scholarly journals Characterization of the genome of the mealybug Planococcus lilacinus, a model organism for studying whole-chromosome imprinting and inactivation

2002 ◽  
Vol 79 (2) ◽  
pp. 111-118 ◽  
Author(s):  
K. NAGA MOHAN ◽  
PARAMITA RAY ◽  
H. SHARAT CHANDRA

The co-occurrence of three chromosome-wide phenomena – imprinting, facultative heterochromatization and diffuse centromere – in the mealybug Planococcus lilacinus makes investigation of the genomics of this species an attractive prospect. In order to estimate the complexity of the genome of this species, 300 random stretches of its DNA, constituting ∼0·1% of the genome, were sequenced. Coding sequences appear to constitute ∼53·5%, repeat sequences ∼44·5% and non-coding single-copy sequences ∼2% of the genome. The proportion of repetitive sequences in the mealybug is higher than that in the fruit fly Drosophila melanogaster (∼30%). The mealybug genome (∼220 Mb) is about 1·3 times the size of the fly genome (∼165 Mb) and its GC content (∼35%) less than that of the fly genome (∼40%). The relative abundance of various dinucleotides, as analysed by the method of Gentles and Karlin, shows that the dinucleotide signatures of the two species are moderately similar and that in the mealybug there is neither over-representation nor under-representation of any dinucleotide.

2021 ◽  
Vol 10 (39) ◽  
Author(s):  
Koichi Nakamura ◽  
Norio Kurosawa ◽  
Hiroyuki D. Sakai

The complete genome sequence of the thermoacidophilic crenarchaeon Stygiolobus sp. strain KN-1 was determined and annotated. The genome was 2,958,410 bp in size, with a GC content of 40.1%. It contained 2,973 coding sequences, a single copy of the 16S-23S rRNA operon, 47 tRNA genes, and 9 CRISPR repeat sequences.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Xiaochan Xu ◽  
Wei Yang ◽  
Binghui Tian ◽  
Xiuwen Sui ◽  
Weilai Chi ◽  
...  

AbstractThe fruit fly, Drosophila melanogaster, has been used as a model organism for the molecular and genetic dissection of sleeping behaviors. However, most previous studies were based on qualitative or semi-quantitative characterizations. Here we quantified sleep in flies. We set up an assay to continuously track the activity of flies using infrared camera, which monitored the movement of tens of flies simultaneously with high spatial and temporal resolution. We obtained accurate statistics regarding the rest and sleep patterns of single flies. Analysis of our data has revealed a general pattern of rest and sleep: the rest statistics obeyed a power law distribution and the sleep statistics obeyed an exponential distribution. Thus, a resting fly would start to move again with a probability that decreased with the time it has rested, whereas a sleeping fly would wake up with a probability independent of how long it had slept. Resting transits to sleeping at time scales of minutes. Our method allows quantitative investigations of resting and sleeping behaviors and our results provide insights for mechanisms of falling into and waking up from sleep.


Author(s):  
Abeer Mohbeddin ◽  
Nawar Haj Ahmed ◽  
Layla Kamareddine

Apart from its traditional role in disease control, recent body of evidence has implicated a role of the immune system in regulating metabolic homeostasis. Owing to the importance of this “immune-metabolic alignment” in dictating a state of health or disease, a proper mechanistic understanding of this alignment is crucial in opening up for promising therapeutic approaches against a broad range of chronic, metabolic, and inflammatory disorders like obesity, diabetes, and inflammatory bowel syndrome. In this project, we addressed the role of the Janus kinase/signal transducer and activator of transcription (JAK/STAT) innate immune pathway in regulating different metabolic parameters using the Drosophila melanogaster (DM) fruit fly model organism. Mutant JAK/STAT pathway flies with a systemic knockdown of either Domeless (Dome) [domeG0282], the receptor that activates JAK/STAT signaling, or the signal-transducer and activator of transcription protein at 92E (Stat92E) [stat92EEY10528], were used. The results of the study revealed that blocking JAK/STAT signaling alters the metabolic profile of mutant flies. Both domeG0282 and stat92EEY10528 mutants had an increase in body weight, lipid deprivation from their fat body (lipid storage organ in flies), irregular accumulation of lipid droplets in the gut, systemic elevation of glucose and triglyceride levels, and differential down-regulation in the relative gene expression of different peptide hormones (Tachykinin, Allatostatin C, and Diuretic hormone 31) known to regulate metabolic homeostasis in flies. Because the JAK/STAT pathway is evolutionary conserved between invertebrates and vertebrates, our potential findings in the fruit fly serves as a platform for further immune-metabolic translational studies in more complex mammalian systems including humans.


2019 ◽  
Vol 11 (12) ◽  
pp. 425-443 ◽  
Author(s):  
Alireza Zabihihesari ◽  
Arthur J Hilliker ◽  
Pouya Rezai

Abstract The fruit fly or Drosophila melanogaster has been used as a promising model organism in genetics, developmental and behavioral studies as well as in the fields of neuroscience, pharmacology, and toxicology. Not only all the developmental stages of Drosophila, including embryonic, larval, and adulthood stages, have been used in experimental in vivo biology, but also the organs, tissues, and cells extracted from this model have found applications in in vitro assays. However, the manual manipulation, cellular investigation and behavioral phenotyping techniques utilized in conventional Drosophila-based in vivo and in vitro assays are mostly time-consuming, labor-intensive, and low in throughput. Moreover, stimulation of the organism with external biological, chemical, or physical signals requires precision in signal delivery, while quantification of neural and behavioral phenotypes necessitates optical and physical accessibility to Drosophila. Recently, microfluidic and lab-on-a-chip devices have emerged as powerful tools to overcome these challenges. This review paper demonstrates the role of microfluidic technology in Drosophila studies with a focus on both in vivo and in vitro investigations. The reviewed microfluidic devices are categorized based on their applications to various stages of Drosophila development. We have emphasized technologies that were utilized for tissue- and behavior-based investigations. Furthermore, the challenges and future directions in Drosophila-on-a-chip research, and its integration with other advanced technologies, will be discussed.


2020 ◽  
Vol 11 ◽  
Author(s):  
Óscar M. Lezcano ◽  
Miriam Sánchez-Polo ◽  
José L. Ruiz ◽  
Elena Gómez-Díaz

The principles and function of chromatin and nuclear architecture have been extensively studied in model organisms, such as Drosophila melanogaster. However, little is known about the role of these epigenetic processes in transcriptional regulation in other insects including mosquitoes, which are major disease vectors and a worldwide threat for human health. Some of these life-threatening diseases are malaria, which is caused by protozoan parasites of the genus Plasmodium and transmitted by Anopheles mosquitoes; dengue fever, which is caused by an arbovirus mainly transmitted by Aedes aegypti; and West Nile fever, which is caused by an arbovirus transmitted by Culex spp. In this contribution, we review what is known about chromatin-associated mechanisms and the 3D genome structure in various mosquito vectors, including Anopheles, Aedes, and Culex spp. We also discuss the similarities between epigenetic mechanisms in mosquitoes and the model organism Drosophila melanogaster, and advocate that the field could benefit from the cross-application of state-of-the-art functional genomic technologies that are well-developed in the fruit fly. Uncovering the mosquito regulatory genome can lead to the discovery of unique regulatory networks associated with the parasitic life-style of these insects. It is also critical to understand the molecular interactions between the vectors and the pathogens that they transmit, which could hold the key to major breakthroughs on the fight against mosquito-borne diseases. Finally, it is clear that epigenetic mechanisms controlling mosquito environmental plasticity and evolvability are also of utmost importance, particularly in the current context of globalization and climate change.


2020 ◽  
Vol 10 (11) ◽  
pp. 4271-4285 ◽  
Author(s):  
Danny E. Miller ◽  
Lily Kahsai ◽  
Kasun Buddika ◽  
Michael J. Dixon ◽  
Bernard Y. Kim ◽  
...  

Balancers are rearranged chromosomes used in Drosophila melanogaster to maintain deleterious mutations in stable populations, preserve sets of linked genetic elements and construct complex experimental stocks. Here, we assess the phenotypes associated with breakpoint-induced mutations on commonly used third chromosome balancers and show remarkably few deleterious effects. We demonstrate that a breakpoint in p53 causes loss of radiation-induced apoptosis and a breakpoint in Fucosyltransferase A causes loss of fucosylation in nervous and intestinal tissue—the latter study providing new markers for intestinal cell identity and challenging previous conclusions about the regulation of fucosylation. We also describe thousands of potentially harmful mutations shared among X or third chromosome balancers, or unique to specific balancers, including an Ankyrin 2 mutation present on most TM3 balancers, and reiterate the risks of using balancers as experimental controls. We used long-read sequencing to confirm or refine the positions of two inversions with breakpoints lying in repetitive sequences and provide evidence that one of the inversions, In(2L)Cy, arose by ectopic recombination between foldback transposon insertions and the other, In(3R)C, cleanly separates subtelomeric and telomeric sequences and moves the subtelomeric sequences to an internal chromosome position. In addition, our characterization of In(3R)C shows that balancers may be polymorphic for terminal deletions. Finally, we present evidence that extremely distal mutations on balancers can add to the stability of stocks whose purpose is to maintain homologous chromosomes carrying mutations in distal genes. Overall, these studies add to our understanding of the structure, diversity and effectiveness of balancer chromosomes.


Author(s):  
Sumira Malik

Homo sapiens and Drosophila malenogaster, a fruit fly, share genetic homology in development process regulated through fundamental biological pathways and conserved mechanisms conserved as a process of evolution among these species. Drosophila melanogaster is an eminent model organism to study diverse biological species. In this chapter, the use of wide variety of nano particles and their impact on Drosophila melanogastsr's development, longevity, characteristics of reproduction has been studied.


2018 ◽  
Vol 80 (4) ◽  
pp. 272-277
Author(s):  
Jennifer Broo ◽  
Jessica Mahoney ◽  
Julie Bokor ◽  
Daniel Hahn

Climate change can drive evolution. This connection is clear both historically and in modern times. The three-lesson curriculum described below provides opportunities for students to make connections between climate change and evolution through various modes of inquiry and self-investigation. Students examine how genetic variation may either facilitate or limit the ability for species to survive changing climates through work with the model organism Drosophila melanogaster. Students are asked to layer new understanding of the mechanisms of evolution onto their observations of genetic variation in fruit fly thermotolerance, and then synthesize this information to make predictions regarding the survival of species threatened by climate change.


Author(s):  
Umar Rehman ◽  
Nighat Sultana ◽  
Abdullah . ◽  
Abbas Jamal ◽  
Maryam Muzaffar ◽  
...  

Family Phyllanthaceae is one of the largest segregates of the eudicot order Malpighiales and its species are herb, shrub, and tree, which are mostly distributed in tropical regions. Certain taxonomic discrepancies exist at genus and family level. Here, we report chloroplast genomes of three Phyllanthaceae species—Phyllanthus emblica, Flueggea virosa, and Leptopus cordifolius— and compare them with six others previously reported Phyllanthaceae chloroplast genomes. The species of Phyllanthaceae displayed quadripartite structure, comprising inverted repeat regions (IRa and IRb) that separate large single copy (LSC) and small single copy (SSC) regions. The length of complete chloroplast genome ranged from 154,707 bp to 161,093 bp; LSC from 83,627 bp to 89,932 bp; IRs from 23,921 bp to 27,128 bp; and SSC from 17,424 bp to 19,441 bp. Chloroplast genomes contained 111 to 112 unique genes, including 77 to 78 protein-coding, 30 transfer RNA (tRNA), and 4 ribosomal RNA (rRNA) that showed similarities in arrangement. The number of protein-coding genes varied due to deletion/pseudogenization of rps16 genes in Baccaurea ramiflora and Leptopus cordifolius. High variability was seen in number of oligonucleotide repeats while analysis of guanine-cytosine (GC) content, codon usage, amino acid frequency, simple sequence repeats analysis, synonymous and non-synonymous substitutions, and transition and transversion substitutions showed similarities in all Phyllanthaceae species. We detected a higher number of transition substitutions in the coding sequences than non-coding sequences. Moreover, the high number of transition substitutions was determined among the distantly related species in comparison to closely related species. Phylogenetic analysis shows the polyphyletic nature of the genus Phyllanthus which requires further verification. We also determined suitable polymorphic coding genes, including rpl22, ycf1, matK, ndhF, and rps15 which may be helpful for the reconstruction of the high-resolution phylogenetic tree of the family Phyllanthaceae using a large number of species in the future. Overall, the current study provides insight into chloroplast genome evolution in Phyllanthaceae.


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