• Title/Summary/Keyword: evolutionary biology

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A genetic approach to comprehend the complex and dynamic event of floral development: a review

  • Jatindra Nath Mohanty;Swayamprabha Sahoo;Puspanjali Mishra
    • Genomics & Informatics
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    • v.20 no.4
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    • pp.40.1-40.8
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    • 2022
  • The concepts of phylogeny and floral genetics play a crucial role in understanding the origin and diversification of flowers in angiosperms. Angiosperms evolved a great diversity of ways to display their flowers for reproductive success with variations in floral color, size, shape, scent, arrangements, and flowering time. The various innovations in floral forms and the aggregation of flowers into different kinds of inflorescences have driven new ecological adaptations, speciation, and angiosperm diversification. Evolutionary developmental biology seeks to uncover the developmental and genetic basis underlying morphological diversification. Advances in the developmental genetics of floral display have provided a foundation for insights into the genetic basis of floral and inflorescence evolution. A number of regulatory genes controlling floral and inflorescence development have been identified in model plants such as Arabidopsis thaliana and Antirrhinum majus using forward genetics, and conserved functions of many of these genes across diverse non-model species have been revealed by reverse genetics. Transcription factors are vital elements in systems that play crucial roles in linked gene expression in the evolution and development of flowers. Therefore, we review the sex-linked genes, mostly transcription factors, associated with the complex and dynamic event of floral development and briefly discuss the sex-linked genes that have been characterized through next-generation sequencing.

Effects of salinity and irradiance on early developmental stages of Grateloupia turuturu (Halymeniaceae, Rhodophyta) tetrasporophytes

  • Jae Woo Jung;Qikun Xing;Ji-Sook Park;Charles Yarish;Jang K. Kim
    • ALGAE
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    • v.38 no.2
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    • pp.151-157
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    • 2023
  • Grateloupia turuturu is a red alga with a flat but firm slippery thallus. Throughout its lifetime, this alga experiences a wide range of environmental stresses in the intertidal rocky shores. The aim of this study is to investigate the effect of salinity and irradiance on the early developmental stages of G. turuturu tetrasporophytes. The released carpospores were cultivated at different salinities (S = 15, 25, and 35) and irradiances (50, 100, and 200 μmol photons m-2 s-1). Germination of carpospores and development of juvenile tetrasporophytes were observed every 5 days and recorded by a digital camera. Discoid crusts were formed at all conditions within 5 days. The discoid crusts at 200 μmol photons m-2 s-1 died within 20 days regardless the salinity. The discoid crusts at S = 35 also died at all irradiance conditions within 25 days. Except for those at S = 35 and 200 μmol photons m-2 s-1, the discoid crusts reached about 8,000-9,000 ㎛2 by day 20. Regardless of irradiance, the upright thalli formation rate from discoid crusts was 85 and 10% at S = 15 and S = 25, respectively. These results suggest that salinity and irradiance are important factors influencing early developmental stages of G. turuturu.

Ruvbl1 is Essential for Ciliary Beating during Xenopus laevis Embryogenesis

  • Chan Young Kim;Hyun-Kyung Lee;Hongchan Lee;Hyun-Shik Lee
    • Development and Reproduction
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    • v.27 no.3
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    • pp.159-165
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    • 2023
  • The Ruvb-like AAA ATPase1 (Ruvbl1; also known as Pontin) is an evolutionary conserved protein belonging to the adenosine triphosphates associated with diverse cellular activities (AAA+) superfamily of ATPases. Ruvbl1 is a component of various protein supercomplexes and is involved in a variety of cellular activities, including chromatin remodeling, DNA damage repair, and mitotic spindle assembly however, the developmental significance of this protein is unknown and needs detailed investigation. We investigated the developmental significance of Ruvbl1 in multiciliated cells of the Xenopus laevis epidermis since ruvbl1 is expressed in the multiciliated cells and pronephros during X. laevis embryogenesis. The knockdown of ruvbl1 significantly impaired cilia-driven fluid flow and basal body polarity in the X. laevis epidermis compared to control embryos, but did not affect cilia morphology. Our results suggest that Ruvbl1 plays a significant role in embryonic development by regulating ciliary beating; however, further investigation is needed to determine the mechanisms involved.

A Comparative Study of Korean and United States College Students' Degree of Religiosity, Evolutionary Interest, Understanding and Acceptance and Their Structures (한국과 미국 대학생들의 종교성, 진화 흥미, 진화 개념, 진화 수용의 수준과 구조 비교)

  • Ha, Minsu;Cha, Heeyoung;Ku, Seulae
    • Journal of The Korean Association For Science Education
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    • v.32 no.10
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    • pp.1537-1550
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    • 2012
  • This study aims to explore the differences between Korean and United States college students regarding their degree of religiosity, interest in, understanding and acceptance of evolution, and the effects of their interaction on these variables. A total of one thousand and fifteen Korean and US biology majors and non-majors college students participated in this study and a sub sample of 516 students were randomly selected for statistical tests. The results illustrated that Korean college students harbored significantly lower degrees of religiosity and interest in evolution but significantly higher degrees of knowledge and acceptance of evolution than US college students. The path analysis uncovered that the knowledge of and interest in evolution played a mediating role between religiosity and acceptance of evolution. Korean college students' interest in evolution was less correlated to other variables than US college students' interest. The acceptance of evolution was less predicted by knowledge of evolution in the Korean biology major sample than in the US biology major sample. The acceptance of evolution was predicted more by religiosity in the Korean non-major sample than in US non-major sample. This study suggests that future Korean science curriculum for evolution needs to enhance the degree of students' interest in evolution. In addition, future Korean science curriculum needs an instructional strategy in developing students' ability to make scientific decisions, such as the acceptance of evolution, without interference from their personal religious belief.

Analysis of Mis-conceptualizations regarding Evolution Originating from TV Animation and Science Books for Children (TV 만화와 아동 과학 도서에 의한 진화의 오개념 분석)

  • Ha, Min-Su;Cha, Hee-Young
    • Journal of Korean Elementary Science Education
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    • v.25 no.4
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    • pp.352-362
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    • 2006
  • Many misconceptions regarding biology and evolution have been reported by students prior to being exposed to a formal education program of evolution which challenged them. This study sought to investigate and to analyze the misconception formation process of evolution originating from TV animation and science books for children. Firstly, to identify TV animation's influence on students' misconceptions of evolution, a questionnaire including TV animation characters was constructed and administered to 146 elementary school students, 161 middle school students, and 156 high school students. The data collected was analyzed. Secondly, 17 science books for children were sampled and the contents related to evolution were selected and analyzed in terms of five evolutionary explanations: creationism internal will explanation, teleological explanations, explanations of use and disuse, mutation and finally, natural selection. Children have understood 'growth' and 'metamorphosis' on TV animation as 'evolution'. The processes by which characters on TV animation undergo some forms of change, which are in fact a kind of metamorphosis has often been understood as 'evolution'. Many respondents have defined evolution incorrectly as the process of growing and changing shape. On the other hand, some science books fur children contained descriptions of evolution including' mutation and finally natural selection explanation'; however, most of the science books fur children sampled in this study were written through the perspectives of alternative evolutionary views such as 'teleology view', 'internal will view', and 'use and disuse view'. It is apparent that TV animation and science books fur children influence the formation of various misconceptions regarding evolution by children.

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Genomic characterization of clonal evolution during oropharyngeal carcinogenesis driven by human papillomavirus 16

  • Chae, Jeesoo;Park, Weon Seo;Kim, Min Jung;Jang, Se Song;Hong, Dongwan;Ryu, Junsun;Ryu, Chang Hwan;Kim, Ji-Hyun;Choi, Moon-Kyung;Cho, Kwan Ho;Moon, Sung Ho;Yun, Tak;Kim, Jong-Il;Jung, Yuh-Seog
    • BMB Reports
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    • v.51 no.11
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    • pp.584-589
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    • 2018
  • Secondary prevention via earlier detection would afford the greatest chance for a cure in premalignant lesions. We investigated the exomic profiles of non-malignant and malignant changes in head and neck squamous cell carcinoma (HNSCC) and the genomic blueprint of human papillomavirus (HPV)-driven carcinogenesis in oropharyngeal squamous cell carcinoma (OPSCC). Whole-exome (WES) and whole-genome (WGS) sequencing were performed on peripheral blood and adjacent non-tumor and tumor specimens obtained from eight Korean HNSCC patients from 2013 to 2015. Next-generation sequencing yielded an average coverage of $94.3{\times}$ for WES and $35.3{\times}$ for WGS. In comparative genomic analysis of non-tumor and tumor tissue pairs, we were unable to identify common cancer-associated early mutations and copy number alterations (CNA) except in one pair. Interestingly, in this case, we observed that non-tumor tonsillar crypts adjacent to HPV-positive OPSCC appeared normal under a microscope; however, this tissue also showed weak p16 expression. WGS revealed the infection and integration of high-risk type HPV16 in this tissue as well as in the matched tumor. Furthermore, WES identified shared and tumor-specific genomic alterations for this pair. Clonal analysis enabled us to infer the process by which this transitional crypt epithelium (TrCE) evolved into a tumor; this evolution was accompanied by the subsequent accumulation of genomic alterations, including an ERBB3 mutation and large-scale CNAs, such as 3q27-qter amplification and 9p deletion. We suggest that HPV16-driven OPSCC carcinogenesis is a stepwise evolutionary process that is consistent with a multistep carcinogenesis model. Our results highlight the carcinogenic changes driven by HPV16 infection and provide a basis for the secondary prevention of OPSCC.

P Element-Mediated Transformation with the rosy Gene in Drosophila melanogaster (D. melanogaster에 있어서 P Element를 이용한 rosy 유전자의 형질전환)

  • Kim, Wook;Kidwell, Margaret G.
    • The Korean Journal of Zoology
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    • v.38 no.3
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    • pp.340-347
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    • 1995
  • We have used two kinds of P element constructs, Pc[(ry+)B] and p[(ry+)$\Delta$SX9], for genetic transformation by microinjection of D. melanogaster. Pc[(ry+)B] construct carrying the rosy gene within an autonomous P element was injected into a true M strain caring the ry506. mutation. The source of transposase for microinjection and transformation was provided by a P element helper plasmid designated p-$\Delta$2-3hs$\pi$, which was co-injected with nonautonomous P[(ry+)$\Delta$SX9] construct into same ry506 M strains. A dechorination method was adopted and 35 independent transformed lines were obtained froin 1143 G0 Injected (35/1143). About 20% of the injected embryos eclosed as adults. Among G0 eclosed flies, approximately 40% exhibited eye color that was similar to wild-type (ry+), but about 60% of fertile G0 transformed lines appeared to have no G1 transformants. Therefore it is unlikely that G0 expression requires integration of the rosy transposon into chromosomes. Pc[(ry+)B] and P[(ry+)$\Delta$SX9] constructs were found to be nearly same in the frequency of element-mediated transformation. On the basis of these results, nonautonomous P elements constructs could he used as same effective vectors in P element-mediated transformation for introducing and fixing genes in insect populations.

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Interaction between the Rice Pathogens, Fusarium graminearum and Burkholderia glumae

  • Lee, Jungkwan;Jung, Boknam;Park, Jungwook;Kim, Sungyoung;Youn, Kihun;Seo, Young-Su
    • 한국균학회소식:학술대회논문집
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    • 2014.10a
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    • pp.13-13
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    • 2014
  • Species belonging to the genus Fusarium are widely distributed and cause diseases in many plants. Isolation of fungal strains from air or cereals is necessary for disease forecasting, disease diagnosis, and population genetics [1]. Previously we showed that Fusarium species are resistant to toxoflavin produced by the bacterial rice pathogen Burkholderia glumae while other fungal genera are sensitive to the toxin, resulting in the development of a selective medium for Fusarium species using toxoflavin [2]. In this study, we have tried to elucidate the resistant mechanism of F. graminearum against toxoflavin and interaction between the two pathogens in nature. To test whether B. glumae affects the development of F. graminearum, the wild-type F. graminearum strains were incubated with either the bacterial strain or supernatant of the bacterial culture. Both conditions increased the conidial production five times more than when the fungus was incubated alone. While co-incubation resulted in dramatic increase of conidial production, conidia germination delayed by either the bacterial strain or supernatant. These results suggest that certain factors produced by B. glumae induce conidial production and delay conidial germination in F. graminearum. To identify genes related to toxoflavin resistance in F. graminearum, we screened the transcriptional factor mutant library previously generated in F. graminearum [3] and identified one mutant that is sensitive to toxoflavin. We analyzed transcriptomes of the wild-type strain and the mutant strain under either absence or presence of toxoflavin through RNAseq. Expression level of total genes of 13,820 was measured by reads per kilobase per million mapped reads (RPKM). Under the criteria with more than two-fold changes, 1,440 genes were upregulated and 1,267 genes were down-regulated in wild-type strain than mutant strain in response to toxoflavin treatment. A comparison of gene expression profiling between the wild type and mutant through gene ontology analysis showed that genes related to metabolic process and oxidation-reduction process were highly enriched in the mutant strain. The data analyses will focus on elucidating the resistance mechanism of F. graminearum against toxoflavin and the interaction between the two pathogens in rice. Further evolutionary history will be traced through figuring out the gene function in populations and in other filamentous fungi.

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Longevity Genes: Insights from Calorie Restriction and Genetic Longevity Models

  • Shimokawa, Isao;Chiba, Takuya;Yamaza, Haruyoshi;Komatsu, Toshimitsu
    • Molecules and Cells
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    • v.26 no.5
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    • pp.427-435
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    • 2008
  • In this review, we discuss the genes and the related signal pathways that regulate aging and longevity by reviewing recent findings of genetic longevity models in rodents in reference to findings with lower organisms. We also paid special attention to the genes and signals mediating the effects of calorie restriction (CR), a powerful intervention that slows the aging process and extends the lifespan in a range of organisms. An evolutionary view emphasizes the roles of nutrient-sensing and neuroendocrine adaptation to food shortage as the mechanisms underlying the effects of CR. Genetic and non-genetic interventions without CR suggest a role for single or combined hormonal signals that partly mediate the effect of CR. Longevity genes fall into two categories, genes relevant to nutrient-sensing systems and those associated with mitochondrial function or redox regulation. In mammals, disrupted or reduced growth hormone (GH)-insulin-like growth factor (IGF)-1 signaling robustly favors longevity. CR also suppresses the GH-IGF-1 axis, indicating the importance of this signal pathway. Surprisingly, there are very few longevity models to evaluate the enhanced anti-oxidative mechanism, while there is substantial evidence supporting the oxidative stress and damage theory of aging. Either increased or reduced mitochondrial function may extend the lifespan. The role of redox regulation and mitochondrial function in CR remains to be elucidated.

Purification and Characterization of Repressor of Temperate S. aureus Phage Φ11

  • Das, Malabika;Ganguly, Tridib;Chattoraj, Partho;Chanda, Palas Kumar;Bandhu, Amitava;Lee, Chia Yen;Sau, Subrata
    • BMB Reports
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    • v.40 no.5
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    • pp.740-748
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    • 2007
  • To gain insight into the structure and function of repressor proteins of bacteriophages of gram-positive bacteria, repressor of temperate Staphylococcus aureus phage ${\phi}11$ was undertaken as a model system here and purified as an N-terminal histidine-tagged variant (His-CI) by affinity chromatography. A ~19 kDa protein copurified with intact His-CI (~ 30 kDa) at low level was resulted most possibly due to partial cleavage at its Ala-Gly site. At ~10 nM and higher concentrations, His-CI forms significant amount of dimers in solution. There are two repressor binding sites in ${\phi}11$ cI-cro intergenic region and binding to two sites occurs possibly by a cooperative manner. Two sites dissected by HincII digestion were designated operators $O_L$ and $O_R$, respectively. Equilibrium binding studies indicate that His-CI binds to $O_R$ with a little more strongly than $O_L$ and binding species is probably dimeric in nature. Interestingly His-CI binding affinity reduces drastically at elevated temperatures ($32-42^{\circ}C$). Both $O_L$ and $O_R$ harbor a nearly identical inverted repeat and studies show that ${\phi}11$ repressor binds to each repeat efficiently. Additional analyses indicate that ${\phi}11$ repressor, like $\lambda$ repressor, harbors an N-terminal domain and a C-terminal domain which are separated by a hinge region. Secondary structure of ${\phi}11$ CI even nearly resembles to that of $\lambda$ phage repressor though they differ at sequence level. The putative N-terminal HTH (helix-turn-helix) motif of ${\phi}11$ repressor belongs to the HTH -XRE-family of proteins and shows significant identity to the HTH motifs of some proteins of evolutionary distant organisms but not to HTH motifs of most S. aureus phage repressors.