Phenotype-phenotype analysis: field application of the gene-for-gene hypothesis in host-pathogen relations.
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Serine hydroxymethyltransferase (SHMT) is an enzyme essential for one-carbon metabolism. In higher plants, multiple SHMT genes code for isoforms that function in the cytosol, nucleus, mitochondria, and chloroplasts. The soybean genome contains two cytosolic SHMTs, GmSHMT05 and GmSHMT08, sharing high sequence identity and similar expression throughout soybean development. In certain soybean genotypes, two amino acid substitutions negatively impact GmSHMT08's ability to bind to tetrahydrofolate (THF), leading to a gain-of-function in resistance to the soybean cyst nematode (SCN). Whether this perturbation to the enzyme has other functional consequences for soybean growth and development remains unknown. Here, we investigated the roles of cytosolic GmSHMTs in soybean growth and development. We determined that the 3D structure and folate-binding affinity of GmSHMT05 are highly similar to the version of GmSHMT08 found in susceptible soybeans. We further measured phenotypic traits of two ethyl methanesulfonate-derived Gmshmt08 mutant plants in an SCN-resistant soybean background. Aboveground soybean growth and development were similar, except the Gmshmt08 mutant plants showed a significant increase in pods/plant in field phenotyping trials. Belowground analyses revealed a significant increase in lateral root and total root length in mutant plants, and CRISPR-Cas9 editing demonstrated an essential role of cytosolic SHMTs in root growth. Taken together, our results indicate that GmSHMT05 sustains overall soybean growth and development in the absence of GmSHMT08; however, GmSHMT08's gain-of-function in SCN resistance negatively influences pod and root growth, highlighting a potential trade-off between soybean defense and development that may impact yield when breeding with GmSHMT08 to develop SCN-resistant varieties.
The present report has shown that a motion sickness questionnaire can be used to predict susceptibility to motion sickness or flight training success, depending on the items scored. There is a discussion of the theory that motion sickness results from conflicting perceptual inputs. This theory is related to aircraft operating conditions. Scores on a personality test which appear to be related to similar perceptual phenomena are related to aviation success. One phenotype, field independence, seems to be promising in this regard. In addition to use of this finding in aviator selection, it is felt that studies of this trait, as it relates to an ability to reconcile conflict and to motion sickness insusceptibility, should be conducted.
Arboviruses including dengue, Zika, and chikungunya are amongst the most significant public health concerns worldwide. Arbovirus control relies on the use of insecticides to control the vector mosquito Aedes aegypti (Linnaeus), the success of which is threatened by widespread insecticide resistance. The work presented here profiled the gene expression of Ae. aegypti larvae from field populations of Ae. aegypti with differential susceptibility to temephos originating from two Colombian urban locations, Bello and Cúcuta, previously reported to have distinctive disease incidence, socioeconomics, and climate. We demonstrated that an exclusive field-to-lab (Ae. aegypti strain New Orleans) comparison generates an over estimation of differential gene expression (DGE) and that the inclusion of a geographically relevant field control yields a more discrete, and likely, more specific set of genes. The composition of the obtained DGE profiles is varied, with commonly reported resistance associated genes including detoxifying enzymes having only a small representation. We identify cuticle biosynthesis, ion exchange homeostasis, an extensive number of long noncoding RNAs, and chromatin modelling among the differentially expressed genes in field resistant Ae. aegypti larvae. It was also shown that temephos resistant larvae undertake further gene expression responses when temporarily exposed to temephos. The results from the sampling triangulation approach here contribute a discrete DGE profiling with reduced noise that permitted the observation of a greater gene diversity, increasing the number of potential targets for the control of insecticide resistant mosquitoes and widening our knowledge base on the complex phenotypic network of the Ae. aegypti response to insecticides.
Rapid running and jumping are core components of escape responses in prey animals and provide measurable traits for studying locomotor performance in large mammals. The genetic basis of these escape-related locomotor traits remains poorly understood in large mammals, partly because repeated, standardized phenotyping under field conditions is challenging. Here, we leveraged a sheep population carrying argali-introgressed genetic components to map genetic variations associated with running speed and jumping height. Through controlled field experiments, automated high-resolution phenotyping, whole-genome analysis, and gene-edited mouse models, we identified two loci associated with escape-related locomotor traits: one in ABCC4 (Chr10:71,849,347; p = 5.03 × 10-7) linked to maximum running speed and another in GRID2 (Chr6:32,120,477; p = 1.30 × 10-9) associated with jumping height. Functional assays in knockout mice reveal that disruption of Grid2 reduces jumping ability, whereas Abcc4 knockout and knockdown increase running speed through enhanced heart contractility under stress. These results elucidated the genetic bases of wild-derived variations in affecting locomotor performance.
Cytoplasmic and polyribosomal RNAs from Rous sarcoma virus-transformed and phenotypically reverted field vole cells were fractionated by rate-zonal sedimentation and hybridized with a (3)H-labeled complementary DNA viral probe to determine the size classes of virus-specific RNA present in these cell types. In contrast to Rous sarcoma virus-infected permissive avian cells, only two of three discrete species of virus-specific RNA were detected in the cytoplasm of these vole cells. These included genome-length 35S RNA and a 21S RNA. However, viral 28S RNA, routinely detected in the cytoplasm of productively infected avian cells, could not be found in cytoplasmic RNA from vole cells. In addition, a low-molecular-weight viral RNA sedimenting less than 16S was detected in both infected avian and vole cells. Because of its heterogeneity this latter species is most likely generated from the intracellular degradation of the larger viral RNAs. Both the viral 35S and 21S RNA were also found to be associated with total polyribosomes from these vole cells. Studies were also performed to determine the distribution of both total viral genomic and sarcoma-specific RNA sequences among the size classes of fractionated total polyribosomes. In both vole cell types the majority of cytoplasmic viral RNA sequences were also associated with polyribosomes and were similarly distributed among the size classes of total polyribosomes. Sarcoma-specific sequences were present on both the 35S and 21S RNA species. These data suggest that the expression of the viral transforming gene in revertant field vole cells may be controlled at some stage subsequent to translation of the viral RNA.
In recent years, accurate and low-cost variant calling has enabled the genotyping of large diversity panels for genome-wide association studies. As a result, phenotyping rather than genotyping is now the rate-limiting step, especially in field experiments. This has created a strong need for high-throughput, accurate, and low-cost in-field phenotyping. Here, we present a genome-wide association study (GWAS) study on 194 field-grown accessions of lettuce (Lactuca sativa). These accessions were non-destructively phenotyped at two time points 15 days apart using a drone equipped with an RGB and multispectral (MSP) camera. Our high-throughput phenotyping approach integrates an RGB- and MSP camera to measure the color and height of lettuce in this large-scale field experiment. We used the mean and other summary statistics, such as median, quantiles, skewness, kurtosis, minimum, and maximum to quantify different aspects of color and height variation in lettuce from the drone images. Using these summary statistics as traits for GWAS, we confirm several previously described genetic associations, now under field conditions, and identify additional novel associations for color and height traits in lettuce.
The third variable domain (V3) of the human immunodeficiency virus type 1 external envelope contains determinants of cell tropism, cytopathicity, and infectivity and elicits antibodies able to block infectivity in vitro and in vivo. Our study encompassed point-mutational analysis of HXB-2 viruses containing patient-derived V3 regions and expressing a non-syncytium-inducing, low-replicating phenotype in T-cell line SupT1. The mutation within V3 of a serine at position 306 into an also naturally occurring arginine (S to R) required an additional, naturally occurring mutation at position 320 (aspartate to glutamine, D to Q) or 324 (aspartate to asparagine, D to N) for full expression of the syncytium-inducing, high-replicating (SI) phenotype. The naturally occurring mutation of an aspartate into an arginine at position 320 (D to R) was sufficient for production of the SI phenotype. This study proves that introduction of a positively charged amino acid at position 306 or 320, previously shown to be strongly associated with the SI phenotype in field isolates (R.A.M. Fouchier, M. Groenink, N.A. Kootstra, M. Tersmette, H.G. Huisman, F. Miedema, and H. Schuitemaker, J. Virol. 66:3183-3187, 1992), is minimally required for production of SI viruses. In addition, naturally occurring mutations at residue 324 also modulate the virus phenotype.
Stripe rust of wheat caused by Puccinia striiformis f. sp. tritici (Pst) remains a major constraint to wheat production in India due to the rapid evolution and frequent emergence of virulent pathotypes. Rapid and reliable discrimination of Pst pathotypes is essential for effective resistance deployment and surveillance. In the present study, transcriptome-wide simple sequence repeats (SSRs) and single nucleotide polymorphisms (SNPs) were exploited to develop and validate molecular markers for pathotype-specific detection of Pst pathotypes prevalent in North India (110S119, 238S119, 46S119, 110S84 and 78S84). Microsatellite mining from 6103 core orthologous clusters comprising 51,127 transcripts mined 14,634 SSR loci, from which 93 primer pairs were synthesized. However, only three SSR markers exhibited polymorphism indicating limited discrimination potential of expressed sequence-derived (EST) SSRs for pathotype differentiation. In contrast, SNP discovery through stringent variant calling and filtration yielded 186 pathotype-specific homokaryotic SNPs, of which 56 high-confidence loci were selected for Kompetitive Allele-Specific PCR (KASP) assay development. A total of 48 KASP markers were synthesized and 14 demonstrated clear pathotype- or cluster-specific polymorphism representing substantially higher resolution than SSR markers. The high SNP-to-KASP conversion efficiency (~ 95%) and reproducible fluorescence-based clustering emphasize the robustness of KASP assay. Comparative evaluation revealed that SNP-based KASP markers provide superior discriminatory capacity for closely related Pst pathotypes and represent a promising complementary molecular approach for rapid identification of predominant Indian Pst pathotypes. The validated marker panel developed in this study can complement conventional virulence phenotyping and field pathogenomics approaches for surveillance of currently known pathotypes, while continued refinement may accommodate future changes in pathogen populations.
Clubroot disease, caused by the obligate intracellular rhizarian protist Plasmodiophora brassicae, is devastating to cruciferous crops worldwide. Widespread field P. brassicae pathotypes frequently overcome the pathotype-specific resistance of modern varieties, posing a challenge for durable control of this disease. Here a genome-wide association study of 3 years of data comprising field clubroot phenotyping of 244 genome-resequenced Brassica napus accessions identified a strong association of β-1,3-glucan synthase-like 5 (GSL5) with clubroot susceptibility. GSL5 was evolutionarily conserved, and inactivation of GSL5 by genome editing in Arabidopsis, B. napus, Brassica rapa and Brassica oleracea conferred broad-spectrum, high-level resistance to P. brassicae pathotypes without yield penalties in B. napus. GSL5 inactivation derepressed the jasmonic acid-mediated immunity during P. brassicae secondary infection, and this immune repression was possibly reinforced through stabilization of GSL5 by a P. brassicae effector, facilitating clubroot susceptibility. Our study provides durable resistance resources for cruciferous clubroot disease control and insights into plant resistance against intracellular eukaryotic phytopathogens.
Phenotyping of erythrocyte acid phosphatase (EAP) and esterase D (ESD) by cellulose acetate membrane isoelectric focusing (CAM-IEF) under a nonequilibrium condition is described. In an attempt to improve the method of CAM-IEF, we shortened the electrode distance to provide a higher field strength at a given (low) voltage. Various carrier ampholytes for EAP typing and various chemical separators for ESD typing were also tested. Good separations were obtained after 30 min IEF for EAP typing and 25 min for ESD typing. When applied to blood stains and stored for various periods at room temperature, the stains up to 8 months old could still be phenotyped for EAP and those up to 4 weeks old for ESD. CAM-IEF is suitable for routine forensic work of EAP and ESD phenotyping.
BACKGROUND: Apple anthracnose, a disease complex that includes Glomerella leaf spot (GLS) and bitter rot caused by Colletotrichum species, is a major disease affecting apple production worldwide. In this study, we combined multi-year field evaluations with controlled inoculation assays to identify genomic regions associated with anthracnose resistance in apple. RESULTS: A total of 440 apple genotypes, including 411 F₁ progenies derived from six parental crosses and 29 cultivars, were evaluated under natural orchard conditions and through artificial fruit and leaf inoculation assays using wound and non-wound methods. Disease severity varied substantially between years, particularly under contrasting environmental conditions, indicating strong genotype-by-environment interactions. Genome-wide association analysis (GWAS) using field-derived disease severity scores from 2019 identified a significant quantitative trait locus (QTL) on chromosome 15 (~ 31.8 Mb) associated with reduced anthracnose severity. This locus was distinct from the previously reported Rgls/MdTNL1 region on chromosome 15 (~ 2-5 Mb), suggesting the presence of a novel resistance-associated locus. In contrast, no genome-wide significant associations were detected from artificial inoculation datasets. CONCLUSIONS: These findings demonstrate the importance of field-based, multi-environment phenotyping for detecting field-relevant resistance loci and improving understanding of the genetic architecture underlying anthracnose resistance in apple.
A collection of Acinetobacter strains consisting of 168 consecutive clinical strains and 30 type and reference strains was studied by DNA-DNA hybridization and a few phenotypic tests. The field strains could be allotted to 13 DNA groups. By means of reference strains ten of these could be identified with groups described by Bouvet & Grimont (1986), while three groups were new; they were given the numbers 13-15. The type strain of A. radioresistens--recently described by Nishimura et al. (1988)--was shown to be a member of DNA group 12, which comprised 31 clinical isolates. Of the 19 strains of A. junii, eight showed hemolytic activity on sheep and human blood agar and an additional four strains on human blood agar only. Strains of this species have previously been regarded as non-hemolytic. Reciprocal DNA pairing data for the reference strains of the DNA groups were treated by UPGMA clustering. The reference strains for A. calcoaceticus, A. baumannii and for DNA groups 3 and 13 formed a cluster with about 70% relatedness within the cluster. Other DNA groups joined at levels below 60%.
Until recently, views on the organization and role of the mesotelencephalic dopaminergic (DA) systems were mostly based on studies of rodents, and it was assumed that homology existed across mammalian species. However, recent studies of both human and non-human primates indicate that this might not be so. The mesocortical DA system in primates, which is directly involved in the pathophysiology of severe illnesses such as Parkinson's disease and psychoses, shows substantial differences from that of rodents. These differences include much larger, re-organized terminal fields, a different phenotype for the co-localization of neuropeptides and a very early prenatal development.
We report a case of primary cutaneous adenoid cystic carcinoma in a 75-year-old man. Electron microscopy revealed similar features to those previously described in adenoid cystic carcinomas of salivary gland origin: wide intercellular spaces, pseudocysts containing replicated basement membrane-like material and true lumina lined by cytoplasmic membranes with numerous microvilli. Immunohistochemistry using antibodies to several cytoskeletal proteins (keratins and actin) indicated the presence of two epithelial tumour cell populations, one with the phenotype of myoepithelial cells, lining the pseudocysts and the periphery of the tumour fields, and another with the phenotype of acinar cells of the secretory coil of sweat glands. In addition, the tumour showed immunoreactivity for epithelial membrane antigen, but not carcinoembryonic antigen. A review of the literature on other cases of primary cutaneous adenoid cystic carcinoma showed that this tumour generally affects older patients with a female to male ratio of 4:1. The most common tumour site appears to be the scalp (40%), and the recurrence rate is 50%. Surgical treatment with extensive resection margins is recommended.
Plant growth-promoting bacteria (PGPB) are gaining attention as scalable biological solutions to enhance crop productivity and resilience. However, accurately identifying and characterizing PGPB remains challenging, particularly under variable environmental conditions where microbial functions are context-dependent and shaped by complex plant-microbe interactions. Advances in high-throughput sequencing have shifted the field from culture-dependent approaches to genome-informed strategies, enabling large-scale taxonomic and functional profiling. Although trait-based databases support the prediction of plant-beneficial genes, they capture only a fraction of the underlying biological complexity and often require labor-intensive analyses. Machine learning (ML) and deep learning (DL) have emerged as powerful tools to integrate genomic, physiological, and ecological data, enabling the prioritization of candidate strains with plant growth-promoting potential. To evaluate advances in the field, we conducted a systematic review of studies integrating ML and DL with PGPB characterization, assessing algorithm selection, performance, and target plant systems. Across 248 observations, only 6.0% of studies directly addressed PGPB screening, whereas the majority (77.4%) focused on plant disease detection, revealing a substantial gap in the application of AI to beneficial microorganisms for plant growth. Convolutional neural networks (CNNs) were the most frequently applied algorithms, largely driven by image-based phenotyping tasks. Overall, the field is constrained by limited datasets, high computational demands, and challenges in modeling multispecies and host-associated interactions. We highlight the need for integrative and interpretable ML and DL frameworks that bridge genomic data and functional validation. Such approaches represent a promising path toward scalable, data-driven discovery and deployment of bioinoculants in sustainable agriculture.
Phenotypes of the infiltrating mononuclear cells of the lower fornix conjunctiva of nine patients with sarcoidosis and six controls were studied using monoclonal antibodies and a modified immunoperoxidase method. Four patients had sarcoidosis of recent onset (duration of 2 years or less) and five patients had a chronic disease (duration of 3 or more years). The inflammatory cells in the sarcoid conjunctival specimens were predominantly T lymphocytes, the vast majority of which were of T helper/inducer subtype expressing Leu-3a + 3b positivity. The ratio of T helper/inducer cells to T suppressor/cytotoxic cells was 3.9 on average but only 0.9 in controls. Epithelioid cell granulomas were seen in three specimens in one case of recent onset and in two chronic cases comprising a marked amount (more than 15 cells/visual field) of cells bearing phenotypes of macrophages, T cells, T helper/inducer cells and HLA-DR antigen, and in smaller quantities of T suppressor/cytotoxic cells. The mean number of all immunocompetent cell subtypes of specimens from newly diagnosed patients exceeded that of specimens from chronic patients. We believe that the sarcoid immune reaction in the conjunctiva is a dynamic process in which proliferation of immunocompetent mononuclear cells precedes the stage of granuloma formation.
The comparison of the HLA A, B, and C phenotypes of 70 patients with primary open-angle glaucoma (POAG) with the phenotypes of 450 healthy control individuals and the rather discordant data published by other investigators show that there is no genetical influence of HLA A, HLA B, or HLA C genes on POAG and on the clinical complications associated with this disease.