scholarly journals High-throughput single nucleotide polymorphism (SNP) discovery and validation through whole-genome resequencing of hundreds of individuals in Nile tilapia (Oreochromis niloticus)

2019 ◽  
Author(s):  
J.M. Yáñez ◽  
G. Yoshida ◽  
A. Barria ◽  
R. Palma-Véjares ◽  
D. Travisany ◽  
...  

ABSTRACTNile Tilapia (Oreochromis niloticus) is the second most important farmed fish in the world and a sustainable source of protein for human consumption. Several genetic improvement programs have been established for this species in the world and so far, they are mainly based on conventional selection using genealogical and phenotypic information to estimate the genetic merit of breeders and make selection decisions. Genome-wide information can be exploited to efficiently incorporate traits that are difficult to measure in the breeding goal. Thus, SNPs are required to investigate phenotype–genotype associations and determine the genomic basis of economically important traits. We performed de novo SNP discovery in three different populations of farmed tilapias. A total of 29.9 million non-redundant SNPs were identified through Illumina (HiSeq 2500) whole-genome resequencing of 326 individual samples. After applying several filtering steps including removing SNP based on genotype and site quality, presence of Mendelian errors, and non unique position in the genome, a total of high quality 50,000 SNP were selected for validation purposes. These SNPs were highly informative in the three populations analyzed showing between 43,869 (94%) and 46,139 (99%) SNP in HWE; 37,843 (76%) and 45,171(90%) SNP with a MAF higher than 0.05 and; 43,450 (87%) and 46,570 (93%) SNPs with a MAF higher than 0.01. The final list of 50K SNPs will be very useful for the dissection of economically relevant traits, enhancing breeding programs through genomic selection as well as supporting genetic studies in farmed populations Nile tilapia using dense genome-wide information.

2013 ◽  
Vol 33 (6) ◽  
pp. 715-722 ◽  
Author(s):  
Jung-Woo Choi ◽  
Won-Hyong Chung ◽  
Kyung-Tai Lee ◽  
Jae-Won Choi ◽  
Kyoung-Sub Jung ◽  
...  

2019 ◽  
Vol 9 (10) ◽  
pp. 3213-3223 ◽  
Author(s):  
Giovanna Cáceres ◽  
María E. López ◽  
María I. Cádiz ◽  
Grazyella M. Yoshida ◽  
Ana Jedlicki ◽  
...  

Nile tilapia (Oreochromis niloticus) is one of the most cultivated and economically important species in world aquaculture. Intensive production promotes the use of monosex animals, due to an important dimorphism that favors male growth. Currently, the main mechanism to obtain all-male populations is the use of hormones in feeding during larval and fry phases. Identifying genomic regions associated with sex determination in Nile tilapia is a research topic of great interest. The objective of this study was to identify genomic variants associated with sex determination in three commercial populations of Nile tilapia. Whole-genome sequencing of 326 individuals was performed, and a total of 2.4 million high-quality bi-allelic single nucleotide polymorphisms (SNPs) were identified after quality control. A genome-wide association study (GWAS) was conducted to identify markers associated with the binary sex trait (males = 1; females = 0). A mixed logistic regression GWAS model was fitted and a genome-wide significant signal comprising 36 SNPs, spanning a genomic region of 536 kb in chromosome 23 was identified. Ten out of these 36 genetic variants intercept the anti-Müllerian (Amh) hormone gene. Other significant SNPs were located in the neighboring Amh gene region. This gene has been strongly associated with sex determination in several vertebrate species, playing an essential role in the differentiation of male and female reproductive tissue in early stages of development. This finding provides useful information to better understand the genetic mechanisms underlying sex determination in Nile tilapia.


2021 ◽  
Author(s):  
Adam Ciezarek ◽  
Antonia Ford ◽  
Graham Etherington ◽  
Kasozi Nasser ◽  
Milan Malinsky ◽  
...  

Cichlid fish of the genus Oreochromis form the basis of the global tilapia aquaculture and fisheries industry. Non-native farmed tilapia populations are known to be widely distributed across Africa and to hybridize with native Oreochromis species. However, many species are difficult to distinguish morphologically, hampering attempts to maintain good quality farmed strains or to identify pure populations of native species. Here, we describe the development of a single nucleotide polymorphism (SNP) genotyping panel from whole-genome resequencing data that enables targeted species identification in Tanzania. We demonstrate that an optimized panel of 96 genome-wide SNPs based on FST outliers performs comparably to whole genome resequencing in distinguishing species and identifying hybrids. We also show this panel outperforms microsatellite-based and phenotype-based classification methods. Case studies indicate several locations where introduced aquaculture species have become established in the wild, threatening native Oreochromis species. The novel SNP markers identified here represent an important resource for assessing broodstock purity and helping to conserve unique endemic biodiversity, and in addition potentially for assessing broodstock purity in hatcheries.


2015 ◽  
Vol 38 (5) ◽  
pp. 466-473 ◽  
Author(s):  
Jung-Woo Choi ◽  
Bong-Hwan Choi ◽  
Seung-Hwan Lee ◽  
Seung-Soo Lee ◽  
Hyeong-Cheol Kim ◽  
...  

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jing Tu ◽  
Mengqin Duan ◽  
Wenli Liu ◽  
Na Lu ◽  
Yue Zhou ◽  
...  

AbstractWe present a user-friendly and transferable genome-wide DNA G-quadruplex (G4) profiling method that identifies G4 structures from ordinary whole-genome resequencing data by seizing the slight fluctuation of sequencing quality. In the human genome, 736,689 G4 structures were identified, of which 45.9% of all predicted canonical G4-forming sequences were characterized. Over 89% of the detected canonical G4s were also identified by combining polymerase stop assays with next-generation sequencing. Testing using public datasets of 6 species demonstrated that the present method is widely applicable. The detection rates of predicted canonical quadruplexes ranged from 32% to 58%. Because single nucleotide variations (SNVs) influence the formation of G4 structures and have individual differences, the given method is available to identify and characterize G4s genome-wide for specific individuals.


PLoS Genetics ◽  
2021 ◽  
Vol 17 (8) ◽  
pp. e1009705
Author(s):  
Masatoshi Nakamoto ◽  
Tsubasa Uchino ◽  
Eriko Koshimizu ◽  
Yudai Kuchiishi ◽  
Ryota Sekiguchi ◽  
...  

Whole-genome duplication and genome compaction are thought to have played important roles in teleost fish evolution. Ayu (or sweetfish), Plecoglossus altivelis, belongs to the superorder Stomiati, order Osmeriformes. Stomiati is phylogenetically classified as sister taxa of Neoteleostei. Thus, ayu holds an important position in the fish tree of life. Although ayu is economically important for the food industry and recreational fishing in Japan, few genomic resources are available for this species. To address this problem, we produced a draft genome sequence of ayu by whole-genome shotgun sequencing and constructed linkage maps using a genotyping-by-sequencing approach. Syntenic analyses of ayu and other teleost fish provided information about chromosomal rearrangements during the divergence of Stomiati, Protacanthopterygii and Neoteleostei. The size of the ayu genome indicates that genome compaction occurred after the divergence of the family Osmeridae. Ayu has an XX/XY sex-determination system for which we identified sex-associated loci by a genome-wide association study by genotyping-by-sequencing and whole-genome resequencing using wild populations. Genome-wide association mapping using wild ayu populations revealed three sex-linked scaffolds (total, 2.03 Mb). Comparison of whole-genome resequencing mapping coverage between males and females identified male-specific regions in sex-linked scaffolds. A duplicate copy of the anti-Müllerian hormone type-II receptor gene (amhr2bY) was found within these male-specific regions, distinct from the autosomal copy of amhr2. Expression of the Y-linked amhr2 gene was male-specific in sox9b-positive somatic cells surrounding germ cells in undifferentiated gonads, whereas autosomal amhr2 transcripts were detected in somatic cells in sexually undifferentiated gonads of both genetic males and females. Loss-of-function mutation for amhr2bY induced male to female sex reversal. Taken together with the known role of Amh and Amhr2 in sex differentiation, these results indicate that the paralog of amhr2 on the ayu Y chromosome determines genetic sex, and the male-specific amh-amhr2 pathway is critical for testicular differentiation in ayu.


2021 ◽  
Author(s):  
Jing Tu ◽  
Mengqin Duan ◽  
Wenli Liu ◽  
Na Lu ◽  
Xiao Sun ◽  
...  

Abstract We present a convenient genome-wide DNA G-quadruplex (G4) profiling method that identifies G4 structures from ordinary whole-genome resequencing data by seizing the slight fluctuation of sequencing quality. We identified 736,689 G4 structures within human genome, in which 44.9% of all predicted canonical G4-froming sequences were contained. We observed that some of the single nucleotide variations (SNVs) influenced the formation of G4 structures, including homozygous SNVs and heterozygous SNVs. Due to SNVs contain individual differences, the given approach is available to identify and characterize G4s genome-wide for specific individuals.


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