scholarly journals Genome-Wide Association Study towards Genomic Predictive Power for High Production and Quality of Milk in American Alpine Goats

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Y. Tilahun ◽  
T. A. Gipson ◽  
T. Alexander ◽  
M. L. McCallum ◽  
P. R. Hoyt

This paper reports an exploratory study based on quantitative genomic analysis in dairy traits of American Alpine goats. The dairy traits are quality-determining components in goat milk, cheese, ice cream, etc. Alpine goat phenotypes for quality components have been routinely recorded for many years and deposited in the Council on Dairy Cattle Breeding (CDCB) repository. The data collected were used to conduct an exploratory genome-wide association study (GWAS) from 72 female Alpine goats originating from locations throughout the U.S. Genotypes were identified with the Illumina Goat 50K single-nucleotide polymorphisms (SNP) BeadChip. The analysis used a polygenic model where the dropping criterion was a call rate≥0.95. The initial dataset was composed of ~60,000 rows of SNPs and 21 columns of phenotypic traits and composed of 53,384 scaffolds containing other informative data points used for genomic predictive power. Phenotypic association with the 50K BeadChip revealed 26,074 reads of candidate genes. These candidate genes segregated as separate novel SNPs and were identified as statistically significant regions for genome and chromosome level trait associations. Candidate genes associated differently for each of the following phenotypic traits: test day milk yield (13,469 candidate genes), test day protein yield (25,690 candidate genes), test day fat yield (25,690 candidate genes), percentage protein (25,690 candidate genes), percentage fat (25,690 candidate genes), and percentage lactose content (25,690 candidate genes). The outcome of this study supports elucidation of novel genes that are important for livestock species in association to key phenotypic traits. Validation towards the development of marker-based selection that provides precision breeding methods will thereby increase the breeding value.

2021 ◽  
Author(s):  
Taeko Shibaya ◽  
Chika Kuroda ◽  
Hisano Tsuruoka ◽  
Chiharu Minami ◽  
Akiko Obara ◽  
...  

Abstract Carrot is a major source of provitamin A in a human diet. Two of the most important traits for carrot breeding are carotenoid contents and root color. To examine genomic regions related to these traits and develop DNA markers for carrot breeding, we performed a genome-wide association study (GWAS) using genome-wide single-nucleotide polymorphisms (SNPs) in two F2 populations, both derived from crosses of orange root carrots bred by a Japanese seed company. The GWAS revealed 21 significant associations, and the physical position of some associations suggested two possible candidate genes. An Orange (Or) gene was a possible candidate for visual color evaluation and the α- and β-carotene contents. Sanger sequencing detected a new allele of Or with an SNP which caused a non-synonymous amino acid substitution. Genotypes of this SNP corresponded to the visual evaluation of root color in another breeding line. A chromoplast-specific lycopene β-cyclase (CYC-B) gene was a possible candidate for the β/α carotene ratio. On CYC-B, five amino acid substitutions were detected between parental plants of the F2 population. The detected associations and SNPs on the possible candidate genes will contribute to carrot breeding and the understanding of carotenoid biosynthesis and accumulation in orange carrots.


2021 ◽  
pp. 1-11
Author(s):  
Kailu Cui ◽  
Feiyan Qi ◽  
Ziqi Sun ◽  
Jingjing Feng ◽  
Bingyan Huang ◽  
...  

Abstract Peanut shell plays key roles in protecting the seed from diseases and pest infestation but also in the processing of peanut and is an important byproduct of peanut production. Most studies on peanut shell have focused on the utilization of its chemical applications, but the genetic basis of shell-related traits is largely unknown. A panel of 320 peanut (Arachis hypogaea) accessions including var. hypogaea, var. vulgaris, var. fastigiata and var. hirsuta was used to study the genetic basis of two physical and five microstructure-related traits in peanut shell. Significant phenotypic differences were revealed among the accessions of var. hypogaea, var. hirsuta, var. vulgaris and var. fastigiata for mechanical strength, thickness, three sclerenchymatous layer projections and main cell shape of the sclerenchymatous layer. We identified 10 significant single nucleotide polymorphisms (SNPs) through genome-wide association study (P < 5.0 × 10−6) combining the shell-related traits and high-quality SNPs. In total, 192 genes were located in physical proximity to the significantly associated SNPs, and 11 candidate genes were predicted related to their potential contribution to the development and structure of the peanut shell. All SNPs were detected on the B genome demonstrating the biased contribution of the B genome for the phenotypical make-up of peanut. Exploring the newly identified candidate genes will provide insight into the molecular pathways that regulate peanut shell-related traits and provide valuable information for molecular marker-assisted breeding of an improved peanut shell.


2021 ◽  
Vol 8 ◽  
Author(s):  
Xinghai Zhu ◽  
Junhao Zhang ◽  
Xiujiang Hou ◽  
Pingping Liu ◽  
Jia Lv ◽  
...  

Molluscan shell color has consistently drawn attention for its abundant diversity and commercial use in shellfish breeding projects. Recently, two new strains of bay scallop (Argopecten irradians irradians) with different shell colors as marked phenotypic traits have been artificially bred to improve their economic values; however, the inheritance mechanism of their shell pigmentation is still unclear. In this study, a genome-wide association study (GWAS) was conducted to determine the genetic basis of shell color in bay scallops utilizing 29,036 high-quality single-nucleotide polymorphisms (SNPs) derived from 80 purple-red (PP) and 80 black-brown (BP) shell color individuals. The result of the GWAS showed that 469 SNPs (p &lt;1.72E−6) significantly associated with shell color were mainly distributed in chromosome 7. The top three SNPs (i.e., chr7-12764003, chr7-13213864, and chr7-11899306) are located in the genic region of G-protein-coupled receptor-like 101 (GRL101), polyketide synthase 1 (PKS1), and phosphoinositide phospholipase C (PLC1), which have been widely reported to be involved in pigmentation. Successfully, the top three SNPs were verified in another non-breeding bay scallop population. Furthermore, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses obtained 38 GO terms covering 297 genes and aggregating pathways involving 252 annotated genes. Specifically, the expression profiles of the top three identified candidate genes were detected in mantles of PP and BP individuals by real-time quantitative reverse transcription PCR. The significantly higher expression levels of GRL101 (6.43-fold) and PLC1 (6.48-fold) in PP, and PKS1 (12.02-fold) in BP implied that GRL101 and PLC1 potentially functioned in PP shell coloration, and black pigmentation in BP might be principally regulated by PKS1. Our data provide valuable information for deciphering the phenotype differences of shell color in the bay scallop.


Agronomy ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1602
Author(s):  
Feng Luo ◽  
Zhongyou Pei ◽  
Xiongwei Zhao ◽  
Huifen Liu ◽  
Yiwei Jiang ◽  
...  

Sorghum is an important grain, forage, and bioenergy crop. The objective of this study was to identify genetic signals associated with plant architecture and bioenergy traits in sorghum and sudangrass germplasm through a genome-wide association study (GWAS). Plant height (HT), tiller number (TN), internode number (IN), stem diameter (SD), panicle length (PL), panicle weight (PW), reducing sugar (RS) content, Brix, and protein (PRO) content were assessed in 300 germplasm consisting of grain sorghum, sweet sorghum, sudangrass, sweet sorghum-sweet sorghum recombinant inbred lines (RILs) and sudangrass-sudangrass RILs grown in three different environments over two years. Large variations of phenotypic traits were observed in the population panel. The heritability of traits were all higher than 0.5, ranging from 0.52 (PRO) to 0.92 (HT) with an average of 0.76. The population exhibited three population structures (Q) and minor relative kinship (K), assessed by using 7982 single-nucleotide polymorphisms (SNPs). After controlling Q and K, GWAS identified 24 SNPs that were significantly associated with traits, including three SNPs with HT, four with TN, four with PL, three with Brix, and ten with RS. Of them, seven SNPs were novel signals that were not identified previously, including one for HT, one for TN, one for Brix, and four for RS. The putative candidate genes involved in brassinosteroid regulatory pathway, auxin biosynthesis, carbohydrate metabolism, and sugar transport were identified underlying the significant SNPs. Identification of SNP signals and related candidate genes would enrich the current genomic resource for further molecular breeding aimed at improvement of food, feed, and biofuel productions of sorghum.


2020 ◽  
Vol 24 (8) ◽  
pp. 836-843
Author(s):  
A. Y. Krivoruchko ◽  
O. A. Yatsyk ◽  
E. Y. Safaryan

Genome-wide association studies allow identification of loci and polymorphisms associated with the formation of relevant phenotypes. When conducting a full genome analysis of sheep, particularly promising is the study of individuals with outstanding productivity indicators – exhibition animals, representatives of the super-elite class. The aim of this study was to identify new candidate genes for economically valuable traits based on the search for single nucleotide polymorphisms (SNPs) associated with belonging to different evaluation classes in rams of the Russian meat merino breed. Animal genotyping was performed using Ovine Infinium HD BeadChip 600K DNA, association search was performed using PLINK v. 1.07 software. Highly reliable associations were found between animals belonging to different evaluation classes and the frequency of occurrence of individual SNPs on chromosomes 2, 6, 10, 13, and 20. Most of the substitutions with high association reliability are concentrated on chromosome 10 in the region 10: 30859297–31873769. To search for candidate genes, 15 polymorphisms with the highest association reliability were selected (–log10(р) > 9). Determining the location of the analyzed SNPs relative to the latest annotation Oar_rambouillet_v1.0 allowed to identify 11 candidate genes presumably associated with the formation of a complex of phenotypic traits of animals in the exhibition group: RXFP2, ALOX5AP, MEDAG, OPN5, PRDM5, PTPRT, TRNAS-GGA, EEF1A1, FRY, ZBTB21-like, and B3GLCT-like. The listed genes encode proteins involved in the control of the cell cycle and DNA replication, regulation of cell proliferation and apoptosis, lipid and carbohydrate metabolism, the development of the inflammatory process and the work of circadian rhythms. Thus, the candidate genes under consideration can influence the formation of exterior features and productive qualities of sheep. However, further research is needed to confirm the influence of genes and determine the exact mechanisms for implementing this influence on the phenotype.


Author(s):  
A. Y. Krivoruchko ◽  
O. A. Yatsyk ◽  
T. Y. Saprikina ◽  
D. D. Petukhova

Genetic technologies used in breeding of small ruminants requires searching for new molecular markers of productive traits. The most effective for this is genome-wide association study (GWAS) of single nucleotide polymorphisms (SNP) with economically valuable traits. The paper presents results of study of associations of the frequency of single nucleotide polymorphisms with a rank assessment according to complex of productive traits (super-elite) in Romanov sheep using DNA biochips Ovine Infinium HD BeadChip 600K. Eleven SNPs have been found having significant correlation with the animals belonging to the “super-elite” group. Five substitutions are located in the genes introns, six are related to intergenic polymorphisms. The highest reliability of association with productivity was observed in substitution rs410516628 (р = 3,14 · 10-9) located on the 3rd chromosome. Substitution rs422028000 on 2nd chromosome differs with the fact that in the “super-elite” group it was found in 90 % of haplotypes. Polymorphisms rs411162754 (1st chromosome) and rs417281100 (10th chromosome) in our study turned out to be the rarest – only in “super-elite” group and only in a quarter of haplotypes. The genes located near the identified SNPs are mainly associated with metabolic and regulatory processes. Our study has identified several new candidate genes with polymorphism probably associated with the ranking in terms of productivity in Romanov sheep: LTBP1, KCNH8, LMX1B, ZBTB43, MSRA, CHPF, PID1 and DNER. The results obtained create a theoretical basis for further study of candidate genes affecting implementation of phenotypic traits in Romanov sheep. The revealed polymorphisms associated with the productive traits of sheep can be used in practical breeding as molecular and genetic markers for selection of parental pairs.


2021 ◽  
Vol 7 (11) ◽  
pp. eabd1239
Author(s):  
Mark Simcoe ◽  
Ana Valdes ◽  
Fan Liu ◽  
Nicholas A. Furlotte ◽  
David M. Evans ◽  
...  

Human eye color is highly heritable, but its genetic architecture is not yet fully understood. We report the results of the largest genome-wide association study for eye color to date, involving up to 192,986 European participants from 10 populations. We identify 124 independent associations arising from 61 discrete genomic regions, including 50 previously unidentified. We find evidence for genes involved in melanin pigmentation, but we also find associations with genes involved in iris morphology and structure. Further analyses in 1636 Asian participants from two populations suggest that iris pigmentation variation in Asians is genetically similar to Europeans, albeit with smaller effect sizes. Our findings collectively explain 53.2% (95% confidence interval, 45.4 to 61.0%) of eye color variation using common single-nucleotide polymorphisms. Overall, our study outcomes demonstrate that the genetic complexity of human eye color considerably exceeds previous knowledge and expectations, highlighting eye color as a genetically highly complex human trait.


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