Repetitive elements and their genetic applications in zebrafish

1997 ◽  
Vol 75 (5) ◽  
pp. 507-523 ◽  
Author(s):  
Zsuzsanna Izsvák ◽  
Zoltan Ivics ◽  
Perry B Hackett
Keyword(s):  
Insertional Mutagenesis ◽  
Repetitive Sequences ◽  
Genetic Research ◽  
Strain Differences ◽  
Gene Families ◽  
Repetitive Elements ◽  
Model Systems ◽  
Evolutionary Forces ◽  
Individual Strain ◽  
Potential Applications

Repetitive elements provide important clues about chromosome dynamics, evolutionary forces, and mechanisms for exchange of genetic information between organisms. Repetitive sequences, especially the mobile elements, have many potential applications in genetic research. DNA transposons and retroposons are routinely used for insertional mutagenesis, gene mapping, gene tagging, and gene transfer in several model systems. Once they are developed for the zebrafish, they will greatly facilitate the identification, mapping, and isolation of genes involved in development as well as the investigation of the evolutionary processes that have been shaping eukaryotic genomes. In this review repetitive elements are characterized in terms of their lengths and other physical properties, copy numbers, modes of amplification, and mobilities within a single genome and between genomes. Examples of how they can be used to screen genomes for species and individual strain differences are presented. This review does not cover repetitive gene families that encode well-studied products such as rRNAs, tRNAs, and the like.

Genetic applications of transposable elements in eukaryotes

Genome ◽  
1994 ◽  
Vol 37 (4) ◽  
pp. 519-525 ◽  
Author(s):  
Chaoqiang Lai
Keyword(s):  
Gene Transfer ◽  
Molecular Biology ◽  
Transposable Elements ◽  
Gene Mapping ◽  
Transposable Element ◽  
Gene Cloning ◽  
Insertional Mutagenesis ◽  
Genetic Research ◽  
Potential Applications ◽  
Mapping Gene

Transposable elements have many potential applications in genetic research, including insertional mutagenesis, gene mapping, gene cloning, gene transfer within and between species, and identification of genes expressed in specific tissues at a particular time. All these genetic approaches are important in the study of molecular biology and evolution. As the number of known transposable element families increases and their properties are further documented, their utility as genetic research tools will become greater. The purpose of this article is to discuss the salient properties of transposable elements in eukaryotes and their applications to genetic research.Key words: transposable elements, mutagenesis, plants, Drosophila, genetic application.

scholarly journals The draft genome of the specialist flea beetle Altica viridicyanea (Coleoptera: Chrysomelidae)

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Huai-Jun Xue ◽  
Yi-Wei Niu ◽  
Kari A. Segraves ◽  
Rui-E Nie ◽  
Ya-Jing Hao ◽  
...  
Keyword(s):  
Host Plant ◽  
Plant Cell Wall ◽  
Flea Beetle ◽  
Repetitive Sequences ◽  
Draft Genome ◽  
Gene Families ◽  
Ecological Speciation ◽  
Secondary Chemistry ◽  
Host Plant Specialization ◽  
Insight Into

Abstract Background Altica (Coleoptera: Chrysomelidae) is a highly diverse and taxonomically challenging flea beetle genus that has been used to address questions related to host plant specialization, reproductive isolation, and ecological speciation. To further evolutionary studies in this interesting group, here we present a draft genome of a representative specialist, Altica viridicyanea, the first Alticinae genome reported thus far. Results The genome is 864.8 Mb and consists of 4490 scaffolds with a N50 size of 557 kb, which covered 98.6% complete and 0.4% partial insect Benchmarking Universal Single-Copy Orthologs. Repetitive sequences accounted for 62.9% of the assembly, and a total of 17,730 protein-coding gene models and 2462 non-coding RNA models were predicted. To provide insight into host plant specialization of this monophagous species, we examined the key gene families involved in chemosensation, detoxification of plant secondary chemistry, and plant cell wall-degradation. Conclusions The genome assembled in this work provides an important resource for further studies on host plant adaptation and functionally affiliated genes. Moreover, this work also opens the way for comparative genomics studies among closely related Altica species, which may provide insight into the molecular evolutionary processes that occur during ecological speciation.

scholarly journals Combined genomic, transcriptomic, and metabolomic analyses provide insights into chayote (Sechium edule) evolution and fruit development

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Anzhen Fu ◽  
Qing Wang ◽  
Jianlou Mu ◽  
Lili Ma ◽  
Changlong Wen ◽  
...  
Keyword(s):  
Fruit Development ◽  
Repetitive Sequences ◽  
Genetic Research ◽  
Future Research ◽  
Agricultural Crop ◽  
Protein Coding ◽  
Third Generation Sequencing ◽  
Sechium Edule ◽  
Generation Sequencing ◽  
Cucurbitaceae Family

AbstractChayote (Sechium edule) is an agricultural crop in the Cucurbitaceae family that is rich in bioactive components. To enhance genetic research on chayote, we used Nanopore third-generation sequencing combined with Hi–C data to assemble a draft chayote genome. A chromosome-level assembly anchored on 14 chromosomes (N50 contig and scaffold sizes of 8.40 and 46.56 Mb, respectively) estimated the genome size as 606.42 Mb, which is large for the Cucurbitaceae, with 65.94% (401.08 Mb) of the genome comprising repetitive sequences; 28,237 protein-coding genes were predicted. Comparative genome analysis indicated that chayote and snake gourd diverged from sponge gourd and that a whole-genome duplication (WGD) event occurred in chayote at 25 ± 4 Mya. Transcriptional and metabolic analysis revealed genes involved in fruit texture, pigment, flavor, flavonoids, antioxidants, and plant hormones during chayote fruit development. The analysis of the genome, transcriptome, and metabolome provides insights into chayote evolution and lays the groundwork for future research on fruit and tuber development and genetic improvements in chayote.

Cultured Cells as Model Systems in Shock Wave Lithotripsy Research: Advantages, Methodological Concerns and Potential Applications

1989 ◽  
pp. 41-47
Author(s):  
James A. McAteer ◽  
Stephen A. Kempson ◽  
Sharon P. Andreoli ◽  
Richard Haak ◽  
Robert A. Harris ◽  
...  
Keyword(s):  
Shock Wave ◽  
Shock Wave Lithotripsy ◽  
Cultured Cells ◽  
Model Systems ◽  
Potential Applications

scholarly journals Mutations in the two component regulator systems PmrAB and PhoPQ give rise to increased colistin resistance in Citrobacter and Enterobacter spp.

2020 ◽  
Vol 69 (4) ◽  
pp. 521-529 ◽  
Author(s):  
Matthew E. Wand ◽  
J. Mark Sutton
Keyword(s):  
Growth Rate ◽  
Type Species ◽  
Galleria Mellonella ◽  
Strain Differences ◽  
Fold Increase ◽  
Colistin Resistance ◽  
Content Type ◽  
Link Type ◽  
Carbapenem Resistant ◽  
Individual Strain

Introduction. Colistin is a last resort antibiotic for treating infections caused by carbapenem-resistant isolates. Mechanisms of resistance to colistin have been widely described in Klebsiella pneumoniae and Escherichia coli but have yet to be characterized in Citrobacter and Enterobacter species. Aim. To identify the causative mutations leading to generation of colistin resistance in Citrobacter and Enterobacter spp. Methodology. Colistin resistance was generated by culturing in increasing concentrations of colistin or by direct culture in a lethal (above MIC) concentration. Whole-genome sequencing was used to identify mutations. Fitness of resistant strains was determined by changes in growth rate, and virulence in Galleria mellonella. Results. We were able to generate colistin resistance upon exposure to sub-MIC levels of colistin, in several but not all strains of Citrobacter and Enterobacter resulting in a 16-fold increase in colistin MIC values for both species. The same individual strains also developed resistance to colistin after a single exposure at 10× MIC, with a similar increase in MIC. Genetic analysis revealed that this increased resistance was attributed to mutations in PmrB for Citrobacter and PhoP in Enterobacter , although we were not able to identify causative mutations in all strains. Colistin-resistant mutants showed little difference in growth rate, and virulence in G. mellonella, although there were strain-to-strain differences. Conclusions. Stable colistin resistance may be acquired with no loss of fitness in these species. However, only select strains were able to adapt suggesting that acquisition of colistin resistance is dependent upon individual strain characteristics.

scholarly journals The First Transcriptome Assembly of Yenyuan Stream Salamander (Batrachuperus yenyuanensis) Provides Novel Insights into Its Molecular Evolution

2019 ◽  
Vol 20 (7) ◽  
pp. 1529 ◽  
Author(s):  
Jianli Xiong ◽  
Yunyun Lv ◽  
Yong Huang ◽  
Qiangqiang Liu
Keyword(s):  
Sequence Similarity ◽  
Transcriptome Assembly ◽  
Repetitive Sequences ◽  
Divergence Time ◽  
Gene Families ◽  
Single Copy ◽  
Phylogenetic Position ◽  
Interesting Insight ◽  
Chinese Giant Salamander ◽  
Lineage Divergence

The Yenyuan stream salamander (Batrachuperus yenyuanensis) has been previously evaluated with regards to phylogeny, population genetics, and hematology, but genomic information is sparse due to the giant genome size of salamanders which contain highly repetitive sequences, thus resulting in the lack of a complete reference genome. This study evaluates the encoding genetic sequences and provides the first transcriptome assembly of Yenyuan stream salamander based on mixed samples from the liver, spermary, muscle and spleen tissues. Using this transcriptome assembly and available encoding sequences from other vertebrates, the gene families, phylogenetic status, and species divergence time were compared or estimated. A total of 13,750 encoding sequences were successfully obtained from the transcriptome assembly of Yenyuan stream salamander, estimated to contain 40.1% of the unigenes represented in tetrapod databases. A total of 88.79% of these genes could be annotated to a biological function by current databases. Through gene family clustering, we found multiple possible isoforms of the Scribble gene—whose function is related to regeneration—based on sequence similarity. Meanwhile, we constructed a robust phylogenetic tree based on 56 single-copy orthologues, which indicates that based on phylogenetic position, the Yenyuan stream salamander presents the closest relationship with the Chinese giant salamander (Andrias davidianus) of the investigated vertebrates. Based on the fossil-calibrated phylogeny, we estimated that the lineage divergence between the ancestral Yenyuan stream salamander and the Chinese giant salamander may have occurred during the Cretaceous period (~78.4 million years ago). In conclusion, this study not only provides a candidate gene that is valuable for exploring the remarkable capacity of regeneration in the future, but also gives an interesting insight into the understanding of Yenyuan stream salamander by this first transcriptome assembly.

scholarly journals The genome and transcriptome analysis of snake gourd provide insights into its evolution and fruit development and ripening

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Lili Ma ◽  
Qing Wang ◽  
Jianlou Mu ◽  
Anzhen Fu ◽  
Changlong Wen ◽  
...  
Keyword(s):  
Genome Assembly ◽  
Transcriptome Analysis ◽  
Fruit Development ◽  
Repetitive Sequences ◽  
Genetic Research ◽  
Future Research ◽  
Comparative Genomic ◽  
Crop Species ◽  
Total Size ◽  
Fruit Development And Ripening

AbstractSnake gourd (Trichosanthes anguina L.), which belongs to the Cucurbitaceae family, is a popular ornamental and food crop species with medicinal value and is grown in many parts of the world. Although progress has been made in its genetic improvement, the organization, composition, and evolution of the snake gourd genome remain largely unknown. Here, we report a high-quality genome assembly for snake gourd, comprising 202 contigs, with a total size of 919.8 Mb and an N50 size of 20.1 Mb. These findings indicate that snake gourd has one of the largest genomes of Cucurbitaceae species sequenced to date. The snake gourd genome assembly harbors 22,874 protein-coding genes and 80.0% of the genome consists of repetitive sequences. Phylogenetic analysis reveals that snake gourd is closely related to sponge gourd but diverged from their common ancestor ~33–47 million years ago. The genome sequence reported here serves as a valuable resource for snake gourd genetic research and comparative genomic studies in Cucurbitaceae and other plant species. In addition, fruit transcriptome analysis reveals the candidate genes related to quality traits during snake gourd fruit development and provides a basis for future research on snake gourd fruit development and ripening at the transcript level.

scholarly journals Taxus yunnanensis genome offers insights into gymnosperm phylogeny and taxol production

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Chi Song ◽  
Fangfang Fu ◽  
Lulu Yang ◽  
Yan Niu ◽  
Zhaoyang Tian ◽  
...  
Keyword(s):  
Biosynthetic Pathway ◽  
Repetitive Sequences ◽  
Divergence Time ◽  
Gene Families ◽  
Long Terminal Repeat Retrotransposons ◽  
Taxus Yunnanensis ◽  
Sequoiadendron Giganteum ◽  
Large Genome Size ◽  
Taxol Production ◽  
Phylogenomic Analyses

AbstractTaxol, a natural product derived from Taxus, is one of the most effective natural anticancer drugs and the biosynthetic pathway of Taxol is the basis of heterologous bio-production. Here, we report a high-quality genome assembly and annotation of Taxus yunnanensis based on 10.7 Gb sequences assembled into 12 chromosomes with contig N50 and scaffold N50 of 2.89 Mb and 966.80 Mb, respectively. Phylogenomic analyses show that T. yunnanensis is most closely related to Sequoiadendron giganteum among the sampled taxa, with an estimated divergence time of 133.4−213.0 MYA. As with most gymnosperms, and unlike most angiosperms, there is no evidence of a recent whole-genome duplication in T. yunnanensis. Repetitive sequences, especially long terminal repeat retrotransposons, are prevalent in the T. yunnanensis genome, contributing to its large genome size. We further integrated genomic and transcriptomic data to unveil clusters of genes involved in Taxol synthesis, located on the chromosome 12, while gene families encoding hydroxylase in the Taxol pathway exhibited significant expansion. Our study contributes to the further elucidation of gymnosperm relationships and the Taxol biosynthetic pathway.

scholarly journals Patterns of putative gene loss suggest rampant developmental system drift in nematodes

2019 ◽  
Author(s):  
Gavin C. Woodruff
Keyword(s):  
Gene Loss ◽  
Developmental Stages ◽  
Genetic Research ◽  
Cell Lineage ◽  
Model Systems ◽  
Comparative Approach ◽  
Putative Gene ◽  
Developmental System ◽  
C Elegans ◽  
Developmental System Drift

AbstractGene loss often contributes to the evolution of adaptive traits. Conversely, null mutations frequently reveal no obvious phenotypic consequences. How pervasive is gene loss, what kinds of genes are dispensable, and what are the consequences of gene loss? The nematode Caenorhabditis elegans has long been at the forefront of genetic research, yet only recently have genomic resources become available to situate this species in its comparative phylogenetic and evolutionary context. Here, patterns of gene loss within Caenorhabditis are evaluated using 28 nematode genomes (most of them sequenced only in the past few years). Orthologous genes detected in every species except one were defined as being lost within that species. Putative functional roles of lost genes were determined using phenotypic information from C. elegans WormBase ontology terms as well as using existing C. elegans transcriptomic datasets. All species have lost multiple genes in a species-specific manner, with a genus-wide average of several dozen genes per species. Counterintuitively, nearly all species have lost genes that perform essential functions in C. elegans (an average of one third of the genes lost within a species). Retained genes reveal no differences from lost genes in C. elegans transcriptional abundance across all developmental stages when considering all 28 Caenorhabitis genomes. However, when considering only genomes in the subgeneric Elegans group, lost genes tend to have lower expression than retained genes. Taken together, these results suggest that the genetics of developmental processes are evolving rapidly despite a highly conserved adult morphology and cell lineage in this group, a phenomenon known as developmental system drift. These patterns highlight the importance of the comparative approach in interpreting findings in model systems genetics.

scholarly journals GeneHummus: A pipeline to define gene families and their expression in legumes and beyond

2018 ◽  
Author(s):  
Jose V. Die ◽  
Moamen Mahmoud Elmassry ◽  
Kimberly Hathaway LeBlanc ◽  
Olaitan I. Awe ◽  
Allissa Dillman ◽  
...  
Keyword(s):  
Large Scale ◽  
Rapid Development ◽  
High Specificity ◽  
Gene Families ◽  
Model Systems ◽  
Auxin Receptor ◽  
Plant Gene ◽  
Sequencing Technologies ◽  
Specificity And Sensitivity ◽  
The Impact

AbstractDuring the last decade, plant biotechnological laboratories have sparked a monumental revolution with the rapid development of next sequencing technologies at affordable prices. Soon, these sequencing technologies and assembling of whole genomes will extend beyond the plant computational biologists and become commonplace within the plant biology disciplines. The current availability of large-scale genomic resources for non-traditional plant model systems (the so-called ‘orphan crops’) is enabling the construction of high-density integrated physical and genetic linkage maps with potential applications in plant breeding. The newly available fully sequenced plant genomes represent an incredible opportunity for comparative analyses that may reveal new aspects of genome biology and evolution. Analysis of the expansion and evolution of gene families across species is a common approach to infer biological functions. To date, the extent and role of gene families in plants has only been partially addressed and many gene families remain to be investigated. Manual identification of gene families is highly time-consuming and laborious, requiring an iterative process of manual and computational analysis to identify members of a given family, typically combining numerous BLAST searches and manually cleaning data. Due to the increasing abundance of genome sequences and the agronomical interest in plant gene families, the field needs a clear, automated annotation tool. Here, we present the GeneHummus pipeline, a step-by-step R-based pipeline for the identification, characterization and expression analysis of plant gene families. The impact of this pipeline comes from a reduction in hands-on annotation time combined with high specificity and sensitivity in extracting only proteins from the RefSeq database and providing the conserved domain architectures based on SPARCLE. As a case study we focused on the auxin receptor factors gene (ARF) family in Cicer arietinum (chickpea) and other legumes. We anticipate that our pipeline should be suitable for any plant gene family, and likely other gene families, vastly improving the speed and ease of genomic data processing.

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