Articles Online (Volume 12, Issue 4)

Perspective

Bringing Biocuration to China

Zhang Zhang , Weimin Zhu, Jingchu Luo

Biocuration involves adding value to biomedical data by the processes of standardization, quality control and information transferring (also known as data annotation). It enhances data interoperability and consistency, and is critical in translating biomedical data into scientific discovery. Although China is becoming a leading scientific data producer, biocuration is still very new to the Chinese biomedical data community. In fact, there currently lacks an equivalent acknowledged word in Chinese for the word “curation”. Here we propose its Chinese translation as “审编” (Pinyin: shěn biān), based on its implied meanings taken by biomedical data community. The 8th International Biocuration Conference to be held in China (http://biocuration2015.tilsi.org) next year bears the potential to raise the general awareness in China of the significant role of biocuration in scientific discovery. However, challenges are ahead in its implementation.

Page 153–155


Review

Genomics in Neurological Disorders

Guangchun Han, Jiya Sun, Jiajia Wang,Zhouxian Bai, Fuhai Song, Hongxing Lei

Neurological disorders comprise a variety of complex diseases in the central nervous system, which can be roughly classified as neurodegenerative diseases and psychiatric disorders. The basic and translational research of neurological disorders has been hindered by the difficulty in accessing the pathological center (i.e., the brain) in live patients. The rapid advancement of sequencing and array technologies has made it possible to investigate the disease mechanism and biomarkers from a systems perspective. In this review, recent progresses in the discovery of novel risk genes, treatment targets and peripheral biomarkers employing genomic technologies will be discussed. Our major focus will be on two of the most heavily investigated neurological disorders, namely Alzheimer’s disease and autism spectrum disorder.

Page 156–163


Review

Repetitive Sequences in Plant Nuclear DNA: Types, Distribution, Evolution and Function

Shweta Mehrotra, Vinod Goyal

Repetitive DNA sequences are a major component of eukaryotic genomes and may account for up to 90% of the genome size. They can be divided into minisatellite, microsatellite and satellite sequences. Satellite DNA sequences are considered to be a fast-evolving component of eukaryotic genomes, comprising tandemly-arrayed, highly-repetitive and highly-conserved monomer sequences. The monomer unit of satellite DNA is 150–400 base pairs (bp) in length. Repetitive sequences may be species- or genus-specific, and may be centromeric or subtelomeric in nature. They exhibit cohesive and concerted evolution caused by molecular drive, leading to high sequence homogeneity. Repetitive sequences accumulate variations in sequence and copy number during evolution, hence they are important tools for taxonomic and phylogenetic studies, and are known as “tuning knobs” in the evolution. Therefore, knowledge of repetitive sequences assists our understanding of the organization, evolution and behavior of eukaryotic genomes. Repetitive sequences have cytoplasmic, cellular and developmental effects and play a role in chromosomal recombination. In the post-genomics era, with the introduction of next-generation sequencing technology, it is possible to evaluate complex genomes for analyzing repetitive sequences and deciphering the yet unknown functional potential of repetitive sequences.

Page 164–171


Letter

Complete Sequence of pABTJ2, A Plasmid from Acinetobacter baumannii MDR-TJ, Carrying Many Phage-like Elements

He Huang, Yan Dong, Zhi-Liang Yang, Hao Luo, Xi Zhang, Feng Gao

Acinetobacter baumannii is an important opportunistic pathogen in hospital, and the multidrug-resistant isolates of A. baumannii have been increasingly reported in recent years. A number of different mechanisms of resistance have been reported, some of which are associated with plasmid-mediated acquisition of genes. Therefore, studies on plasmids in A. baumannii have been a hot issue lately. We have performed complete genome sequencing of A. baumannii MDR-TJ, which is a multidrug-resistant isolate. Finalizing the remaining large scaffold of the previous assembly, we found a new plasmid pABTJ2, which carries many phage-like elements. The plasmid pABTJ2 is a circular double-stranded DNA molecule, which is 110,967 bp in length. We annotated 125 CDSs from pABTJ2 using IMG ER and ZCURVE_V, accounting for 88.28% of the whole plasmid sequence. Many phage-like elements and a tRNA-coding gene were detected in pABTJ2, which is rarely reported among A. baumannii. The tRNA gene is specific for asparagine codon GTT, which may be a small chromosomal sequence picked up through incorrect excision during plasmid formation. The phage-like elements may have been acquired during the integration process, as the GC content of the region carrying phage-like elements was higher than that of the adjacent regions. The finding of phage-like elements and tRNA-coding gene in pABTJ2 may provide a novel insight into the study of A. baumannii pan-plasmidome.

Page 172–177


Method

FunMod: A Cytoscape Plugin for Identifying Functional Modules in Undirected Protein–Protein Networks

Massimo Natale, Alfredo Benso, Stefano Di Carlo, Elisa Ficarra

The characterization of the interacting behaviors of complex biological systems is a primary objective in protein–protein network analysis and computational biology. In this paper we present FunMod, an innovative Cytoscape version 2.8 plugin that is able to mine undirected protein–protein networks and to infer sub-networks of interacting proteins intimately correlated with relevant biological pathways. This plugin may enable the discovery of new pathways involved in diseases. In order to describe the role of each protein within the relevant biological pathways, FunMod computes and scores three topological features of the identified sub-networks. By integrating the results from biological pathway clustering and topological network analysis, FunMod proved to be useful for the data interpretation and the generation of new hypotheses in two case studies.

Page 178–186