• Title/Summary/Keyword: evolutionary biology

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Occurrence and Evolutionary Analysis of Coat Protein Gene Sequences of Iranian Isolates of Sugarcane mosaic virus

  • Moradi, Zohreh;Nazifi, Ehsan;Mehrvar, Mohsen
    • The Plant Pathology Journal
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    • v.33 no.3
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    • pp.296-306
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    • 2017
  • Sugarcane mosaic virus (SCMV) is one of the most damaging viruses infecting sugarcane, maize and some other graminaceous species around the world. To investigate the genetic diversity of SCMV in Iran, the coat protein (CP) gene sequences of 23 SCMV isolates from different hosts were determined. The nucleotide sequence identity among Iranian isolates was more than 96%. They shared nucleotide identities of 75.5-99.9% with those of other SCMV isolates available in GenBank, the highest with the Egyptian isolate EGY7-1 (97.5-99.9%). The results of phylogenetic analysis suggested five divergent evolutionary lineages that did not completely reflect the geographical origin or host plant of the isolates. Population genetic analysis revealed greater between-group than within-group evolutionary divergence values, further supporting the results of the phylogenetic analysis. Our results indicated that natural selection might have contributed to the evolution of isolates belonging to the five identified SCMV groups, with infrequent genetic exchanges occurring between them. Phylogenetic analyses and the estimation of genetic distance indicated that Iranian isolates have low genetic diversity. No recombination was found in the CP cistron of Iranian isolates and the CP gene was under negative selection. These findings provide a comprehensive analysis of the population structure and driving forces for the evolution of SCMV with implications for global exchange of sugarcane germplasm. Gene flow, selection and somehow homologous recombination were found to be the important evolutionary factors shaping the genetic structure of SCMV populations.

Optimization and Molecular Characterization of Exoelectrogenic Isolates for Enhanced Microbial Fuel Cell Performance

  • Nwagu, Kingsley Ekene;Ekpo, Imo A.;Ekaluo, Benjamin Utip;Ubi, Godwin Michael;Elemba, Munachimso Odinakachi;Victor, Uzoh Chukwuma
    • Microbiology and Biotechnology Letters
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    • v.47 no.4
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    • pp.621-629
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    • 2019
  • In this study we attempted to screen bacteria and fungi that generate electricity while treating wastewater using optimized double-chamber microbial fuel cell (MFC) system parameters. Optimization was carried out for five best exoelectrogenic isolates (two bacteria and three fungi) at pH values of 6.0, 7.5, 8.5, and 9.5, and temperatures of 30, 35, 40, and 45℃; the generated power densities were measured using a digital multimeter (DT9205A). The isolates were identified using molecular characterization, followed by the phylogenetic analysis of isolates with known exoelectrogenic microorganisms. The bacterium, Proteus species, N6 (KX548358.1) and fungus, Candida parapsilosis, S10 (KX548360) produced the highest power densities of 1.59 and 1.55 W/m2 (at a pH of 8.5 and temperatures of 35 and 40℃) within 24 h, respectively. Other fungi-Clavispora lusitaniae, S9 (KX548359.1) at 40℃, Clavispora lusitaniae, S14 (KX548361.1) at 35℃-and bacterium-Providencia species, N4 (KX548357.1) at 40℃-produced power densities of 1.51, 1.46, and 1.44 W/m2, respectively within 24 h. The MFCs achieved higher power densities at a pH of 8.5, temperature of 40℃ within 24 h. The bacterial isolates have a close evolutionary relationship with other known exoelectrogenic microorganisms. These findings helped us determine the optimal pH, temperature, evolutionary relationship, and exoelectrogenic fungal species other than bacteria that enhance MFC performance.

In vitro Constructive Approaches to the Origin of Coding Sequences

  • Shiba, Kiyotaka
    • BMB Reports
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    • v.31 no.3
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    • pp.209-220
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    • 1998
  • How did nature create the first set of genes at the beginning of life on Earth? One of the goals of molecular biology is to elucidate the fundamental rules governing how genes and, therefore, proteins were created. Through experiments carried out in the emerging field of "in vitro" or "benchtop" evolution studies, we are gaining new insights into the origins of genes and proteins as well as the origins of their functions (e.g., catalysis). In this review, I present an overview of recent experimental approaches to the question of the origin and evolution of genes. In addition, I will introduce a novel in vitro protein emergence system that was recently developed in my laboratory.

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Bioinformatic approaches for the structure and function of membrane proteins

  • Nam, Hyun-Jun;Jeon, Jou-Hyun;Kim, Sang-Uk
    • BMB Reports
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    • v.42 no.11
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    • pp.697-704
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    • 2009
  • Membrane proteins play important roles in the biology of the cell, including intercellular communication and molecular transport. Their well-established importance notwithstanding, the high-resolution structures of membrane proteins remain elusive due to difficulties in protein expression, purification and crystallization. Thus, accurate prediction of membrane protein topology can increase the understanding of membrane protein function. Here, we provide a brief review of the diverse computational methods for predicting membrane protein structure and function, including recent progress and essential bioinformatics tools. Our hope is that this review will be instructive to users studying membrane protein biology in their choice of appropriate bioinformatics methods.

Individual Recognition between Siblings of the Young Black-tailed Gull (Larus crassirostris)

  • Chung, Hoon;Lee, Hyun-Jung;Park, Shi-Ryong
    • The Korean Journal of Ecology
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    • v.25 no.6
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    • pp.365-369
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    • 2002
  • We had 18 eggs artificially hatched in a mass breeding place of black-tailed gulls and examined the individual recognition between young siblings in a laboratory environment. The results of the experiment showed that the young gulls selectively responded to their siblings and non-siblings at an early stage after hatching. It was shown that they began to recognize the begging call among the voice signals of siblings and non-siblings 15-16 days after hatching, and the chirirah call 11-12 days after hatching. Also, more significant results were shown with the chirirah call than with the begging call. In an experiment of visual recognition between siblings and non-siblings, the young black-tailed gulls approached their siblings significantly 9-10 days after hatching. The recognition between young siblings in a mass breeding place provides an important evolutionary indicator in terms of their social behaviors.

Comparative analyses of susceptibility to chemicals associated with fermentation between Drosophila melanogaster and Drosophila suzukii

  • KIM, YiSeul;LEE, Sungho;KIM, Yeong Ho;KIM, Young Ho
    • Entomological Research
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    • v.48 no.6
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    • pp.514-521
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    • 2018
  • Drosophila melanogaster Meigen and Drosophila suzukii Matsumura are taxonomically close Drosophila species belonging to the family Drosophilidae and melanogaster group. D. melanogaster is thought to be evolutionarily adapted to overripe, decaying, and fermented fruits, in which large amounts of chemicals such as ethanol, acetic acid, and 2-phenylethanol are produced, whereas, D. suzukii is attracted to fresh ripening fruit. Considering the distinct habitats of the two flies, D. suzukii is hypothesized to exhibit higher susceptibility to these chemicals than D. melanogaster. Therefore, in this study, we investigated the survival rate of the flies at various concentrations of three chemicals (2-phenlyethanol, acetic acid, and ethanol) and calculated the lethal concentration (LC) values to compare the tolerance and susceptibility of D. melanogaster and D. suzukii to the chemicals. Our results revealed that D. melanogaster exhibited higher tolerance than D. suzukii to all chemicals, supporting the hypothesis of different evolutionary adaptations to distinct habitats of the two flies.

Endless debates on the extant basal-most angiosperm (현생 기저 피자식물에 대한 끝나지 않는 논쟁)

  • Kim, Sangtae
    • Korean Journal of Plant Taxonomy
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    • v.40 no.1
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    • pp.1-15
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    • 2010
  • Recognizing a basal group in a taxon is one of the most important factors involved in understanding the evolutionary history of that group of life. Many botanists have suggested a sister to all other angiosperms to understand the origin and rapid diversification of angiosperms based on morphological and fossil evidence. Recent technical advances in molecular biology and the accumulation of molecular phylogenetic data have provided evidence of the extant basal-most angiosperm which is a sister to all other angiosperms. Although it is still arguable, most plant taxonomists agree that Amborella trichopoda Baill., a species (monotypic genus and monotypic family) distributed in New Caledonia, is a sister to all other extant angiosperms based on evidence from the following molecular approaches: 1) classical phylogenetic analyses based on multiple genes (or DNA regions), 2) analyses of a tree network of duplicated gene families, and 3) gene-structural evidence. As an alternative hypothesis with relatively minor evidence, some researchers have also suggested that Amborella and Nymphaeaceae form a clade that is a sister to all other angiosperms. Debate regarding the basal-most angiosperms is still ongoing and is currently one of the hot issues in plant evolutionary biology. We expect that sequencing of the whole genome of Amborella as an evolutionary model plant and subsequent studies based on this genome sequence will provide information regarding the origin and rapid diversification of angiosperms, which is Darwin's so called abominable mystery.

Pre-service Biology Teachers' Understanding of the Real-World Application of Evolutionary Theory (생물 예비교사들의 진화 이론의 실용성에 관한 인식)

  • Ha, Min-Su;Lee, Jun-Ki
    • Journal of The Korean Association For Science Education
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    • v.31 no.8
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    • pp.1186-1198
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    • 2011
  • The understanding of real-world application of scientific knowledge such as the evolutionary theory has been emphasized in science curriculum. Despite this, many students and biology educators misunderstand the use and practical application of the evolution theory. The purpose of this study is to explore variables related to the understanding of practical application of evolution. Methodologically, we employed large-scale survey that examined three independent variables (major, academic year, and religion) and five dependent variables (understanding of practical application of evolution, knowledge of, interest in, and acceptance of evolution, and religiosity). Two hundred and thirty three biology pre-service teachers and 405 non-biology pre-service teachers participated in the survey. The results demonstrate that the biology teacher education program does not help in increasing the understanding of the practical application of evolution. Rather, the understanding of practical application of evolution was associated with their religion. In addition, the understanding of the practical application of evolution was associated with the acceptance of and interest in evolution. The results of this study inform the development of new biology teacher education programs to improve their understanding of practical application of the evolution theory. We also suggest further areas of research for other scientific concepts that could be used to gauge teachers' understanding of the practical application of scientific knowledge.

The Analysis of Pre-Service Biology Teachers' Natural Selection Conceptions in Multiple-Choice and Open-Response Instruments (생물 예비 교사의 선택형과 개방형 문항에서 나타난 자연선택 설명 분석)

  • Ha, Min-Su;Lee, Jun-Ki
    • Journal of The Korean Association For Science Education
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    • v.31 no.6
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    • pp.887-900
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    • 2011
  • Teachers use explanations to communicate important scientific ideas to students. Consequently, all biology teachers should be evaluated to determine how effective they are at constructing and communicating biological explanations. Open response questions are required to detect pre-service biology teachers' abilities to communicate robust and accurate scientific explanations. Nevertheless, multiple-choice questions are typically preferred by educators because of the common drawbacks of using open-response instruments, such as scoring time, inter-rater scoring disagreements, and delayed feedback to test takers. This study aims to measure pre-service biology teachers' competence in building scientific explanations and to investigate how accurately multiple-choice questions predict the results of open-response questions. One hundred twenty four pre-service biology teachers participated in the study and were administered 20 multiple-choice items and three open-response items designed to measure the accuracy and quality of their explanations of evolutionary change. The results demonstrated that pre-service teachers displayed higher competence when tested with multiple choice items than when tested with open response items. Moreover, scores derived from multiple-choice items poorly predicted the scores derived from open-response items. Multiple-choice items were also found to be poor measures of the consistency, purity and abundance of conceptual elements in teachers' evolutionary explanations. Additionally, many teachers held mixed-models composed of both scientific and naive ideas, which were difficult to detect using multiple-choice formats. Overall, the study indicates that multiple-choice formats are poorly suited to measuring several aspects of biology teachers' knowledge of evolution, including their ability to generate scientific explanations. This study suggests that open-response items should be used in teacher education programs to assess pre-service teachers' explanatory competency prior to being permitted to teach science to children.

A study on computer based work by human based on evolutionary biology (진화생물학을 기초로 한 인간의 컴퓨터기반 작업에 관한 연구)

  • Lee, Ook;Choi, Jung-Woon;Choi, Bo-Yoen
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.7
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    • pp.283-304
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    • 2018
  • mankind has evolved to stand upright a million years ago. However entering an industrial society, much has changed in only a few decades. Human beings spend more time sitting down and working, which negatively affects their bodies. Leading medical studies have shown that the prolonged working conditions have significantly affected the causes of adult illnesses that we have known. Human beings have evolved in a moving direction. So, like modern societies, sitting or standing in one space for long periods of time without movement brings various side effects to the body. Reflecting this background, this study has led to think of work in an environment that is taking the evolutionary biology perspective from a traditional standing, standing work environment. They also plan to conduct an experiment to handle work with smartphones in the hopes of expanding their mobile office environment to use smartphones in the field, which is a type of smart work. The study could help build and establish a mobile office environment, a type of smart work. In addition to using smartphones, a working environment can be created that works by moving around. Furthermore, the paradigm of the work environment of businesses and students could be changed.