scholarly journals The first draft genome of feather grasses using SMRT sequencing and its implications in molecular studies of Stipa

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Evgenii Baiakhmetov ◽  
Cervin Guyomar ◽  
Ekaterina Shelest ◽  
Marcin Nobis ◽  
Polina D. Gudkova

AbstractThe Eurasian plant Stipa capillata is the most widespread species within feather grasses. Many taxa of the genus are dominants in steppe plant communities and can be used for their classification and in studies related to climate change. Moreover, some species are of economic importance mainly as fodder plants and can be used for soil remediation processes. Although large-scale molecular data has begun to appear, there is still no complete or draft genome for any Stipa species. Thus, here we present a single-molecule long-read sequencing dataset generated using the Pacific Biosciences Sequel System. A draft genome of about 1004 Mb was obtained with a contig N50 length of 351 kb. Importantly, here we report 81,224 annotated protein-coding genes, present 77,614 perfect and 58 unique imperfect SSRs, reveal the putative allopolyploid nature of S. capillata, investigate the evolutionary history of the genus, demonstrate structural heteroplasmy of the chloroplast genome and announce for the first time the mitochondrial genome in Stipa. The assembled nuclear, mitochondrial and chloroplast genomes provide a significant source of genetic data for further works on phylogeny, hybridisation and population studies within Stipa and the grass family Poaceae.

2021 ◽  
Vol 11 (2) ◽  
Author(s):  
Suzanne V Saenko ◽  
Dick S J Groenenberg ◽  
Angus Davison ◽  
Menno Schilthuizen

Abstract Studies on the shell color and banding polymorphism of the grove snail Cepaea nemoralis and the sister taxon Cepaea hortensis have provided compelling evidence for the fundamental role of natural selection in promoting and maintaining intraspecific variation. More recently, Cepaea has been the focus of citizen science projects on shell color evolution in relation to climate change and urbanization. C. nemoralis is particularly useful for studies on the genetics of shell polymorphism and the evolution of “supergenes,” as well as evo-devo studies of shell biomineralization, because it is relatively easily maintained in captivity. However, an absence of genomic resources for C. nemoralis has generally hindered detailed genetic and molecular investigations. We therefore generated ∼23× coverage long-read data for the ∼3.5 Gb genome, and produced a draft assembly composed of 28,537 contigs with the N50 length of 333 kb. Genome completeness, estimated by BUSCO using the metazoa dataset, was 91%. Repetitive regions cover over 77% of the genome. A total of 43,519 protein-coding genes were predicted in the assembled genome, and 97.3% of these were functionally annotated from either sequence homology or protein signature searches. This first assembled and annotated genome sequence for a helicoid snail, a large group that includes edible species, agricultural pests, and parasite hosts, will be a core resource for identifying the loci that determine the shell polymorphism, as well as in a wide range of analyses in evolutionary and developmental biology, and snail biology in general.


2021 ◽  
Vol 99 ◽  
pp. 122-146
Author(s):  
Anna Shnukal

AbstractThroughout its European history, Australia has solved recurrent labor shortages by importing workers from overseas. Situated on shipping lanes between the Pacific and Indian Oceans, the northern Australian pearlshelling industry became a significant locus of second-wave transnational labor flows (1870–1940) and by the 1880s was dependent on indentured workers from the Pacific and Southeast Asia. Exempted from the racially discriminatory Immigration Restriction Act of 1901, indentured Asian seamen, principally Japanese, maintained the industry until the outbreak of the Pacific War in 1941. The Torres Strait pearlshelling industry, centered on Thursday Island in Far North Queensland, resumed in 1946 amid general agreement that the Japanese must not return. Nevertheless, in 1958, 162 Okinawan pearling indents arrived on Thursday Island in a controversial attempt to restore the industry's declining fortunes. This article is intended as a contribution to the history of transnational labor movements. It consults a range of sources to document this “Okinawan experiment,” the last large-scale importation of indentured Asian labor into Australia. It examines Australian Commonwealth-state tensions in formulating and adopting national labor policy; disputes among Queensland policy makers; the social characteristics of the Okinawan cohort; and local Indigenous reactions. Also discussed are the economics of labor in the final years of the Torres Strait pearling industry. This study thus extends our knowledge of transnational labor movements and the intersection of early postwar Australian-Asian relations with Queensland Indigenous labor policy. It also foreshadows contemporary Indigenous demands for control of local marine resources.


2021 ◽  
Author(s):  
Gábor Torma ◽  
Dóra Tombácz ◽  
Norbert Moldován ◽  
Ádám Fülöp ◽  
István Prazsák ◽  
...  

Abstract In this study, we used two long-read sequencing (LRS) techniques, Sequel from the Pacific Biosciences and MinION from Oxford Nanopore Technologies, for the transcriptional characterization of a prototype baculovirus, Autographacalifornica multiple nucleopolyhedrovirus. LRS is able to read full-length RNA molecules, and thereby to distinguish between transcript isoforms, mono- and polycistronic RNAs, and overlapping transcripts. Altogether, we detected 875 transcripts, of which 759 are novel and 116 have been annotated previously. These RNA molecules include 41 novel putative protein coding transcript (each containing 5’-truncated in-frame ORFs), 14 monocistronic transcripts, 99 multicistronic RNAs, 101 non-coding RNA, and 504 length isoforms. We also detected RNA methylation in 12 viral genes and RNA hyper-editing in the longer 5’-UTR transcript isoform of ORF 19 gene.


2021 ◽  
Author(s):  
Chi yang ◽  
Lu Ma ◽  
Donglai Xiao ◽  
Xiaoyu Liu ◽  
Xiaoling Jiang ◽  
...  

Sparassis latifolia is a valuable edible mushroom cultivated in China. In 2018, our research group reported an incomplete and low quality genome of S. latifolia was obtained by Illumina HiSeq 2500 sequencing. These limitations in the available genome have constrained genetic and genomic studies in this mushroom resource. Herein, an updated draft genome sequence of S. latifolia was generated by Oxford Nanopore sequencing and the Hi-C technique. A total of 8.24 Gb of Oxford Nanopore long reads representing ~198.08X coverage of the S. latifolia genome were generated. Subsequently, a high-quality genome of 41.41 Mb, with scaffold and contig N50 sizes of 3.31 Mb and 1.51 Mb, respectively, was assembled. Hi-C scaffolding of the genome resulted in 12 pseudochromosomes containing 93.56% of the bases in the assembled genome. Genome annotation further revealed that 17.47% of the genome was composed of repetitive sequences. In addition, 13,103 protein-coding genes were predicted, among which 98.72% were functionally annotated. BUSCO assay results further revealed that there were 92.07% complete BUSCOs. The improved chromosome-scale assembly and genome features described here will aid further molecular elucidation of various traits, breeding of S. latifolia, and evolutionary studies with related taxa.


2019 ◽  
Author(s):  
Lillian K. Padgitt-Cobb ◽  
Sarah B. Kingan ◽  
Jackson Wells ◽  
Justin Elser ◽  
Brent Kronmiller ◽  
...  

AbstractHop (Humulus lupulus L. var Lupulus) is a diploid, dioecious plant with a history of cultivation spanning more than one thousand years. Hop cones are valued for their use in brewing, and around the world, hop has been used in traditional medicine to treat a variety of ailments. Efforts to determine how biochemical pathways responsible for desirable traits are regulated have been challenged by the large, repetitive, and heterozygous genome of hop. We present the first report of a haplotype-phased assembly of a large plant genome. Our assembly and annotation of the Cascade cultivar genome is the most extensive to date. PacBio long-read sequences from hop were assembled with FALCON and phased with FALCON-Unzip. Using the diploid assembly to assess haplotype variation, we discovered genes under positive selection enriched for stress-response, growth, and flowering functions. Comparative analysis of haplotypes provides insight into large-scale structural variation and the selective pressures that have driven hop evolution. Previous studies estimated repeat content at around 60%. With improved resolution of long terminal retrotransposons (LTRs) due to long-read sequencing, we found that hop is nearly 78% repetitive. Our quantification of repeat content provides context for the size of the hop genome, and supports the hypothesis of whole genome duplication (WGD), rather than expansion due to LTRs. With our more complete assembly, we have identified a homolog of cannabidiolic acid synthase (CBDAS) that is expressed in multiple tissues. The approaches we developed to analyze a phased, diploid assembly serve to deepen our understanding of the genomic landscape of hop and may have broader applicability to the study of other large, complex genomes.


2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Baohua Chen ◽  
Zhixiong Zhou ◽  
Qiaozhen Ke ◽  
Yidi Wu ◽  
Huaqiang Bai ◽  
...  

Abstract Larimichthys crocea is an endemic marine fish in East Asia that belongs to Sciaenidae in Perciformes. L. crocea has now been recognized as an “iconic” marine fish species in China because not only is it a popular food fish in China, it is a representative victim of overfishing and still provides high value fish products supported by the modern large-scale mariculture industry. Here, we report a chromosome-level reference genome of L. crocea generated by employing the PacBio single molecule sequencing technique (SMRT) and high-throughput chromosome conformation capture (Hi-C) technologies. The genome sequences were assembled into 1,591 contigs with a total length of 723.86 Mb and a contig N50 length of 2.83 Mb. After chromosome-level scaffolding, 24 scaffolds were constructed with a total length of 668.67 Mb (92.48% of the total length). Genome annotation identified 23,657 protein-coding genes and 7262 ncRNAs. This highly accurate, chromosome-level reference genome of L. crocea provides an essential genome resource to support the development of genome-scale selective breeding and restocking strategies of L. crocea.


2020 ◽  
Vol 12 (7) ◽  
pp. 1074-1079 ◽  
Author(s):  
Ruihao Shu ◽  
Jihong Zhang ◽  
Qian Meng ◽  
Huan Zhang ◽  
Guiling Zhou ◽  
...  

Abstract Ophiocordyceps sinensis (Berk.) is an entomopathogenic fungus endemic to the Qinghai-Tibet Plateau. It parasitizes and mummifies the underground ghost moth larvae, then produces a fruiting body. The fungus-insect complex, called Chinese cordyceps or “DongChongXiaCao,” is not only a valuable traditional Chinese medicine, but also a major source of income for numerous Himalayan residents. Here, taking advantage of rapid advances in single-molecule sequencing, we assembled a highly contiguous genome assembly of O. sinensis. The assembly of 23 contigs was ∼110.8 Mb with a N50 length of 18.2 Mb. We used RNA-seq and homologous protein sequences to identify 8,916 protein-coding genes in the IOZ07 assembly. Moreover, 63 secondary metabolite gene clusters were identified in the improved assembly. The improved assembly and genome features described in this study will further inform the evolutionary study and resource utilization of Chinese cordyceps.


Diagnostics ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 60 ◽  
Author(s):  
Adriana Franco-Acevedo ◽  
Zesergio Melo ◽  
Raquel Echavarria

End-stage renal disease is a public health problem responsible for millions of deaths worldwide each year. Although transplantation is the preferred treatment for patients in need of renal replacement therapy, long-term allograft survival remains challenging. Advances in high-throughput methods for large-scale molecular data generation and computational analysis are promising to overcome the current limitations posed by conventional diagnostic and disease classifications post-transplantation. Non-coding RNAs (ncRNAs) are RNA molecules that, despite lacking protein-coding potential, are essential in the regulation of epigenetic, transcriptional, and post-translational mechanisms involved in both health and disease. A large body of evidence suggests that ncRNAs can act as biomarkers of renal injury and graft loss after transplantation. Hence, the focus of this review is to discuss the existing molecular signatures of non-coding transcripts and their value to improve diagnosis, predict the risk of rejection, and guide therapeutic choices post-transplantation.


2017 ◽  
Vol 5 (28) ◽  
Author(s):  
Su-Yeon Lee ◽  
Ji-eun An ◽  
Sun-Hwa Ryu ◽  
Myungkil Kim

ABSTRACT Polyporus brumalis is able to synthesize several sesquiterpenes during fungal growth. Using a single-molecule real-time sequencing platform, we present the 53-Mb draft genome of P. brumalis, which contains 6,231 protein-coding genes. Gene annotation and isolation support genetic information, which can increase the understanding of sesquiterpene metabolism in P. brumalis.


1983 ◽  
Vol 20 (6) ◽  
pp. 994-999 ◽  
Author(s):  
Zvi Ben-Avraham ◽  
Amos Nur

On land much of the Pacific margin is composed of allochthonous terranes, which are of continental and noncontinental origins. In the oceans numerous oceanic rises, some of which are submerged continental fragments, are presently embedded in the oceanic plates. These oceanic rises are probably future accreted terranes. They thus represent one stage in the development of allochthonous terranes found in orogenic zones. Minerals found in these terranes were formed at locations that in the past could have been thousands of kilometres away. This is because some oceanic terranes were split into several parts that moved with their respective plates in different directions. Also, faulting at the continental margins caused large-scale concurrent and post-accretionary horizontal translations of hundreds of kilometres of the allochthonous terranes.Studying the allochthonous terranes may provide important information about the Paleozoic and early Mesozoic history of the Pacific Ocean, because most of the oceanic crust of this age has disappeared leaving only those allochthonous terranes that were once oceanic plateaus within this crust. Understanding the history of the Pacific basin plates and of the allochthonous terranes may lead to the discovery of minerals within the submerged oceanic plateaus.


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