sorted and sorted. Sperms in sorted group were processed with flowcytometer for cell sorting with 100 uM nozzle under the 20 psi pressure. Measurements on each parameter were made at two time points, 0hr (right after sorting) and 24 hr post sorting. Although there was a tendency of lower viability in sorted group than none sorted control group, the percentage of live cells in control(75.83+-6.92 & 59.53+-10.34) was not significantly different from sorted (59.7+-7.34 & 43.97+-3.76) at both 0 and 24 hr post sorting. However, sorted sperm showed significantly lower mitochondrial function compared to the control at both 0 h (79.37+-3.22 vs. 63.50+-10.05) and 24hr(67.27+-3.22 vs. 46.97+-5.37) time points (p<0.007). Sperm DNA fragmentation rate was significantly lower in control (22.0+-7.04) than that of sorted (32.27+-7.49) at 24 hr time point (p<0.0002). Taken together, these data suggested thatsorting process by flowcytometer may have influenced sperm motility rather than viability. Also high speed sperm sorting by flowcytometer has significant effects on DNA fragmentation on elapsed time after sorting.

The mason bee (Osmia cornifrons Radoszkowsky) is an excellent pollinator of apple. To understand geographic genetic variation of the species and relationships among populations sequenced a portion of mitochondrial COI gene, which corresponds to “DNA Barcode” region (658 bp) from 81 individuals collected over eight localities in Korea. The sequence data were used to investigate genetic diversity within populations and species, geographic variation within species, phylogeographic relationship among populations, and phylogenetic relationship among haplotypes. Summarized, overall moderate to low genetic diversity within populations and species was characteristic, concordant with the high potential to disperse of O. cornifrons in Korea. Although two populations were genetically subdivided from the remaining localities, no clear regional bias was observed. Overall, high rate of gene flow among localities and low FST was characteristic considering other relevant studies that investigated population genetic structure of other insects occurring in Korean peninsula.

To understand geographic genetic variation of the species and relationships among populations of the bumble bee, Bombus ardens, we sequenced a portion of mitochondrial COI gene, which corresponds to "DNA Barcode" region (658 bp) from 101 B. ardens individuals collected over 11 localities in Korea. The sequence data were used to investigate genetic diversity within populations and species, geographic variation within species, phylogeographic relationship among populations, and phylogenetic relationship among haplotypes. A total of nine haplortpes were found, but they very close to each other (a maximum sequence divergence of 0. 304%). Summarized, overall moderate to low genetic diversity within populations and species was characteristic, concordant with the high potential to disperse of B. ardens in Korea. There was no clear regional subdivision was observed and relatively high rate of gene flow among localities and low FST was characteristic.

본 연구는 젖소(Holstein종)의 mtDNA D-loop 영역 염기변이 다형성과 경제형질간의 관련성을 분석하기 위하여 수행하였다. 젖소의 mtDNA D-loop 영역에서 단일염기의 치환에 의해 총 35개의 polymorphic site가 확인되었다. 그중 주요 Polymorphic site의 염기변이 빈도는 106, 169, 16057, 16231 및 16255 지역에서 높은 빈도의 염기치환이 검출되었다. 169 지역은 A가 G로 염기치환이 일어났고 그 빈도는 0.555로 높게 나타났으며 염기치환에 의한 산유량 효과는 1259.6 kg(P<0.05)로 나타났다. 유지방과의 관계를 분석한 결과 16118 지역은 A가 G로 치환되는 빈도가 0.02로 검출되었으며, 16135 지역은 T가 C로 치환되는 빈도가 0.02로 검출되었고, 16302 지역은 G가 A로 치환되는 빈도가 0.04로 검출되었다. 이 지역들이 유지방에 미치는 변이 효과는 - 156, - 118.15 및 - 67.77 kg(P<0.1)으로 나타났다. 본 연구에서 검출한 젖소 mtDNA내 D-loop 영역의 염기서열 변이 빈도와 유량, 유지방과의 연관성 분석 결과 등은 젖소집단의 유전적 변이성 추정과 좀 더 다양한 경제형질과의 관련성 분석으로 다양한 유전적 지표인자 발굴에 도움이 될 것이며 이를 통해 분자유전학적 기법을 이용한 젖소의 육종전략을 확립하는데 기초 자료가 되는 것은 물론 분자육종학적인 연구에 기초 자료로서 유용하게 활용할 수 있을 것으로 기대된다.