scholarly journals Continuous Mapping Identifies Loci Associated With Weevil Resistance [Cosmopolites sordidus (Germar)] in a Triploid Banana Population

2021 ◽  
Vol 12 ◽  
Author(s):  
Brigitte Uwimana ◽  
Gerald Mwanje ◽  
Michael Batte ◽  
Violet Akech ◽  
Trushar Shah ◽  
...  

The first step toward marker-assisted selection is linking the phenotypes to molecular markers through quantitative trait loci (QTL) analysis. While the process is straightforward in self-pollinating diploid (2x) species, QTL analysis in polyploids requires unconventional methods. In this study, we have identified markers associated with weevil Cosmopolites sordidus (Germar) resistance in bananas using 138 triploid (2n = 3x) hybrids derived from a cross between a tetraploid “Monyet” (2n = 4x) and a 2x “Kokopo” (2n = 2x) banana genotypes. The population was genotyped by Diversity Arrays Technology Sequencing (DArTSeq), resulting in 18,009 polymorphic single nucleotide polymorphisms (SNPs) between the two parents. Marker–trait association was carried out by continuous mapping where the adjusted trait means for the corm peripheral damage (PD) and total cross-section damage (TXD), both on the logit scale, were regressed on the marker allele frequencies. Forty-four SNPs that were associated with corm PD were identified on the chromosomes 5, 6, and 8, with 41 of them located on chromosome 6 and segregated in “Kokopo.” Eleven SNPs associated with corm total TXD were identified on chromosome 6 and segregated in “Monyet.” The additive effect of replacing one reference allele with the alternative allele was determined at each marker position. The PD QTL was confirmed using conventional QTL linkage analysis in the simplex markers segregating in “Kokopo” (AAAA × RA). We also identified 43 putative genes in the vicinity of the markers significantly associated with the two traits. The identified loci associated with resistance to weevil damage will be used in the efforts of developing molecular tools for marker-assisted breeding in bananas.

2018 ◽  
Vol 66 (2) ◽  
pp. 215-225 ◽  
Author(s):  
István Anton ◽  
Balázs Húth ◽  
Imre Füller ◽  
György Gábor ◽  
Gabriella Holló ◽  
...  

The objective of this study was to estimate the effect of single-nucleotide polymorphisms (SNPs) on the breeding value of fertility (BVF) and the breeding value of beef (BVB) in Hungarian Simmental cattle. Genotypes were determined on a high-density Illumina Bovine DNA Chip. Data screening and data identification were performed by multi-locus mixed-model. Statistical analyses were carried out to find associations between individual genotypes and the investigated quality values. Three loci showed considerable association with BVF (–log10 P = 9.5, 9.9 and 14.5, respectively) on chromosomes 9, 28 and 29, respectively. The frequencies of their minor alleles (MAF) were 0.375, 0.355 and 0.354, respectively. Two loci showed association with BVB (–log10 P = 25.3 and 22.7) on chromosomes 2 and 11, respectively (their MAF were 0.438 and 0.229). The abovementioned loci provide a straightforward possibility to assist selection by molecular tools.


2018 ◽  
Vol 18 (3) ◽  
pp. 685-698 ◽  
Author(s):  
Reza Talebi ◽  
Ahmad Ahmadi ◽  
Fazlollah Afraz ◽  
Julien Sarry ◽  
Florent Woloszyn ◽  
...  

Abstract The present study aimed to investigate the presence of polymorphisms at four known genes controlling ovine prolificacy i.e. BMP15, GDF9, BMPR1B and B4GALNT2 in a sample of 115 Iranian Mehraban ewes and their association with litter size (LS) and lambs’ birth weight (BW) traits. Using Sanger sequencing of exons and polymorphism specific genotyping, ten SNPs (Single Nucleotide Polymorphisms) were observed in only two genes, GDF9 and BMPR1B. Seven SNPs were found in the GDF9 gene on the chromosome 5. Among them, six were already described in the coding sequence, and a new one (g.41840985C>T) was found in the 3’UTR. In the BMPR1B gene on the chromosome 6, three novel SNPs were detected in the exon 7 (g.29382184G>A; g.29382337G>A and g.29382340G>A). Allelic frequencies were established for six SNPs among the ten identified and they were in Hardy-Weinberg equilibrium. A significant association was found between the novel SNPs found in the exon 7 of BMPR1B and LS. Present results indicate the potential role of the BMPR1B locus in controlling prolificacy of Mehraban sheep and provide genetic markers for further exploitation in selection to improve reproductive efficiency.


2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Niwat Saksit ◽  
Nontaya Nakkam ◽  
Parinya Konyoung ◽  
Usanee Khunarkornsiri ◽  
Wongwiwat Tassaneeyakul ◽  
...  

Severe cutaneous adverse drug reactions (SCARs) are life-threatening reactions. The strong association between the HLA-B∗58 : 01 allele and allopurinol-induced SCARs is well recognized. Screening for HLA-B∗58 : 01 allele before prescribing allopurinol in some populations has been recommended. Several single-nucleotide polymorphisms (SNPs) in chromosome 6 have been found to be tightly linked with the HLA allele, and these SNPs have been proposed as surrogate markers of the HLA-B∗58 : 01 allele. This study aimed to evaluate the association between three SNPs in chromosome 6 and allopurinol-induced SCARs in a Thai population. The linkage disequilibrium between the HLA-B∗58 : 01 allele and these SNPs was also evaluated. Results showed that three SNPs including rs9263726, rs2734583, and rs3099844 were significantly associated with allopurinol-induced SCARs but with a lower degree of association when compared with the HLA-B∗58 : 01 allele. The sensitivity, specificity, PPV, and NPV of these SNPs were comparable to those of the HLA-B∗58 : 01 allele. Although detection of the SNP is simpler and less expensive compared with that of the HLA-B∗58 : 01 allele, these SNPs were not perfectly linked with the HLA-B∗58 : 01 allele. Screening using these SNPs as surrogate markers of the HLA-B∗58 : 01 allele to avoid SCARs prior to allopurinol administration needs caution because of their imperfect linkage with the HLA-B∗58 : 01 allele.


Author(s):  
Werner Koch ◽  
Petra Hoppmann ◽  
Elena Michou ◽  
Vanessa Jung ◽  
Arne Pfeufer ◽  
...  

AbstractMultiple single-nucleotide polymorphisms in the


2004 ◽  
Vol 40 ◽  
pp. 157-167 ◽  
Author(s):  
Maria Nilsson ◽  
Karin Dahlman-Wright ◽  
Jan-Åke Gustafsson

For several decades, it has been known that oestrogens are essential for human health. The discovery that there are two oestrogen receptors (ERs), ERalpha and ERbeta, has facilitated our understanding of how the hormone exerts its physiological effects. The ERs belong to the family of ligand-activated nuclear receptors, which act by modulating the expression of target genes. Studies of ER-knockout (ERKO) mice have been instrumental in defining the relevance of a given receptor subtype in a certain tissue. Phenotypes displayed by ERKO mice suggest diseases in which dysfunctional ERs might be involved in aetiology and pathology. Association between single-nucleotide polymorphisms (SNPs) in ER genes and disease have been demonstrated in several cases. Selective ER modulators (SERMs), which are selective with regard to their effects in a certain cell type, already exist. Since oestrogen has effects in many tissues, the goal with a SERM is to provide beneficial effects in one target tissue while avoiding side effects in others. Refined SERMs will, in the future, provide improved therapeutic strategies for existing and novel indications.


2010 ◽  
Vol 34 (8) ◽  
pp. S75-S75
Author(s):  
Weifeng Zhu ◽  
Zhuoqi Liu ◽  
Daya Luo ◽  
Xinyao Wu ◽  
Fusheng Wan

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