• Molecules and Cells
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• 제26권3호
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• pp.291-298
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• 2008

Human karyopherin ${\beta}3$, highly homologous to a yeast protein secretion enhancer (PSE1), has often been reported to be associated with a mediator of a nucleocytoplasmic transport pathway. Previously, we showed that karyopherin ${\beta}3$ complemented the PSE1 and KAP123 double mutant. Our research suggested that karyopherin beta has an evolutionary function similar to that of yeast PSE1 and/or KAP 123. In this study, we performed yeast two-hybrid screening to find a protein which would interact with karyopherin ${\beta}3$ and identified apolipoprotein A-I (apo A-I), a secretion protein with a primary function in cholesterol transport. By using in vitro binding assay, co-immunoprecipitation, and colocalization studies, we defined an interaction between karyopherin ${\beta}3$ and apo A-I. In addition, overexpression of karyopherin ${\beta}3$ significantly increased apo A-I secretion. These results suggest that karyopherin ${\beta}3$ plays a crucial role in apo A-I secretion. These findings may be relevant to the study of a novel function of karyopherin ${\beta}3$ and coronary artery diseases associated with apo A-I.

• Genomics & Informatics
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• 제13권4호
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• pp.102-111
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• 2015

The karyotypes of most species of crocodilians were studied using conventional and molecular cytogenetics. These provided an important contribution of chromosomal rearrangements for the evolutionary processes of Crocodylia and Sauropsida (birds and reptiles). The karyotypic features of crocodilians contain small diploid chromosome numbers (30~42), with little interspecific variation of the chromosome arm number (fundamental number) among crocodiles (56~60). This suggested that centric fusion and/or fission events occurred in the lineage, leading to crocodilian evolution and diversity. The chromosome numbers of Alligator, Caiman, Melanosuchus, Paleosuchus, Gavialis, Tomistoma, Mecistops, and Osteolaemus were stable within each genus, whereas those of Crocodylus (crocodylians) varied within the taxa. This agreed with molecular phylogeny that suggested a highly recent radiation of Crocodylus species. Karyotype analysis also suggests the direction of molecular phylogenetic placement among Crocodylus species and their migration from the Indo-Pacific to Africa and The New World. Crocodylus species originated from an ancestor in the Indo-Pacific around 9~16 million years ago (MYA) in the mid-Miocene, with a rapid radiation and dispersion into Africa 8~12 MYA. This was followed by a trans-Atlantic dispersion to the New World between 4~8 MYA in the Pliocene. The chromosomes provided a better understanding of crocodilian evolution and diversity, which will be useful for further study of the genome evolution in Crocodylia.

• Journal of Plant Biology
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• 제35권3호
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• pp.205-210
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• 1992

한국산 나리속 7종 2변종에 대하여 광학현미경과 주사전자현미경으로 화분의 크기와 형태를 조사하였으며 이들의 진화경향성 및 계통을 고찰하였다. 이상의 조사 결과 한국산 나리속 식물은 2유형으로 구분할 수 있었다. 즉, 소망상형은 화분립의 크기와 망강의 크가가 비교적 작은 유형으로 하늘나리와 땅나리에서만 관찰되었고, 대망상형은 화분립의 크기와 망강의 크기가 비교적 큰 유형으로 그 밖의 모든 분류군에서 관찰되었는네, 소망상형이 대망상형보다 원시적인 것으로 생각된다. 또한 화분형질에서 소망상형으로 관찰된 하늘나리와 땅나리는 개화방향은 다르지만 린편, 화피편의 형태가 유사하므로, 이들을 개화방향에 따라 다른 절로 취급한 Wilson(1925)의 체계보다는 종자, 린편의 형태 등의 형질에 의해 같은 절로 취급한 Comber(1949)의 체계가 보다 타당한 것으로 생각되며, 이들을 같은 아절로서 취급해야 한다고 생각한다.

• Animal cells and systems
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• 제6권2호
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• pp.167-170
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• 2002

The long terminal repeats (LTRs) of human endogenous retrovirus (HERV) have been found to be coexpressed with sequences of closely located genes. It has been suggested that the LTR elements have contributed to the structural change or genetic variation of human genome connected to various diseases and evolution. We examined the HERV-W LTR elements in various cancer cells (2F7, A43l , A549, HepG2, MIA-PaCa-2, PC-3, RT4, SiHa, U-937, and UO-31). Using genomic DNA from the cancer cells, we performed PCR amplification and identified twelve new HERV-W LTR elements. Those LTR elements showed a high degree of sequence similarity (88-99％) with HERV-W LTR (AF072500). A phylogenetic tree obtained by the neighbor-joining method revealed that HERV-W LTR elements could be mainly divided into two groups through evolutionary divergence. Three HERV-W LTR elements (RT4-2, A43l-1, and UO3l-2) belonged to Group 1, whereas nine LTR elements (2F7-2, A549-1, A549-3, HepG2-3, MP2-2, PC3-1, SiHa-8, SiHa-10, and U937-1) belonged to Group 11. Taken together, our new sequence data of the HERV-W LTR elements may contribute to an understanding of tissue-specific cancer by genomic instability of LTR integration.

• 한국동물학회지
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• 제35권2호
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• pp.211-218
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• 1992

한국산 노랑초파리 군에 속하는 8종의 유전적 유연관계를 밝히고자 생식적 격리 그리고 수용성 단백질을 전기영동법으로 분석하였다. 생리적 격리 실험에서 교배전격리 실험결과를 Watanane와 Kawanishi model에 근거하여 보면 D. aurario complex 3종 중 D. triauror물가 원시종이며 남 auraria는 팍생종으로 나타났다. 교배후 격리 실험에서 나. melonogaster와 D. simuions의 교배시, D. melonogoster를 수컷으로 하였을 때는 불임의 수컷만이, 또 D. melonogaster를 암컷으로 곯였을 때는 불임의 암컷만이 출현하였다. 그리고 남 ouraria complex 3종간의 교배에서는 수정 능력이 있는 수컷과 암컷이 출현하였는데, 이는 아직 남 auraria Complex가 semispecies단계에 있음을 나타내는 것이라 할 수 있다. SDS-PAGE로 분석한 노랑초파리 군 8종의 band pattern을 densitometer로 scanning한 결과 남 susu상가 가장 특이하였으며, TDE에 의한 유전적 거리(Aquadro and Avise's)는 남 auror지와 봉 triauror지사이가 0.155로 가장 낮았고, D. melonogaster와 고. mfa 사이가 0.422로 가장 높았다. 본 연구의 결과를 UPGMA법 뜨로 분석하면, 한국산 노랑초파리 군 8종은 4개의 아군으로 나뉘어지며 이들은 2개의 다른 큰무리로 구분되었는데, D. suzu가기 아군, D. lutescens의 아군, D. melanogoster와 봉 simulons의 아군이 속한 큰무리와, D. mfa,0. ouroria, D. biauroria 그리고 남 triourario가 속한 다른 큰무리로 나눌 수 있다.

• 식물분류학회지
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• 제40권4호
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• pp.208-217
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• 2010

Crossosomatales is a recently recognized order in the rosid II clade with about 64 species in eight morphologically distinct families that have been previously classified in as many as 15 other orders. Phylogenetic relationships among the families and genera within Crossosomatales were investigated using chloroplast atpB, matK, and rbcL sequences employing maximum parsimony, maximum likelihood, and Bayesian methods. The phylogenetic framework was used to examine the patterns of morphological evolution and synapomorphies for subclades within Crossosomatales. The combined data with representative species from all genera in the order strongly supported monophyly of Crossosomatales. Strong support was found for the families in the Southern Hemisphere, in which Aphloiaceae is sister to the clade of (Geissolomataceae, (Ixerbaceae + Strasburgeriaceae)). The sister relationship between the Southern Hemisphere clade and families distributed primarily in the Northern Hemisphere was also supported. As in the previous studies, following relationships were found within the Northern Hemisphere clade: Staphyleaceae is sister to a clade of (Guamatelaceae, (Stachyuraceae + Crossosomataceae)). The pattern analysis indicates that evolutionary pattern of morphological characters is complex, requiring multiple changes within Crossosomatales. Several reproductive traits, such as inflorescence, aril, stigma, and conspicuous protrusion from pollen aperture, corroborate the molecular phylogeny.

• Animal cells and systems
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• 제7권2호
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• pp.159-164
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• 2003

The RAD3 gene of Saccharomyces cerevisiae is required for excision repair and is essential for cell viability. The RAD3 encoded protein possesses a single stranded DNA-dependent ATPase and DNA and DNA-RNA helicase activities. To examine the extent of conservation of structure and function of a S. pombe RAD3 during eukaryotic evolution, the RAD3 homolog gene was isolated by screening of genomic DNA library. The isolated gene was designated as HRD3 (homolog of RAD3 gene). Southern blot analysis confirmed that S. pombe chromosome contains the same DNA as HRD3 gene and this gene exists as a single copy in S. pombe. The transcript of 2.8 kb was detected by Northern blot analysis, The level of transcripts increased by ultraviolet (UV) irradiation, indicating that HRD3 is one of the UV-inducible genes in S. pombe. Furthermore, the predicted partial sequence of HRD3 protein has 60％ identity to S. cerevisiae RAD3 gene. This homology was particularly striking in the regions identified as being conserved in a group of DNA helicases. Gene deletion experiments indicate that the HRD3 gene is essential for viability and DNA repair function. These observations suggest evolutionary conservation of other protein components with which HRD3 might interact in mediating its DNA repair and viability functions.

• Animal cells and systems
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• 제3권1호
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• pp.1-7
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• 1999

Gonadotropin-releasing hormone (GnRH) was originally isolated as a hypothalamic peptide that regulates reproduction by stimulating the release of gonadotropins. Using comparative animal models has led to the discovery that GnRH has a more ancient evolutionary origin. Durinq evolution GnRH peptide underwent gene duplication and structural changes to give rise to multiple molecular forms of GnRHs. Mammalian GnRH initially considered to be the sole molecular form, is now grouped as a family of peptides along with GnRH variants determined from representatives in all classes of vertebrates. Vertebrate species including primates and humanshave more than one GnRH variant in individual brains; a unique GnRH form in the forebrain and chicken IIGnRH in the midbrain. Furthermore, several species of bony fish have three molecular variants of GnRH: salmon GnRH sea-bream GnRH and chicken II GnRH. Also, it has been shown that in addition to the olfactory placodes and the midbrain, there is a third embryonic source of GnRH neurons from the basal diencephalon in birds and fish, which might be true for other vertebrates. Therefore, comparative animal models like fish with discrete sites of expression of three molecular variants of GnRH in individual brains, could provide insight into novel functions of GnRH variants, conservation of gene regulation, and mechanisms governing reproduction in vertebrates.

• Molecules and Cells
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• 제22권3호
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• pp.360-363
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• 2006

Human endogenous retroviruses (HERVs) contribute to various kinds of genomic instability via rearrangement and retrotransposition events. In the present study the formation of a new human-specific solo-LTR belonging to the HERV-H family (AP001667; chromosome 21q21) was detected by a comparative analysis of human chromosome 21 and chimpanzee chromosome 22. The solo-LTR was formed as a result of an equal homologous recombination excision event. Several evolutionary processes have occurred at this locus during primate evolution, indicating that mammalian-wide interspersed repeat (MIR) and full-length HERV-H elements integrated into hominoid genomes after the divergence of Old World monkeys and hominoids, and that the solo-LTR element was created by recombination excision of the HERV-H only in the human genome.

• Journal of Ecology and Environment
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• 제29권4호
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• pp.353-360
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• 2006

Ecological correlates of flowering times often are examined to infer evolutionary mechanisms for flowering time diversities. We examined ecological characteristic associations such as growth habits and pollination modes with flowering times among 3,037 Korean angiosperms experiencing strong climatic seasonalities. We first examined taxonomic membership effects on flowering times across diverse taxonomic levels. Phylogeny constrained flowering times at all levels down to the genus level. We then analyzed the effects of ecological characteristics using subset data consisting of species randomly selected from each genus to control phylogenetic effects. The commonly observed patterns of early flowering of woody species in temperate regions existed. Spring flowering shrubs and trees, however, both being woody, were involved with biotic and abiotic vectors, respectively. In two herbaceous groups of annuals and perennials, annuals flowered later in the growing season than perennials although both herbs tended to be associated with abiotic vectors when flowering in autumn. These results support our hypothesis that species able to decouple vegetative and reproductive growth flower in spring's dry season, but species with different habits, even when they flower within the same season, are subjected to different selective pressures for efficient pollination.