[Show abstract][Hide abstract] ABSTRACT: The 15,389-bp long complete mitogenome of the endangered red-spotted apollo butterfly, Parnassius bremeri (Lepidoptera: Papilionidae) was determined in this study. The start codon for the COI gene in insects has been extensively
discussed, and has long remained a matter of some controversy. Herein, we propose that the CGA (arginine) sequence functions
as the start codon for the COI gene in lepidopteran insects, on the basis of complete mitogenome sequences of lepidopteran
insects, including P. bremeri, as well as additional sequences of the COI start region from a diverse taxonomic range of lepidopteran species (a total
of 53 species from 15 families). In our extensive search for a tRNA-like structure in the A+T-rich region, one tRNATrp-like sequence and one tRNALeu (UUR)-like sequence were detected in the P. bremeri A+T-rich region, and one or more tRNA-like structures were detected in the A+T-rich region of the majority of other sequenced
lepidopteran insects, thereby indicating that such features occur frequently in the lepidopteran mitogenomes. Phylogenetic
analysis using the concatenated 13 amino acid sequences and nucleotide sequences of PCGs of the four macrolepidopteran superfamilies
together with the Tortricoidea and Pyraloidea resulted in the successful recovery of a monophyly of Papilionoidea and a monophyly
of Bombycoidea. However, the Geometroidea were unexpectedly identified as a sister group of the Bombycoidea, rather than the
Full-text · Article · Oct 2009 · Molecules and Cells
[Show abstract][Hide abstract] ABSTRACT: Root-knot nematode species, such as Meloidogyne hapla, M. incognita, M. arenaria, and M. javanica are the most economically notorious nematode pests, causing serious damage to a variety of crops throughout the world. In this study, DNA sequence analyses were performed on the D3 expansion segment of the 28S gene in the ribosomal DNA in an effort to characterize genetic variations in the three Meloidogyne species obtained from Korea and four species from the United States. Further, PCR-RFLP (Polymerase Chain Reaction-Restriction Fragment Length Polymorphism), SCAR (Sequence Characterized Amplified Region) PCR and RAPD (Randomly Amplified Polymorphic DNA) were also utilized to develop methods for the accurate and rapid species identification of the root-knot nematode species. In the sequence analysis of the D3 expansion segment, only a few nucleotide sequence variations were detected among M. incognita, M. arenaria, and M, javanica, but not M. hapla. As a result of our haplotype analysis, haplotype 5 was shown to be common in M. arenaria, M. incognita, M. javanica, but not in the facultatively parthenogenetic species, M. hapla. PCR-RFLP analysis involving the amplification of the mitochondrial COII and large ribosomal RNA (lrRNA) regions yielded one distinct amplicon for M. hapla at 500 bp, thereby enabling us to distinguish M. hapla from M. incognita, M. arenaria, and M. javanica reproduced via obligate mitotic parthenogenesis. SCAR markers were used to successfully identify the four tested root-knot nematode species. Furthermore, newly attempted RAPD primers for some available root-knot nematodes also provided some species-specific amplification patterns that could also be used to distinguish among root-knot nematode species for quarantine purposes.
[Show abstract][Hide abstract] ABSTRACT: Currently, the palaeopteran lineages (insect orders Ephemeroptera and Odonata) that have a problematic relationship with neopteran lineages are poorly represented by mitogenome sequences. In this study, we have determined the complete mitogenome of the oriental mayfly, Ephemera orientalis (Ephemeroptera: Ephemeridae), and the dragonfly Davidius lunatus (Odonata: Gomphidae). The 16 463 bp mitogenome of E. orientalis and the 15 912 bp mitogenome of D. lunatus have many of the features typically detected in insect mitogenomes. Although the initiation codon for the D. lunatus COI gene is the typical ATA, E. orientalis is unusual in that no typical start codon was detected in the start region of the COI gene. The A+T-rich regions of both mitogenomes have some unusual features. The E. orientalis A+T-rich region harbors two identical 55 bp sequences separated by 158 bp, and the D. lunatus A+T-rich region harbors a tandem repeat comprising two identical 261 bp copies and one partial copy of the repeat. Additionally, the A+T-rich regions of both mitogenomes harbor the stem-and-loop structures flanked by the conserved sequences "TA(A)TA" at the 5' end and "G(A)nT" at the 3' end, which have been suggested to be the signals involved in minor strand replication initiation. Furthermore, the D. lunatus A+T-rich region contains two tRNA-like structures with proper anticodon and cloverleaf structures.
[Show abstract][Hide abstract] ABSTRACT: The bumblebee species,Bombus, is an invaluable natural resource for greenhouse pollination. Low levels of genetic variation ofBombus ardens have been reported in a previous mitochondrial (mt) gene study. In this study, we sequenced the complete internal transcribed
spacer 2 (ITS2) of the nuclear rDNA obtained from 100B. ardens individuals collected from several Korean localities, in an effort to assess its usefulness in characterizing the genetic
diversity and relationships among populations of B. ardens. The ITS2 sequences ofB. ardens were shown to be longest among known insects, ranging in size from 1,971–1,984 bp. The sequences harbor four duplicated repeats-≈27
bp repeats, ≈20 bp repeats, ≈33 bp repeats, and ≈34 bp repeats-which have never before been reported in other insect ITS2
rDNA. The maximum sequence divergence of 1.01% among 96 sequence types confirmed the applicability of this molecule to the
study of intraspecific variation, revealing higher sequence variation as compared to the previously studied mt COI gene. Overall,
a very high per generation migration ratio (Nm = 5.83 ≈ infinite) and a very low level of genetic fixation (FST =0 –0.08) were noted to exist among populations ofB. ardens. The high estimation of gene flow among most populations-in particular, between the remote island Ulleungdo and several inland
populations-suggest that historical events may be more responsible for the contemporary population structure of B. ardens.
The finding of the lowest genetic diversity (π) in the population on Ulleungdo Island (π = 0.007434) may be reflective of
a relatively small population size and the geographical isolation of the population as compared with other inland populations.
-Hymenoptera-geographic variation-genetic diversity
[Show abstract][Hide abstract] ABSTRACT: We have determined the complete mitochondrial genome of the yellow-spotted long horned beetle, Psacothea hilaris (Coleoptera: Cerambycidae), an endangered insect species in Korea. The 15,856-bp long P. hilaris mitogenome harbors gene content typical of the animal mitogenome and a gene arrangement identical to the most common type found in insect mitogenomes. As with all other sequenced coleopteran species, the 5-bp long TAGTA motif was also detected in the intergenic space sequence located between tRNA(Ser)(UCN) and ND1 of P. hilaris. The 1,190-bp long non-coding A+T-rich region harbors an unusual series of seven identical repeat sequences of 57-bp in length and several stretches of sequences with the potential to form stem-and-loop structures. Furthermore, it contains one tRNA(Arg)-like sequence and one tRNA(Lys)-like sequence. Phylogenetic analysis among available coleopteran mitogenomes using the concatenated amino acid sequences of PCGs appear to support the sister group relationship of the suborder Polyphaga to all remaining suborders, including Adephaga, Myxophaga, and Archostemata. Among the two available infraorders in Polyphaga, a monophyletic Cucujiformia was confirmed, with the placement of Cleroidea as the basal lineage for Cucujiformia. On the other hand, the infraorder Elateriformia was not identified as monophyletic, thereby indicating that Scirtoidea and Buprestoidea are the basal lineages for Cucujiformia and the remaining Elateriformia.
[Show abstract][Hide abstract] ABSTRACT: Interaction of Delta,Delta- and Lambda,Lambda-bis-Ru(II) complexes with native DNA was investigated by isotropic absorption and polarized spectroscopy including circular and linear dichroism (CD and LD). Despite the steric hindrance originating from its four bulky phenanthroline ligands at both ends of the molecule, this molecule rapidly intercalates between DNA base pairs. Intercalation was judged by large hypochromism and red shift in the UV-visible absorption spectra in the absorption region of the bridging moiety as well as in the metal-to-ligand-charge transfer absorption region. Further support for the intercalation is found in the fact that the magnitude of negative reduced LD signal in the absorption region of the bridging moiety was comparable to that of the DNA absorption region, indicating that the bridge connecting the two Ru(II) complexes is nearly parallel to the DNA base planes. No difference in the binding mode between the two enantiomers was observed. In the presence of either bis-Ru(II) complex, ethidium bromide, a classical intercalator, can intercalate into the empty sites but was not able to replace the Ru(II) complexes. Near the saturation, ground state interaction between ethidium and bis-Ru(II) complex was evident by LD.
No preview · Article · Nov 2008 · Journal of inorganic biochemistry
[Show abstract][Hide abstract] ABSTRACT: The time-dependent binding mode of a porphyrin dimer to poly[d(G-C)2] and poly[d(A-T)2] was investigated by spectroscopic methods including absorption and circular and linear dichroism (CD and LD) spectroscopy. Immediately after mixing with poly[d(G-C)2], the porphyrin dimer exhibited red-shift and hypochromism in the absorption spectrum and negative CD and LD spectra. With further red-shift in absorption, the CD and LD magnitude in the Soret region became increasingly negative over time. After it was stabilized, the magnitude of the reduced LD (LDr) in the Soret region was larger than that in the DNA absorption region, indicating that the second porphyrin was also intercalated. Following the rapid intercalation of the first porphyrin, the very slow intercalation of the second followed with first-order kinetics. In the poly[d(A-T)2] case, a bisignate CD spectrum was observed in the Soret region suggesting stacking of the porphyrins. The small alteration in the CD spectrum and increased absorbance, which followed the initial rapid spectral change, was of the second order. This alteration in the spectral properties was attributed to the conformational change of poly[d(A-T)2] near the binding site because the overall shape of the CD spectrum was conserved in spite of the changes in the absorption spectrum.
No preview · Article · Mar 2008 · The Journal of Physical Chemistry B
[Show abstract][Hide abstract] ABSTRACT: The binding site and the geometry of Co(III)meso-tetrakis(N-methylpyridinium-4-yl)porphyrin (CoTMPyP) complexed with double helical poly(dA).poly(dT) and poly(dG).poly(dC), and with triple helical poly(dA).[poly(dT)](2) and poly(dC).poly(dG).poly(dC)(+) were investigated by circular and linear dichroism (CD and LD). The appearance of monomeric positive CD at a low [porphyrin]/[DNA] ratio and bisignate CD at a high ratio of the CoTMPyP-poly(dA).poly(dT) complex is almost identical with its triplex counterpart. Similarity in the CD spectra was also observed for the CoTMPyP-poly(dG).poly(dC) and -poly(dC).poly(dG).poly(dC)(+) complex. This observation indicates that both monomeric binding and stacking of CoTMPyP to these polynucleotides occur at the minor groove. However, different binding geometry of CoTMPyP, when bind to AT- and GC-rich polynucleotide, was observed by LD spectrum. The difference in the binding geometry may be attributed to the difference in the interaction between polynucleotides and CoTMPyP: in the GC polynucleotide case, amine group protrude into the minor groove while it is not present in the AT polynucleotide.
No preview · Article · Aug 2006 · Biochimica et Biophysica Acta