• Journal of Veterinary Science
• /
• 제23권5호
• /
• pp.63.1-63.14
• /
• 2022

Background: Chicken anemia virus (CAV) causes chicken infectious anemia, which results in immunosuppression; the virus has spread widely in chicken flocks in China. Objectives: The aim of this study was to understand recent CAV genetic evolution in chicken flocks in Guangxi Province, southern China. Methods: In total, 350 liver samples were collected from eight commercial broiler chicken farms in Guangxi Province in southern China from 2018 to 2020. CAV was detected by conventional PCR, and twenty CAV complete genomes were amplified and used for the phylogenetic analysis and recombination analysis. Results: The overall CAV-positive rate was 17.1%. The genetic analysis revealed that 84 CAVs were distributed in groups A, B, C (subgroups C1-C3) and D. In total, 30 of 47 Chinese CAV sequences from 2005-2020 belong to subgroup C3, including 15 CAVs from this study. There were some specific mutation sites among the intergenotypes in the VP1 protein. The amino acids at position 394Q in the VP1 protein of 20 CAV strains were consistent with the characteristics of a highly pathogenic strain. GX1904B was a putative recombinant. Conclusions: Subgroup C3 was the dominant genotype in Guangxi Province from 2018-2020. The 20 CAV strains in this study might be virulent according to the amino acid residue analysis. These data help improve our understanding of the epidemiological trends of CAV in southern China.

• 천문학회보
• /
• 제46권2호
• /
• pp.66.3-67
• /
• 2021

Low-mass stars form by the gravitational collapse of dense molecular cores. Observations and theories of low-mass protostars both suggest that accretion bursts happen in timescales of ~100 years with high accretion rates, so called episodic accretion. One mechanism that triggers accretion bursts is infalling fragments from the outer disk. Such fragmentation happens when the disk is massive enough, preferentially activated during the embedded phase of star formation (Class 0 and I). Most observations and models focus on the gas structure of the protostars undergoing episodic accretion. However, the dust and ice composition are poorly understood, but crucial to the chemical evolution through thermal and energetic processing via accretion burst. During the burst phase, the surrounding material is heated up, and the chemical compositions of gas and ice in the disk and envelope are altered by sublimation of icy molecules from grain surfaces. Such alterations leave imprints in the ice composition even when the temperature returns to the pre-burst level. Thus, chemical compositions of gas and ice retain the history of past bursts. Infrared spectral observations of the Spitzer and AKARI revealed a signature caused by substantial heating, toward many embedded protostars at the quiescent phase. We present the AKARI IRC 2.5-5.0 ㎛ spectra for embedded protostars to trace down the characteristics of accretion burst across the evolutionary stages. The ice compositions obtained from the absorption features therein are used as a clock to measure the timescale after the burst event, comparing the analyses of the gas component that traced the burst frequency using the different refreeze-out timescales. We discuss ice abundances, whose chemical change has been carved in the icy mantle, during the different timescales after the burst ends.

• Molecules and Cells
• /
• 제46권6호
• /
• pp.374-386
• /
• 2023

Thermal stress induces dynamic changes in nuclear proteins and relevant physiology as a part of the heat shock response (HSR). However, how the nuclear HSR is fine-tuned for cellular homeostasis remains elusive. Here, we show that mitochondrial activity plays an important role in nuclear proteostasis and genome stability through two distinct HSR pathways. Mitochondrial ribosomal protein (MRP) depletion enhanced the nucleolar granule formation of HSP70 and ubiquitin during HSR while facilitating the recovery of damaged nuclear proteins and impaired nucleocytoplasmic transport. Treatment of the mitochondrial proton gradient uncoupler masked MRP-depletion effects, implicating oxidative phosphorylation in these nuclear HSRs. On the other hand, MRP depletion and a reactive oxygen species (ROS) scavenger non-additively decreased mitochondrial ROS generation during HSR, thereby protecting the nuclear genome from DNA damage. These results suggest that suboptimal mitochondrial activity sustains nuclear homeostasis under cellular stress, providing plausible evidence for optimal endosymbiotic evolution via mitochondria-to-nuclear communication.

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2022년도 추계학술대회
• /
• pp.191-191
• /
• 2022

Heterostyly continues to fascinate evolutionary biologists interested in heredity, evolution, breeding, and adaptive function. Polymorphism demonstrates how simply inherited developmental changes in the location of plant sexual associations can have important consequences for population pollination and mating biology. In contrast to homozygous self incompatibility, only a small number of mating phenotypes can be maintained in the population because insect pollinators have limitations in achieving multiple segregation sites for pollen deposition. Field studies of pollen tube growth have shown that reciprocal style-stamen polymorphisms function to increase the capacity of insect-mediated cross-pollination. The genetic pattern of style morphs is well established in various taxa, but despite recent advances, the identity, number, and structure of the genes controlling the heteromorphic syndrome have been poorly elucidated. The phenomenon of heterostyly in buckwheat has been controlled by gene complex concentrate to S-locus. Homomorphic autogamous buckwheat strains were established by the interspecific hybridization. Backcrossing of this line to the common buckwheat (pin) and selecting homostylar progenies made it possible to introduce the self-compatible gene into common buckwheat. In the result, we obtained the BC₉F₂ generation, and defined the strong linkage between flower type and self-incompatibility by microscopic observation of pollen tube growth. This finding suggests that self-incompatibility character is not controlled by one gene. Moreover, we defined the strong linkage between flower type and self-incompatibility. It strongly supports the S supergene theory. Therefore, we have plan to elucidate the heterostyly self-incompatibility by using molecular genetics, proteome analysis and apply to exploitation of buckwheat improvement. In near future, the expression of heterozygous syndromes in genus Fagopyrum with single isolated heterozygous species may provide clues to early stages of polymorphic assembly and shed light on evolutionary models of heterozygous strains.

• ALGAE
• /
• 제38권4호
• /
• pp.253-264
• /
• 2023

The Ceramiales is the most diverse and species-rich group (2,669 spp.) of red algae, and it is widely distributed from tropical to polar oceans. Mitochondrial genomes (mitogenomes) and other genes have contributed to our knowledge regarding the classification and phylogeny of this diverse red algal group; however, the mitogenome architecture remains understudied. Here, we compared 42 mitogenomes, including 19 newly generated in this study, to expand our knowledge. The number of genes in mitogenome varied from 43 to 68 due to gene duplication. The mitogenome architecture was also variable, categorized into four types (A-D): type A = ancestral type with a basic composition; type B = those with inverse transpositions; type C = those with inverted duplications; and type D = those with both inversion and duplication. The palindromic and inverted repeats were consistently found in flanking regions of the rearrangement, especially near the cob and nad6 genes. The three rearranged mitogenome architectures (types B, C, D) are the first report of these in red algae. Phylogenetic analyses of 23 protein-coding genes supported the current familial classification of the Ceramiales, implying that the diversity of mitogenome architecture preceded the phylogenetic relationships. Our study suggests that palindromic and inverted repeats may drive mitogenome architectural variation.

• 천문학회지
• /
• 제24권2호
• /
• pp.217-271
• /
• 1991

We have observed dense core around young stellar objects, DR21, S140, Orion-KL, and L1551 using four millimeter-wave transitions of $HC_3N\;J$=4-3, J=5-4, J=10-9, and J=12-11. The spatial distribution of $HC_3N$ emission closely resembles the morphology of the previous CS observations that trace high density gas. These observations reveal the existence of $HC_3N$ dense cores around central IR source, elliptical in shape and almost perpendicular to the CO bipolar outflow axis. Small differences can be explained by that $HC_3N$ molecular line is more optically thin and is seen to be more detailed structure in the neighborhood of central IR sources. In S140 and Orion-KL, massive(${\sim}10\;M_{\odot}$), slowly rotating dense cores lie near at the central IR sources of bipolar outflows. The velocity channel maps of DR21 show that the bipolar outflow gas may have a correlation with the dense core of DR21. We analyzed intensities of the four lines to derive physical conditions in dense core from two methods, LTE and LVG. The column density of $HC_3N$, $N(HC_3N)$, between LTE and LVG calculations agree well with each other. The abundances of $HC_3N$ in each observing source have been estimated using the average values of $n(H_2)$ and $N(HC_3N)$ and assuming the size of dense core. The fractional $HC_3N$ abundances in massive dense cores of DR21, S140, and Orion-KL have a range of $(2-7){\times}10^{-10}$, while that of low mass dense core, L1551, has one order of magnitude greater value of $2{\times}10^{-9}$. This should be considered good agreement with the result by Morris et al.(1976). It may be considered that dense cores of DR21, S140, and Orion-KL may have almost same stage of chemical evolution, and their abundances have a small values relative to that of L1551. The column density $N(HC_3N)$ decreases with increasing distance from the densest part of the cloud, the central infrared source, and have the relation of $N(HC_3N){\varpropto}R^{\alpha}$, where a has a range of 0.65 to 0.89. The values of $n(H_2)$ are not varied with increasing distance from the dense core, and have almost same values. Therefore, it is considered that the dense cores in these regions probably consist of dense clumps in diffuse molecular gas medium, and $n(H_2)$ of each clump is ${\sim}10^5\;cm^{-3}$. Levels in the $T_{ex}$ increases with $n(H_2)$. It is considered that the $HC_3N$ dense cores are not completely thermalized. We examine the relationships between the luminosity of central infrared sources versus mass of the dense cores, and the luminosity of central infrared sources versus molecular hydrogen column density. Luminosities of the central IR sources show good correlation with mass and hydrogen column density of the dense core. Same has been found from CS observations. However, mass and size derived from $HC_3N$ observations are one order of magnitude smaller than those from CS. It can be interpreted that we see more central part of the cloud cores in $NC_3N$ lines than CS lines.

• 한국광학회지
• /
• 제14권1호
• /
• pp.23-32
• /
• 2003

타원법(ellipsometry)을 사용하여 광기록 매체용 Ge$_2$ Sb$_2$ Te$^{5}$ (GST) 박막의 성장과정에 따른 타원상수 Ψ와 $\Delta$를 측정하여. GST 박막의 최적성장조건을 연구하였다. 아르곤기체압력과 DC 출력 그리고 기판의 온도를 변화시키면서 GST 박막을 성장시켰다. 제작된 시료들의 분광타원 데이터를 모델링 분석하여 GST박막의 밀도분포를 구하고 한편으로는 GST 박막이 성장하는 동안 측정한 in situ 타원 성장곡선을 분석하여 박막의 밀도분포의 변화를 추적하였다. 아르곤기체압력이 7 mTorr일 때 박막의 상대적인 밀도분포가 고르게 되었고 DC출력이 증가함에 따라 그리고 기판의 온도가 증가함에 따라 GST 박막의 밀도 균일성은 크게 향상되었다. 주사형전자현미경(SEM)을 사용하여 최적 밀도 균일성을 가지는 성장조건(7 mTorr, 45 W, 15$0^{\circ}C$)에서 제작된 GST 시료가 가장 균일한 구조를 보여줌을 확인하였다. 균일한 밀도 분포를 가지는 GST 박막의 성장조건 확립을 통하여 여러번 기록/재생할 때 광기록 박막의 안정성을 유지하는데 크게 기여할 것이다.

• 생명과학회지
• /
• 제18권2호
• /
• pp.264-272
• /
• 2008

풀망둑(Acanthogobius hasta) 조직의 젖산탈수소효소(EC 1.1.1.27 Lactate dehydrogenase, LDH) 동위 효소의 특성을 생화학적, 면역화학적 및 역학적 방법에 의해 연구하였다. 풀망둑 골격근과 눈 조직의 젖산탈수소효소 활성이 65.30과 53.25 units였고, 심장과 간 조직에서는 낮게 나타났다. 골격근 조직의 LDH/CS는 22.29로 가장 높고, LDH 특이활성도는 뇌 56.45, 눈 38.04 및 골격근 11.04 units/mg였다. 각 조직에 대해 $A_4,\;B_4$, eye-specific $C_4$, 및 liver-specific $C_4$에 대한 항혈청으로 면역 침강 반응시킨 후 Polyacrylamide gel 전기영동 하였다. 골격근, 뇌 및 눈 조직에서 $A_4$ 동위효소가 우세하게 확인되었고, 심장에서는 $A_4$ 동위효소가 확인되었다. 또한 양극의 eye-specific t와 음극의 liver-specific $C_4$가 한 종에서 함께 발현되었으며, 눈 조직의 eye-specific $C_4$는 활성이 크고 간 조직의 liver-Specific $C_4$의 활성은 낮게 나타났다. 결과 $A_4$와 $C_4,\;A_4$와 $B_4$ 및 eye-specific $C_4$와 liver-specific $C_4$의 분자구조의 일부가 서로 유사하지만 $B_4$와 $C_4$의 구조는 서로 다른 것으로 나타났으므로 하부단위체 A는 보존적이고 하부단위체 B는 하부단위체 A보다 빠르게 진화된 것으로 사료된다. 골격근 조직의 LDH $A_4$ 동위효소는 affinity chromatography에서 $NAD^+$를 함유한 buffer를 유입한 후 용출된 분획에서 정제되었고, eye-specific $C_4$ 동위효소는 $A_4$ 분획에 이어 용출되었으므로 eye-specific $C_4$가 $A_4$의 분자 구조와 유사한 것으로 보인다. 그리고 LDH에 대한 피루브산의 저해 실험 결과 35.22-43.47% 의 활성이 남았고, $Km_{pyr}$은 0.080-0.098 mM이고 골격근과 눈조직의 Vmax은 153.85와 35.09 units였다. 또한 $B_4$ 동위효소가 열에 대해 가장 안정하였고 $C_4$는 $A_4$보다 안정하였으며, 최적 pH는 6.5로 나타났다. 본 실험 결과 풀망둑은 저 산소 환경조건에 적응되어져 조직들의 동위효소들이 $A_4$와 $B_4$ 동위효소 사이의 특성을 나타냈고, 골격근과 눈 조직에서 피루브산에 대한 LDH의 친화력이 상당히 크므로 LDH가 혐기적 조건에서 효율적으로 기능을 하는 것으로 사료된다.

• 생명과학회지
• /
• 제18권12호
• /
• pp.1733-1738
• /
• 2008

SLC6A18은 neurotransmitter로서 고혈압과 연관성이 보고 되었고, 유전자 내에 총 8개의 minisatellites가 존재함이 밝혀졌다. 본 연구에서 8개 minisatellites 중 가장 높은 heterozygosity를 나타내는 SLC6A18-MS5 영역에 대하여 생물정보학적 방법으로 Transfac software를 이용하여 transcription factor binding site를 분석한 결과, Pax4와 HNF4의 binding site를 발견하였다. HNF4는 당뇨병 대사에 관여하는 것으로 고혈압과의 연관성이 있을 것으로 사료된다. 그러므로 본 연구에서는 SLC6A18-MS5 영역과 고혈압과의 연관성을 조사하기 위하여, 대조군 301명과 고혈압 환자군 184명의 genomic DNA를 이용하여 대립형질의 패턴을 조사하였다. SLC6A18-MS5의 대립형질 분포와 고혈압은 직접적인 영향을 주지 않는 것으로 나타났다. 반면 높은 heterozygosity를 나타내는 SLC6A18-MS5에 친자확인 및 DNA typing 마커로서의 유용성을 알아보기 위해 20가족의 샘플을 이용하여, 감수분열 후 자손에의 분리 형태를 조사한 결과 부모에게서 자손으로 정확히 전달되는 멘델의 법칙에 의해 분리됨을 확인하였다. 또한 SLC6A18 유전자 내의 minisatellites들의 진화적 관계를 조사한 결과, 인간과 원숭이에서만 보존적으로 나타났다. 이러한 결과는 intron영역의 minisatellites 분석이 영장류의 비암호화 영역의 중요한 진화 마커로 사용될 수 있음을 나타내어, 영장류 특이적 진화를 이해하는데 도움이 될 것으로 사료된다.

• 공업화학
• /
• 제20권3호
• /
• pp.322-328
• /
• 2009

Octamethylcyclotetrasiloxane (OMCTS)을 에멀젼 상태에서 초음파를 조사하여 polydimethylsiloxane (PDMS)을 중합하였다. 중합에 활용된 초음파 반응기는 주파수가 20 KHz의 horn 유형과 40 KHz의 bath 유형이었으며, horn과 bath를 혼용한 경우의 중합 공정의 특성도 평가해 보았다. 고려된 주요 변수들은 반응 온도와 초음파 조사 시간 이었으며, 중합물에 대하여 각 시료의 고유 점도와 전환율 측정을 통하여 각 중합공정의 효율성과 특성을 조사하고, 최적의 공정 조건을 도출해 보고자 하였다. Horn 유형의 반응기에서는 수 분 이내에 80% 이상의 전환율이 달성되고 높은 점도의 PDMS를 얻을 수 있었으나, 조사 시간에 따라 전환율과 점도는 최대값을 보인 이후에 감소하는 경향을 나타내었다. 초음파의 강도가 상대적으로 약하게 유지되는 bath 유형의 반응기에서는 1 h 이상의 조사가 필요하였으며, horn 유형과 달리 전환율과 점도가 조사 시간에 따라 지속적으로 증가하는 경향이 지배적이었다. Horn유형과 bath유형을 조합한 혼합형 반응기에서는 다른 반응기와는 매우 다른 결과들이 나타났으며, 각 반응기의 특성은 전산 모사를 이용한 반응기 내의 음파 해석을 바탕으로 설명되었다.