Life Sciences Commons^™

An Expanded Toolkit For Gene Tagging Based On Mimic And Scarless Crispr Tagging In, David Li-Kroeger, Oguz Kanca, Pei-Tseng Lee, Sierra Cowan, Michael T Lee, Manish Jaiswal, Jose Luis Salazar, Yuchun He, Zhongyuan Zuo, Hugo J Bellen

Faculty Publications

We generated two new genetic tools to efficiently tag genes in Drosophila. The first, Double Header (DH) utilizes intronic MiMIC/CRIMIC insertions to generate artificial exons for GFP mediated protein trapping or T2A-GAL4 gene trapping in vivo based on Cre recombinase to avoid embryo injections. DH significantly increases integration efficiency compared to previous strategies and faithfully reports the expression pattern of genes and proteins. The second technique targets genes lacking coding introns using a two-step cassette exchange. First, we replace the endogenous gene with an excisable compact dominant marker using CRISPR making a null allele. Second, the insertion is replaced …

Identification Of A Novel Gene On 10q22.1 Causing Autosomal Dominant Retinitis Pigmentosa (Adrp)., Stephen P Daiger, Lori S Sullivan, Sara J Bowne, Daniel C Koboldt, Susan H Blanton, Dianna K Wheaton, Cheryl E Avery, Elizabeth D Cadena, Robert K Koenekoop, Robert S Fulton, Richard K Wilson, George M Weinstock, Richard A Lewis, David G Birch

Faculty Publications

Whole-genome linkage mapping identified a region on chromosome 10q21.3-q22.1 with a maximum LOD score of 3.0 at 0 % recombination in a six-generation family with autosomal dominant retinitis pigmentosa (adRP). All known adRP genes and X-linked RP genes were excluded in the family by a combination of methods. Whole-exome next-generation sequencing revealed a missense mutation in hexokinase 1, HK1 c.2539G > A, p.Glu847Lys, tracking with disease in all affected family members. One severely-affected male is homozygous for this region by linkage analysis and has two copies of the mutation. No other potential mutations were detected in the linkage region nor were …

Large-Scale Identification Of Chemically Induced Mutations In Drosophila Melanogaster., Nele A Haelterman, Lichun Jiang, Yumei Li, Vafa Bayat, Hector Sandoval, Berrak Ugur, Kai Li Tan, Ke Zhang, Danqing Bei, Bo Xiong, Wu-Lin Charng, Theodore Busby, Adeel Jawaid, Gabriela David, Manish Jaiswal, Koen J T Venken, Shinya Yamamoto, Rui Chen, Hugo J Bellen

Faculty Publications

Forward genetic screens using chemical mutagens have been successful in defining the function of thousands of genes in eukaryotic model organisms. The main drawback of this strategy is the time-consuming identification of the molecular lesions causative of the phenotypes of interest. With whole-genome sequencing (WGS), it is now possible to sequence hundreds of strains, but determining which mutations are causative among thousands of polymorphisms remains challenging. We have sequenced 394 mutant strains, generated in a chemical mutagenesis screen, for essential genes on the Drosophila X chromosome and describe strategies to reduce the number of candidate mutations from an average of …

An Unbiased Approach To Identify Genes Involved In Development In A Turtle With Temperature-Dependent Sex Determination, Jena L. Chojnowski, Edward L. Braun

Faculty Publications

Many reptiles exhibit temperature-dependent sex determination (TSD). The initial cue in TSD is incubation temperature, unlike genotypic sex determination (GSD) where it is determined by the presence of specific alleles (or genetic loci). We used patterns of gene expression to identify candidates for genes with a role in TSD and other developmental processes without making a priori assumptions about the identity of these genes (ortholog-based approach). We identified genes with sexually dimorphic mRNA accumulation during the temperature sensitive period of development in the Red-eared slider turtle (Trachemys scripta), a turtle with TSD. Genes with differential mRNA accumulation in response to …

Using Jackknife To Assess The Quality Of Gene Order Phylogenies, Jian Shi, Yiwei Zhang, Haiwei Luo, Jijun Tang

Faculty Publications

Background
In recent years, gene order data has attracted increasing attention from both biologists and computer scientists as a new type of data for phylogenetic analysis. If gene orders are viewed as one character with a large number of states, traditional bootstrap procedures cannot be applied. Researchers began to use a jackknife resampling method to assess the quality of gene order phylogenies.

Results
In this paper, we design and conduct a set of experiments to validate the performance of this jackknife procedure and provide discussions on how to conduct it properly. Our results show that jackknife is very useful to …

Gene Order Phylogeny And The Evolution Of Methanogens, Haiwei Luo, Zhiyi Sun, William Arndt, Jian Shi, Robert Friedman, Jijun Tang

Faculty Publications

Methanogens are a phylogenetically diverse group belonging to Euryarchaeota. Previously, phylogenetic approaches using large datasets revealed that methanogens can be grouped into two classes, “Class I” and “Class II”. However, some deep relationships were not resolved. For instance, the monophyly of “Class I” methanogens, which consist of Methanopyrales, Methanobacteriales and Methanococcales, is disputable due to weak statistical support. In this study, we use MSOAR to identify common orthologous genes from eight methanogen species and a Thermococcale species (outgroup), and apply GRAPPA and FastME to compute distance-based gene order phylogeny. The gene order phylogeny supports two classes of methanogens, but it …

Gene Rearrangement Analysis And Ancestral Order Inference From Chloroplast Genomes With Inverted Repeat, Feng Yue, Liying Cui, Claude W. Depamphilis, Bernard M.E. Moret, Jijun Tang

Faculty Publications

Background
Genome evolution is shaped not only by nucleotide substitutions, but also by structural changes including gene and genome duplications, insertions, deletions and gene order rearrangements. The most popular methods for reconstructing phylogeny from genome rearrangements include GRAPPA and MGR. However these methods are limited to cases where equal gene content or few deletions can be assumed. Since conserved duplicated regions are present in many chloroplast genomes, the inference of inverted repeats is needed in chloroplast phylogeny analysis and ancestral genome reconstruction.

Results
We extend GRAPPA and develop a new method GRAPPA-IR to handle chloroplast genomes. A test of GRAPPA-IR …