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Interactions in multi-layer biological networks

Student:

Kate Petrenko

Supervisor:

Yury Barbioff, Institute of Bioinformatics Research & Education (IBRE)

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Introduction

Biological systems are often represented as networks: networks of protein-protein interactions, genetic interactions, or other types of molecular interactions. Although single-layer networks are widely used and studied in computational biology, few studies have attempted to systematically map and compare multiple network layers in different species. However, such analyses can provide interesting insights into the complexity of biological systems and their role in evolution.

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Aim and objectives of the project

Aim: explore correspondence between interactions in different biological networks (PPI, GI, CX)* for yeast and human. Find common patterns between organisms

Objectives:

  • Network data acquisition and preprocessing
  • Analysis of PPI, GI, CX
  • Investigation of the correspondence between interactions in these networks
  • Enrichment analysis of genes involved in common interactions of all networks
  • Comparison of results between other organisms

*PPI - protein-protein interactions, GI - gene interactions, CX - co-expression data

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Databases

Yeast:

GI - TheCellMap

PPI - BioGRID

CX - YeastNet

Human:

GI - HumanNet

PPI - BioGRID

CX - GeneMANIA

First step:

Second step:

All networks from GeneMANIA

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Results

The results of the intersection of the three networks in the vienna diagrams

H. sapiens

S. cerevisiae

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Results

The common interactions included genes that, on average, have slightly more interactions in different networks

H. sapiens

S. cerevisiae

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Results

Modularity metrics were calculated. The values indicate high modularity of the obtained networks

H. sapiens

S. cerevisiae

The figures show networks of genes with common interactions in all 3 networks

Modularity score:

0.86

Modularity score:

0.73

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Results

Yeast gene enrichment analysis reveals translation processes, chromosome organization, and other processes related to complex intermolecular structures

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Results

Human gene enrichment analysis reveals translation processes, energy metabolism, and other processes related to complex intermolecular structures

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Results

Next, we used a database GeneMANIA with more data, but the data were less homogeneous and genetic interactions were represented by more than screening studies.

S. cerevisiae

H. sapiens

6814

8 656

14 617

16 076

17 796

15 008

17 467

4 190

4 427

5 641

5 470

5 728

5 668

5 571

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Results

The modularity of these networks was lower, but the enrichment results were similar

H. sapiens

S. cerevisiae

Different databases

0.73

0.86

GeneMANIA

0.59

0.54

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Future plans

  • A more detailed comparison of the obtained networks for yeast and humans
  • Inclusion of other organisms in the analysis

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