Displaying publications 301 - 320 of 3447 in total

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  1. Fulltext Centromeres of Cucumis melo L. comprise Cmcent and two novel repeats, CmSat162 and CmSat189
    Setiawan AB, Teo CH, Kikuchi S, Sassa H, Kato K, Koba T
    PLoS One, 2020;15(1):e0227578.
    PMID: 31945109 DOI: 10.1371/journal.pone.0227578
    Centromeres are prerequisite for accurate segregation and are landmarks of primary constrictions of metaphase chromosomes in eukaryotes. In melon, high-copy-number satellite DNAs (SatDNAs) were found at various chromosomal locations such as centromeric, pericentromeric, and subtelomeric regions. In the present study, utilizing the published draft genome sequence of melon, two new SatDNAs (CmSat162 and CmSat189) of melon were identified and their chromosomal distributions were confirmed using fluorescence in situ hybridization. DNA probes prepared from these SatDNAs were successfully hybridized to melon somatic and meiotic chromosomes. CmSat162 was located on 12 pairs of melon chromosomes and co-localized with the centromeric repeat, Cmcent, at the centromeric regions. In contrast, CmSat189 was found to be located not only on centromeric regions but also on specific regions of the chromosomes, allowing the characterization of individual chromosomes of melon. It was also shown that these SatDNAs were transcribed in melon. These results suggest that CmSat162 and CmSat189 might have some functions at the centromeric regions.
    Matched MeSH terms: DNA, Satellite; DNA Probes
  2. Amycolatopsis saalfeldensis sp. nov., a novel actinomycete isolated from a medieval alum slate mine
    Carlsohn MR, Groth I, Tan GYA, Schütze B, Saluz HP, Munder T, et al.
    Int J Syst Evol Microbiol, 2007 Jul;57(Pt 7):1640-1646.
    PMID: 17625209 DOI: 10.1099/ijs.0.64903-0
    Three actinomycetes isolated from the surfaces of rocks in a medieval slate mine were examined in a polyphasic taxonomic study. Chemotaxonomic and morphological characteristics of the isolates were typical of strains of the genus Amycolatopsis. The isolates had identical 16S rRNA gene sequences and formed a distinct phyletic line towards the periphery of the Amycolatopsis mediterranei clade, being most closely related to Amycolatopsis rifamycinica. The organisms shared a wide range of genotypic and phenotypic markers that distinguished them from their closest phylogenetic neighbours. On the basis of these results, a novel species, Amycolatopsis saalfeldensis sp. nov., is proposed. The type strain is HKI 0457(T) (=DSM 44993(T)=NRRL B-24474(T)).
    Matched MeSH terms: DNA, Bacterial/genetics; DNA, Bacterial/chemistry; DNA, Ribosomal/genetics; DNA, Ribosomal/chemistry; DNA Fingerprinting; Sequence Analysis, DNA
  3. Fulltext Reassessment of species distribution and occurrence of mud crab (Scylla spp., Portunidae) in Malaysia through morphological and molecular identification
    Naim DM, Nor SAM, Mahboob S
    Saudi J Biol Sci, 2020 Feb;27(2):643-652.
    PMID: 32210683 DOI: 10.1016/j.sjbs.2019.11.030
    This study utilized genetic and morphometric approaches to assess the molecular and morphometric differentiation among commercially important species of mud crab. Molecular investigations were derived from 542 bp mitochondrial DNA COI on 249 individuals within genus Scylla from nine states in Malaysia represents four marine regions; South China Sea, Sulu Sea, Straits of Singapore and Straits of Malacca. Four specimens were obtained from Indonesia to give a robust analysis in this study. For species delimitation, Automatic Barcode Gap Discovery (ABGD) method on a web interface was employed. Analysis on phylogenetics was implemented utilizing Neighbour joining (NJ) and Maximum Parsimony (MP) methods. The inter- and intraspecies genetic distances (Ds ) was computed using Kimura 2-parameter distance and executed in MEGA version 5.05. All samples were genetically and morphologically identified and clustered into four distinct species. Among the species, S. olivacea was the most abundant (n = 111), on the other hand the occurrence of S. paramamosain in Malaysia was very low (n = 29). No single individual of S. serrata from Malaysia was recorded in this study. Both genetic distance and phylogenetic approaches exhibited a correlative monophyletic association among all specimens analysed. This present study is crucial as it reports the reassessment of all species within genus Scylla in Malaysia, eventually could be employed as a reference source for subsequent research mainly on mariculture and other conservation efforts for the species.
    Matched MeSH terms: DNA, Mitochondrial; DNA Barcoding, Taxonomic
  4. DNA/Nano based advanced genetic detection tools for authentication of species: Strategies, prospects and limitations
    Khalil I, Hashem A, Nath AR, Muhd Julkapli N, Yehye WA, Basirun WJ
    Mol Cell Probes, 2021 10;59:101758.
    PMID: 34252563 DOI: 10.1016/j.mcp.2021.101758
    Authentication, detection and quantification of ingredients, and adulterants in food, meat, and meat products are of high importance these days. The conventional techniques for the detection of meat species based on lipid, protein and DNA biomarkers are facing challenges due to the poor selectivity, sensitivity and unsuitability for processed food products or complex food matrices. On the other hand, DNA based molecular techniques and nanoparticle based DNA biosensing strategies are gathering huge attention from the scientific communities, researchers and are considered as one of the best alternatives to the conventional strategies. Though nucleic acid based molecular techniques such as PCR and DNA sequencing are getting greater successes in species detection, they are still facing problems from its point-of-care applications. In this context, nanoparticle based DNA biosensors have gathered successes in some extent but not to a satisfactory stage to mark with. In recent years, many articles have been published in the area of progressive nucleic acid-based technologies, however there are very few review articles on DNA nanobiosensors in food science and technology. In this review, we present the fundamentals of DNA based molecular techniques such as PCR, DNA sequencing and their applications in food science. Moreover, the in-depth discussions of different DNA biosensing strategies or more specifically electrochemical and optical DNA nanobiosensors are presented. In addition, the significance of DNA nanobiosensors over other advanced detection technologies is discussed, focusing on the deficiencies, advantages as well as current challenges to ameliorate with the direction for future development.
    Matched MeSH terms: DNA/genetics
  5. Somatic mitochondrial DNA mutations in different grades of glioma
    Soon BH, Abu N, Abdul Murad NA, Then SM, Abu Bakar A, Fadzil F, et al.
    Per Med, 2022 01;19(1):25-39.
    PMID: 34873928 DOI: 10.2217/pme-2021-0033
    Aim: Mitochondrial DNA (mtDNA) alterations play an important role in the multistep processes of cancer development. Gliomas are among the most diagnosed brain cancer. The relationship between mtDNA alterations and different grades of gliomas are still elusive. This study aimed to elucidate the profile of somatic mtDNA mutations in different grades of gliomas and correlate it with clinical phenotype. Materials & methods: Forty histopathologically confirmed glioma tissue samples and their matched blood were collected and subjected for mtDNA sequencing. Results & conclusion: About 75% of the gliomas harbored at least one somatic mutation in the mtDNA gene, and 45% of these mutations were pathogenic. Mutations were scattered across the mtDNA genome, and the commonest nonsynonymous mutations were located at complex I and IV of the mitochondrial respiratory chain. These findings may have implication for future research to determine the mitochondrial energetics and its downstream metabolomics on gliomas.
    Matched MeSH terms: DNA, Mitochondrial/genetics
  6. Electrotransformation of thermophilic bacterium Caldimonas manganoxidans
    Arai T, Aikawa S, Sudesh K, Kondo T, Kosugi A
    J Microbiol Methods, 2022 01;192:106375.
    PMID: 34793853 DOI: 10.1016/j.mimet.2021.106375
    Caldimonas manganoxidans is a Gram-negative, thermophilic, bioplastic-producing bacterium that is a promising strain to overcome the drawbacks of existing bioplastic manufacturing methods. However, genetic manipulation of this species has not previously been studied. Here, we developed an optimized electrotransformation protocol for C. manganoxidans by screening conditions, including the bacterial growth phase, electroporation buffer, pulse strength, and recovery time. The optimized transformation protocol obtained (3.1 ± 0.78) × 108 colony-forming units/μg DNA of plasmid pBBR1MCS-2. High transformation efficiency was observed when using plasmid DNA isolated from C. manganoxidans. The DNA methylases of Escherichia coli did not affect the transformation efficiency of C. manganoxidans. The electrotransformation technique proposed here will be beneficial for the genetic manipulation of thermophilic Caldimonas species.
    Matched MeSH terms: DNA, Bacterial/genetics
  7. A biological inspired fuzzy adaptive window median filter (FAWMF) for enhancing DNA signal processing
    Ahmad M, Jung LT, Bhuiyan AA
    Comput Methods Programs Biomed, 2017 Oct;149:11-17.
    PMID: 28802326 DOI: 10.1016/j.cmpb.2017.06.021
    BACKGROUND AND OBJECTIVE: Digital signal processing techniques commonly employ fixed length window filters to process the signal contents. DNA signals differ in characteristics from common digital signals since they carry nucleotides as contents. The nucleotides own genetic code context and fuzzy behaviors due to their special structure and order in DNA strand. Employing conventional fixed length window filters for DNA signal processing produce spectral leakage and hence results in signal noise. A biological context aware adaptive window filter is required to process the DNA signals.

    METHODS: This paper introduces a biological inspired fuzzy adaptive window median filter (FAWMF) which computes the fuzzy membership strength of nucleotides in each slide of window and filters nucleotides based on median filtering with a combination of s-shaped and z-shaped filters. Since coding regions cause 3-base periodicity by an unbalanced nucleotides' distribution producing a relatively high bias for nucleotides' usage, such fundamental characteristic of nucleotides has been exploited in FAWMF to suppress the signal noise.

    RESULTS: Along with adaptive response of FAWMF, a strong correlation between median nucleotides and the Π shaped filter was observed which produced enhanced discrimination between coding and non-coding regions contrary to fixed length conventional window filters. The proposed FAWMF attains a significant enhancement in coding regions identification i.e. 40% to 125% as compared to other conventional window filters tested over more than 250 benchmarked and randomly taken DNA datasets of different organisms.

    CONCLUSION: This study proves that conventional fixed length window filters applied to DNA signals do not achieve significant results since the nucleotides carry genetic code context. The proposed FAWMF algorithm is adaptive and outperforms significantly to process DNA signal contents. The algorithm applied to variety of DNA datasets produced noteworthy discrimination between coding and non-coding regions contrary to fixed window length conventional filters.

    Matched MeSH terms: DNA/chemistry*
  8. Genetic and phenotype recovery of Ananas comosus var. MD2 in response to ionizing radiation
    Ma S, Mohd Raffi AN, Rosli MA, Mohd Zain NA, Ibrahim MH, Karsani SA, et al.
    Sci Rep, 2023 Jan 05;13(1):182.
    PMID: 36604574 DOI: 10.1038/s41598-022-26745-3
    Due to their sessile nature, plants are exposed to various environmental stressors such as exposure to high levels of harmful ultraviolet (UV), ionizing, and non-ionizing radiations. This exposure may result in various damages, ranging from DNA and chromosomal aberrations to phenotypic abnormalities. As an adaptation, plants have evolved efficient DNA repair mechanisms to detect and repair any damage caused by exposure to these harmful stressors to ensure their survival. In this study, the effects of gamma radiation (as a source of ionizing radiation) on clonal Ananas comosus var. MD2 was evaluated. The morphology and physiology of the clonal plantlets before and after exposure to gamma radiation were monitored at specific time intervals. The degree of genetic variation between the samples pre- and post-irradiation was also analyzed by using inter-simple sequence repeat (ISSR) markers. The resulting data revealed that the heights of the irradiated plantlets were significantly reduced (compared to control), but improved with the recovery period. Irradiated samples also exhibited relatively good photosynthetic efficiency that further improved as the plantlets recover. These observations were supported by the ISSR analysis, where the genetic dissimilarities between the irradiated samples and control were reduced by 0.1017, after 4 weeks of recovery. Overall, our findings suggested that the phenotype recovery of the clonal A. comosus var. MD2 plantlets was contributed by their ability to detect and repair the DNA lesions (as exemplified by the reduction in genetic dissimilarity after 4 weeks) and hence allow the plantlets to undergo phenotype reversion to normal plant stature.
    Matched MeSH terms: DNA Repair/genetics
  9. Lions and brown bears colonized North America in multiple synchronous waves of dispersal across the Bering Land Bridge
    Salis AT, Bray SCE, Lee MSY, Heiniger H, Barnett R, Burns JA, et al.
    Mol Ecol, 2022 Dec;31(24):6407-6421.
    PMID: 34748674 DOI: 10.1111/mec.16267
    The Bering Land Bridge connecting North America and Eurasia was periodically exposed and inundated by oscillating sea levels during the Pleistocene glacial cycles. This land connection allowed the intermittent dispersal of animals, including humans, between Western Beringia (far northeast Asia) and Eastern Beringia (northwest North America), changing the faunal community composition of both continents. The Pleistocene glacial cycles also had profound impacts on temperature, precipitation and vegetation, impacting faunal community structure and demography. While these palaeoenvironmental impacts have been studied in many large herbivores from Beringia (e.g., bison, mammoths, horses), the Pleistocene population dynamics of the diverse guild of carnivorans present in the region are less well understood, due to their lower abundances. In this study, we analyse mitochondrial genome data from ancient brown bears (Ursus arctos; n = 103) and lions (Panthera spp.; n = 39), two megafaunal carnivorans that dispersed into North America during the Pleistocene. Our results reveal striking synchronicity in the population dynamics of Beringian lions and brown bears, with multiple waves of dispersal across the Bering Land Bridge coinciding with glacial periods of low sea levels, as well as synchronous local extinctions in Eastern Beringia during Marine Isotope Stage 3. The evolutionary histories of these two taxa underline the crucial biogeographical role of the Bering Land Bridge in the distribution, turnover and maintenance of megafaunal populations in North America.
    Matched MeSH terms: DNA, Mitochondrial/genetics
  10. Fulltext Pattern Matching for DNA Sequencing Data Using Multiple Bloom Filters
    Najam M, Rasool RU, Ahmad HF, Ashraf U, Malik AW
    Biomed Res Int, 2019;2019:7074387.
    PMID: 31111064 DOI: 10.1155/2019/7074387
    Storing and processing of large DNA sequences has always been a major problem due to increasing volume of DNA sequence data. However, a number of solutions have been proposed but they require significant computation and memory. Therefore, an efficient storage and pattern matching solution is required for DNA sequencing data. Bloom filters (BFs) represent an efficient data structure, which is mostly used in the domain of bioinformatics for classification of DNA sequences. In this paper, we explore more dimensions where BFs can be used other than classification. A proposed solution is based on Multiple Bloom Filters (MBFs) that finds all the locations and number of repetitions of the specified pattern inside a DNA sequence. Both of these factors are extremely important in determining the type and intensity of any disease. This paper serves as a first effort towards optimizing the search for location and frequency of substrings in DNA sequences using MBFs. We expect that further optimizations in the proposed solution can bring remarkable results as this paper presents a proof of concept implementation for a given set of data using proposed MBFs technique. Performance evaluation shows improved accuracy and time efficiency of the proposed approach.
    Matched MeSH terms: Sequence Analysis, DNA/methods*
  11. Mitochondrial Replacement Therapy: An Islamic Perspective
    Ibrahim AH, Rahman NNA, Saifuddeen SM
    J Bioeth Inq, 2023 Sep;20(3):485-495.
    PMID: 37440155 DOI: 10.1007/s11673-023-10279-y
    Mitochondrial replacement technology (MRT) is an emerging and complex bioethical issue. This treatment aims to eliminate maternal inherited mitochondrial DNA (mtDNA) disorders. For Muslims, its introduction affects every aspect of human life, especially the five essential interests of human beings-namely, religion, life, lineage, intellect, and property. Thus, this technology must be assessed using a comprehensive and holistic approach addressing these human essential interests. Consequently, this article analyses and assesses tri-parent baby technology from the perspective of Maqasidic bioethics-that is, Islamic bioethics based on the framework of Maqasid al-Shariah. Using this analysis, this article suggests that tri-parent baby technology should not be permitted for Muslims due to the existence of third-party cell gametes which lead to lineage mixing and due to the uncertain safety of the therapy itself and because the major aim of the technology is to fulfil the affected couples interest to conceive their own genetically healthy child, not to treat and cure mtDNA disorders sufferers.
    Matched MeSH terms: DNA, Mitochondrial/genetics
  12. DNA Hairpins and Stabilization of Gold Nanoparticles: Effect of Stem Length and Toehold Composition
    Ooi JSY, Lim CR, Hua CX, Ng JF, New SY
    Langmuir, 2023 Oct 31;39(43):15200-15207.
    PMID: 37851548 DOI: 10.1021/acs.langmuir.3c01748
    This study investigates the effect of DNA hairpins on the stabilization of gold nanoparticles (AuNPs) against salt-induced aggregation (SIA) in label-free colorimetric biosensors. AuNPs were incubated with DNA hairpins of varying stem lengths and toehold sequences, followed by the addition of NaCl, before being subjected to ultraviolet-visible (UV-vis) measurement. Results showed that hairpins with longer stems generally provide better stabilization of AuNPs (18-bp >14-bp >10-bp). No improvement was observed for 14- and 18-bp hairpins with a toehold beyond 8A, which may be attributed to saturated adsorption of hairpins on the gold surface. For 14-bp hairpins with an 8-mer homopolymeric toehold, we observed a stabilization trend of A > C > G > T, similar to the reported trend of ssDNA. For variants containing ≥50% adenine as terminal bases, introducing cytosine or guanine as preceding bases could also result in strong stabilization. As the proportion of adenine decreases, variants with guanine or thymine provide less protection against SIA, especially for guanine-rich hairpins (≥6G) that could form G-quadruplexes. Such findings could serve as guidelines for researchers to design suitable DNA hairpins for label-free AuNP-based biosensors.
    Matched MeSH terms: DNA/genetics
  13. DNA Morphology: Global Alteration of DNA Topological States Induced by Chemotherapeutic Agents and Its Implication in Cancer
    Ahammed KS, Pachal S, Majumdar P, Dutta S
    Chembiochem, 2023 Apr 17;24(8):e202200715.
    PMID: 36747378 DOI: 10.1002/cbic.202200715
    The dynamic topological states of chromosomal DNA regulate many cellular fundamental processes universally in all three domains of life, that is, bacteria, archaea, and eukaryotes. DNA-binding proteins maintain the regional and global supercoiling of the chromosome and thereby regulate the chromatin architecture that ultimately influences the gene expression network and other DNA-centric molecular events in various microenvironments and growth phases. DNA-binding small molecules are pivotal weapons for treating a wide range of cancers. Recent advances in single-molecule biophysical tools have uncovered the fact that many DNA-binding ligands not only alter the regional DNA supercoiling but also modulate the overall morphology of DNA. Here we provide insight into recent advances in atomic force microscopy (AFM) acquired DNA structural change induced by therapeutically important mono- and bis-intercalating anticancer agents as well as DNA-adduct-forming anticancer drugs. We also emphasize the growing evidence of the mechanistic relevance of changes in DNA topology in the anticancer cellular responses of DNA-targeting chemotherapeutic agents.
    Matched MeSH terms: DNA/chemistry
  14. Effects of high stocking density on growth performance and expression of MyD88, and its temporal expression under the challenge of Vibrio parahaemolyticus in the noble scallop Chlamys nobilis
    Feng M, Tan K, Zhang H, Duan X, Li S, Ma H, et al.
    Fish Shellfish Immunol, 2023 Oct;141:109059.
    PMID: 37678479 DOI: 10.1016/j.fsi.2023.109059
    High stocking density has been regarded as an adverse factor in bivalve aquaculture. However, its subsequent molecular response to pathogenic bacteria has been little studied. In order to study the question, a novel MyD88 was first cloned using adult noble scallops Chlamys nobilis (CnMyD88), and its tissue distribution was investigated. Then, 1860 juvenile scallops were divided into two groups with two initial densities of high density (200 individuals/layer, HD) and normal density (110 individuals/layer, ND) and in-situ cultured for three months, in which their growth, survival, and the differential expression of CnMyD88 were examined, respectively. Finally, scallops were injected with the Vibrio parahaemolyticus to assess the temporal expression of CnMyD88. As the results show, CnMyD88 cDNA has a full length of 2241 bp and contains an 1107 bp ORF that encodes a 368-derived protein. It was widely expressed in examined tissues with a significantly higher level in hemolymph, intestine, mantle, and gonad than others. Besides, the HD group showed lower growth (0.39 ± 0.05 mm/day) and survival (37.00 ± 8.49%) than the ND group (0.55 ± 0.02 mm/day and 76.82 ± 5.78%). More importantly, the HD group exhibited significantly lower expression levels of CnMyD88 in their examined tissues than the ND group. After V. parahaemolyticus challenging, CnMyD88 had significantly lower expression levels in the scallops from the HD group than that of the scallops from the ND group at 6th, 24th, and 36th. The present results indicated that high stocking density not only made adverse impacts on growth and survival but also may induce immunosuppression in the noble scallop. Therefore, appropriate low stocking density may be worth considering to adopt in scallop aquaculture.
    Matched MeSH terms: DNA, Complementary/genetics
  15. Internal validation of reduced PCR reaction volume of the Qiagen Investigator® Argus X-12 QS Kit from blood samples on FTA cards
    Alwi AR, Mahat NA, Mohd Salleh F, Ishar SM, Kamaluddin MR, Rashid MRA
    J Forensic Sci, 2023 Nov;68(6):2103-2115.
    PMID: 37646344 DOI: 10.1111/1556-4029.15370
    The onus of proof in criminal cases is beyond any reasonable doubt, and the issue on the lack of complete internal validation data can be manipulated when it comes to justifying the validity and reliability of the X-chromosomal short tandem repeats analysis for court representation. Therefore, this research evaluated the efficiency of the optimized 60% reduced volumes for polymerase chain reaction (PCR) amplification using the Qiagen Investigator® Argus X-12 QS Kit, as well as the capillary electrophoresis (CE) sample preparation for blood samples on Flinder's Technology Associates (FTA) cards. Good-quality DNA profile (3000-12,000 RFU) from the purified blood sample on FTA card (1.2 mm) were obtained using the optimized PCR (10.0 μL of PCR reaction volume and 21 cycles) and CE (9.0 μL Hi-Di™ Formamide and 0.3 μL DNA Size Standard 550 [BTO] and 27 s injection time) conditions. The analytical and stochastic thresholds were 100 and 200 RFU, respectively. Hence, the internal validation data supported the use of the optimized 60% reduced PCR amplification reaction volume of the Qiagen Investigator® Argus X-12 QS Kit as well as the CE sample preparation for producing reliable DNA profiles that comply with the quality assurance standards for forensic DNA testing laboratories, while optimizing the analytical cost.
    Matched MeSH terms: DNA/genetics
  16. Fulltext Analysis of rDNA reveals a high genetic diversity of Halophila major in the Wallacea region
    Nguyen XV, Nguyen-Nhat NT, Nguyen XT, Dao VH, M Liao L, Papenbrock J
    PLoS One, 2021;16(10):e0258956.
    PMID: 34679102 DOI: 10.1371/journal.pone.0258956
    The genus Halophila shows the highest species diversity within the seagrass genera. Southeast Asian countries where several boundary lines exist were considered as the origin of seagrasses. We hypothesize that the boundary lines, such as Wallace's and Lydekker's Lines, may act as marine geographic barriers to the population structure of Halophila major. Seagrass samples were collected at three islands in Vietnamese waters and analyzed by the molecular maker ITS. These sequences were compared with published ITS sequences from seagrasses collected in the whole region of interest. In this study, we reveal the haplotype and nucleotide diversity, linking population genetics, phylogeography, phylogenetics and estimation of relative divergence times of H. major and other members of the Halophila genus. The morphological characters show variation. The results of the ITS marker analysis reveal smaller groups of H. major from Myanmar, Shoalwater Bay (Australia) and Okinawa (Japan) with high supporting values. The remaining groups including Sri Lanka, Viet Nam, the Philippines, Thailand, Malaysia, Indonesia, Two Peoples Bay (Australia) and Tokushima (Japan) showed low supporting values. The Wallacea region shows the highest haplotype and also nucleotide diversity. Non-significant differences were found among regions, but significant differences were presented among populations. The relative divergence times between some members of section Halophila were estimated 2.15-6.64 Mya.
    Matched MeSH terms: DNA, Ribosomal*
  17. Fulltext Sperm epigenetics landscape: correlation with embryo quality, reproductive outcomes and offspring's health
    Garrido N, Boitrelle F, Saleh R, Durairajanayagam D, Colpi G, Agarwal A
    Panminerva Med, 2023 Jun;65(2):166-178.
    PMID: 37335245 DOI: 10.23736/S0031-0808.23.04871-1
    Epigenetics refers to how gene expression and function are modulated without modifying the DNA sequence but through subtle molecular changes or interactions with it. As spermatogenesis progresses, male germ cells suffer plenty of epigenetic modifications, resulting in the definitive epigenome of spermatozoa conditioning its functionality, and this process can be altered by several internal and external factors. The paternal epigenome is crucial for sperm function, fertilization, embryo development, and offspring's health, and altered epigenetic states are associated with male infertility with or without altered semen parameters, embryo quality impairment, and worse ART outcomes together with the future offspring's health risks mainly through intergenerational transmission of epigenetic marks. Identifying epigenetic biomarkers may improve male factor diagnosis and the development of targeted therapies, not only to improve fertility but also to allow an early detection of risk and disease prevention in the progeny. While still there is much research to be done, hopefully in the near future, improvements in high-throughput technologies applied to epigenomes will permit our understanding of the underlying epigenetic mechanisms and the development of diagnostics and therapies leading to improved reproductive outcomes. In this review, we discuss the mechanisms of epigenetics in sperm and how epigenetics behave during spermatogenesis. Additionally, we elaborate on the relationship of sperm epigenetics with sperm parameters and male infertility, and highlight the impact of sperm epigenetic alterations on sperm parameters, embryo quality, ART outcomes, miscarriage rates and offspring's health. Furthermore, we provide insights into the future research of epigenetic alterations in male infertility.
    Matched MeSH terms: DNA Methylation/genetics
  18. Molecular characterization of genes encoding the quinolone resistance determining regions of Malaysian Streptococcus pneumoniae strains
    Kumari N, Subramaniam G, Navaratnam P, Sekaran SD
    Indian J Med Microbiol, 2008 5 1;26(2):148-50.
    PMID: 18445951
    Genes encoding the quinolones resistance determining regions (QRDRs) in Streptococcus pneumoniae were detected by PCR and the sequence analysis was carried out to identify point mutations within these regions. The study was carried out to observe mutation patterns among S. pneumoniae strains in Malaysia. Antimicrobial susceptibility testing of 100 isolates was determined against various antibiotics, out of which 56 strains were categorised to have reduced susceptibility to ciprofloxacin (>or=2 microg/mL). These strains were subjected to PCR amplification for presence of the gyrA, parC , gyrB and parE genes. Eight representative strains with various susceptibilities to fluoroquinolones were sequenced. Two out of the eight isolates that were sequenced were shown to have a point mutation in the gyrA gene at position Ser81. The detection of mutation at codon Ser81 of the gyrA gene suggested the potential of developing fluoroquinolone resistance among S. pneumoniae isolates in Malaysia. However, further experimental work is required to confirm the involvement of this mutation in the development of fluoroquinolone resistance in Malaysia.
    Matched MeSH terms: DNA, Bacterial/genetics; DNA, Bacterial/chemistry; Sequence Analysis, DNA; DNA Gyrase/genetics; DNA Topoisomerase IV/genetics
  19. In-silico discovery of inhibitors against human papillomavirus E1 protein
    Gunasinghe J, Hwang SS, Yam WK, Rahman T, Wezen XC
    J Biomol Struct Dyn, 2023;41(12):5583-5596.
    PMID: 35751129 DOI: 10.1080/07391102.2022.2091659
    High-risk (HR) Human papillomavirus (e.g. HPV16 and HPV18) causes approximately two-thirds of all cervical cancers in women. Although the first and second-generation vaccines confer some protection against individuals, there are no approved drugs to treat HR-HPV infections to-date. The HPV E1 protein is an attractive drug target because the protein is highly conserved across all HPV types and is crucial for the regulation of viral DNA replication. Hence, we used the Random Forest algorithm to construct a Quantitative-Structure Activity Relationship (QSAR) model to predict the potential inhibitors against the HPV E1 protein. Our QSAR classification model achieved an accuracy of 87.5%, area under the receiver operating characteristic curve of 1.00, and F-measure of 0.87 when evaluated using an external test set. We conducted a drug repurposing campaign by deploying the model to screen the Drugbank database. The top three compounds, namely Cinalukast, Lobeglitazone, and Efatutazone were analyzed for their cell membrane permeability, toxicity, and carcinogenicity. Finally, these three compounds were subjected to molecular docking and 200 ns-long Molecular Dynamics (MD) simulations. The predicted binding free energies for the candidates were calculated using the MM-GBSA method. The binding free energies for Cinalukast, Lobeglitazone, and Efatutazone were -37.84 kcal/mol, -25.30 kcal/mol, and -29.89 kcal/mol respectively. Therefore, we propose their chemical scaffolds for future rational design of E1 inhibitors.Communicated by Ramaswamy H. Sarma.
    Matched MeSH terms: DNA Replication; DNA, Viral
  20. Sperm DNA fragmentation test: usefulness in assessing male fertility and assisted reproductive technology outcomes
    Evgeni E, Sabbaghian M, Saleh R, Gül M, Vogiatzi P, Durairajanayagam D, et al.
    Panminerva Med, 2023 Jun;65(2):135-147.
    PMID: 37103485 DOI: 10.23736/S0031-0808.23.04836-X
    Male infertility is attributed to multiple factors including high levels of sperm DNA fragmentation (SDF). Conventional semen analysis continues to be the gold standard for diagnosis of male factor infertility around the world. However, the limitations of basic semen analysis have prompted the search for complementary assessments of sperm function and integrity. Sperm DNA fragmentation assays (direct or indirect) are emerging as important diagnostic tools in male infertility workups, and have been advocated for use in infertile couples for a variety of reasons. While a controlled degree of DNA nicking is required for appropriate DNA compaction, excessive fragmentation of sperm DNA is linked to impaired male fertility potential, decreased fertilization, poor embryo quality, recurrent pregnancy loss, and failure of assisted reproductive technology procedures. However, there is an ongoing debate regarding whether or not to employ SDF as a routine test for male infertility. This review compiles up-to-date information regarding the pathophysiology of SDF, the currently available SDF tests, and the role of SDF tests in natural and assisted conception conditions.
    Matched MeSH terms: DNA; DNA Fragmentation
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