scholarly journals Unveiling Comparative Genomic Trajectories of Selection and Key Candidate Genes in Egg-Type Russian White and Meat-Type White Cornish Chickens

Biology ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 876
Author(s):  
Alexandra S. Abdelmanova ◽  
Arsen V. Dotsev ◽  
Michael N. Romanov ◽  
Olga I. Stanishevskaya ◽  
Elena A. Gladyr ◽  
...  
Keyword(s):  
Candidate Genes ◽  
Artificial Selection ◽  
Genomic Diversity ◽  
Comparative Genomic ◽  
Phenotypic Traits ◽  
Selection History ◽  
History Of ◽  
Efficient Breeding ◽  
Genomic Regions ◽  
Meat Type

Comparison of genomic footprints in chicken breeds with different selection history is a powerful tool in elucidating genomic regions that have been targeted by recent and more ancient selection. In the present work, we aimed at examining and comparing the trajectories of artificial selection in the genomes of the native egg-type Russian White (RW) and meat-type White Cornish (WC) breeds. Combining three different statistics (top 0.1% SNP by FST value at pairwise breed comparison, hapFLK analysis, and identification of ROH island shared by more than 50% of individuals), we detected 45 genomic regions under putative selection including 11 selective sweep regions, which were detected by at least two different methods. Four of such regions were breed-specific for each of RW breed (on GGA1, GGA5, GGA8, and GGA9) and WC breed (on GGA1, GGA5, GGA8, and GGA28), while three remaining regions on GGA2 (two sweeps) and GGA3 were common for both breeds. Most of identified genomic regions overlapped with known QTLs and/or candidate genes including those for body temperatures, egg productivity, and feed intake in RW chickens and those for growth, meat and carcass traits, and feed efficiency in WC chickens. These findings were concordant with the breed origin and history of their artificial selection. We determined a set of 188 prioritized candidate genes retrieved from the 11 overlapped regions of putative selection and reviewed their functions relative to phenotypic traits of interest in the two breeds. One of the RW-specific sweep regions harbored the known domestication gene, TSHR. Gene ontology and functional annotation analysis provided additional insight into a functional coherence of genes in the sweep regions. We also showed a greater candidate gene richness on microchromosomes relative to macrochromosomes in these genomic areas. Our results on the selection history of RW and WC chickens and their key candidate genes under selection serve as a profound information for further conservation of their genomic diversity and efficient breeding.

scholarly journals Genome-wide screening of copy number variants in children born small for gestational age reveals several candidate genes involved in growth pathways

2014 ◽  
Vol 171 (2) ◽  
pp. 253-262 ◽  
Author(s):  
Ana P M Canton ◽  
Sílvia S Costa ◽  
Tatiane C Rodrigues ◽  
Debora R Bertola ◽  
Alexsandra C Malaquias ◽  
...  
Keyword(s):  
Short Stature ◽  
Candidate Genes ◽  
Gestational Age ◽  
Small For Gestational Age ◽  
Copy Number ◽  
De Novo ◽  
Copy Number Variants ◽  
Comparative Genomic ◽  
Growth Disorders ◽  
Genomic Regions

BackgroundThe etiology of prenatal-onset short stature with postnatal persistence is heterogeneous. Submicroscopic chromosomal imbalances, known as copy number variants (CNVs), may play a role in growth disorders.ObjectiveTo analyze the CNVs present in a group of patients born small for gestational age (SGA) without a known cause.Patients and methodsA total of 51 patients with prenatal and postnatal growth retardation associated with dysmorphic features and/or developmental delay, but without criteria for the diagnosis of known syndromes, were selected. Array-based comparative genomic hybridization was performed using DNA obtained from all patients. The pathogenicity of CNVs was assessed by considering the following criteria: inheritance; gene content; overlap with genomic coordinates for a known genomic imbalance syndrome; and overlap with CNVs previously identified in other patients with prenatal-onset short stature.ResultsIn 17 of the 51 patients, 18 CNVs were identified. None of these imbalances has been reported in healthy individuals. Nine CNVs, found in eight patients (16%), were categorized as pathogenic or probably pathogenic. Deletions found in three patients overlapped with known microdeletion syndromes (4q, 10q26, and 22q11.2). These imbalances are de novo, gene rich and affect several candidate genes or genomic regions that may be involved in the mechanisms of growth regulation.ConclusionPathogenic CNVs in the selected patients born SGA were common (at least 16%), showing that rare CNVs are probably among the genetic causes of short stature in SGA patients and revealing genomic regions possibly implicated in this condition.

scholarly journals Genomic Diversity ofLactobacillus salivarius

2010 ◽  
Vol 77 (3) ◽  
pp. 954-965 ◽  
Author(s):  
Emma J. Raftis ◽  
Elisa Salvetti ◽  
Sandra Torriani ◽  
Giovanna E. Felis ◽  
Paul W. O'Toole
Keyword(s):  
Hot Spots ◽  
Gene Clusters ◽  
Genomic Variation ◽  
Genomic Diversity ◽  
Comparative Genomic ◽  
Phenotypic Traits ◽  
Lactobacillus Salivarius ◽  
Genome Content ◽  
High Level ◽  
Selection Of

ABSTRACTStrains ofLactobacillus salivariusare increasingly employed as probiotic agents for humans or animals. Despite the diversity of environmental sources from which they have been isolated, the genomic diversity ofL. salivariushas been poorly characterized, and the implications of this diversity for strain selection have not been examined. To tackle this, we applied comparative genomic hybridization (CGH) and multilocus sequence typing (MLST) to 33 strains derived from humans, animals, or food. The CGH, based on total genome content, including small plasmids, identified 18 major regions of genomic variation, or hot spots for variation. Three major divisions were thus identified, with only a subset of the human isolates constituting an ecologically discernible group. Omission of the small plasmids from the CGH or analysis by MLST provided broadly concordant fine divisions and separated human-derived and animal-derived strains more clearly. The two gene clusters for exopolysaccharide (EPS) biosynthesis corresponded to regions of significant genomic diversity. The CGH-based groupings of these regions did not correlate with levels of production of bound or released EPS. Furthermore, EPS production was significantly modulated by available carbohydrate. In addition to proving difficult to predict from the gene content, EPS production levels correlated inversely with production of biofilms, a trait considered desirable in probiotic commensals.L. salivariusdisplays a high level of genomic diversity, and while selection ofL. salivariusstrains for probiotic use can be informed by CGH or MLST, it also requires pragmatic experimental validation of desired phenotypic traits.

scholarly journals Background selection and biased gene conversion affect more than 95% of the human genome and bias demographic inferences

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Fanny Pouyet ◽  
Simon Aeschbacher ◽  
Alexandre Thiéry ◽  
Laurent Excoffier
Keyword(s):  
Gene Conversion ◽  
Purifying Selection ◽  
Genomic Diversity ◽  
Background Selection ◽  
Recombination Rates ◽  
Biased Gene Conversion ◽  
Synonymous Sites ◽  
History Of ◽  
Demographic Inference ◽  
Genomic Regions

Disentangling the effect on genomic diversity of natural selection from that of demography is notoriously difficult, but necessary to properly reconstruct the history of species. Here, we use high-quality human genomic data to show that purifying selection at linked sites (i.e. background selection, BGS) and GC-biased gene conversion (gBGC) together affect as much as 95% of the variants of our genome. We find that the magnitude and relative importance of BGS and gBGC are largely determined by variation in recombination rate and base composition. Importantly, synonymous sites and non-transcribed regions are also affected, albeit to different degrees. Their use for demographic inference can lead to strong biases. However, by conditioning on genomic regions with recombination rates above 1.5 cM/Mb and mutation types (C↔G, A↔T), we identify a set of SNPs that is mostly unaffected by BGS or gBGC, and that avoids these biases in the reconstruction of human history.

scholarly journals Background selection and biased gene conversion affect more than 95% of the human genome and bias demographic inferences

2019 ◽  
Author(s):  
Fanny Pouyet
Keyword(s):  
Gene Conversion ◽  
Purifying Selection ◽  
Genomic Diversity ◽  
Background Selection ◽  
Recombination Rates ◽  
Biased Gene Conversion ◽  
Synonymous Sites ◽  
History Of ◽  
Demographic Inference ◽  
Genomic Regions

Disentangling the effect on genomic diversity of natural selection from that of demography is notoriously difficult, but necessary to properly reconstruct the history of species. Here, we use high-quality human genomic data to show that purifying selection at linked sites (i.e. background selection, BGS) and GC-biased gene conversion (gBGC) together affect as much as 95% of the variants of our genome. We find that the magnitude and relative importance of BGS and gBGC are largely determined by variation in recombination rate and base composition. Importantly, synonymous sites and non-transcribed regions are also affected, albeit to different degrees. Their use for demographic inference can lead to strong biases. However, by conditioning on genomic regions with recombination rates above 1.5 cM/Mb and mutation types (C↔G, A↔T), we identify a set of SNPs that is mostly unaffected by BGS or gBGC, and that avoids these biases in the reconstruction of human history.

scholarly journals Genome-wide scans for signatures of selection in Mangalarga Marchador horses using high-throughput SNP genotyping

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Wellington B. Santos ◽  
Gustavo P. Schettini ◽  
Amanda M. Maiorano ◽  
Fernando O. Bussiman ◽  
Júlio C. C. Balieiro ◽  
...  
Keyword(s):  
Positive Selection ◽  
Candidate Genes ◽  
Limb Development ◽  
Balancing Selection ◽  
Phenotypic Traits ◽  
Nadh Regeneration ◽  
Recent Positive Selection ◽  
Signatures Of Selection ◽  
Genomic Regions ◽  
Tajima’S D

Abstract Background The detection of signatures of selection in genomic regions provides insights into the evolutionary process, enabling discoveries regarding complex phenotypic traits. In this research, we focused on identifying genomic regions affected by different selection pressures, mainly highlighting the recent positive selection, as well as understanding the candidate genes and functional pathways associated with the signatures of selection in the Mangalarga Marchador genome. Besides, we seek to direct the discussion about genes and traits of importance in this breed, especially traits related to the type and quality of gait, temperament, conformation, and locomotor system. Results Three different methods were used to search for signals of selection: Tajima’s D (TD), the integrated haplotype score (iHS), and runs of homozygosity (ROH). The samples were composed of males (n = 62) and females (n = 130) that were initially chosen considering well-defined phenotypes for gait: picada (n = 86) and batida (n = 106). All horses were genotyped using a 670 k Axiom® Equine Genotyping Array​ (Axiom MNEC670). In total, 27, 104 (chosen), and 38 candidate genes were observed within the signatures of selection identified in TD, iHS, and ROH analyses, respectively. The genes are acting in essential biological processes. The enrichment analysis highlighted the following functions: anterior/posterior pattern for the set of genes (GLI3, HOXC9, HOXC6, HOXC5, HOXC4, HOXC13, HOXC11, and HOXC10); limb morphogenesis, skeletal system, proximal/distal pattern formation, JUN kinase activity (CCL19 and MAP3K6); and muscle stretch response (MAPK14). Other candidate genes were associated with energy metabolism, bronchodilator response, NADH regeneration, reproduction, keratinization, and the immunological system. Conclusions Our findings revealed evidence of signatures of selection in the MM breed that encompass genes acting on athletic performance, limb development, and energy to muscle activity, with the particular involvement of the HOX family genes. The genome of MM is marked by recent positive selection. However, Tajima’s D and iHS results point also to the presence of balancing selection in specific regions of the genome.

scholarly journals A Comparative Genomic Analysis of Diverse Clonal Types of EnterotoxigenicEscherichia coliReveals Pathovar-Specific Conservation

2010 ◽  
Vol 79 (2) ◽  
pp. 950-960 ◽  
Author(s):  
Jason W. Sahl ◽  
Hans Steinsland ◽  
Julia C. Redman ◽  
Samuel V. Angiuoli ◽  
James P. Nataro ◽  
...  
Keyword(s):  
Vaccine Development ◽  
Genomic Sequence ◽  
Genomic Analysis ◽  
Genomic Diversity ◽  
Comparative Genomic ◽  
Middle Income ◽  
E Coli ◽  
Colonization Factor ◽  
Genomic Core ◽  
Genomic Regions

ABSTRACTEnterotoxigenicEscherichia coli(ETEC) is a major cause of diarrheal illness in children less than 5 years of age in low- and middle-income nations, whereas it is an emerging enteric pathogen in industrialized nations. Despite being an important cause of diarrhea, little is known about the genomic composition of ETEC. To address this, we sequenced the genomes of five ETEC isolates obtained from children in Guinea-Bissau with diarrhea. These five isolates represent distinct and globally dominant ETEC clonal groups. Comparative genomic analyses utilizing a gene-independent whole-genome alignment method demonstrated that sequenced ETEC strains share approximately 2.7 million bases of genomic sequence. Phylogenetic analysis of this “core genome” confirmed the diverse history of the ETEC pathovar and provides a finer resolution of theE. colirelationships than multilocus sequence typing. No identified genomic regions were conserved exclusively in all ETEC genomes; however, we identified more genomic content conserved among ETEC genomes than among non-ETECE. coligenomes, suggesting that ETEC isolates share a genomic core. Comparisons of known virulence and of surface-exposed and colonization factor genes across all sequenced ETEC genomes not only identified variability but also indicated that some antigens are restricted to the ETEC pathovar. Overall, the generation of these five genome sequences, in addition to the two previously generated ETEC genomes, highlights the genomic diversity of ETEC. These studies increase our understanding of ETEC evolution, as well as provide insight into virulence factors and conserved proteins, which may be targets for vaccine development.

scholarly journals Comparative genomic analysis of Mycobacterium intracellulare: implications for clinical taxonomic classification in pulmonary Mycobacterium avium-intracellulare complex disease

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yoshitaka Tateishi ◽  
Yuriko Ozeki ◽  
Akihito Nishiyama ◽  
Mari Miki ◽  
Ryoji Maekura ◽  
...  
Keyword(s):  
Complex Disease ◽  
Genomic Analysis ◽  
Comparative Genomic Analysis ◽  
Genomic Diversity ◽  
Comparative Genomic ◽  
Mycobacterium Intracellulare ◽  
Clinical Strains ◽  
Genetic Components ◽  
Genomic Regions ◽  
Insight Into

Abstract Background Mycobacterium intracellulare is a representative etiological agent of emerging pulmonary M. avium-intracellulare complex disease in the industrialized countries worldwide. The recent genome sequencing of clinical strains isolated from pulmonary M. avium-intracellulare complex disease has provided insight into the genomic characteristics of pathogenic mycobacteria, especially for M. avium; however, the genomic characteristics of M. intracellulare remain to be elucidated. Results In this study, we performed comparative genomic analysis of 55 M. intracellulare and related strains such as M. paraintracellulare (MP), M. indicus pranii (MIP) and M. yonogonense. Based on the average nucleotide identity, the clinical M. intracellulare strains were phylogenetically grouped in two clusters: (1) the typical M. intracellulare (TMI) group, including ATCC13950 and virulent M.i.27 and M.i.198 that we previously reported, and (2) the MP-MIP group. The alignment of the genomic regions was mostly preserved between groups. Plasmids were identified between groups and subgroups, including a plasmid common among some strains of the M.i.27 subgroup. Several genomic regions including those encoding factors involved in lipid metabolism (e.g., fadE3, fadE33), transporters (e.g., mce3), and type VII secretion system (genes of ESX-2 system) were shown to be hypermutated in the clinical strains. M. intracellulare was shown to be pan-genomic at the species and subspecies levels. The mce genes were specific to particular subspecies, suggesting that these genes may be helpful in discriminating virulence phenotypes between subspecies. Conclusions Our data suggest that genomic diversity among M. intracellulare, M. paraintracellulare, M. indicus pranii and M. yonogonense remains at the subspecies or genovar levels and does not reach the species level. Genetic components such as mce genes revealed by the comparative genomic analysis could be the novel focus for further insight into the mechanism of human pathogenesis for M. intracellulare and related strains.

scholarly journals The natural adaptation and human selection history of African sheep genomes

2021 ◽  
Author(s):  
Abulgasim M Ahbara ◽  
Christelle Robert ◽  
Adebabay Kebede ◽  
Ayele Abebe ◽  
Suliman Latairish ◽  
...  
Keyword(s):  
Genomic Analysis ◽  
Gene Families ◽  
Comparative Genomic ◽  
Selection History ◽  
Ear Morphology ◽  
Geographic Origins ◽  
History Of ◽  
Pleiotropic Gene ◽  
Fat Depot ◽  
Human Selection

African sheep manifest diverse but distinct physio-anatomical traits which are the outcomes of natural- and human-driven selection. Here, we generated 34.8 million variants from 150 indigenous African sheep genomes sequenced at an average depth of ∼54x for 130 samples (Ethiopia, Libya) and ∼10x for 20 samples (Sudan), representing sheep from diverse environments, tail morphology and post-Neolithic introductions to Africa. Phylogenetic and model-based admixture analysis provided evidence of four genetic groups that correspond to altitudinal geographic origins and tail morphotypes. Comparative genomic analysis identified targets of selection spanning conserved haplotype structures overlapping genes and gene families relating to hypoxia responses, caudal vertebrae and tail skeleton length, ear morphology, and tail fat-depot structure. Our findings provide novel insights underpinning variation and response to human selection and environmental adaptation, and possible pleiotropic gene interactions in indigenous African sheep genomes, which guaranteed the successful establishment of the species on the continent.

scholarly journals Genome-wide scans for signatures of selection in Mangalarga Marchador horses using high-throughput SNP genotyping

2020 ◽  
Author(s):  
Wellington Bizarria dos Santos ◽  
Gustavo Schettini ◽  
Amanda Marchi Maiorano ◽  
Fernando Oliveira Bussiman ◽  
Júlio Carvalho Balieiro ◽  
...  
Keyword(s):  
Candidate Genes ◽  
Evolutionary Process ◽  
Phenotypic Traits ◽  
Nadh Regeneration ◽  
Locomotor System ◽  
Bronchodilator Response ◽  
Local Adaptations ◽  
Jun Kinase ◽  
Signatures Of Selection ◽  
Genomic Regions

Abstract Background: The Mangalarga Marchador horse (MM) is one of the breeds shaped over generations by local adaptations and specific preferences of Brazilian breeders to morphology, functionality, and locomotion. The animals genetically have “batida” or “picada” natural gait trait, which is a trademark of the breed. The movement biomechanics of this breed promote stability during the execution, comfort, and softness of the ride. The detection of signatures of selection in genomic regions provides insights into the evolutionary process, enabling discoveries regarding complex phenotypic traits. In this research, we focused on the identification of genomic regions affected by different selection pressures, mainly highlighting recent selection, as well as understanding the candidate genes and functional pathways associated with the signatures of selection in the MM genome. A broader discussion of genes and traits of importance in this breed, especially traits related to the type and quality of the gait, temperament, conformation, and locomotor system, was also provided.Results: Three different methods were used to search for signals of selection: Tajima’s D (TD), the integrated haplotype score (iHS), and runs of homozygosity (ROH). The samples were composed of males (n=62) and females (n=130) that were initially chosen considering well-defined phenotypes for gait: picada (n=86) and batida (n=106). All horses were genotyped using a 670k Axiom ® Equine Genotyping Array​ (Axiom MNEC670). In total, 169 pruned candidate genes harboring important biological processes were found, highlighting the following: anterior/posterior pattern for the set of genes (GLI3, HOXC9, HOXC6, HOXC5, HOXC4, HOXC13, HOXC11, and HOXC10); limb morphogenesis, skeletal system, proximal/distal pattern formation, JUN kinase activity (CCL19 and MAP3K6); and muscle stretch response (MAPK14). Other candidate genes were associated with energy metabolism, bronchodilator response, NADH regeneration, reproduction, keratinization, and the immunological system.Conclusions: Collectively, our findings revealed for the first time some pieces of evidence for selection signals acting on athletic performance, gait type, and energy to muscle activity in the MM breed, with the particular involvement of the HOX family of genes. Gene network analysis showed no relationship between the signals observed in this population and the DMRT3 gene, a relevant gene associated with gait trait, however candidate genes that were located close (~28Mb) to DMRT3 were identified.

scholarly journals Genome-wide selection signatures detection in Shanghai Holstein cattle population identified genes related to adaption, health and reproduction traits

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Dengying Liu ◽  
Zhenliang Chen ◽  
Wei Zhao ◽  
Longyu Guo ◽  
Hao Sun ◽  
...  
Keyword(s):  
Candidate Genes ◽  
Artificial Selection ◽  
Sequence Data ◽  
Holstein Cattle ◽  
Cattle Population ◽  
Economic Traits ◽  
Selection Signatures ◽  
Wide Range ◽  
Candidate Regions ◽  
Genomic Regions

Abstract Background Over several decades, a wide range of natural and artificial selection events in response to subtropical environments, intensive pasture and intensive feedlot systems have greatly changed the customary behaviour, appearance, and important economic traits of Shanghai Holstein cattle. In particular, the longevity of the Shanghai Holstein cattle population is generally short, approximately the 2nd to 3rd lactation. In this study, two complementary approaches, integrated haplotype score (iHS) and runs of homozygosity (ROH), were applied for the detection of selection signatures within the genome using genotyping by genome-reduced sequence data from 1092 cows. Results In total, 101 significant iHS genomic regions containing selection signatures encompassing a total of 256 candidate genes were detected. There were 27 significant |iHS| genomic regions with a mean |iHS| score > 2. The average number of ROH per individual was 42.15 ± 25.47, with an average size of 2.95 Mb. The length of 78 % of the detected ROH was within the range of 1–2 MB and 2–4 MB, and 99 % were shorter than 8 Mb. A total of 168 genes were detected in 18 ROH islands (top 1 %) across 16 autosomes, in which each SNP showed a percentage of occurrence > 30 %. There were 160 and 167 genes associated with the 52 candidate regions within health-related QTL intervals and 59 candidate regions within reproduction-related QTL intervals, respectively. Annotation of the regions harbouring clustered |iHS| signals and candidate regions for ROH revealed a panel of interesting candidate genes associated with adaptation and economic traits, such as IL22RA1, CALHM3, ITGA9, NDUFB3, RGS3, SOD2, SNRPA1, ST3GAL4, ALAD, EXOSC10, and MASP2. In a further step, a total of 1472 SNPs in 256 genes were matched with 352 cis-eQTLs in 21 tissues and 27 trans-eQTLs in 6 tissues. For SNPs located in candidate regions for ROH, a total of 108 cis-eQTLs in 13 tissues and 4 trans-eQTLs were found for 1092 SNPs. Eighty-one eGenes were significantly expressed in at least one tissue relevant to a trait (P value < 0.05) and matched the 256 genes detected by iHS. For the 168 significant genes detected by ROH, 47 gene-tissue pairs were significantly associated with at least one of the 37 traits. Conclusions We provide a comprehensive overview of selection signatures in Shanghai Holstein cattle genomes by combining iHS and ROH. Our study provides a list of genes associated with immunity, reproduction and adaptation. For functional annotation, the cGTEx resource was used to interpret SNP-trait associations. The results may facilitate the identification of genes relevant to important economic traits and can help us better understand the biological processes and mechanisms affected by strong ongoing natural or artificial selection in livestock populations.

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