scholarly journals Genome Based Research in Aquaculture

2021 ◽  
Vol 8 (1) ◽  
pp. 55-74
Author(s):  
Somia Liaqat ◽  
Mubashar Hussain ◽  
Muhammad Faheem Malik ◽  
Asifa Aslam

Genome -based technologies are being instigated to manipulate the structure and function of the genome and to identify the genes of interest for genetic modification of economically important species. Genome editing technologies have also been designed for genetic manipulation of aquaculture species to increase production and quality with minimum investment costs. DNA marker technologies are the most widely used genome technologies. DNA fingerprints are used to construct physical maps while genetic maps are based upon meiotic recombination. BAC fingerprinting is the commonly used method for physical mapping. Next- generation sequencers revolutionized science and allowed the de-novo whole genome sequencing. QTL mapping has made it possible to identify the genes responsible for a particular trait. Government involvement and better training of aqualturists are direly needed to reinforce the practical implications of genome- based technologies.

Genetics ◽  
1996 ◽  
Vol 142 (2) ◽  
pp. 537-548 ◽  
Author(s):  
Michael W Nachman ◽  
Gary A Churchill

Abstract If loci are randomly distributed on a physical map, the density of markers on a genetic map will be inversely proportional to recombination rate. First proposed by MARY LYON, we have used this idea to estimate recombination rates from the Drosophila melanogaster linkage map. These results were compared with results of two other studies that estimated regional recombination rates in D. melanogaster using both physical and genetic maps. The three methods were largely concordant in identifying large-scale genomic patterns of recombination. The marker density method was then applied to the Mus musculus microsatellite linkage map. The distribution of microsatellites provided evidence for heterogeneity in recombination rates. Centromeric regions for several mouse chromosomes had significantly greater numbers of markers than expected, suggesting that recombination rates were lower in these regions. In contrast, most telomeric regions contained significantly fewer markers than expected. This indicates that recombination rates are elevated at the telomeres of many mouse chromosomes and is consistent with a comparison of the genetic and cytogenetic maps in these regions. The density of markers on a genetic map may provide a generally useful way to estimate regional recombination rates in species for which genetic, but not physical, maps are available.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Huihui Li ◽  
Mingzhe Xie ◽  
Yan Wang ◽  
Ludong Yang ◽  
Zhi Xie ◽  
...  

AbstractriboCIRC is a translatome data-oriented circRNA database specifically designed for hosting, exploring, analyzing, and visualizing translatable circRNAs from multi-species. The database provides a comprehensive repository of computationally predicted ribosome-associated circRNAs; a manually curated collection of experimentally verified translated circRNAs; an evaluation of cross-species conservation of translatable circRNAs; a systematic de novo annotation of putative circRNA-encoded peptides, including sequence, structure, and function; and a genome browser to visualize the context-specific occupant footprints of circRNAs. It represents a valuable resource for the circRNA research community and is publicly available at http://www.ribocirc.com.


2015 ◽  
Vol 81 (17) ◽  
pp. 5907-5916 ◽  
Author(s):  
Z. J. Jay ◽  
J. P. Beam ◽  
A. Dohnalkova ◽  
R. Lohmayer ◽  
B. Bodle ◽  
...  

ABSTRACTThermoproteales(phylumCrenarchaeota) populations are abundant in high-temperature (>70°C) environments of Yellowstone National Park (YNP) and are important in mediating the biogeochemical cycles of sulfur, arsenic, and carbon. The objectives of this study were to determine the specific physiological attributes of the isolatePyrobaculum yellowstonensisstrain WP30, which was obtained from an elemental sulfur sediment (Joseph's Coat Hot Spring [JCHS], 80°C, pH 6.1, 135 μM As) and relate this organism to geochemical processes occurringin situ. Strain WP30 is a chemoorganoheterotroph and requires elemental sulfur and/or arsenate as an electron acceptor. Growth in the presence of elemental sulfur and arsenate resulted in the formation of thioarsenates and polysulfides. The complete genome of this organism was sequenced (1.99 Mb, 58% G+C content), revealing numerous metabolic pathways for the degradation of carbohydrates, amino acids, and lipids. Multiple dimethyl sulfoxide-molybdopterin (DMSO-MPT) oxidoreductase genes, which are implicated in the reduction of sulfur and arsenic, were identified. Pathways for thede novosynthesis of nearly all required cofactors and metabolites were identified. The comparative genomics ofP. yellowstonensisand the assembled metagenome sequence from JCHS showed that this organism is highly related (∼95% average nucleotide sequence identity) toin situpopulations. The physiological attributes and metabolic capabilities ofP. yellowstonensisprovide an important foundation for developing an understanding of the distribution and function of these populations in YNP.


Endocrinology ◽  
2011 ◽  
Vol 152 (7) ◽  
pp. 2870-2882 ◽  
Author(s):  
Unmesh Jadhav ◽  
J. Larry Jameson

Steroidogenic factor 1 (SF-1) is essential for the development and function of steroidogenic tissues. Stable incorporation of SF-1 into embryonic stem cells (SF-1-ES cells) has been shown to prime the cells for steroidogenesis. When provided with exogenous cholesterol substrate, and after treatment with retinoic acid and cAMP, SF-1-ES cells produce progesterone but do not produce other steroids such as cortisol, estradiol, or testosterone. In this study, we explored culture conditions that optimize SF-1-mediated differentiation of ES cells into defined steroidogenic lineages. When embryoid body formation was used to facilitate cell lineage differentiation, SF-1-ES cells were found to be restricted in their differentiation, with fewer cells entering neuronal pathways and a larger fraction entering the steroidogenic lineage. Among the differentiation protocols tested, leukemia inhibitory factor (LIF) removal, followed by prolonged cAMP treatment was most efficacious for inducing steroidogenesis in SF-1-ES cells. In this protocol, a subset of SF-1-ES cells survives after LIF withdrawal, undergoes morphologic differentiation, and recovers proliferative capacity. These cells are characterized by induction of steroidogenic enzyme genes, use of de novo cholesterol, and production of multiple steroids including estradiol and testosterone. Microarray studies identified additional pathways associated with SF-1 mediated differentiation. Using biotinylated SF-1 in chromatin immunoprecipitation assays, SF-1 was shown to bind directly to multiple target genes, with induction of binding to some targets after steroidogenic treatment. These studies indicate that SF-1 expression, followed by LIF removal and treatment with cAMP drives ES cells into a steroidogenic pathway characteristic of gonadal steroid-producing cells.


2017 ◽  
Vol 28 (22) ◽  
pp. 3095-3111 ◽  
Author(s):  
Courtney A. Copeland ◽  
Bing Han ◽  
Ajit Tiwari ◽  
Eric D. Austin ◽  
James E. Loyd ◽  
...  

Caveolin-1 (CAV1) is an essential component of caveolae and is implicated in numerous physiological processes. Recent studies have identified heterozygous mutations in the CAV1 gene in patients with pulmonary arterial hypertension (PAH), but the mechanisms by which these mutations impact caveolae assembly and contribute to disease remain unclear. To address this question, we examined the consequences of a familial PAH-associated frameshift mutation in CAV1, P158PfsX22, on caveolae assembly and function. We show that C-terminus of the CAV1 P158 protein contains a functional ER-retention signal that inhibits ER exit and caveolae formation and accelerates CAV1 turnover in Cav1–/– MEFs. Moreover, when coexpressed with wild-type (WT) CAV1 in Cav1–/– MEFs, CAV1-P158 functions as a dominant negative by partially disrupting WT CAV1 trafficking. In patient skin fibroblasts, CAV1 and caveolar accessory protein levels are reduced, fewer caveolae are observed, and CAV1 complexes exhibit biochemical abnormalities. Patient fibroblasts also exhibit decreased resistance to a hypo-osmotic challenge, suggesting the function of caveolae as membrane reservoir is compromised. We conclude that the P158PfsX22 frameshift introduces a gain of function that gives rise to a dominant negative form of CAV1, defining a new mechanism by which disease-associated mutations in CAV1 impair caveolae assembly.


2021 ◽  
Author(s):  
Myung-Shin Kim ◽  
Taeyoung Lee ◽  
Jeonghun Baek ◽  
Ji Hong Kim ◽  
Changhoon Kim ◽  
...  

AbstractMassive resequencing efforts have been undertaken to catalog allelic variants in major crop species including soybean, but the scope of the information for genetic variation often depends on short sequence reads mapped to the extant reference genome. Additional de novo assembled genome sequences provide a unique opportunity to explore a dispensable genome fraction in the pan-genome of a species. Here, we report the de novo assembly and annotation of Hwangkeum, a popular soybean cultivar in Korea. The assembly was constructed using PromethION nanopore sequencing data and two genetic maps, and was then error-corrected using Illumina short-reads and PacBio SMRT reads. The 933.12 Mb assembly was annotated 79,870 transcripts for 58,550 genes using RNA-Seq data and the public soybean annotation set. Comparison of the Hwangkeum assembly with the Williams 82 soybean reference genome sequence revealed 1.8 million single-nucleotide polymorphisms, 0.5 million indels, and 25 thousand putative structural variants. However, there was no natural megabase-scale chromosomal rearrangement. Incidentally, by adding two novel groups, we found that soybean contains four clearly separated groups of centromeric satellite repeats. Analyses of satellite repeats and gene content suggested that the Hwangkeum assembly is a high-quality assembly. This was further supported by comparison of the marker arrangement of anthocyanin biosynthesis genes and of gene arrangement at the Rsv3 locus. Therefore, the results indicate that the de novo assembly of Hwangkeum is a valuable additional reference genome resource for characterizing traits for the improvement of this important crop species.


2017 ◽  
Author(s):  
Arnaud Meng ◽  
Camille Marchet ◽  
Erwan Corre ◽  
Pierre Peterlongo ◽  
Adriana Alberti ◽  
...  

AbstractBackgroundStudy of meta-transcriptomic datasets involving non-model organisms represents bioinformatic challenges. The production of chimeric sequences and our inability to distinguish the taxonomic origins of the sequences produced are inherent and recurrent difficulties in de novo assembly analyses. The study of holobiont transcriptomes shares similarities with meta-transcriptomic, and hence, is also affected by challenges invoked above. Here we propose an innovative approach to tackle such difficulties which was applied to the study of marine holobiont models as a proof of concept.ResultsWe considered three holobionts models, of which two transcriptomes were previously assembled and published, and a yet unpublished transcriptome, to analyze their raw reads and assign them to the host and/or to the symbiont(s) using Short Read Connector, a k-mer based similarity method. We were able to define four distinct categories of reads for each holobiont transcriptome: host reads, symbiont reads, shared reads and unassigned reads. The result of the independent assemblies for each category within a transcriptome led to a significant diminution of de novo assembled chimeras compared to classical assembly methods. Combining independent functional and taxonomic annotations of each partner’s transcriptome is particularly convenient to explore the functional diversity of an holobiont. Finally, our strategy allowed to propose new functional annotations for two well-studied holobionts and a first transcriptome from a planktonic Radiolaria-Dinophyta system forming widespread symbiotic association for which our knowledge is limited. ConclusionsIn contrast to classical assembly approaches, our bioinformatic strategy not only allows biologists to studying separately host and symbiont data from a holobiont mixture, but also generates improved transcriptome assemblies. The use of Short Read Connector has proven to be an effective way to tackle meta-transcriptomic challenges to study holobiont systems composed of either well-studied or poorly characterized symbiotic lineages such as the newly sequenced marine plankton Radiolaria-Dinophyta symbiosis and ultimately expand our knowledge about these marine symbiotic associations.


2020 ◽  
Author(s):  
Qian Dong ◽  
Michael Zavortink ◽  
Francesca Froldi ◽  
Sofya Golenkina ◽  
Tammy Lam ◽  
...  

AbstractThe final size and function of the adult central nervous system (CNS) is determined by neuronal lineages generated by neural stem cells (NSCs) in the developing brain. In Drosophila, NSCs called neuroblasts (NBs) reside within a specialised microenvironment called the glial niche. Here, we explore non-autonomous glial regulation of NB proliferation. We show that lipid droplets (LDs) which reside within the glial niche are closely associated with the signalling molecule Hedgehog (Hh). Under physiological conditions, cortex glial Hh is autonomously required to sustain niche chamber formation, and non-autonomously restrained to prevent ectopic Hh signalling in the NBs. In the context of cortex glial overgrowth, induced by Fibroblast Growth Factor (FGF) activation, Hh and lipid storage regulators Lsd-2 and Fasn1 were upregulated, resulting in activation of Hh signalling in the NBs; which in turn disrupted NB cell cycle progression and reduced neuronal production. We show that the LD regulator Lsd-2 modulates Hh’s ability to signal to NBs, and de novo lipogenesis gene Fasn1 regulates Hh post-translational modification via palmitoylation. Together, our data suggest that the glial niche non-autonomously regulates NB proliferation and neural lineage size via Hh signaling that is modulated by lipid metabolism genes.


Reproduction ◽  
2018 ◽  
Vol 156 (2) ◽  
pp. 145-161 ◽  
Author(s):  
E Canon ◽  
L Jouneau ◽  
T Blachère ◽  
N Peynot ◽  
N Daniel ◽  
...  

ThePOU5F1gene encodes one of the ‘core’ transcription factors necessary to establish and maintain pluripotency in mammals. Its function depends on its precise level of expression, so its transcription has to be tightly regulated. To date, few conserved functional elements have been identified in its 5′ regulatory region: a distal and a proximal enhancer, and a minimal promoter, epigenetic modifications of which interfere withPOU5F1expression and function inin vitro-derived cell lines. Also, its permanent inactivation in differentiated cells depends onde novomethylation of its promoter. However, little is known about the epigenetic regulation ofPOU5F1expression in the embryo itself. We used the rabbit blastocyst as a model to analyze the methylation dynamics of thePOU5F15′ upstream region, relative to its regulated expression in different compartments of the blastocyst over a 2-day period of development. We evidenced progressive methylation of the 5′ regulatory region and the first exon accompanying differentiation and the gradual repression ofPOU5F1. Methylation started in the early trophectoderm before complete transcriptional inactivation. Interestingly, the distal enhancer, which is known to be active in naïve pluripotent cells only, retained a very low level of methylation in primed pluripotent epiblasts and remained less methylated in differentiated compartments than the proximal enhancer. This detailed study identified CpGs with the greatest variations in methylation, as well as groups of CpGs showing a highly correlated behavior, during differentiation. Moreover, our findings evidenced few CpGs with very specific behavior during this period of development.


Sign in / Sign up

Export Citation Format

Share Document