scholarly journals Genomics and introgression: Discovery and mapping of thousands of species-diagnostic SNPs using RAD sequencing

2015 ◽  
Vol 61 (1) ◽  
pp. 146-154 ◽  
Author(s):  
Brian K. Hand ◽  
Tyler D. Hether ◽  
Ryan P. Kovach ◽  
Clint C. Muhlfeld ◽  
Stephen J. Amish ◽  
...  

Abstract Invasive hybridization and introgression pose a serious threat to the persistence of many native species. Understanding the effects of hybridization on native populations (e.g., fitness consequences) requires numerous species-diagnostic loci distributed genome-wide. Here we used RAD sequencing to discover thousands of single-nucleotide polymorphisms (SNPs) that are diagnostic between rainbow trout (RBT, Oncorhynchus mykiss), the world’s most widely introduced fish, and native westslope cutthroat trout (WCT, O. clarkii lewisi) in the northern Rocky Mountains, USA. We advanced previous work that identified 4,914 species-diagnostic loci by using longer sequence reads (100 bp vs. 60 bp) and a larger set of individuals (n = 84). We sequenced RAD libraries for individuals from diverse sampling sources, including native populations of WCT and hatchery broodstocks of WCT and RBT. We also took advantage of a newly released reference genome assembly for RBT to align our RAD loci. In total, we discovered 16,788 putatively diagnostic SNPs, 10,267 of which we mapped to anchored chromosome locations on the RBT genome. A small portion of previously discovered putative diagnostic loci (325 of 4,914) were no longer diagnostic (i.e., fixed between species) based on our wider survey of non-hybridized RBT and WCT individuals. Our study suggests that RAD loci mapped to a draft genome assembly could provide the marker density required to identify genes and chromosomal regions influencing selection in admixed populations of conservation concern and evolutionary interest.

BMC Genomics ◽  
2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Jessica Purcell ◽  
Jonathan N. Pruitt

Abstract Background Recent research has revealed that polymorphic behavioral strategies shape intra-and interspecific interactions and contribute to fitness in many animal species. A better understanding of the proximate mechanisms underlying these behavioral syndromes will enhance our grasp this phenomenon. Spiders in the genus Anelosimus exhibit inter-individual behavioral variation on several axes: individuals have consistent responses to stimuli (e.g. bold vs. shy individuals) and they are subsocial (exhibiting extended maternal care and sibling cooperation) across most of their range, but they sometimes form permanent social groups in northern temperate regions. Here, we seek genetic variants associated with boldness and with social structure in a socially polymorphic population of the spider Anelosimus studiosus. We also develop preliminary genomic resources, including a genome assembly and linkage map, that support this and future genomic research on this group. Results Remarkably, we identify a small genomic scaffold (~ 1200 bp) that harbors seven single nucleotide polymorphisms (SNPs) associated with boldness. Moreover, heterozygotes are less common than expected based on Hardy-Weinberg equilibrium, suggesting that either assortative mating or selection against heterozygotes may be occurring in this system. We find no loci significantly associated with social organization. Our draft genome assembly allows us to localize SNPs of interest in this study and to carry out genetic comparisons with other published genomes, although it remains highly fragmented. Conclusions By identifying a locus associated with a well-studied animal personality trait, this study opens up avenues for future research to link behavioral studies of animal personality with genotype and fitness.


2016 ◽  
Vol 4 (2) ◽  
Author(s):  
Bhavani Manivannan ◽  
Niranjana Mahalingam ◽  
Sudhir Jadhao ◽  
Amrita Mishra ◽  
Pravin Nilawe ◽  
...  

We present the draft genome assembly of an extensively drug-resistant (XDR) Pseudomonas aeruginosa strain isolated from a patient with a history of genito urinary tuberculosis. The draft genome is 7,022,546 bp with a G+C content of 65.48%. It carries 7 phage genomes, genes for quorum sensing, biofilm formation, virulence, and antibiotic resistance.


2012 ◽  
Vol 71 (6) ◽  
pp. 895-906 ◽  
Author(s):  
Luming Yang ◽  
Dal-Hoe Koo ◽  
Yuhong Li ◽  
Xuejiao Zhang ◽  
Feishi Luan ◽  
...  

2021 ◽  
Author(s):  
Zhijin Liu ◽  
Xuekun Qian ◽  
Ziming Wang ◽  
Huamei Wen ◽  
Ling Han ◽  
...  

Abstract BcakgroundLoaches of the superfamily Cobitoidea (Cypriniformes, Nemacheilidae) are small elongated bottom-dwelling freshwater fishes with several barbels near the mouth. The genus Oreonectes with 18 currently recognized species contains representatives for all three key stages of the evolutionary process (a surface-dwelling lifestyle, facultative cave persistence, and permanent cave dwelling). Some Oreonectes species show typical cave dwelling-related traits, such as partial or complete leucism and regression of the eyes, rendering them as suitable study objects of micro-evolution. Genome information of Oreonectes species is therefore an indispensable resource for research into the evolution of cavefishes.ResultsHere we assembled the genome sequence of O. shuilongensis, a surface-dwelling species, using an integrated approach that combined PacBio single-molecule real-time sequencing and Illumina X-ten paired-end sequencing. Based on in total 50.9 Gb of sequencing data, our genome assembly from Canu and Pilon spans approximately 515.64 Mb (estimated coverage of 100 ×), containing 803 contigs with N50 values of 5.58 Mb. 25,247 protein-coding genes were predicted, of which 95.65% have been functionally annotated. We also performed genome re-sequencing of three additional cave-dwelling Oreonectes fishes. Twenty-nine pseudogenes annotated using DAVID showed significant enrichment for the GO terms of “eye development” and “retina development in camera-type eye”. It is presumed that these pseudogenes might lead to eye degeneration of semi/complete cave-dwelling Oreonectes species. Furthermore, Mc1r (melanocortin-1 receptor) is a pseudogenization by a deletion in O. daqikongensis, likely blocking biosynthesis of melanin and leading to the albino phenotype.ConclusionsWe here report the first draft genome assembly of Oreonectes fishes, which is also the first genome reference for Cobitidea fishes. Pseudogenization of genes related to body color and eye development may be responsible for loss of pigmentation and vision deterioration in cave-dwelling species. This genome assembly will contribute to the study of the evolution and adaptation of fishes within Oreonectes and beyond (Cobitidea).


Author(s):  
Jian-Zhi Huang ◽  
Chih-Peng Lin ◽  
Ting-Chi Cheng ◽  
Ya-Wen Huang ◽  
Yi-Jung Tsai ◽  
...  

Phalaenopsis orchid is an important potted flower with high economic value around the world. We report the 3.1 Gb draft genome assembly of an important winter flowering Phalaenopsis ‘KHM190’ cultivar. We generated 89.5 Gb RNA-seq and 113 million sRNA-seq reads to use these data to identify 41,153 protein-coding genes and 188 miRNA families. We also generated a draft genome for Phalaenopsis pulcherrima ‘B8802’, a summer flowering species, via resequencing. Comparison of genome data between the two Phalaenopsis cultivars allowed the identification of 691,532 single-nucleotide polymorphisms. In this study, we reveal the key role of PhAGL6b in the regulation of flower organ development involves alternative splicing. We also show gibberellin pathways that regulate the expression of genes control flowering time during the stage in reproductive phase change induced by cool temperature. Our work should contribute a valuable resource for the flowering control, flower architecture development, and breeding of the Phalaenopsis orchids.


2021 ◽  
Author(s):  
Roger Huerlimann ◽  
Jeff A Cowley ◽  
Nicholas M Wade ◽  
Yinan Wang ◽  
Naga Kasinadhuni ◽  
...  

Shrimp are a valuable aquaculture species globally; however, disease remains a major hindrance to shrimp aquaculture sustainability and growth. Mechanisms mediated by endogenous viral elements (EVEs) have been proposed as a means by which shrimp that encounter a new virus start to accommodate rather than succumb to infection over time. However, evidence on the nature of such EVEs and how they mediate viral accommodation is limited. More extensive genomic data on Penaeid shrimp from different geographical locations should assist in exposing the diversity of EVEs. In this context, reported here is a PacBio Sequel-based draft genome assembly of an Australian black tiger shrimp (Penaeus monodon) inbred for one generation. The 1.89 Gbp draft genome is comprised of 31,922 scaffolds (N50: 496,398 bp) covering 85.9% of the projected genome size. The genome repeat content (61.8% with 30% representing simple sequence repeats) is almost the highest identified for any species. The functional annotation identified 35,517 gene models, of which 25,809 were protein-coding and 17,158 were annotated using interproscan. Scaffold scanning for specific EVEs identified an element comprised of a 9,045 bp stretch of repeated, inverted and jumbled genome fragments of Infectious hypodermal and hematopoietic necrosis virus (IHHNV) bounded by a repeated 591/590 bp host sequence. As only near complete linear ~4 kb IHHNV genomes have been found integrated in the genome of P. monodon previously, its discovery has implications regarding the validity of PCR tests designed to specifically detect such linear EVE types. The existence of conjoined inverted IHHNV genome fragments also provides a means by which hairpin dsRNAs could be expressed and processed by the shrimp RNA interference (RNAi) machinery.


2020 ◽  
Vol 12 (2) ◽  
pp. 3917-3925
Author(s):  
Greer A Dolby ◽  
Matheo Morales ◽  
Timothy H Webster ◽  
Dale F DeNardo ◽  
Melissa A Wilson ◽  
...  

Abstract Toll-like receptors (TLRs) are a complex family of innate immune genes that are well characterized in mammals and birds but less well understood in nonavian sauropsids (reptiles). The advent of highly contiguous draft genomes of nonmodel organisms enables study of such gene families through analysis of synteny and sequence identity. Here, we analyze TLR genes from the genomes of 22 tetrapod species. Findings reveal a TLR8 gene expansion in crocodilians and turtles (TLR8B), and a second duplication (TLR8C) specifically within turtles, followed by pseudogenization of that gene in the nonfreshwater species (desert tortoise and green sea turtle). Additionally, the Mojave desert tortoise (Gopherus agassizii) has a stop codon in TLR8B (TLR8-1) that is polymorphic among conspecifics. Revised orthology further reveals a new TLR homolog, TLR21-like, which is exclusive to lizards, snakes, turtles, and crocodilians. These analyses were made possible by a new draft genome assembly of the desert tortoise (gopAga2.0), which used chromatin-based assembly to yield draft chromosomal scaffolds (L50 = 26 scaffolds, N50 = 28.36 Mb, longest scaffold = 107 Mb) and an enhanced de novo genome annotation with 25,469 genes. Our three-step approach to orthology curation and comparative analysis of TLR genes shows what new insights are possible using genome assemblies with chromosome-scale scaffolds that permit integration of synteny conservation data.


2020 ◽  
Vol 9 (7) ◽  
Author(s):  
Mayank Gupta ◽  
Puneet Singh Chauhan ◽  
Sudhir K. Sopory ◽  
Sneh L. Singla-Pareek ◽  
Nidhi Adlakha ◽  
...  

Here, we report the 4.34-Mb draft genome assembly of Bacillus marisflavi CK-NBRI-03 (or P3), a Gram-positive bacterium, with an average G+C content of 48.66%. P3 was isolated from agricultural soil from the Badaun (midwestern plain zone) region of Uttar Pradesh, India.


2016 ◽  
Vol 4 (6) ◽  
Author(s):  
Mohammad H. A. Ibrahim ◽  
Brady F. Cress ◽  
Robert J. Linhardt ◽  
Mattheos A. G. Koffas ◽  
Richard A. Gross

We report here the 4.092-Mb high-quality draft genome assembly of a newly isolated poly-γ-glutamic acid–producing strain,Bacillus subtilisIa1a. The genome sequence is considered a critical tool to facilitate the engineering of improved production strains. Exopolysaccharides and many industrially important enzymes can be produced by this new strain utilizing different carbon sources.


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.


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