scholarly journals Contemporary and historical selection in Tasmanian devils ( Sarcophilus harrisii ) support novel, polygenic response to transmissible cancer

2021 ◽  
Vol 288 (1951) ◽  
pp. 20210577
Author(s):  
Amanda R. Stahlke ◽  
Brendan Epstein ◽  
Soraia Barbosa ◽  
Mark J. Margres ◽  
Austin H. Patton ◽  
...  
Keyword(s):  
Candidate Genes ◽  
Rapid Evolution ◽  
Gene Sets ◽  
Devil Facial Tumour Disease ◽  
Evolutionary Response ◽  
Recent Emergence ◽  
Transmissible Cancer ◽  
Or Gene ◽  
Genomic Regions ◽  
Sarcophilus Harrisii

Tasmanian devils ( Sarcophilus harrisii ) are evolving in response to a unique transmissible cancer, devil facial tumour disease (DFTD), first described in 1996. Persistence of wild populations and the recent emergence of a second independently evolved transmissible cancer suggest that transmissible cancers may be a recurrent feature in devils. Here, we compared signatures of selection across temporal scales to determine whether genes or gene pathways under contemporary selection (six to eight generations) have also been subject to historical selection (65–85 Myr). First, we used targeted sequencing, RAD-capture, in approximately 2500 devils in six populations to identify genomic regions subject to rapid evolution. We documented genome-wide contemporary evolution, including 186 candidate genes related to cell cycling and immune response. Then we used a molecular evolution approach to identify historical positive selection in devils compared to other marsupials and found evidence of selection in 1773 genes. However, we found limited overlap across time scales, with only 16 shared candidate genes, and no overlap in enriched functional gene sets. Our results are consistent with a novel, multi-locus evolutionary response of devils to DFTD. Our results can inform conservation by identifying high priority targets for genetic monitoring and guiding maintenance of adaptive potential in managed populations.

scholarly journals Historical and contemporary signatures of selection in response to transmissible cancer in the Tasmanian Devil (Sarcophilus harrisii)

2020 ◽  
Author(s):  
Amanda R. Stahlke ◽  
Brendan Epstein ◽  
Soraia Barbosa ◽  
Austin Patton ◽  
Sarah A. Hendricks ◽  
...  
Keyword(s):  
Recurrent Selection ◽  
Rapid Evolution ◽  
Tasmanian Devil ◽  
Management Actions ◽  
Devil Facial Tumour Disease ◽  
Evolutionary Response ◽  
Recent Emergence ◽  
Transmissible Cancer ◽  
Genomic Regions ◽  
Sarcophilus Harrisii

AbstractTasmanian devils (Sarcophilus harrisii) are evolving in response to a unique transmissible cancer, devil facial tumour disease (DFTD), first described in 1996. Persistence of wild populations and the recent emergence of a second independently evolved transmissible cancer suggest that transmissible cancers may be a recurrent feature in devils. We used a targeted sequencing approach, RAD-capture, to identify genomic regions subject to rapid evolution in approximately 2,500 devils as DFTD spread across the species range. We found evidence for genome-wide contemporary evolution, including 186 candidate genes related to cell cycling and immune response. We then searched for signatures of recurrent selection with a molecular evolution approach and found widespread evidence of historical positive selection in devils relative to other marsupials. We identified both contemporary and historical selection in 19 genes and enrichment for contemporary and historical selection independently in 22 gene sets. Nonetheless, the overlap between candidates for historical selection and for contemporary response to DFTD was lower than expected, supporting novelty in the evolutionary response of devils to DFTD. Our results can inform management actions to conserve adaptive capacity of devils by identifying high priority targets for genetic monitoring and maintenance of functional diversity in managed populations.

scholarly journals Identification of Genomic Regions Associated with Concentrations of Milk Fat, Protein, Urea and Efficiency of Crude Protein Utilization in Grazing Dairy Cows

Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 456
Author(s):  
Hewa Bahithige Pavithra Chathurangi Ariyarathne ◽  
Martin Correa-Luna ◽  
Hugh Thomas Blair ◽  
Dorian John Garrick ◽  
Nicolas Lopez-Villalobos
Keyword(s):  
Gene Ontology ◽  
New Zealand ◽  
Dairy Cows ◽  
Candidate Genes ◽  
Milk Fat ◽  
Crude Protein ◽  
Single Locus ◽  
Protein Utilization ◽  
Grazing Dairy Cows ◽  
Genomic Regions

The objective of this study was to identify genomic regions associated with milk fat percentage (FP), crude protein percentage (CPP), urea concentration (MU) and efficiency of crude protein utilization (ECPU: ratio between crude protein yield in milk and dietary crude protein intake) using grazing, mixed-breed, dairy cows in New Zealand. Phenotypes from 634 Holstein Friesian, Jersey or crossbred cows were obtained from two herds at Massey University. A subset of 490 of these cows was genotyped using Bovine Illumina 50K SNP-chips. Two genome-wise association approaches were used, a single-locus model fitted to data from 490 cows and a single-step Bayes C model fitted to data from all 634 cows. The single-locus analysis was performed with the Efficient Mixed-Model Association eXpedited model as implemented in the SVS package. Single nucleotide polymorphisms (SNPs) with genome-wide association p-values ≤ 1.11 × 10−6 were considered as putative quantitative trait loci (QTL). The Bayes C analysis was performed with the JWAS package and 1-Mb genomic windows containing SNPs that explained > 0.37% of the genetic variance were considered as putative QTL. Candidate genes within 100 kb from the identified SNPs in single-locus GWAS or the 1-Mb windows were identified using gene ontology, as implemented in the Ensembl Genome Browser. The genes detected in association with FP (MGST1, DGAT1, CEBPD, SLC52A2, GPAT4, and ACOX3) and CPP (DGAT1, CSN1S1, GOSR2, HERC6, and IGF1R) were identified as candidates. Gene ontology revealed six novel candidate genes (GMDS, E2F7, SIAH1, SLC24A4, LGMN, and ASS1) significantly associated with MU whose functions were in protein catabolism, urea cycle, ion transportation and N excretion. One novel candidate gene was identified in association with ECPU (MAP3K1) that is involved in post-transcriptional modification of proteins. The findings should be validated using a larger population of New Zealand grazing dairy cows.

scholarly journals Genome-scale comparative analysis for host resistance against sea lice between Atlantic salmon and rainbow trout

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pablo Cáceres ◽  
Agustín Barría ◽  
Kris A. Christensen ◽  
Liane N. Bassini ◽  
Katharina Correa ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Atlantic Salmon ◽  
Candidate Genes ◽  
Protein Phosphatase ◽  
Sea Lice ◽  
Genome Wide Association Studies ◽  
Dual Specificity ◽  
Dual Specificity Protein Phosphatase ◽  
Genomic Regions ◽  
Specificity Protein

AbstractSea lice (Caligus rogercresseyi) is an ectoparasite which causes major production losses in the salmon aquaculture industry worldwide. Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) are two of the most susceptible salmonid species to sea lice infestation. The objectives of this study were to: (1) identify genomic regions associated with resistance to Caligus rogercresseyi in Atlantic salmon and rainbow trout by performing single-step Genome-Wide Association studies (ssGWAS), and (2) identify candidate genes related to trait variation based on exploring orthologous genes within the associated regions across species. A total of 2626 Atlantic salmon and 2643 rainbow trout were challenged and genotyped with 50 K and 57 K SNP panels, respectively. We ran two independent ssGWAS for sea lice resistance on each species and identified 7 and 13 regions explaining more than 1% of the genetic variance for the trait, with the most important regions explaining 3% and 2.7% for Atlantic salmon and rainbow trout, respectively. We identified genes associated with immune response, cytoskeleton function, and cell migration when focusing on important genomic regions for each species. Moreover, we found 15 common orthogroups which were present in more than one associated genomic region, within- or between-species; however, only one orthogroup showed a clear potential biological relevance in the response against sea lice. For instance, dual-specificity protein phosphatase 10-like (dusp10) and dual-specificity protein phosphatase 8 (dusp8) were found in genomic regions associated with lice density in Atlantic salmon and rainbow trout, respectively. Dusp10 and dusp8 are modulators of the MAPK pathway and might be involved in the differences of the inflammation response between lice resistant and susceptible fish from both species. Our results provide further knowledge on candidate genes related to sea lice resistance and may help establish better control for sea lice in fish populations.

scholarly journals Candidate Genes for the High-Altitude Adaptations of Two Mountain Pine Taxa

2021 ◽  
Vol 22 (7) ◽  
pp. 3477
Author(s):  
Julia Zaborowska ◽  
Bartosz Łabiszak ◽  
Annika Perry ◽  
Stephen Cavers ◽  
Witold Wachowiak
Keyword(s):  
Population Structure ◽  
Candidate Genes ◽  
Genetic Basis ◽  
Redox Homeostasis ◽  
Snp Markers ◽  
Regulation Of Transcription ◽  
Single Nucleotide ◽  
Homeostasis Regulation ◽  
Genomic Regions ◽  
Mountain Plants

Mountain plants, challenged by vegetation time contractions and dynamic changes in environmental conditions, developed adaptations that help them to balance their growth, reproduction, survival, and regeneration. However, knowledge regarding the genetic basis of species adaptation to higher altitudes remain scarce for most plant species. Here, we attempted to identify such corresponding genomic regions of high evolutionary importance in two closely related European pines, Pinus mugo and P. uncinata, contrasting them with a reference lowland relative—P. sylvestris. We genotyped 438 samples at thousands of single nucleotide polymorphism (SNP) markers, tested their genetic differentiation and population structure followed by outlier detection and gene ontology annotations. Markers clearly differentiated the species and uncovered patterns of population structure in two of them. In P. uncinata three Pyrenean sites were grouped together, while two outlying populations constituted a separate cluster. In P. sylvestris, Spanish population appeared distinct from the remaining four European sites. Between mountain pines and the reference species, 35 candidate genes for altitude-dependent selection were identified, including such encoding proteins responsible for photosynthesis, photorespiration and cell redox homeostasis, regulation of transcription, and mRNA processing. In comparison between two mountain pines, 75 outlier SNPs were found in proteins involved mainly in the gene expression and metabolism.

scholarly journals Genome-Wide Association Study (GWAS) to Identify Salt-Tolerance QTLs Carrying Novel Candidate Genes in Rice During Early Vegetative Stage

Rice ◽  
2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Leila Nayyeripasand ◽  
Ghasem Ali Garoosi ◽  
Asadollah Ahmadikhah
Keyword(s):  
Association Study ◽  
Candidate Gene ◽  
Candidate Genes ◽  
Salinity Tolerance ◽  
Genome Wide Association Study ◽  
Dry Weight ◽  
Genome Wide Association ◽  
Vegetative Stage ◽  
Genome Wide ◽  
Genomic Regions

Abstract Background Rice is considered as a salt-sensitive plant, particularly at early vegetative stage, and its production is suffered from salinity due to expansion of salt affected land in areas under cultivation. Hence, significant increase of rice productivity on salinized lands is really necessary. Today genome-wide association study (GWAS) is a method of choice for fine mapping of QTLs involved in plant responses to abiotic stresses including salinity stress at early vegetative stage. In this study using > 33,000 SNP markers we identified rice genomic regions associated to early stage salinity tolerance. Eight salinity-related traits including shoot length (SL), root length (RL), root dry weight (RDW), root fresh weight (RFW), shoot fresh weight (SFW), shoot dry weight (SDW), relative water content (RWC) and TW, and 4 derived traits including SL-R, RL-R, RDW-R and RFW-R in a diverse panel of rice were evaluated under salinity (100 mM NaCl) and normal conditions in growth chamber. Genome-wide association study (GWAS) was applied based on MLM(+Q + K) model. Results Under stress conditions 151 trait-marker associations were identified that were scattered on 10 chromosomes of rice that arranged in 29 genomic regions. A genomic region on chromosome 1 (11.26 Mbp) was identified which co-located with a known QTL region SalTol1 for salinity tolerance at vegetative stage. A candidate gene (Os01g0304100) was identified in this region which encodes a cation chloride cotransporter. Furthermore, on this chromosome two other candidate genes, Os01g0624700 (24.95 Mbp) and Os01g0812000 (34.51 Mbp), were identified that encode a WRKY transcription factor (WRKY 12) and a transcriptional activator of gibberellin-dependent alpha-amylase expression (GAMyb), respectively. Also, a narrow interval on the same chromosome (40.79–42.98 Mbp) carries 12 candidate genes, some of them were not so far reported for salinity tolerance at seedling stage. Two of more interesting genes are Os01g0966000 and Os01g0963000, encoding a plasma membrane (PM) H+-ATPase and a peroxidase BP1 protein. A candidate gene was identified on chromosome 2 (Os02g0730300 at 30.4 Mbp) encoding a high affinity K+ transporter (HAK). On chromosome 6 a DnaJ-encoding gene and pseudouridine synthase gene were identified. Two novel genes on chromosome 8 including the ABI/VP1 transcription factor and retinoblastoma-related protein (RBR), and 3 novel genes on chromosome 11 including a Lox, F-box and Na+/H+ antiporter, were also identified. Conclusion Known or novel candidate genes in this research were identified that can be used for improvement of salinity tolerance in molecular breeding programmes of rice. Further study and identification of effective genes on salinity tolerance by the use of candidate gene-association analysis can help to precisely uncover the mechanisms of salinity tolerance at molecular level. A time dependent relationship between salt tolerance and expression level of candidate genes could be recognized.

scholarly journals Identification of candidate genes for devil facial tumour disease tumourigenesis

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Robyn L. Taylor ◽  
Yiru Zhang ◽  
Jennifer P. Schöning ◽  
Janine E. Deakin
Keyword(s):  
Candidate Genes ◽  
Devil Facial Tumour Disease

scholarly journals Analysis of 200,000 exome-sequenced UK Biobank subjects fails to identify genes influencing probability of developing a mood disorder resulting in psychiatric referral

2021 ◽  
Author(s):  
David Curtis
Keyword(s):  
Affective Disorder ◽  
Multiple Testing ◽  
Major Effect ◽  
Self Report ◽  
Uk Biobank ◽  
Recurrent Depression ◽  
Functional Variants ◽  
Gene Sets ◽  
Or Gene ◽  
Genetic Contributions

AbstractBackgroundDepression is moderately heritable but there is no common genetic variant which has a major effect on susceptibility. A previous analysis of 50,000 subjects failed to implicate any genes or sets of genes associated with risk of affective disorder requiring specialist treatment. A large exome-sequenced dataset is now available.MethodsData from 200,632 exome-sequenced UK Biobank participants was analysed. Subjects were treated as cases if they had reported having seen a psychiatrist for “nerves, anxiety, tension or depression”. Gene-wise weighted burden analysis was performed to see if there were any genes or sets of genes for which there was an excess of rare, functional variants in cases.ResultsThere were 22,886 cases and 176,486 controls. There were 22,642 informative genes but no gene or gene set produced a statistically significant result after correction for multiple testing. None of the genes or gene sets with the lowest p values appeared to be a biologically plausible candidate.LimitationsThe phenotype is based on self-report and the cases are likely to somewhat heterogeneous. Likewise, it is expected that some of the subjects classed as controls will in fact have suffered from depression or some other psychiatric diagnosis.ConclusionsThe results conform exactly with the expectation under the null hypothesis. It seems unlikely that the use of common, poorly defined phenotypes will produce useful advances in understanding genetic contributions to affective disorder and it might be preferable to focus instead on obtaining large exome-sequenced samples of conditions such as bipolar 1 disorder and severe, recurrent depression.

scholarly journals Why Do Centromeres Evolve So Fast: BIR Replication, Hypermutation, Transposition, and Molecular-Drive

2020 ◽  
Author(s):  
William Rice
Keyword(s):  
Rapid Evolution ◽  
Evolutionary Process ◽  
Epigenetic Mark ◽  
Replication Forks ◽  
Nucleotide Substitutions ◽  
Molecular Drive ◽  
Repeat Structure ◽  
Repeat Units ◽  
Initiation Of Replication ◽  
Genomic Regions

Centromeres are among the fastest evolving genomic regions in a diverse array of organisms. The evolutionary process driving this rapid evolution has not been unambiguously established. Here I integrate diverse information to motivate a model in which centromeres evolve rapidly because of their intrinsic molecular phenotype: they tightly bind centromeric proteins throughout the cell cycle. DNA-bound proteins have been shown to cause stalling and collapse of DNA replication forks in many genomic regions, including centromeres. Collapsed replication forks generate one-sided double strand breaks (DSBs) that are repaired by the Break-Induced Repair (BIR) pathway. Here I show why this repair is expected to generate tandem repeat structure and three key features at centromeres: i) increased nucleotide substitution mutation rates, ii) out-of- register re-initiation of replication that leads to indels spanning one or more repeat units, and iii) elevated rates of large and small transpositions within centromeres and between genomic regions. These phenotypes lead to: i) a rapid rate of nucleotide substitutions within a clade of centromeric sequences, ii) continual turnover of monomers within centromeres that fosters molecular-drift and molecular-drive, and iii) recurrent quantum leaps in centromere sequence due to the formation of mosaic monomers and new sequences transposed into non-homologous centromeres. These features are plausibly the major reason centromeres evolve so rapidly. I also speculate on how the DNA sequence of centromeres might perpetually coevolve with the protein sequence of histone CENH3 –the major epigenetic mark of centromeres.

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