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Daniela Puiu

Publications and source records attributed to Daniela Puiu.

6 recordsLinked to original sources

Efficient evidence-based genome annotation with EviAnn.

For many years, machine learning-based ab initio gene finding approaches have been central components of eukaryotic genome annotation pipelines, and they remain so today. The reliance on these approaches was originally sustained by the high cost and low availability of gene expression data, a primary source of evidence for gene annotation along with protein homology. However, innovations in modern sequencing technologies have revolutionized the acquisition of gene expression data, allowing scientists to rely more heavily on this class of evidence. In addition, proteins found in a multitude of well-annotated genomes represent another invaluable resource for gene annotation. Existing annotation packages often underutilize these data sources, which prompted us to develop EviAnn (Evidence-based Annotator), a novel evidence-based eukaryotic gene annotation system. EviAnn takes a strongly data-driven approach, building the exon-intron structure of genes from transcript alignments or protein-sequence homology rather than from purely ab initio gene finding techniques. We show that when provided with the same input data, EviAnn consistently outperforms current state-of-the-art packages including BRAKER3, MAKER2, and FINDER, while utilizing considerably less computer time. Annotation of a mammalian genome can be completed in less than an hour on a single multi-core server. EviAnn is freely available under an open-source license from https://github.com/alekseyzimin/EviAnn_release and from Bioconda as "eviann".

Journal Article↗

Genomic variability in Zika virus in GBS cases in Colombia.

Major clusters of Guillain-Barré Syndrome (GBS) emerged during the Zika virus (ZIKV) outbreaks in the South Pacific and the Americas from 2014 to 2016. The factors contributing to GBS susceptibility in ZIKV infection remain unclear, although considerations of viral variation, patient susceptibility, environmental influences, and other potential factors have been hypothesized. Studying the role of viral genetic factors has been challenging due to the low viral load and rapid viral clearance from the blood after the onset of Zika symptoms. The prolonged excretion of ZIKV in urine by the time of GBS onset, when the virus is no longer present in the blood, provides an opportunity to unravel whether specific ZIKV mutations are related to the development of GBS in certain individuals. This study aimed to investigate the association between specific ZIKV genotypes and the development of GBS, taking advantage of a unique collection of ZIKV-positive urine samples obtained from GBS cases and controls during the 2016 ZIKV outbreak in Colombia. Utilizing Oxford-Nanopore technology, we conducted complete genome sequencing of ZIKV in biological samples from 15 patients with GBS associated with ZIKV and 17 with ZIKV infection without neurological complications. ZIKV genotypes in Colombia exhibited distribution across three clades (average bootstrap of 90.9±14.9%), with two clades dominating the landscape. A comparative analysis of ZIKV genomes from GBS and non-neurological complications, alongside 1368 previously reported genomes, revealed no significant distinctions between the two groups. Both genotypes were similarly distributed among observed clades in Colombia. Furthermore, no variations were identified in the amino acid composition of the viral genome between the two groups. Our findings suggest that GBS in ZIKV infection is perhaps associated with patient susceptibility and/or other para- or post-infectious immune-mediated mechanisms rather than with specific ZIKV genome variations.

Zika Virus↗

The genome of Cryptosporidium hominis.

Cryptosporidium species cause acute gastroenteritis and diarrhoea worldwide. They are members of the Apicomplexa--protozoan pathogens that invade host cells by using a specialized apical complex and are usually transmitted by an invertebrate vector or intermediate host. In contrast to other Apicomplexans, Cryptosporidium is transmitted by ingestion of oocysts and completes its life cycle in a single host. No therapy is available, and control focuses on eliminating oocysts in water supplies. Two species, C. hominis and C. parvum, which differ in host range, genotype and pathogenicity, are most relevant to humans. C. hominis is restricted to humans, whereas C. parvum also infects other mammals. Here we describe the eight-chromosome approximately 9.2-million-base genome of C. hominis. The complement of C. hominis protein-coding genes shows a striking concordance with the requirements imposed by the environmental niches the parasite inhabits. Energy metabolism is largely from glycolysis. Both aerobic and anaerobic metabolisms are available, the former requiring an alternative electron transport system in a simplified mitochondrion. Biosynthesis capabilities are limited, explaining an extensive array of transporters. Evidence of an apicoplast is absent, but genes associated with apical complex organelles are present. C. hominis and C. parvum exhibit very similar gene complements, and phenotypic differences between these parasites must be due to subtle sequence divergence.

Animals↗

CryptoDB: the Cryptosporidium genome resource.

CryptoDB (http://CryptoDB.org) represents a collaborative effort to locate all genome data for the apicomplexan parasite Cryptosporidium parvum in a single user-friendly database. CryptoDB currently houses the genomic sequence data for both the human type 1 H strain and the bovine type 2 IOWA strain in addition to all other available EST and GSS sequences obtained from public repositories. All data are available for data mining via BLAST, keyword searches of pre-computed BLASTX results and user-defined or PROSITE motif pattern searches. Release 1.0 of CryptoDB contains approximately 19 million bases of genome sequence for the H and IOWA strains and an additional approximately 24 million bases of GSS and EST sequence obtained from other sources. Open reading frames greater than 50 and 100 amino acids have been generated for all sequences and all data are available for bulk download. This database, like other apicomplexan parasite databases, has been built utilizing the PlasmoDB model.

Animals↗

Partitioning of rearranged Ig genes by mutation analysis demonstrates D-D fusion and V gene replacement in the expressed human repertoire.

The accurate partitioning of Ig H chain V(H)DJ(H) junctions and L chain V(L)J(L) junctions is problematic. We have developed a statistical approach for the partitioning of such sequences, by analyzing the distribution of point mutations between a determined V gene segment and putative Ig regions. The establishment of objective criteria for the partitioning of sequences between V(H), D, and J(H) gene segments has allowed us to more carefully analyze intervening putative nontemplated (N) nucleotides. An analysis of 225 IgM H chain sequences, with five or fewer V mutations, led to the alignment of 199 sequences. Only 5.0% of sequences lacked N nucleotides at the V(H)D junction (N1), and 10.6% at the DJ(H) junction (N2). Long N regions (>9 nt) were seen in 20.6% of N1 regions and 17.1% of N2 regions. Using a statistical analysis based upon known features of N addition, and mutation analysis, two of these N regions aligned with D gene segments, and a third aligned with an inverted D gene segment. Nine additional sequences included possible alignments with a second D segment. Four of the remaining 40 long N1 regions included 5' sequences having six or more matches to V gene end motifs, which may be the result of V gene replacement. Such sequences were not seen in long N2 regions. The long N regions frequently seen in the expressed repertoire of human Ig gene rearrangements can therefore only partly be explained by V gene replacement and D-D fusion.

Antibody Diversity↗

GeneX Va: VBC open source microarray database and analysis software.

Developed by the Virginia Bioinformatics Consortium (VBC), GeneX Va is an open source, freeware database and bioinformatics analysis software for archiving and analyzing Affymetrix GeneChip data. It provides an integrated framework for management, documentation, and analysis of microarray experiments and data to support a range of users, from individual research laboratories to institutional microarray facilities. GeneX Va also provides web-based access to a PostgreSQL relational database system with a comprehensive security system. Data can be extracted from the database and delivered to interactive or scriptable statistical analysis protocols. The security system allows each investigator to manage their own array data and analysis output files and also provides custom access privileges for other users, groups, and internal/external collaborators. The analysis interface uses "Analysis Trees," an innovative user interface that allows researchers to interactively create a tree-structured flow chart of analysis routines. The latest GeneX Va software is available from and can be freely downloaded at the Sourceforge web site http://va-genex.sourceforge.net. To allow researchers to access the database and analysis capabilities of the GeneX Va system, microarray data from many VBC GeneChip experiments have been deposited into a public section of the GeneX Va system at the University of Virginia. The VBC GeneX Va sites, which include documentation, are at http://genes.med.virginia.edu/ of the University of Virginia and at http://genex.csbc.vcu.edu/ of the Virginia Commonwealth University.

Computer Security↗