• Title/Summary/Keyword: population biology

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Isolation and Genotyping of Acanthamoeba spp. as Neglected Parasites in North of Iran

  • Shokri, Azar;Sarvi, Shahabeddin;Daryani, Ahmad;Sharif, Mehdi
    • Parasites, Hosts and Diseases
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    • v.54 no.4
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    • pp.447-453
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    • 2016
  • Acanthamoeba, a free-living amoeba, is widely distributed in the environment, water sources, soil, dust, and air. It can cause keratitis in contact lens wearers with poor hygiene and also fatal granulomatous amebic encephalitis (GAE) in immunocompromised hosts. The aim of this study was to gain some insights into the distribution and genotypes of the potentially pathogenic species of Acanthamoeba present in water sources in north of Iran. Total 43 Acanthamoeba species were isolated from 77 water samples taken from different water sources within the Mazandaran province in Northern Iran (Sari city and suburbs). Isolates were identified based on cyst and trophozoite morphological characteristics as well genetics. PCR fragments corresponding to the small-subunit 18S rRNA gene were sequenced for 20 of 43 positive isolates. The results revealed that 83.3% of sequenced isolates belonged to the T4 genotype and the rest belonged to the T2 genotype. Our results indicated that Acanthamoeba is widely distributed in Sari city. As the incidence in Iran of amoebic keratitis has increased in recent years, the exact estimation of the prevalence of this amoeba and its predominant genotype may play a crucial role in prevention of the disease. Sari city has several rivers, seashores, and natural recreational amenities, which attract visitors during the year. This is the first report of Acanthamoeba genotypes from water sources in Sari city, Mazandaran province of Iran, and the results suggest that more attention is needed to protect the visiting population and immunocompromised individuals.

Current Status of Human Taeniasis in Lao People's Democratic Republic

  • Jeon, Hyeong-Kyu;Yong, Tai-Soon;Sohn, Woon-Mok;Chai, Jong-Yil;Min, Duk-Young;Yun, Cheong-Ha;Rim, Han-Jong;Pongvongsa, Tiengkham;Banouvong, Virasack;Insisiengmay, Bounnaloth;Phommasack, Bounlay;Eom, Keeseon S.
    • Parasites, Hosts and Diseases
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    • v.51 no.2
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    • pp.259-263
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    • 2013
  • Human taeniasis was investigated in Lao People's Democratic Republic (Lao PDR) between 2000 and 2011 as part of the nation's helminthiasis survey. A total of 55,038 inhabitants, including 29,846 school children, were examined using the Kato-Katz and scotch-tape anal swab method, and morphological observation of adult worms. Molecular identification of Taenia tapeworms was performed by multiplex PCR or DNA sequence analysis of the mitochondrial cox1 gene. Taenia eggs were present at a rate of 1.5% (845/55,038) in the subject population. Adult tapeworms were identified as T. solium or T. saginata by analyzing the collectable stool specimens (n=126). Three specimens identified as T. solium were found in Luang Prabang, while the remaining 123 specimens, which were T. saginata, were found in Bokeo, Bolikhamxay, Champasak, Houaphan, Khammouane, Luang Namta, Luang Prabang, Oudomxay, Phongsaly, Saysomboune, Saravane, Savannakhet, Xayaboury, Xekong, Xieng Khouang Province, and Vientiane Municipality.

Assessment of Population Structure and Genetic Diversity of 15 Chinese Indigenous Chicken Breeds Using Microsatellite Markers

  • Chen, Guohong;Bao, Wenbin;Shu, Jingting;Ji, Congliang;Wang, Minqiang;Eding, Herwin;Muchadeyi, Farai;Weigend, Steffen
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.3
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    • pp.331-339
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    • 2008
  • The genetic structure and diversity of 15 Chinese indigenous chicken breeds was investigated using 29 microsatellite markers. The total number of birds examined was 542, on average 36 birds per breed. A total of 277 alleles (mean number 9.55 alleles per locus, ranging from 2 to 25) was observed. All populations showed high levels of heterozygosity with the lowest estimate of 0.440 for the Gushi chickens, and the highest one of 0.644 observed for Wannan Three-yellow chickens. The global heterozygote deficit across all populations (FIT) amounted to 0.180 (p<0.001). About 16% of the total genetic variability originated from differences between breeds, with all loci contributing significantly to this differentiation. An unrooted consensus tree was constructed using the Neighbour-Joining method and pair-wise distances based on marker estimated kinships. Two main groups were found. The heavy-body type populations grouped together in one cluster while the light-body type populations formed the second cluster. The STRUCTURE software was used to assess genetic clustering of these chicken breeds. Similar to the phylogenetic analysis, the heavy-body type and light-body type populations separated first. Clustering analysis provided an accurate representation of the current genetic relations among the breeds. Remarkably similar breed rankings were obtained with all methods.

Reproductive Cycle of the Venus Fish, Aphycypris chinensis (왜몰개, Aphyocypris chinensis의 생식주기)

  • Lee, Sung-Kyu;Choi, Shin-Sok;Yeom, Dong-Hyuk
    • Korean Journal of Ecology and Environment
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    • v.33 no.4 s.92
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    • pp.395-404
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    • 2000
  • The gonadosomatic index (GSI), hepatosomatic Index (HSI), egg size distribution, gonad development and reproductive characteristics of venus fish, Aphyocypris chinensis, were examined during March 1997- March 1998 in agricultural waterways of the Sedo-myun, Puyo county, Chungnam Province, Korea. Annual reproductive cycle was classified into the following five successive phases by monthly changes in GSI and the characteristics of ovary: quiescent phase (January- February), secondary growing and mature phase (March-May), ripe and spawning phase (June-July), degenerating and resting phase (August-September) and primary growing phase (October-December). The hepatosomatic index (HSI) showed clear seasonal pattern with two separate peaks. However, it exhibited a negative correlation to changes of GSI values. The regression analysis suggested that fecundity showed a strong positive linear relationship ($r^2\;=\;0.91$, n = 34) with body weight. The sex ratio of female to male was 1.4 : 1 in the natural population during the study. The minimum reproductive size of female and male venus fish was 38 mm and 33 mm in fork length, respectively.

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The Biocontrol Activity of Chromobacterium sp. Strain C-61 against Rhizoctonia solani Depends on the Productive Ability of Chitinase

  • Park, Seur-Kee;Lee, Myung-Chul;Harman, Gary E.
    • The Plant Pathology Journal
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    • v.21 no.3
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    • pp.275-282
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    • 2005
  • A chitinolytic bacterium, Chromobacterium sp. strain C-61, was found strongly antagonistic to Rhizoctonia solani, a causal agent of damping-off of eggplant. In this study, the biocontrol activity and enzymatic characteristics of strain C-61 were compared with its four Tn5 insertion mutants (C61-A, -B, -C, and -D) that had lower chitinolytic ability. The chitinase activity of a 2-day old culture was about $76\%,\;49\%\;and\;6\%$ level in C61-A, C61-B and in C61-C, respectively, compared with that of strain C-61. The $\beta-N-acetylhexosaminidase$(Nahase) activity was little detected in strain C-61 but increased largely in C-61A, C61-B and C61-C. Activities of chitinase and Nahase appeared to be negatively correlated in these strains. Another mutant, C-61D, produced no detectable extracellular chitinase and Nahase. The in vitro and in vivo biocontrol activities of strain C-61 and its mutants were closely related to their ability to produce chitinase but not Nahase. No significant differences in population densities between strain C-61 and its mutants were observed in soil around eggplant roots. The results of SDS-PAGE and isoelectrofocusing showed that a major chitinase of strain C-61 is 54-kDa with pI of approximately 8.5. This study provides evidence that the biocontrol activity of Chromobacterium sp. strain C-61 against Rhizoctonia solani depends on the ability to produce chitinase with molecular weight of 54-kDa and pI of 8.5.

Induction of S phase Arrest of the Cell Cycle by Oak Smoke Flavoring (Holyessing) in Human Prostate Carcinoma Cells (인체 전립선 암세포에서 참나무 목초액에 의한 세포주기 S기 arrest 유발에 관한 연구)

  • Park Cheol;Lee Won Ho;Choi Byung Tae;Kim Kyoung Chul;Lee Yong Tae;Choi Yung Hyun
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.17 no.5
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    • pp.1309-1314
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    • 2003
  • We examined the effects of Oak Smoke Flavoring (OSF, Holyessing) on the cell proliferation of DU145 and PC3 human prostate carcinoma cell line. OSF treatment resulted in a concentration-dependent inhibition of the cell viability in both DU145 and PC3 cell lines. The anti-proliferative effects by OSF treatment in DU145 and PC3 cells were associated with morphological changes such as membrane shrinking and cell rounding up. DNA flow cytometric histograms showed that population of S phase of the cell cycle was increased by OSF treatment in a dose-dependent manner. Western blot analysis revealed that cyclin B1 and cdc2 proteins were reduced by OSF treatment in DU145 cells, whereas cyclin A was markedly inhibited in PC3 cells. Furthermore, we observed an increase of Cdk inhibitor p16 and p27 protein, and an inhibition of phosphorylation of pRB by OSF treatment in a dose-dependent manner. The present results indicated that OSF-induced inhibition of human prostate carcinoma cell proliferation is associated with the blockage of S phase progression.

Strategies of development of environmentally friendly industrial sweetpotato on marginal lands by molecular breeding (분자육종을 통한 조건불리지역 친환경 산업용 고구마 개발 전략)

  • Kim, Myoung-Duck;Ahn, Young-Ock;Kim, Yun-Hee;Kim, Cha-Young;Lee, Jeung-Joo;Jeong, Jae-Cheol;Lee, Haeng-Soon;Mok, Il-Gin;Kwak, Sang-Soo
    • Journal of Plant Biotechnology
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    • v.36 no.3
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    • pp.197-201
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    • 2009
  • The food self-support rate on the basis of cereals in Korea is approximately 27%, which will threaten the national food security. The dramatic increase in population accompanied by rapid industrialization in developing countries has caused imbalances in the supply of food and energy. To cope with these global crises over food and energy supplies as well as environmental problems, it is urgently required to develop new environmentally friendly industrial crop varieties to be grown on marginal lands including desertification areas for sustainable development. Sweetpotato (Ipomoea batatas (L.) Lam.) ranks seventh in annual production among food crops in the world. Its wide adaptability on marginal lands and rich nutritional content provide a high potential for preventing malnutrition and enhancing food security in the developing countries. In addition, sweetpotato can be developed as a bioreactor to produce valuable industrial materials including bio-ethanol, functional feed and antioxidants by molecular breeding. In this respect, we focus on the molecular breeding of sweetpotato with multi-function on marginal lands. The strategies for development of environmentally friendly industrial sweetpotato will be introduced and discussed.

Position Effects on Abortion of Reproductive Characters in Vicia cracca (Leguminosae) (등갈퀴나물 ( Vicia cracca : Leguminosae ) 번식기관의 발육정지에 대한 위치효과)

  • Kang, Hyesoon
    • The Korean Journal of Ecology
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    • v.19 no.2
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    • pp.107-123
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    • 1996
  • The position effects on the abortion of flowers, fruits, and ovules were examined in relation to the resource limitation hypothesis using a temperate legume species, Vicia cracca. Fifty plants were randomly sampled from a natural population located at the Belmont Conservation Site in Belmont, MA, USA. Due to indeterminant growth and acropetal flowering of this species, the position of flower or fruit on the plant was able to be coded by the combination of architectural levels such as plant half (lower and upper half) and inflorescence half (lower and upper half) within each plant half. Overall, only 17.3% of the flowers on an inflorescence began to develop into fruits, while overall 36.0% of the fruits initiated failed to mature. Consequently, 11.5% of the flowers successfully matured into fruits. The mean flower number per inflorescence differed significantly among plants as well as between plant halves. Although the probability of fruit initiation was higher in the lower halves of both plant and inflorescence than in the upper halves of the latter, fruit abortion rate differed significantly only between plant halves. The overall mean seed set was 33.6%, implying that about two out of six ovules in a fruit matured into seeds. The seed set was independent of both plant identity and architectural level unlike other reproductive characters examined. When the ovule developmental stage was examined on data pooled over all fruits, the proportion of ovules in varying developmental stages decreased in order of early abortion, seed maturation, late abortion, and seed predation (48.4, 34.9, 12.2, and 4.5%, respectively). A within-fruit ovule position was also used as a class variable for the analysis of position effects on ovule development. All architectural levels considered exerted singificant influence over the ovule development. In particular, ovule development was strongly affected by the within-fruit ovule position. Ovules in both extreme ends within a fruit tended to abort early, while those in the middle position were more likely to mature into seeds. The strong position effects detected from the flowering to seed maturation stage were interpreted as an indication of competitive interaction among reproductive characters which are largely constrained by plant architecture.

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Genetic Polymorphism of Glutathione S-transferase P1 and Breast Cancer Risk

  • Kim, Sook-Un;Lee, Kyoung-Mu;Park, Sue-Kyung;Yoo, Keun-Young;Noh, Dong-Young;Choe, Kook-Jin;Ahn, Sei-Hyun;Hirvonen, Ari;Kang, Dae-Hee
    • BMB Reports
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    • v.37 no.5
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    • pp.582-585
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    • 2004
  • To evaluate the potential association between the GSTP1 genotype and the development of breast cancer, a hospital based case-control study was conducted on Korean women. The study population consisted of 171 histologically confirmed incident breast cancer cases and 171 age-matched controls with no present or previous history of cancer. PCR-RFLP was used for the GSTP1 genotyping and statistical evaluations were performed using an unconditional logistic regression model. Postmenopausal women with the GSTP1 Val allele were found to have a reduced risk of breast cancer (OR = 0.3, 95% CI = 0.10 - 0.74). A significant interaction was observed between the GSTP1 genotype and alcohol consumption (p for interaction = 0.01); compared with never-drinking women with Ile/Ile genotype, ever-drinking women with the GSTP1 Val allele had almost a three-fold risk of breast cancer (OR = 2.9, 95% CI = 1.05-7.85), whereas never-drinking women with Val allele had half this risk (OR = 0.5, 95% CI = 0.27-0.93). Our findings suggest that the GSTP1 polymorphism influences individual susceptibility to breast cancer in the Korean women and this effect may be modified by alcohol consumption.

Association between the Angiotensin-converting Enzyme Gene Insertion/Deletion Polymorphism and Essential Hypertension in Young Pakistani Patients

  • Ismail, Muhammad;Akhtar, Naveed;Nasir, Muhammad;Firasat, Sadaf;Ayub, Qasim;Khaliq, Shagufta
    • BMB Reports
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    • v.37 no.5
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    • pp.552-555
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    • 2004
  • Several studies have demonstrated the importance of angiotensin-converting enzyme (ACE) insertion (I)/deletion (D) polymorphisms in the pathogenesis of hypertension. This study sought to determine the association between the ACE I/D polymorphism and essential hypertension in young Pakistanis. The frequency of the ACE I/D polymorphism was established by a comparative cross-sectional survey of Pakistani patients suffering from essential hypertension and ethnically matched normotensive controls. Samples were collected from tertiary care hospitals in northern Pakistan. Hypertensive individuals were defined as those with a systolic blood pressure > 140 mmHg and/or diastolic blood pressure > 90 mmHg on three separate occasions, or those currently receiving one, or more, anti-hypertensive agents. DNA samples obtained from hypertensive (n=211) and normotensive (n=108) individuals were typed by PCR. The frequency of the ACE I/I genotype was significantly higher in hypertensive patients, aged 20-40 years, than in normotensive controls of the same age group ($\chi^2$ = 4.0, P = 0.041). Whereas no overall significant differences were observed between the I/I, I/D and D/D ACE genotypes (One way ANOVA, F=0.672; P=0.413). The association between the ACE I/I genotype and essential hypertension in individuals aged $\leq$ 40 years suggests that ACE has a role in early onset essential hypertension in Pakistan.