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Suba S, Muthulakshmi M. A systematic review: Chest radiography images (X-ray images) analysis and COVID-19 categorization diagnosis using artificial intelligence techniques. Network 2023; 34:26-64. [PMID: 36420865 DOI: 10.1080/0954898x.2022.2147231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 10/27/2022] [Accepted: 11/08/2022] [Indexed: 06/16/2023]
Abstract
COVID-19 pandemic created a turmoil across nations due to Severe Acute Respiratory Syndrome Corona virus-1(SARS - Co-V-2). The severity of COVID-19 symptoms is starting from cold, breathing problems, issues in respiratory system which may also lead to life threatening situations. This disease is widely contaminating and transmitted from man-to-man. The contamination is spreading when the human organs like eyes, nose, and mouth get in contact with contaminated fluids. This virus can be screened through performing a nasopharyngeal swab test which is time consuming. So the physicians are preferring the fast detection methods like chest radiography images and CT scans. At times some confusion in finding out the accurate disorder from chest radiography images can happen. To overcome this issue this study reviews several deep learning and machine learning procedures to be implemented in X-ray images of chest. This also helps the professionals to find out the other types of malfunctions happening in the chest other than COVID-19 also. This review can act as a guidance to the doctors and radiologists in identifying the COVID-19 and other types of viruses causing illness in the human anatomy and can provide aid soon.
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Affiliation(s)
- Saravanan Suba
- Department of Computer Science, Kamarajar Government Arts College, Tirunelveli, Surandai 627859, India
| | - M Muthulakshmi
- Department of Computer Science, Kamarajar Government Arts College, Tirunelveli, Surandai 627859, India
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Muthulakshmi M, Murugeswari G, Raja S. An empirical evaluation of compression techniques for genome sequences. IJBM 2021. [DOI: 10.1504/ijbm.2021.10038944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Muthulakshmi M, Murugeswari G, Raja S. An empirical evaluation of compression techniques for genome sequences. IJBM 2021. [DOI: 10.1504/ijbm.2021.117870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Muthulakshmi M, Kavitha G. Cardiovascular Disorder Severity Detection Using Myocardial Anatomic Features Based Optimized Extreme Learning Machine Approach. Ing Rech Biomed 2020. [DOI: 10.1016/j.irbm.2020.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Muthulakshmi M, Kavitha G. An integrated multi-objective whale optimized support vector machine and local texture feature model for severity prediction in subjects with cardiovascular disorder. Int J Comput Assist Radiol Surg 2020; 15:601-615. [PMID: 32152831 DOI: 10.1007/s11548-020-02133-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 02/27/2020] [Indexed: 11/25/2022]
Abstract
PURPOSE The left ventricle (LV) myocardium undergoes deterioration with the reduction in ejection fraction (EF). The analysis of its texture pattern plays a major role in diagnosis of heart muscle disease severity. Hence, a classification framework with co-occurrence of local ternary pattern feature (COALTP) and whale optimization algorithm has been attempted to improve the prediction accuracy of disease severity level. METHODS This analysis is carried out on 600 slices of 76 participants from Kaggle challenge that include subjects with normal and reduced EF. The myocardium of LV is segmented using optimized edge-based local Gaussian distribution energy (LGE)-based level set, and end-diastolic and end-systolic volumes were calculated. COALTP is extracted for two distance levels (d = 1 and 2). The t-test has been performed between the features of individual binary classes. The features are ranked using feature ranking methods. The experiments have been performed to analyze the performance of various percentages of features in each combination of bin for fivefold cross-validation. An integrated whale optimized feature selection and multi-classification framework is developed to classify the normal and pathological subjects using CMR images, and DeLong test has been performed to compare the ROCs. RESULTS The optimized edge embedded to level set has produced better segmented myocardium that correlates with R = 0.98 with gold standard volume. The t-test shows that texture features extracted from severe subjects with distance level "1" are more statistically significant with a p value (< 0.00004) compared to other pathologies. This approach has produced an overall multi-class accuracy of 75% [confidence interval (CI) 63.74-84.23%] and effective subclass specificity of 70% (CI 55.90-81.22%). CONCLUSION The obtained results show that the multi-objective whale optimized multi-class support vector machine framework can effectively discriminate the healthy and patients with reduced ejection fraction and potentially support the treatment process.
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Affiliation(s)
- M Muthulakshmi
- Department of Electronics Engineering, MIT Campus, Anna University, Chromepet, Chennai, Tamilnadu, 600044, India.
| | - G Kavitha
- Department of Electronics Engineering, MIT Campus, Anna University, Chromepet, Chennai, Tamilnadu, 600044, India
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Muthulakshmi M, Kavitha G. Deep CNN with LM learning based myocardial ischemia detection in cardiac magnetic resonance images. Annu Int Conf IEEE Eng Med Biol Soc 2019; 2019:824-827. [PMID: 31946022 DOI: 10.1109/embc.2019.8856838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Cardiovascular disease (CVD) is a chronic dysfunction caused by deterioration in cardiac physiology. It results in about 31% of mortality worldwide. Among CVDs, myocardial ischemia (MI) leads to restriction in blood supply to heart tissues. There is a need to develop an effective computer aided detection (CAD) system to reduce the fatality. In this work, an attempt is made to perform mass screening of myocardial ischemic subjects and left ventricle (LV) volume estimation from cardiac magnetic resonance (CMR) images using deep convolutional neural network (CNN) with Levenberg-Marquardt (LM) learning. LV volume measurement is an important predictor of myocardial ischemia. The CMR samples used in this analysis are obtained from Medical Image Computing and Computer Assisted Intervention (MICCAI) 2009 database. The results of the proposed model are compared with deep CNN based on gradient descent (GD) learning algorithm. The results show that deep CNN architecture with LM learning classifies ischemic subjects with high accuracy (86.39%) and sensitivity (90%). The LM learning based method gives an AUC of 0.93. The estimated LV volumes obtained from the trained network gives high correlation with the ground truth. Thus the results support that proposed framework of deep CNN architecture with LM learning can be used as an effective CAD system for diagnosis of cardiovascular disorders.
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Gopalakrishnan S, Eashwar VMA, Muthulakshmi M. Health-seeking behaviour among antenatal and postnatal rural women in Kancheepuram District of Tamil Nadu: A cross-sectional Study. J Family Med Prim Care 2019; 8:1035-1042. [PMID: 31041247 PMCID: PMC6482804 DOI: 10.4103/jfmpc.jfmpc_323_18] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Introduction: Maternal morbidity and mortality is still a major public health challenge. Lack of proper birth plan and delay in identification of pregnancy complications is one of the major causes of maternal morbidities and deaths, especially in the rural areas. Aim: The study was conducted with the aim to evaluate the health-seeking behaviour for obstetric care services among the antenatal and postnatal mothers in a rural area of Tamil Nadu. Materials and Methods: This descriptive cross-sectional study was done among antenatal and postnatal mothers registered in the Rural Health Training Centre, in Sripuram area of Kancheepuram district, Tamil Nadu during 2017. About 150 antenatal and 150 postnatal mothers were selected by simple random sampling method. A pre-tested structured questionnaire was used to collect relevant data which was analysed using the SPSS version 22. Results: Only 21% of the study participants had adequate knowledge regarding the danger signs of pregnancy and the major determinants were maternal literacy and adequate prenatal care. Regarding the health-seeking behaviour, 62.3% of them preferred primary health centres as preferred place of delivery, 87.3% of them had received adequate prenatal care and it was found to have statistically significant association with adequate gestational weight gain, exclusive breastfeeding, proper weaning practices and consumption of iron and folic acid supplements. Conclusion: The study shows the need to provide health education regarding the danger signs of pregnancy and importance of adequate prenatal care to all pregnant women and expectant mothers, to make them aware of when and how to seek medical care, which in turn could reduce the overall maternal morbidity and mortality.
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Affiliation(s)
- S Gopalakrishnan
- Department of Community Medicine, Sree Balaji Medical College and Hospital, Bharath Institute of Higher Education and Research, Chrompet, Chennai, Tamil Nadu, India
| | - V M Anantha Eashwar
- Department of Community Medicine, Sree Balaji Medical College and Hospital, Bharath Institute of Higher Education and Research, Chrompet, Chennai, Tamil Nadu, India
| | - M Muthulakshmi
- Department of Community Medicine, Saveetha Medical College, Thandalam, Chennai, Tamil Nadu, India
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Gopalakrishnan S, Eashwar VMA, Muthulakshmi M, Geetha A. Intestinal parasitic infestations and anemia among urban female school children in Kancheepuram district, Tamil Nadu. J Family Med Prim Care 2018; 7:1395-1400. [PMID: 30613531 PMCID: PMC6293916 DOI: 10.4103/jfmpc.jfmpc_89_18] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
INTRODUCTION In India, intestinal parasitic infection and anemia remain the most important cause of morbidity especially among the adolescent school children due to lack of awareness of personal hygiene practices, leading to intestinal parasite infections which could in turn lead to anemia. AIM This study was conducted with the aim to find out the prevalence of intestinal parasitic infection and anemia among adolescent female school children in an urban area of Tamil Nadu. MATERIALS AND METHOD This descriptive cross-sectional study was done among adolescent female school children in Anakaputhur area of Kancheepuram district. Three schools were selected randomly from a total of eight schools in the study area. Universal sampling was applied in each school, and a total of 250 willing children participated in the study. Early morning stool specimen was collected for microscopic examination and hemoglobin estimation was done. A pretested structured questionnaire was used to collect relevant data which were analyzed using SPSS version 22. RESULTS The prevalence of intestinal parasitic infection was found to be 36% with Entamoeba histolytica being the commonly isolated organism (23.2%) followed by Giardia intestinalis (5.2%), Hookworm (4.4%), and Ascaris lumbricoides (3.2%). The prevalence of anemia among them was found to be 84.8% with mild, moderate, and severe anemia being 12.8%, 46.8%, and 25.2%, respectively. Statistically significant association was found between intestinal parasitic infection and open field defecation, inadequate hand washing practices, and anemia. CONCLUSION The study reveals high prevalence of anemia and intestinal parasitic infection among female school children. Preventive measures such as periodic deworming and health education about nutritional balanced diet, iron supplements, and personal hygiene practices have to be given to both the parents and their children to prevent and reduce disease burden.
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Affiliation(s)
- S. Gopalakrishnan
- Department of Community Medicine, Sree Balaji Medical College and Hospital, Bharath Institute of Higher Education and Research, Chrompet, Chennai, Tamil Nadu, India
| | - V. M. Anantha Eashwar
- Department of Community Medicine, Sree Balaji Medical College and Hospital, Bharath Institute of Higher Education and Research, Chrompet, Chennai, Tamil Nadu, India
| | - M. Muthulakshmi
- Department of Community Medicine, Sree Balaji Medical College and Hospital, Bharath Institute of Higher Education and Research, Chrompet, Chennai, Tamil Nadu, India
| | - A. Geetha
- Department of Community Medicine, Sree Balaji Medical College and Hospital, Bharath Institute of Higher Education and Research, Chrompet, Chennai, Tamil Nadu, India
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Mohankumar P, Gopalakrishnan S, Muthulakshmi M. Morbidity Profile and Associated Risk Factors among Construction Workers in an Urban Area of Kancheepuram District, Tamil Nadu, India. J Clin Diagn Res 2018. [DOI: 10.7860/jcdr/2018/34678.11773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Gopalakrishnan S, Muthulakshmi M. Knowledge and Practice of Small Family Norm among Married Women in an Urban Area of Tamil Nadu. J Clin Diagn Res 2018. [DOI: 10.7860/jcdr/2018/34579.11502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Muthulakshmi M, Subramani PA, Michael RD. Immunostimulatory effect of the aqueous leaf extract of Phyllanthus niruri on the specific and nonspecific immune responses of Oreochromis mossambicus Peters. Iran J Vet Res 2016; 17:200-202. [PMID: 27822251 PMCID: PMC5090155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/27/2015] [Revised: 12/28/2015] [Accepted: 02/27/2016] [Indexed: 06/06/2023]
Abstract
Plant derived immunostimulants are a promising alternative to chemotherapeutics and also perhaps vaccines. In the present study, we examined the immunostimulating properties of aqueous leaf extract of Phyllanthus niruri, an Indian traditional medicinal herb, on neutrophil activation and antibody response of Oreochromis mossambicus (Peters). Serial ten-fold diluted doses of P. niruri ranging from 0.002 mg to 20 mg were administered to two groups of O. mossambicus (n=8). One group of fishes was administered with sheep red blood cells and the primary and secondary antibody responses were estimated using direct haemagglutination assay. The other group of fishes was administered heat-aggregated BSA to assess the ability of plant extract to elicit neutrophil activation. Our results indicate a significant enhancement of both neutrophil activation and antibody response. Among the various doses tested, fishes administered 20 mg/kg body weight caused the maximal enhancement of both primary and secondary antibody response and 0.002 mg/kg showed higher neutrophil activation compared to that of the control group. This short study indicates that aqueous leaf extract of P. niruri has the potential to be used as an immunostimulant and after confirming its immunostimulatory properties by a battery of tests on other nonspecific and specific parameters and disease-protective property by challenging the fish with virulent fish pathogens, it can be used either as a routine feed supplement to activate the immune system of farmed fishes or as an adjuvant to enhance the efficacy of vaccines.
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Affiliation(s)
- M. Muthulakshmi
- MSc in Zoology, Science Section, Government Higher Secondary School, Avadi, Chennai-600062, India
| | - P. A. Subramani
- Ph.D. Student in Nanobiotechnology, Centre for Fish Immunology, School of Life Sciences, Vels University, Pallavaram, Chennai-600117, India
| | - R. D. Michael
- Centre for Fish Immunology, School of Life Sciences, Vels University, Pallavaram, Chennai-600117, India
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Meglécz E, Anderson SJ, Bourguet D, Butcher R, Caldas A, Cassel-Lundhagen A, d'Acier AC, Dawson DA, Faure N, Fauvelot C, Franck P, Harper G, Keyghobadi N, Kluetsch C, Muthulakshmi M, Nagaraju J, Patt A, Péténian F, Silvain JF, Wilcock HR. Microsatellite flanking region similarities among different loci within insect species. Insect Mol Biol 2007; 16:175-85. [PMID: 17298557 DOI: 10.1111/j.1365-2583.2006.00713.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Although microsatellites are ubiquitous in eukaryota, the number of available markers varies strongly among taxa. This meta-analysis was conducted on 32 insect species. Sequences were obtained from two assembled whole genomes, whole genome shotgun (WGS) sequences from 10 species and screening partial genomic libraries for microsatellites from 23 species. We have demonstrated: (1) strong differences in the abundance of microsatellites among species; (2) that microsatellites within species are often grouped into families based on similarities in their flanking sequences; (3) that the proportion of microsatellites grouped into families varies strongly among taxa; and (4) that microsatellite families were significantly more often associated with transposable elements - or their remnants - than unique microsatellite sequences.
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Affiliation(s)
- E Meglécz
- Evolution Génome et Environnement, CASE 36, Université de Provence, Marseille, France.
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Nagaraja GM, Mahesh G, Satish V, Madhu M, Muthulakshmi M, Nagaraju J. Genetic mapping of Z chromosome and identification of W chromosome-specific markers in the silkworm, Bombyx mori. Heredity (Edinb) 2005; 95:148-57. [PMID: 15931240 DOI: 10.1038/sj.hdy.6800700] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
In the silkworm, Bombyx mori, the female is the heterogametic (ZW) sex and the male is homogametic (ZZ). The female heterogamety is a typical situation in the insect order Lepidoptera. Although the W chromosome in silkworm is strongly female determining, no W-linked gene for a morphological character has been found on it. The Z chromosome carries important traits of economic value as well as genes for various phenotypic traits, but only 2% of molecular information based on its relative size is known. Studies conducted so far indicate that the Z-linked genes are not dosage compensated. In the present study, we constructed a genetic map of randomly amplified polymorphic DNA fragments (RAPD), simple sequence repeats (SSR), and fluorescent intersimple sequence repeat PCR (FISSR) markers for the Z chromosome using a backcross mapping population. A total of 16 Z-linked markers were identified, characterized, and mapped using od, a recessive trait for translucent skin as an anchor marker yielding a total recombination map of 334.5 cM. The linkage distances obtained suggested that the markers were distributed throughout the Z chromosome. Four RAPD and four SSR markers that were linked to W chromosome were also identified. The proposed mapping approach should be useful to identify and map sex-linked traits in the silkworm. The economic and evolutionary significance of Z- and W-linked genes in silkworm, in particular, and lepidopterans, in general, is discussed.
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Affiliation(s)
- G M Nagaraja
- Laboratory of Molecular Genetics, Centre for DNA Fingerprinting and Diagnostics, ECIL Road, Nacharam, Hyderabad 500076, India
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Prasad MD, Muthulakshmi M, Arunkumar KP, Madhu M, Sreenu VB, Pavithra V, Bose B, Nagarajaram HA, Mita K, Shimada T, Nagaraju J. SilkSatDb: a microsatellite database of the silkworm, Bombyx mori. Nucleic Acids Res 2005; 33:D403-6. [PMID: 15608226 PMCID: PMC540053 DOI: 10.1093/nar/gki099] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The SilkSatDb (silkmoth microsatellite database) (http://www.cdfd.org.in/silksatdb) is a relational database of microsatellites extracted from the available expressed sequence tags and whole genome shotgun sequences of the silkmoth, Bombyx mori. The database has been rendered with a simple and robust web-based search facility, developed using PHP. The SilkSatDb also stores information on primers developed and validated in the laboratory. Users can retrieve information on the microsatellite and the protocols used, along with informative figures and polymorphism status of those microsatellites. In addition, the interface is coupled with Autoprimer, a primer-designing program, using which users can design primers for the loci of interest.
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Affiliation(s)
- M D Prasad
- Laboratories of Molecular Genetics, Centre for DNA Fingerprinting and Diagnostics, ECIL Road, Nacharam, Hyderabad 500076, India
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Nageswara Rao S, Muthulakshmi M, Kanginakudru S, Nagaraju J. Phylogenetic relationships of three new microsporidian isolates from the silkworm, Bombyx mori. J Invertebr Pathol 2004; 86:87-95. [PMID: 15261772 DOI: 10.1016/j.jip.2004.05.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2004] [Accepted: 05/17/2004] [Indexed: 11/26/2022]
Abstract
The pathogenicity, mode of transmission, tissue specificity of infection and the small subunit rRNA (SSU-rRNA) gene sequences of the three new microsporidian isolates from the silkworm Bombyx mori were studied. Out of the three, NIK-2r revealed life cycle features and SSU-rRNA gene sequence similar to Nosema bombycis, suggesting that it is N. bombycis. The other two, NIK-4m and NIK-3h, differed from each other as well as from N. bombycis. NIK-4m was highly pathogenic and did not show any vertical transmission, in accordance with the apparent lack of gonadal infection, whereas NIK-3h was less pathogenic and vertical transmission was not detected but could not be excluded. Phylogenetic analysis based on SSU-rRNA gene sequence placed NIK-3h and NIK-4m in a distinct clade that included almost all the Vairimorpha species and Nosema species that infect lepidopteran and non-lepidopteran hosts, while NIK-2r was included in a clade containing almost all the Nosema isolates that infect only lepidopteran hosts. Thus, we have presented molecular evidence that one of the three isolates is in fact the type species N. bombycis, while the other two isolates are Vairimorpha spp. There was distinct separation of microsporidian isolates infecting only lepidopteran hosts and those infecting lepidopteran and non-lepidopteran hosts, reflecting possible co-evolution of hosts and microsporidian isolates.
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Affiliation(s)
- S Nageswara Rao
- Laboratory of Molecular Genetics, Centre for DNA Fingerprinting and Diagnostics, ECIL Road, Nacharam, Hyderabad, 500 076 India
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Prasad MD, Muthulakshmi M, Madhu M, Archak S, Mita K, Nagaraju J. Survey and analysis of microsatellites in the silkworm, Bombyx mori: frequency, distribution, mutations, marker potential and their conservation in heterologous species. Genetics 2004; 169:197-214. [PMID: 15371363 PMCID: PMC1448858 DOI: 10.1534/genetics.104.031005] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We studied microsatellite frequency and distribution in 21.76-Mb random genomic sequences, 0.67-Mb BAC sequences from the Z chromosome, and 6.3-Mb EST sequences of Bombyx mori. We mined microsatellites of >/=15 bases of mononucleotide repeats and >/=5 repeat units of other classes of repeats. We estimated that microsatellites account for 0.31% of the genome of B. mori. Microsatellite tracts of A, AT, and ATT were the most abundant whereas their number drastically decreased as the length of the repeat motif increased. In general, tri- and hexanucleotide repeats were overrepresented in the transcribed sequences except TAA, GTA, and TGA, which were in excess in genomic sequences. The Z chromosome sequences contained shorter repeat types than the rest of the chromosomes in addition to a higher abundance of AT-rich repeats. Our results showed that base composition of the flanking sequence has an influence on the origin and evolution of microsatellites. Transitions/transversions were high in microsatellites of ESTs, whereas the genomic sequence had an equal number of substitutions and indels. The average heterozygosity value for 23 polymorphic microsatellite loci surveyed in 13 diverse silkmoth strains having 2-14 alleles was 0.54. Only 36 (18.2%) of 198 microsatellite loci were polymorphic between the two divergent silkworm populations and 10 (5%) loci revealed null alleles. The microsatellite map generated using these polymorphic markers resulted in 8 linkage groups. B. mori microsatellite loci were the most conserved in its immediate ancestor, B. mandarina, followed by the wild saturniid silkmoth, Antheraea assama.
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Affiliation(s)
- M Dharma Prasad
- Laboratory of Molecular Genetics, Centre for DNA Fingerprinting and Diagnostics, Hyderabad 500 076, India
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Nagaraju J, Kathirvel M, Subbaiah EV, Muthulakshmi M, Kumar LD. FISSR-PCR: a simple and sensitive assay for highthroughput genotyping and genetic mapping. Mol Cell Probes 2002; 16:67-72. [PMID: 12005450 DOI: 10.1006/mcpr.2001.0404] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The recently developed Inter-Simple Sequence Repeat PCR (ISSR-PCR) or microsatellite primed PCR or Simple Sequence Repeat (SSR)-Anchored PCR technique detects polymorphic markers in a wide variety of genomes. Usually the ISSR primers are either 5' end-labeled with gamma[32P]ATP or one of the alpha[32P] labeled dNTPs is added to the PCR reaction and the PCR products are resolved on PAGE and autoradiographed. Alternatively, cold PCR products are resolved on agarose gel electrophoresis. In the present study, we show that informativity, sensitivity and speed of the ISSR-PCR can be substantially enhanced by adding fluorescent nucleotide in the PCR reaction followed by resolution of PCR products on an ABI 377 automated sequencer. The informativeness, measured as a number of detectable amplified fragments, was two-fold higher and the quantity of required template DNA is two-fold lower than the regular ISSR-PCR. We have termed this method as FISSR-PCR and show its usefulness in generating large number of species and varietal specific markers in plants, insects, parasites of insects and human and various infectious organisms. Further, we show that the FISSR markers are inherited and segregated in Mendelian fashion as demonstrated on a panel of 99 F2 offspring derived from a cross of two divergent silkworm strains. The FISSR-PCR marker assay could be a method of choice for large scale screening of varieties/cultivars and highthroughput genotyping in mapping of genomes where microsatellite information is scanty or absent.
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Affiliation(s)
- J Nagaraju
- Laboratory of Molecular Genetics, Centre for DNA Fingerprinting and Diagnostics, Nacharam, Hyderabad, India.
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