Effect of minor allele frequency on the number of single nucleotide polymorphisms needed for accurate parentage assignment: A methodology illustrated using Atlantic salmon

2017 ◽  
Vol 49 (3) ◽  
pp. 1368-1372 ◽  
Author(s):  
Forest M Dussault ◽  
Elizabeth G Boulding
2017 ◽  
Author(s):  
Θωμάς Σοκολάκης

Ιστορικό: Υπαρχουν συσσωρεύμενα στοιχεία για την ύπαρξη γενετικής ευαισθησίας στην ανάπτυξη διαβητικής αμφιβληστροειδοπάθειας (ΔΑ). Ο ρόλος του αναστολέα του ενεργοποιητή του πλασμινογόνου-1 (PAI-1) στον κινδυνο αναπτυξης ΔΑ παραμένει αμφιλεγόμενος.Σκοπός: Η παρούσα μελέτη σχεδιάστηκε για να διερευνήσει την πιθανή επίδραση των πολυμορφισμών της περιοχής του γονιδίου PAI-1 στον κίνδυνο ανάπτυξης της ΔΑ και στον κίνδυνο ανάπτυξης ΔΑ πρώιμα έναντι καθυστερημένα κατά τη διάρκεια του σακχαρώδους διαβήτη τύπου 2 (ΣΔ2). Μέθοδοι: Συνολικά 138 ασθενείς με ΔΑ, 107 ασθενείς με ΣΔ2 χωρίς ΔΑ και 315 υγιείς μάρτυρες προσλήφθηκαν. Για να καλυφθεί η πλειοψηφία της γενετικής μεταβλητότητας στην εκτεταμένη περιοχή του γονιδίου ΡΑΙ-1, πέντε πολυμορφισμοί μονού νουκλεοτιδίου (single-nucleotide polymorphisms SNPs) από το HapMap χρησιμοποιώντας μια προσέγγιση ανά ζεύγη και r2> 0,8 και μία μικρή συχνότητα αλληλόμορφων (minor allele frequency MAF)> 0,05 εντοπίστηκαν. Χρησιμοποιώντας αναλύσεις λογιστικής παλινδρόμησης, ετικέτες SNPs και απλότυποι δοκιμάστηκαν για ενώσεις με κίνδυνο ανάπτυξης ΔΑ και με κίνδυνο ανάπτυξης ΔΑ νωρίς ή αργά κατά τη διάρκεια του ΣΔ2. Ο γενικευμένος λόγος πιθανότητας (generalized odds ratio ORG) υπολογίστηκε για την εκτίμηση της επίδρασης μεταλλακτικού φορτίου στην ανάπτυξη ΔΑ μεταξύ όλων των συμμετεχόντων. Διενεργήθηκαν διορθώσεις για πολλαπλές συγκρίσεις (p-τιμή <0,01).Αποτελέσματα: Ένα σημαντικό αποτέλεσμα του rs2070682 στον κίνδυνο πρόωρης έναρξης ΔΑ βρέθηκε στο συνκυριαρχο μοντέλο κληρονομικότητας [αναλογία πιθανότητας, OR (95% διάστημα εμπιστοσύνης, CI): 5.04 (1.47-17.28), p = 0.018]. Ωστόσο, αυτή η σχέση οριακά δεν επιβίωσε πολλαπλών διορθώσεων και δοκιμών. Δεν αποκαλύφθηκε καμία άλλη σημαντική συσχέτιση μεταξύ των επισημάνσεων-SNPs και των απλοτύπων ΡΑΙ-1. Επιπλέον, δεν βρέθηκε σημαντική επίδραση του μεταλλακτικού φορτίου της ετικέττας SNPs στον PAI-1 στον κίνδυνο ανάπτυξης ΔΑ στη διαρκεια του ΣΔ2. Συμπεράσματα: Συμπερασματικά, η παρούσα μελέτη δεν παρέχει καμία ισχυρή απόδειξη ότι οι παραλλαγές του γονιδίου PAI-1 εμπλέκονται στον κίνδυνο ανάπτυξης της ΔΑ ή στην ανάπτυξη της ΔΑ κατά τη διάρκεια του ΣΔ2.


2020 ◽  
Vol 61 (1) ◽  
pp. 17-23
Author(s):  
Michelle M. Nay ◽  
Stephen L. Byrne ◽  
Eduardo A. Pérez ◽  
Achim Walter ◽  
Bruno Studer

Genomics-assisted breeding of buckwheat (Fagopyrum esculentum Moench) depends on robust genotyping methods. Genotyping by sequencing (GBS) has evolved as a flexible and cost-effective technique frequently used in plant breeding. Several GBS pipelines are available to genetically characterize single genotypes but these are not able to represent the genetic diversity of buckwheat accessions that are maintained as genetically heterogeneous, open-pollinating populations. Here we report the development of a GBS pipeline which, rather than reporting the state of bi-allelic single nucleotide polymorphisms (SNPs), resolves allele frequencies within populations on a genome-wide scale. These genome-wide allele frequency fingerprints (GWAFFs) from 100 pooled individual plants per accession were found to be highly reproducible and revealed the genetic similarity of 20 different buckwheat accessions analysed in our study. The GWAFFs cannot only be used as an efficient tool to precisely describe buckwheat breeding material, they also offer new opportunities to investigate the genetic diversity between different buckwheat accessions and establish variant databases for key material. Furthermore, GWAFFs provide the opportunity to associate allele frequencies to phenotypic traits and quality parameters that are most reliably described on population level. This is the key to practically implement powerful genomics-assisted breeding concepts such as marker-assisted selection and genomic selection in future breeding schemes of allogamous buckwheat. Key words: Buckwheat (Fagopyrum esculentum Moench), genotyping by sequencing (GBS), population genomics, genome-wide allele frequency fingerprints (GWAFFs)   Izvleček Genomsko podprto žlahtnjenje ajde (Fagopyrum esculentum Moench) je odvisno od robustnih metod genotipiziranja. Genotipiziranje s spremljanjem sekvenc (genotyping by sequencing, GBS) se je razvilo kot fleksibilna in razmeroma poceni metoda, ki se jo uporablja pri žlahtnjenju rastlin. Uporabnih je več virov GBS za genetsko karakterizacijo posamičnih genotipov, toda te metode niso primerne za predstavitev genetske raznolikosti vzorcev ajde, ki jih vzdržujemo v heterozigotni obliki, kar velja za odprto oplodne populacije. Tu poročamo o razvoju GBS metode, ki, namesto prikazovanja bi-alelnega polimorfizma posameznih nukleotidov (single nucleotide polymorphisms, SNPs), pokaže frekvence alelov v populaciji na nivoju genoma. Ta prikaz frekvence alelov na nivoju genoma (genome-wide allele frequency fingerprints, GWAFFs) z združenimi sto posameznimi rastlinami vsakega vzorca se je pokazal kot visoko ponovljiv in je prikazal genetsko podobnost 20 različnih vzorcev ajde, ki smo jih analizirali v naši raziskavi. Metoda GWAFFs ni uporabna samo kot učinkovito orodje za natančen opis materiala za žlahtnjenje ajde, ponuja tudi možnosti raziskave  genetskih razlik med različnimi vzorci ajde in omogoča zbirke podatkov. Nadalje, metoda GWAFFs omogoča povezovanje frekvenc alelov s fenotipskimi lastnostmi in kvalitativnih parametrov, ki so najbolj zanesljivo opisani na nivoju populacij. To je ključ za praktično uporabo z genomiko podprtega žlahtnjenja, kot je z genskimi markerji podprta selekcija in genomska selekcija z GWAFFs. Ključne besede: ajda (Fagopyrum esculentum Moench), genotipizacija s sekvenciranjem (GBS), populacijska genomika, GWAFFs


2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Stephanie C Bohaczuk ◽  
Varykina G Thackray ◽  
Pamela L Mellon

Abstract Polycystic ovary syndrome (PCOS) is the most common cause of female infertility, affecting approximately 10 percent of women by Rotterdam criteria, and is comorbid with obesity, type II diabetes, hypertension, and non-alcoholic fatty liver disease. As twin studies reveal that genetics account for approximately 70% of PCOS risk, genome-wide association studies (GWAS) can provide powerful insight into PCOS etiology. PCOS GWAS studies from several populations identified a risk locus containing the FSHB gene, which encodes the beta subunit of follicle-stimulating hormone (FSH). As FSH supplementation can restore ovulation in some PCOS patients, deficient FSH signaling could be a causative factor of anovulation and potentially other facets of PCOS. Two of the lead single nucleotide polymorphisms (SNPs) in association with PCOS, rs11031005 and rs11031006, fall within a highly conserved genomic region in mammals. We hypothesized that the conserved region (~450 base pairs) enhances FSHB transcription, and that one or both PCOS-related SNPs alter its function. We have shown that the conserved region from both human and mouse can act as an enhancer of FSHB in LβT2 cells, an immortalized, mouse-derived, mature pituitary gonadotrope cell line, and that its function is altered by the rs11031006 minor allele through modification of an SF1 consensus site. As elimination of the SF1 site reduced but did not completely abolish the function of the enhancer, we continued our investigation to identify additional regulatory sites. Transient transfection of LβT2 cells revealed a possible role for the rs11031005 SNP in FSHB regulation, with the minor allele decreasing enhancer-mediated FSHB transcription. This effect may be due to decreased binding of an unidentified transcription factor, as gel shift revealed that the rs11031005 minor allele reduced the intensity of a binding complex. Using truncations and sliding deletions, we identified three additional putative transcription factor binding sites with consensus sequences for ZEB1, PTX1, and SMAD. To support a role for the conserved region as an enhancer in native chromatin, we assessed the histone status in LβT2 chromatin. Compared to the proximal Fshb promoter, the enhancer-specific marker, H3K4me1, was enriched near the conserved region. Neither promoter/enhancer markers of active (H3K27Ac) or repressed (H3K27me3) chromatin were enriched near the conserved region, although levels of both modifications were consistent with the Fshb proximal promoter. Overall, our data support the role of this conserved region as a novel regulator of FSHB/Fshb transcription and reveal a possible mechanism to explain the contribution of PCOS-associated SNPs through FSHB regulation.


2013 ◽  
Vol 3 (1) ◽  
pp. 23-29 ◽  
Author(s):  
Lei Jiang ◽  
Dana Willner ◽  
Patrick Danoy ◽  
Huji Xu ◽  
Matthew A Brown

Abstract Most genome-wide association studies to date have been performed in populations of European descent, but there is increasing interest in expanding these studies to other populations. The performance of genotyping chips in Asian populations is not well established. Therefore, we sought to test the performance of widely used fixed-marker, genome-wide association studies chips in the Han Chinese population. Non-HapMap Chinese samples (n = 396) were genotyped using the Illumina OmniExpress and Affymetrix 6.0 platforms, whereas a subset also were genotyped using the Immunochip. Genotyped markers from the Affymetrix 6.0 and Illumina OmniExpress were used for full genome imputation based on the HapMap 2 JPT+CHB (Japanese from Tokyo, Japan and Chinese from Beijing, China) reference panel. The concordance between markers genotypes for the three platforms was very high whether directly genotyped or genotyped and imputed single nucleotide polymorphisms (SNPs; &gt;99.8% for directly genotyped and &gt;99.5% for genotyped and imputed SNPs, respectively) were compared. The OmniExpress chip data enabled more SNPs to be imputed, particularly SNPs with minor allele frequency &gt;5%. The OmniExpress chip achieved better coverage of HapMap SNPs than the Affymetrix 6.0 chip (73.6% vs. 65.9%, respectively, for minor allele frequency &gt;5%). The Affymetrix 6.0 and Illumina OmniExpress chip have similar genotyping accuracy and provide similar accuracy of imputed SNPs. The OmniExpress chip however provides better coverage of Asian HapMap SNPs, although its coverage of HapMap SNPs is moderate.


2020 ◽  
Author(s):  
Xiufang Xing ◽  
Yongyu Bai ◽  
Kai Sun ◽  
Min Yan

Abstract Background: Postoperative inadequate analgesia following video-assisted thoracoscopic surgery (VATS) is a common and significant clinical problem. While genetic polymorphisms may play role in the variability of postoperative analgesia effect, few studies have evaluated the associations between genetic mutations and inadequate analgesia after single-port VATS. Methods: Twenty-eight single nucleotide polymorphisms (SNPs) among 18 selected genes involved in pain perception and modulation were genotyped in 198 Chinese patients undergoing single-port VATS. The primary outcome was the occurrence of inadequate analgesia in the first night and morning after surgery which was defined by a comprehensive postoperative evaluation. Multivariable logistic regression analyses were used to identify the association between genetic variations and postoperative inadequate analgesia. Results: The prevalence of postoperative inadequate analgesia was 45.5% in the present study. After controlling for age and education level, association with inadequate analgesia was observed in four SNPs among three genes encoding voltage-gated sodium channels. Patients with the minor allele of rs33985936 (SCN11A), rs6795970 (SCN10A), and 3312G>T (SCN9A) have an increased risk of suffering from inadequate analgesia. While the patients carrying the minor allele of rs11709492 (SCN11A) have lower risk experiencing inadequate analgesia. Conclusions: We identified that SNPs in SCN9A, SCN10A, and SCN11A play a role in the postoperative inadequate analgesia after single-port VATS. Although future larger and long-term follow up studies are warranted to confirm our findings, the results of the current study may be utilized as predictors for forecasting postoperative analgesic effect for patients receiving this type of surgery.Trial registration: This study was retrospectively registered in the ClinicalTrials.gov Registry (NCT03916120) on April 16, 2019.


2017 ◽  
Vol 4 (11) ◽  
pp. 171394 ◽  
Author(s):  
Nicholas W. Jeffery ◽  
Ryan R. E. Stanley ◽  
Brendan F. Wringe ◽  
Javier Guijarro-Sabaniel ◽  
Vincent Bourret ◽  
...  

Clinal variation across replicated environmental gradients can reveal evidence of local adaptation, providing insight into the demographic and evolutionary processes that shape intraspecific diversity. Using 1773 genome-wide single nucleotide polymorphisms we evaluated latitudinal variation in allele frequency for 134 populations of North American and European Atlantic salmon ( Salmo salar ). We detected 84 (4.74%) and 195 (11%) loci showing clinal patterns in North America and Europe, respectively, with 12 clinal loci in common between continents. Clinal single nucleotide polymorphisms were evenly distributed across the salmon genome and logistic regression revealed significant associations with latitude and seasonal temperatures, particularly average spring temperature in both continents. Loci displaying parallel clines were associated with several metabolic and immune functions, suggesting a potential basis for climate-associated adaptive differentiation. These climate-based clines collectively suggest evidence of large-scale environmental associated differences on either side of the North Atlantic. Our results support patterns of parallel evolution on both sides of the North Atlantic, with evidence of both similar and divergent underlying genetic architecture. The identification of climate-associated genomic clines illuminates the role of selection and demographic processes on intraspecific diversity in this species and provides a context in which to evaluate the impacts of climate change.


Sign in / Sign up

Export Citation Format

Share Document