Y. Hu, S.G. Tattikota, Y. Liu, A. Comjean, Y. Gao, C. Forman, G. Kim, J. Rodiger, I. Papatheodorou, G. dos Santos, S.E. Mohr, and N. Perrimon. Submitted. “DRscDB: A single-cell RNA-seq resource for data mining and data comparison across species.” BioRxiv. Publisher's VersionAbstract
With the advent of single-cell RNA sequencing (scRNA-seq) technologies, there has been a spike in studies involving scRNA-seq of several tissues across diverse species including Drosophila. Although a few databases exist for users to query genes of interest within the scRNA-seq studies, search tools that enable users to find orthologous genes and their cell type-specific expression patterns across species are limited. Here, we built a new search database, called DRscDB ( to address this need. DRscDB serves as a comprehensive repository for published scRNA-seq datasets for Drosophila and the relevant datasets from human and other model organisms. DRscDB is based on manual curation of Drosophila scRNA-seq studies of various tissue types and their corresponding analogous tissues in vertebrates including zebrafish, mouse, and human. Of note, our search database provides most of the literature-derived marker genes, thus preserving the original analysis of the published scRNA-seq datasets. DRscDB serves as a web-based user interface that allows users to mine, utilize and compare gene expression data pertaining to scRNA-seq datasets from the published literature.
Yanhui Hu, Verena Chung, Aram Comjean, Jonathan Rodiger, Fnu Nipun, Norbert Perrimon, and Stephanie E Mohr. 2020. “BioLitMine: Advanced Mining of Biomedical and Biological Literature About Human Genes and Genes from Major Model Organisms.” G3 (Bethesda).Abstract
The accumulation of biological and biomedical literature outpaces the ability of most researchers and clinicians to stay abreast of their own immediate fields, let alone a broader range of topics. Although available search tools support identification of relevant literature, finding relevant and key publications is not always straightforward. For example, important publications might be missed in searches with an official gene name due to gene synonyms. Moreover, ambiguity of gene names can result in retrieval of a large number of irrelevant publications. To address these issues and help researchers and physicians quickly identify relevant publications, we developed BioLitMine, an advanced literature mining tool that takes advantage of the medical subject heading (MeSH) index and gene-to-publication annotations already available for PubMed literature. Using BioLitMine, a user can identify what MeSH terms are represented in the set of publications associated with a given gene of the interest, or start with a term and identify relevant publications. Users can also use the tool to find co-cited genes and a build a literature co-citation network. In addition, BioLitMine can help users build a gene list relevant to a MeSH terms, such as a list of genes relevant to "stem cells" or "breast neoplasms." Users can also start with a gene or pathway of interest and identify authors associated with that gene or pathway, a feature that makes it easier to identify experts who might serve as collaborators or reviewers. Altogether, BioLitMine extends the value of PubMed-indexed literature and its existing expert curation by providing a robust and gene-centric approach to retrieval of relevant information.
Andrey A Parkhitko, Patrick Jouandin, Stephanie E Mohr, and Norbert Perrimon. 2019. “Methionine metabolism and methyltransferases in the regulation of aging and lifespan extension across species.” Aging Cell, Pp. e13034.Abstract
Methionine restriction (MetR) extends lifespan across different species and exerts beneficial effects on metabolic health and inflammatory responses. In contrast, certain cancer cells exhibit methionine auxotrophy that can be exploited for therapeutic treatment, as decreasing dietary methionine selectively suppresses tumor growth. Thus, MetR represents an intervention that can extend lifespan with a complementary effect of delaying tumor growth. Beyond its function in protein synthesis, methionine feeds into complex metabolic pathways including the methionine cycle, the transsulfuration pathway, and polyamine biosynthesis. Manipulation of each of these branches extends lifespan; however, the interplay between MetR and these branches during regulation of lifespan is not well understood. In addition, a potential mechanism linking the activity of methionine metabolism and lifespan is regulation of production of the methyl donor S-adenosylmethionine, which, after transferring its methyl group, is converted to S-adenosylhomocysteine. Methylation regulates a wide range of processes, including those thought to be responsible for lifespan extension by MetR. Although the exact mechanisms of lifespan extension by MetR or methionine metabolism reprogramming are unknown, it may act via reducing the rate of translation, modifying gene expression, inducing a hormetic response, modulating autophagy, or inducing mitochondrial function, antioxidant defense, or other metabolic processes. Here, we review the mechanisms of lifespan extension by MetR and different branches of methionine metabolism in different species and the potential for exploiting the regulation of methyltransferases to delay aging.
Screenshot of online tools

Navigating our online tools -- orthologs, literature mining, qPCR primers, and so much more!

February 14, 2019

We have been taking a critical look at how we organize our online tools on the Online Tools Overview page. And more generally, we have been thinking about new ways to spread the word about the many resources in our suite of online tools. One way that we at the DRSC like to think about these tools is how they fit into the start-to-finish order of events in a screen or other experimental project. Various tools help define lists of genes to be studied, help identify reagents for the study,...

Read more about Navigating our online tools -- orthologs, literature mining, qPCR primers, and so much more!
Figure 2 from Housden et al 2017 PNAS

Variable Dose Analysis: a new DRSC-supported cell screen approach that leverages existing reagents to perform robust screens

December 1, 2017

We are excited to report the publication of a paper from Benjamin Housden and colleagues describing development and use of the Variable Dose Analysis (VDA) approach. Ben developed a way to use existing TRiP shRNA plasmids originally developed for fly stock production in a new, effective approach to high-throughput cell screening.

The VDA approach is particularly useful for combinatorial approaches that are acutely sensitive to assay robustness. The screen Ben and colleagues report focused on synthetic effects in Drosophila tumor model cells.  The...

Read more about Variable Dose Analysis: a new DRSC-supported cell screen approach that leverages existing reagents to perform robust screens
Ben Ewen-Campen, Stephanie E Mohr, Yanhui Hu, and Norbert Perrimon. 10/9/2017. “Accessing the Phenotype Gap: Enabling Systematic Investigation of Paralog Functional Complexity with CRISPR.” Dev Cell, 43, 1, Pp. 6-9.Abstract
Single-gene knockout experiments can fail to reveal function in the context of redundancy, which is frequently observed among duplicated genes (paralogs) with overlapping functions. We discuss the complexity associated with studying paralogs and outline how recent advances in CRISPR will help address the "phenotype gap" and impact biomedical research.
Julia Wang, Rami Al-Ouran, Yanhui Hu, Seon-Young Kim, Ying-Wooi Wan, Michael F Wangler, Shinya Yamamoto, Hsiao-Tuan Chao, Aram Comjean, Stephanie E Mohr, Undiagnosed Diseases Network, Norbert Perrimon, Zhandong Liu, and Hugo J Bellen. 6/1/2017. “MARRVEL: Integration of Human and Model Organism Genetic Resources to Facilitate Functional Annotation of the Human Genome.” Am J Hum Genet, 100, 6, Pp. 843-853.Abstract
One major challenge encountered with interpreting human genetic variants is the limited understanding of the functional impact of genetic alterations on biological processes. Furthermore, there remains an unmet demand for an efficient survey of the wealth of information on human homologs in model organisms across numerous databases. To efficiently assess the large volume of publically available information, it is important to provide a concise summary of the most relevant information in a rapid user-friendly format. To this end, we created MARRVEL (model organism aggregated resources for rare variant exploration). MARRVEL is a publicly available website that integrates information from six human genetic databases and seven model organism databases. For any given variant or gene, MARRVEL displays information from OMIM, ExAC, ClinVar, Geno2MP, DGV, and DECIPHER. Importantly, it curates model organism-specific databases to concurrently display a concise summary regarding the human gene homologs in budding and fission yeast, worm, fly, fish, mouse, and rat on a single webpage. Experiment-based information on tissue expression, protein subcellular localization, biological process, and molecular function for the human gene and homologs in the seven model organisms are arranged into a concise output. Hence, rather than visiting multiple separate databases for variant and gene analysis, users can obtain important information by searching once through MARRVEL. Altogether, MARRVEL dramatically improves efficiency and accessibility to data collection and facilitates analysis of human genes and variants by cross-disciplinary integration of 18 million records available in public databases to facilitate clinical diagnosis and basic research.
Yanhui Hu, Aram Comjean, Stephanie E Mohr, The FlyBase Consortium, and Norbert Perrimon. 8/7/2017. “Gene2Function: An Integrated Online Resource for Gene Function Discovery.” G3 (Bethesda).Abstract
One of the most powerful ways to develop hypotheses regarding biological functions of conserved genes in a given species, such as in humans, is to first look at what is known about function in another species. Model organism databases (MODs) and other resources are rich with functional information but difficult to mine. Gene2Function (G2F) addresses a broad need by integrating information about conserved genes in a single online resource.
Amino acid alignment of the fly paralogs kek1 and kek2

DIOPT 6.0 released -- with eggNOG and paralog searches added

November 29, 2016

DIOPT 6.0 went live this week. Newly added features include results from eggNOG, bringing the total number of alrogithms incorporated in our integrated search tool to 14. In addition, you can now search for paralogs. To do this, choose the same species for input and output. Examples for fly-fly and human-human paralog searches are shown. As always, your feedback is welcome.


Read more about DIOPT 6.0 released -- with eggNOG and paralog searches added