Control of Thousand-Grain Weight by OsMADS56 in Rice

Grain weight and size are important traits determining grain yield and influencing grain quality in rice. In a previous study, a quantitative trait locus controlling thousand-grain weight (TGW) in rice, qTGW10-20.8, was mapped in a 70.7 kb region on chromosome 10. Validation of the candidate gene for qTGW10-20.8, OsMADS56 encoding a MADS-box transcription factor, was performed in this study. In a near-isogenic line (NIL) population segregated only at the OsMADS56 locus, NILs carrying the OsMADS56 allele of IRBB52 were 1.9% and 2.9% lower in TGW than NILs carrying the OsMADS56 allele of Teqing in 2018 and 2020, respectively. Using OsMADS56 knock-out mutants and overexpression transgenic plants, OsMADS56 was validated as the causal gene for qTGW10-20.8. Compared with the recipients, the TGW of the mutants was reduced by 6.0–15.0%. In these populations, decreased grain weight and size were associated with a reduction in the expression of OsMADS56. In transgenic populations of OsMADS56 driven by a strong constitutive promoter, grain weight and size of the positive plants were significantly higher than those of the negative plants. Haplotype analysis showed that the Teqing-type allele of OsMADS56 is the major type presented in cultivated rice and used in variety improvement. Cloning of OsMADS56 provides a new gene resource to improve grain weight and size through molecular design breeding.

Haplotype Analysis of Varroa destructor and Deformed Wing Virus Using Long Reads

As a phoretic parasite and virus vector, the mite Varroa destructor and the associated Deformed wing virus (DWV) form a lethal combination to the honey bee, Apis mellifera. Routine acaricide treatment has been reported to reduce the diversity of mites and select for tolerance against these treatments. Further, different DWV strains face selective pressures when transmitted via mites. In this study, the haplotypes of Varroa mites and associated DWV variants were quantified using long reads. A single haplotype dominated the mite mitochondrial gene cytochrome oxidase subunit I, reflecting an ancient bottleneck. However, highly polymorphic genes were present across the mite genome, suggesting the diversity of mites could be actively maintained at a regional level. DWV detected in both mites and honey bees show a dominant variant with only a few low-frequency alternate haplotypes. The relative abundances of DWV haplotypes isolated from honey bees and mites were highly consistent, suggesting that some variants are favored by ongoing selection.

METTL14 gene polymorphisms decrease Wilms tumor susceptibility in Chinese children

Background Wilms tumor is a highly heritable malignancy. Aberrant METTL14, a critical component of N6-methyladenosine (m6A) methyltransferase, is involved in carcinogenesis. The association between genetic variants in the METTL14 gene and Wilms tumor susceptibility remains to be fully elucidated. We aimed to assess whether variants within this gene are implicated in Wilms tumor susceptibility. Methods A total of 403 patients and 1198 controls were analyzed. METTL14 genotypes were assessed by TaqMan genotyping assay. Result Among the five SNPs analyzed, rs1064034 T > A and rs298982 G > A exhibited a significant association with decreased susceptibility to Wilms tumor. Moreover, the joint analysis revealed that the combination of five protective genotypes exerted significantly more protective effects against Wilms tumor than 0–4 protective genotypes with an OR of 0.69. The stratified analysis further identified the protective effect of rs1064034 T > A, rs298982 G > A, and combined five protective genotypes in specific subgroups. The above significant associations were further validated by haplotype analysis and false-positive report probability analysis. Preliminary mechanism exploration indicated that rs1064034 T > A and rs298982 G > A are correlated with the expression and splicing event of their surrounding genes. Conclusions Collectively, our results suggest that METTL14 gene SNPs may be genetic modifiers for the development of Wilms tumor.

Wheat genetic loci conferring resistance to stripe rust in the face of genetically diverse races of the fungus Puccinia striiformis f. sp. tritici

Key message Analysis of a wheat multi-founder population identified 14 yellow rust resistance QTL. For three of the four most significant QTL, haplotype analysis indicated resistance alleles were rare in European wheat. Abstract Stripe rust, or yellow rust (YR), is a major fungal disease of wheat (Triticum aestivum) caused by Puccinia striiformis Westend f. sp. tritici (Pst). Since 2011, the historically clonal European Pst races have been superseded by the rapid incursion of genetically diverse lineages, reducing the resistance of varieties previously showing durable resistance. Identification of sources of genetic resistance to such races is a high priority for wheat breeding. Here we use a wheat eight-founder multi-parent population genotyped with a 90,000 feature single nucleotide polymorphism array to genetically map YR resistance to such new Pst races. Genetic analysis of five field trials at three UK sites identified 14 quantitative trait loci (QTL) conferring resistance. Of these, four highly significant loci were consistently identified across all test environments, located on chromosomes 1A (QYr.niab-1A.1), 2A (QYr.niab-2A.1), 2B (QYr.niab-2B.1) and 2D (QYr.niab-2D.1), together explaining ~ 50% of the phenotypic variation. Analysis of these four QTL in two-way and three-way combinations showed combinations conferred greater resistance than single QTL, and genetic markers were developed that distinguished resistant and susceptible alleles. Haplotype analysis in a collection of wheat varieties found that the haplotypes associated with YR resistance at three of these four major loci were rare (≤ 7%) in European wheat, highlighting their potential utility for future targeted improvement of disease resistance. Notably, the physical interval for QTL QYr.niab-2B.1 contained five nucleotide-binding leucine-rich repeat candidate genes with integrated BED domains, of which two corresponded to the cloned resistance genes Yr7 and Yr5/YrSp. Graphical abstract

Genetic Analysis of Hexaploid Wheat (Triticum aestivum L.) Using the Complete Sequencing of Chloroplast DNA and Haplotype Analysis of the Wknox1 Gene

The aim of the presented study is a genetic characterization of the hexaploid wheat Triticum aestivum L. Two approaches were used for the genealogical study of hexaploid wheats—the complete sequencing of chloroplast DNA and PCR-based haplotype analysis of the fourth intron of Wknox1d and of the fifth-to-sixth-exon region of Wknox1b. The complete chloroplast DNA sequences of 13 hexaploid wheat samples were determined: Free-threshing—T. aestivum subsp. aestivum, one sample; T. aestivum subsp. compactum, two samples; T. aestivum subsp. sphaerococcum, one sample; T. aestivum subsp. carthlicoides, four samples. Hulled—T. aestivum subsp. spelta, three samples; T. aestivum subsp. vavilovii jakubz., two samples. The comparative analysis of complete cpDNA sequences of 20 hexaploid wheat samples (13 samples in this article plus 7 samples sequenced in this laboratory in 2018) was carried out. PCR-based haplotype analysis of the fourth intron of Wknox1d and of the fifth-to-sixth exon region of Wknox1b of all 20 hexaploid wheat samples was carried out. The 20 hexaploid wheat samples (13 samples in this article plus 7 samples in 2018) can be divided into two groups—T. aestivum subsp. spelta, three samples and T. aestivum subsp. vavilovii collected in Armenia, and the remaining 16 samples, including T. aestivum subsp. vavilovii collected in Europe (Sweden). If we take the cpDNA of Chinese Spring as a reference, 25 SNPs can be identified. Furthermore, 13–14 SNPs can be identified in T. aestivum subsp. spelta and subsp. vavilovii (Vav1). In the other samples up to 11 SNPs were detected. 22 SNPs are found in the intergenic regions, 2 found in introns, and 10 SNPs were found in the genes, of which seven are synonymous. PCR-based haplotype analysis of the fourth intron of Wknox1d and the fifth-to-sixth-exon region of Wknox1b provides an opportunity to make an assumption that hexaploid wheats T. aestivum subsp. macha var. palaeocolchicum and var. letshckumicum differ from other macha samples by the absence of a 42 bp insertion in the fourth intron of Wknox1d. One possible explanation for this observation would be that two Aegilops tauschii Coss. (A) and (B) participated in the formation of hexaploids through the D genome: Ae. tauschii (A)—macha (1–5, 7, 8, 10–12), and Ae. tauschii (B)—macha M6, M9, T. aestivum subsp. aestivum cv. ‘Chinese Spring’ and cv. ‘Red Doly’.

A Matrilineal Study on the Origin and Genetic Relations of the Ecuadorian Pillareño Creole Pig Population through D-Loop Mitochondrial DNA Analysis

Domestic pig breeds reached America on the second Columbus trip; from this date, Iberian pig genetic resources were disseminated throughout the continent, forming diverse creole breeds. These Ecuadorian Creole pigs are important for food production but have been genetically eroded since the introduction of transboundary breeds. In this study, we sought to characterize this erosion more thoroughly through mitochondrial DNA D-Loop analysis of Ecuadorian Pillareño Creole pigs from seven regions of Ecuador. To allow comparison, we also included in our analysis sequences from wild species, commercial lines, and domestic pigs, which were obtained from the NCBI GenBank database. Creole pigs’ population showed overall moderate Hd values and low π values, and a negative value of Tajima’s D was observed. The greatest differentiation from the Ecuadorian Pillareño Creole pigs was observed between Asian wild and Asian domestic pigs. The haplotype analysis revealed three different phylogenetic clades (A, E I, and E II) and 65 haplotypes. Ecuadorian Creole populations were grouped into nine haplotypes for Clade E I and E II, which have not previously been reported for Creole Pillareño populations. Our analysis indicates that in the establishment of Creole Pillareño pigs, individuals most likely separated from the Asian pig population and appear to be genetically influenced by European and Iberian populations raised in Spain.

Association of Gem-associated protein 4 gene polymorphisms with the risk of colorectal cancer in the Polish population

Aim: Gem-associated protein 4 (GEMIN4), a member of the GEMIN gene family, is a key compound of the regulating factors responsible for miRNA biogenesis. Genetic variability within this gene can alter the risk for development of colorectal cancer (CRC) as was shown for other genes involved in miRNA biogenesis. Therefore, presented study was intended to identify genetic variants of three single nucleotide polymorphisms (SNPs) in the GEMIN4 gene (rs1062923, rs2740348 and rs910925) and their relationship with CRC. Methods: The study comprised 203 patients and 179 age and sex matched controls. Genotyping of GEMIN4 gene variants was done using Taqman® assay. The association of GEMIN4 variants with CRC was done by odds ratio analysis. Haplotype analysis was done to see the combined effect of studied variants on CRC. Results: Patients carrying all variant genotypes for GEMIN4 rs1062923 (odds ratio [OR]= 0.205; 95% confidence interval [CI]= 0.1034-0.4065 for CC variant and [OR] = 0.1436; [CI] = 0.0869-0.2373 for CT variant, respectively) and GEMIN4 rs2740348 (odds ratio [OR]= 0.4498; 95% confidence interval [CI]= 0.2342-0.8637for CC variant and [OR] = 0.3986; [CI] = 0.2043-0.7776 for CG variant, respectively) showed significant association in lower occurrence of cancer, whereas in case of GEMIN4 G/C rs910925 variant genotype, no significance correlation was found. Conclusions: Our study gives a substantive support for the association between the GEMIN4 gene variants/miRNA biogenesis and CRC risk.

Geographical Variation in the profile of RET Variants in Patients with Medullary Thyroid Cancer: A Comprehensive Review

Genetic variability in humans is influenced by many factors, such as natural selection, mutations, genetic drift, and migrations. Molecular epidemiology evaluates the contribution of genetic risk factors in the etiology, diagnosis, and prevention of a particular disease. Few areas of medicine have been so clearly affected by genetic diagnosis and management as multiple neoplasia type 2 (MEN2), in which activating pathogenic variants in the RET gene results in the development of medullary thyroid carcinoma (MTC), pheochromocytoma, and hyperparathyroidism in nearly 98%, 50% and 25% of gene carriers, respectively. Here, we aimed to collect RET genotyping data worldwide to analyze the distribution and frequency of RET variants from a global perspective. We show that the mutational spectrum of RET is observed worldwide. The codon 634 variants seem to be the most prevalent, but there are differences in the type of amino acid exchanges among countries and in the frequencies of the other RET codon variants. Most interestingly, studies using haplotype analysis or pedigree linkage have demonstrated that some pathogenic RET variants have been transmitted to offspring for centuries, explaining some local prevalence due to a founder effect. Unfortunately, after almost three decades after the causative role of the germline RET variants have been reported in hereditary MTC, comprehensive genotyping data remain limited to a few countries. The heterogeneity of RET variants justifies the need for a global effort to describe epidemiological data of families with MEN2 to further understand the genetic background and environmental circumstances that affect disease presentation.

The Evolutionary Landscape of SARS-CoV-2 Variant B.1.1.519 and Its Clinical Impact in Mexico City

The SARS-CoV-2 pandemic is one of the most concerning health problems around the globe. We reported the emergence of SARS-CoV-2 variant B.1.1.519 in Mexico City. We reported the effective reproduction number (Rt) of B.1.1.519 and presented evidence of its geographical origin based on phylogenetic analysis. We also studied its evolution via haplotype analysis and identified the most recurrent haplotypes. Finally, we studied the clinical impact of B.1.1.519. The B.1.1.519 variant was predominant between November 2020 and May 2021, reaching 90% of all cases sequenced in February 2021. It is characterized by three amino acid changes in the spike protein: T478K, P681H, and T732A. Its Rt varies between 0.5 and 2.9. Its geographical origin remain to be investigated. Patients infected with variant B.1.1.519 showed a highly significant adjusted odds ratio (aOR) increase of 1.85 over non-B.1.1.519 patients for developing a severe/critical outcome (p = 0.000296, 1.33–2.6 95% CI) and a 2.35-fold increase for hospitalization (p = 0.005, 1.32–4.34 95% CI). The continuous monitoring of this and other variants will be required to control the ongoing pandemic as it evolves.