• Ramakrishna Ramaswamy

      Articles written in Journal of Biosciences

    • Ab initio gene identification: Prokaryote genome annotation with GeneScan and GLIMMER

      Gautam Aggarwal Ramakrishna Ramaswamy

      More Details Abstract Fulltext PDF

      We compare the annotation of three complete genomes using theab initio methods of gene identification GeneScan and GLIMMER. The annotation given in GenBank, the standard against which these are compared, has been made using GeneMark. We find a number of novel genes which are predicted by both methods used here, as well as a number of genes that are predicted by GeneMark, but are not identified by either of the nonconsensus methods that we have used. The three organisms studied here are all prokaryotic species with fairly compact genomes. The Fourier measure forms the basis for an efficient non-consensus method for gene prediction, and the algorithm GeneScan exploits this measure. We have bench-marked this program as well as GLIMMER using 3 complete prokaryotic genomes. An effort has also been made to study the limitations of these techniques for complete genome analysis. GeneScan and GLIMMER are of comparable accuracy insofar as gene-identification is concerned, with sensitivities and specificities typically greater than 0.9. The number of false predictions (both positive and negative) is higher for GeneScan as compared to GLIMMER, but in a significant number of cases, similar results are provided by the two techniques. This suggests that there could be some as-yet unidentified additional genes in these three genomes, and also that some of the putative identifications made hitherto might require re-evaluation. All these cases are discussed in detail.

    • Subtype-specific network organization of molecular complexes in breast cancer


      More Details Abstract Fulltext PDF

      Breast cancer, a leading cause of death in women, is a complex heterogeneous disease comprising multiple molecular subtypes with different treatment responses and hence clinical outcomes. The present study aims to gain a deeper insight into the disease complexities at the level of molecular subtypes. For this, first, three subtype networks of breast cancer, viz., ER−/HER2−, ER+/HER2−, and HER2+, were constructed utilizing mRNA expression profiles of tumor tissues. Subsequently, these networks were used to construct three exclusively subtype-specific networks. Further, the mRNA expression profiles of all three subtypes were analyzed using differential correlations based on z-statistics of the F-test. Finally, functional enrichment analysis was carried out to elucidate functions and processes of important genes involved in subtype networks. From this analysis, it was observed that these subtype networks share a commonality among them in terms of preserved patterns. However, these networks possess specific patterns that result in exclusively subtype-specific networks having unique sets of wiring among the genes. Additionally, the significantly differentially correlated gene pairs between two subtypes demonstrate subtype-specific expressional patterns which make them different at the molecular level. Furthermore, the network analysis also revealed ER−/HER2−-specific genes, viz., LUM, RARB, and ERCC6. Thus, the present analysis provides new insights for further research on breast cancer subtypes and hence the development of the most effective diagnosis and treatment.

  • Journal of Biosciences | News

      Forthcoming Special issue.

    • To trigger further research on plant mitochondria, the Journal of Biosciences is bringing out a special issue titled "Plant Mitochondria: Properties and Interactions with Other Organelles".

      Plant mitochondria are quite distinct and have unique features, such as a cyanide-insensitive alternate pathway. They also interact with chloroplasts to optimize photosynthetic carbon assimilation.

      Submissions are welcome until 30 July 2023. The contributions can be original articles, short communications, reviews, or mini-reviews on any topic related to plant mitochondria.

      Authors can submit their articles online at https://www.editorialmanager.com/jbsc/default2.aspx

      Posted on April 12, 2023
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      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

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