scholarly journals Species-Specific Marker Discovery in Tilapia

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Mochamad Syaifudin ◽  
Michaël Bekaert ◽  
John B. Taggart ◽  
Kerry L. Bartie ◽  
Stefanie Wehner ◽  
...  

Abstract Tilapias (family Cichlidae) are of importance in aquaculture and fisheries. Hybridisation and introgression are common within tilapia genera but are difficult to analyse due to limited numbers of species-specific genetic markers. We tested the potential of double digested restriction-site associated DNA (ddRAD) sequencing for discovering single nucleotide polymorphism (SNP) markers to distinguish between 10 tilapia species. Analysis of ddRAD data revealed 1,371 shared SNPs in the de novo-based analysis and 1,204 SNPs in the reference-based analysis. Phylogenetic trees based on these two analyses were very similar. A total of 57 species-specific SNP markers were found among the samples analysed of the 10 tilapia species. Another set of 62 species-specific SNP markers was identified from a subset of four species which have often been involved in hybridisation in aquaculture: 13 for Oreochromis niloticus, 23 for O. aureus, 12 for O. mossambicus and 14 for O. u. hornorum. A panel of 24 SNPs was selected to distinguish among these four species and validated using 91 individuals. Larger numbers of SNP markers were found that could distinguish between the pairs of species within this subset. This technique offers potential for the investigation of hybridisation and introgression among tilapia species in aquaculture and in wild populations.

2020 ◽  
Vol 145 (2) ◽  
pp. 104-109
Author(s):  
Hsuan Chen ◽  
Jason D. Lattier ◽  
Kelly Vining ◽  
Ryan N. Contreras

Lilacs (Syringa sp.) have been used as ornamental plants since the mid-16th century and remain important in modern gardens due to their attractive and fragrant flowers. However, a short flowering season is a critical drawback for their ornamental value. Breeders have identified remontancy (reblooming) in dwarf lilac (Syringa pubescens), and have tried to introgress this trait into related species by interspecific hybridization. Molecular tools for lilac breeding are limited because of the shortage of genome sequence knowledge and currently no molecular markers are available to use in breeding for remontancy. In this study, an F1 population from crossing Syringa meyeri ‘Palibin’ × S. pubescens ‘Penda’ Bloomerang® Purple was created and subjected to genotyping-by-sequencing (GBS) analysis and phenotyped for remontancy. Plants were categorized as remontant, semi-remontant, and nonremontant based on the relative quantity of inflorescences during the second flush of flowers. A total of 20,730 single-nucleotide polymorphism (SNP) markers from GBS were used in marker-trait association to find remontant-specific marker(s) without marker position information. Two SNP markers, TP70580 (A locus) and TP82604 (B locus), were correlated with remontancy. The two loci showed a partial epistasis and additive interaction effects on the level of remontancy. Accumulation of recessive alleles at the two loci was positively correlated with increased reblooming. For example, 87% of aabb plants were remontant, and only 9% were nonremontant. In contrast, 100% of AaBB plants were nonremontant. These two SNP markers associated with remontancy will be useful in developing markers for future breeding and demonstrate the feasibility of developing markers for breeding woody ornamental taxa that lack a reference genome or extensive DNA sequence information.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9291
Author(s):  
Jérémy Gauthier ◽  
Charlotte Mouden ◽  
Tomasz Suchan ◽  
Nadir Alvarez ◽  
Nils Arrigo ◽  
...  

Restriction site Associated DNA Sequencing (RAD-Seq) is a technique characterized by the sequencing of specific loci along the genome that is widely employed in the field of evolutionary biology since it allows to exploit variants (mainly Single Nucleotide Polymorphism—SNPs) information from entire populations at a reduced cost. Common RAD dedicated tools, such as STACKS or IPyRAD, are based on all-vs-all read alignments, which require consequent time and computing resources. We present an original method, DiscoSnp-RAD, that avoids this pitfall since variants are detected by exploiting specific parts of the assembly graph built from the reads, hence preventing all-vs-all read alignments. We tested the implementation on simulated datasets of increasing size, up to 1,000 samples, and on real RAD-Seq data from 259 specimens of Chiastocheta flies, morphologically assigned to seven species. All individuals were successfully assigned to their species using both STRUCTURE and Maximum Likelihood phylogenetic reconstruction. Moreover, identified variants succeeded to reveal a within-species genetic structure linked to the geographic distribution. Furthermore, our results show that DiscoSnp-RAD is significantly faster than state-of-the-art tools. The overall results show that DiscoSnp-RAD is suitable to identify variants from RAD-Seq data, it does not require time-consuming parameterization steps and it stands out from other tools due to its completely different principle, making it substantially faster, in particular on large datasets.


2021 ◽  
Author(s):  
Xia Kan ◽  
Guoliang Wang ◽  
Lili Zhang ◽  
Xin Zhao ◽  
Shuangshuang Shan ◽  
...  

Abstract Hynobius amjiensis was considered as one of the 29 most threatened amphibian in China. To effectively conserve, manage and recover the population of this critically endangered species, 33 single nucleotide polymorphism (SNP) markers were developed using double digest restriction-site associated DNA (ddRAD) sequencing. The minor allele frequency per locus ranged from 0.0161 to 0.5000. The observed heterozygosity and expected heterozygosity varied from 0.0323 to 0.6667 (average 0.3303) and from 0.0317 to 0.5000 (average 0.2772), respectively. The inbreeding coefficient value ranged between − 0.3315 and 0.0000. No significant deviation from Hardy-Weinberg equlibrium (P > 0.05) were found in all loci. These novel SNPs will be helpful for the population genetic assessment and conservation of H. amjiensis.


Author(s):  
R. Andrew King ◽  
Jamie R. Stevens

AbstractThe rivers of the Hampshire Basin, southern England contain a genetically unique group of Atlantic salmon that have suffered dramatic declines in numbers over the last 40 years. Knowledge of levels and patterns of genetic diversity is essential for effective management of these vulnerable populations. Using restriction site-associated DNA sequencing (RADseq) data, we describe the development and characterisation of a panel of 94 single nucleotide polymorphism (SNP) loci for salmon from this region and investigate their applicability and variability in both target (i.e. southern English) and non-target populations. The SNP loci will be useful for population genetic and assignment studies on Atlantic salmon within the UK and beyond.


2007 ◽  
Vol 85 (11) ◽  
pp. 1082-1091 ◽  
Author(s):  
Patrick G. Meirmans ◽  
Manuel Lamothe ◽  
Pierre Périnet ◽  
Nathalie Isabel

The increasing use of exotic and hybrid poplar species in forestry and the lack of genetic barriers between most poplar species may present a risk to the genetic integrity of native poplar species. To monitor any spontaneous hybridization and (or) introgression from exotics into native species, it is essential to have a system for the quick and reliable identification of species. We developed a set of single nucleotide polymorphism (SNP) markers that allows the distinction between five commercially important species of poplar ( Populus balsamifera L., Populus deltoides Marsh., Populus trichocarpa Toor. ex Gray, Populus nigra L., and Populus maximowiczii Henry) and their hybrids. Six genomic regions spanning 6.1 kb were screened at the DNA sequence level to search for discriminating SNPs among the five species. A total of 245 SNPs and indels were found, 86 of which were species specific. A subset of 12 species-specific SNPs was chosen for use with high-throughput SNPstream technology. In addition, 32 species-specific SNPs and indels were found that can be assayed using restriction enzymes. Application of the developed markers to a set of hybrid clones showed that the markers are not only useful for monitoring introgression but also for the verification of breeding material.


2021 ◽  
Author(s):  
Shengman Zhang ◽  
Wenhui He ◽  
Haisu Zheng ◽  
Yiran Xiong ◽  
Meng Tan ◽  
...  

Abstract Daphnia magna belongs to the Cladocera and plays an important role in the water ecosystem. With the intensification of water pollution, the wild population of D. magna has declined rapidly in recent years, and insufficient molecular markers have limited effective research and conservation of this species. In this research, 30 novel single nucleotide polymorphism (SNP) markers were developed in a cultivar of Daphnia magna and 12 wild Daphnia magna using restriction site-associated DNA sequencing (RAD-seq). The minor allele frequency, observed heterozygosity, and expected heterozygosity ranged from 0.115 to 0.721, 0.073 to 0.800, and 0.077 to 0.520, respectively. The PIC ranged from 0.071 to 0.403. Six loci showed significant deviations from the Hardy-Weinberg equilibrium after Bonferroni correction (p < 0.05).These newly developed polymorphic SNP markers for D. magna are of great significance in terms of the genetic breeding of D. magna, identification of wild and artificially domesticated species and conservation genetics research.


Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 705
Author(s):  
John Carlos I. Ignacio ◽  
Maricris Zaidem ◽  
Carlos Casal ◽  
Shalabh Dixit ◽  
Tobias Kretzschmar ◽  
...  

Direct seeded rice (DSR) is a mainstay for planting rice in the Americas, and it is rapidly becoming more popular in Asia. It is essential to develop rice varieties that are suitable for this type of production system. ASD1, a landrace from India, possesses several traits desirable for direct-seeded fields, including tolerance to anaerobic germination (AG). To map the genetic basis of its tolerance, we examined a population of 200 F2:3 families derived from a cross between IR64 and ASD1 using the restriction site-associated DNA sequencing (RAD-seq) technology. This genotyping platform enabled the identification of 1921 single nucleotide polymorphism (SNP) markers to construct a high-resolution genetic linkage map with an average interval of 0.9 cM. Two significant quantitative trait loci (QTLs) were detected on chromosomes 7 and 9, qAG7 and qAG9, with LOD scores of 7.1 and 15.0 and R2 values of 15.1 and 29.4, respectively. Here, we obtained more precise locations of the QTLs than traditional simple sequence repeat and low-density SNP genotyping methods and may help further dissect the genetic factors of these QTLs.


2021 ◽  
Vol 19 (1) ◽  
pp. 20-28
Author(s):  
Abush Tesfaye Abebe ◽  
Adesike Oladoyin Kolawole ◽  
Nnanna Unachukwu ◽  
Godfree Chigeza ◽  
Hailu Tefera ◽  
...  

AbstractSoybean (Glycine max (L.) Merr.) is an important legume crop with high commercial value widely cultivated globally. Thus, the genetic characterization of the existing soybean germplasm will provide useful information for enhanced conservation, improvement and future utilization. This study aimed to assess the extent of genetic diversity of soybean elite breeding lines and varieties developed by the soybean breeding programme of the International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria. The genetic diversity of 65 soybean genotypes was studied using single-nucleotide polymorphism (SNP) markers. The result revealed that 2446 alleles were detected, and the indicators for allelic richness and diversity had good differentiating power in assessing the diversity of the genotypes. The three complementary approaches used in the study grouped the germplasm into three major clusters based on genetic relatedness. The analysis of molecular variance revealed that 71% (P < 0.001) variation was due to among individual genotypes, while 11% (P < 0.001) was ascribed to differences among the three clusters, and the fixation index (FST) was 0.11 for the SNP loci, signifying moderate genetic differentiation among the genotypes. The identified private alleles indicate that the soybean germplasm contains diverse variability that is yet to be exploited. The SNP markers revealed high diversity in the studied germplasm and found to be efficient for assessing genetic diversity in the crop. These results provide valuable information that might be utilized for assessing the genetic variability of soybean and other legume crops germplasm by breeding programmes.


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Weifan Gao ◽  
Sukumar Saha ◽  
Din-Pow Ma ◽  
Yufang Guo ◽  
Johnie N. Jenkins ◽  
...  

A cotton fiber cDNA and its genomic sequences encoding an A-type cyclin-dependent kinase (GhCDKA) were cloned and characterized. The encoded GhCDKA protein contains the conserved cyclin-binding, ATP binding, and catalytic domains. Northern blot and RT-PCR analysis revealed that the GhCDKA transcript was high in 5–10 DPA fibers, moderate in 15 and 20 DPA fibers and roots, and low in flowers and leaves. GhCDKA protein levels in fibers increased from 5–15 DPA, peaked at 15 DPA, and decreased from 15 t0 20 DPA. The differential expression of GhCDKA suggested that the gene might play an important role in fiber development. The GhCDKA sequence data was used to develop single nucleotide polymorphism (SNP) markers specific for the CDKA gene in cotton. A primer specific to one of the SNPs was used to locate the CDKA gene to chromosome 16 by deletion analysis using a series of hypoaneuploid interspecific hybrids.


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