Current issues

Table of contents: 2024

Research Article

Phosphorus (P) is a vital macronutrient for plant growth and development. Thus, P deficiency represents a bottleneck in the production of maize (Zea mays, L.). Therefore, there is a need for a prompt identification of new P-use efficient lineages and hybrids. The Canadian landrace Gaspé Flint (GF) race of maize was used to identify molecular and morphological traits due to its short life cycle and ease of growing in a hydroponic system under controlled conditions. First, GF was grown in a hydroponic system containing different Pi regimes for 15 d, and harvested tissues were assayed for various morphophysiological and molecular traits. Second, GF was grown in hydroponics under P+ (250 µM) and P- (10 µM) conditions until seed maturity. Pi deficiency led to a lack of synchrony between male and female reproductive organs, reducing fertilization, cob development, and productivity. Although typical Pi deficiency-mediated morphophysiological responses, such as increased root biomass relative to the shoot, accumulation of anthocyanins in the roots and leaves, and elevated acid phosphatase activity in the shoot could be observed in any maize variety, the use of GF abbreviated the analysis of these traits from 120 days in commercial varieties to 40 days. Furthermore, Pi transporters ZmPT5 and ZmPT6 were induced in Pi-deprived roots and leaves and suppressed upon Pi replenishment, suggesting a transcriptional regulation. The study validated the efficacy of GF for accelerating studies on agronomic traits and plant response to stress, from seeds to seeds, in the grass family. The Gaspé Flint corn was confirmed as a plant model to study the effect of phosphorus on the growth and development of maize in a hydroponic system.

Genet. Mol. Res. 2024
DOI: 10.4238/gmr19213
Research Article

The aim was to verify, using multivariate techniques, which growth and carcass traits, and their variations throughout the reproductive season, are related to the sexual precocity of Nellore heifers. Data from ANCP (Ribeirão Preto, SP) and Bacuri farm (Barretos, SP) were used from heifers exposed to reproduction between 10 and 14 months of age, recording pregnancy status (pregnant and empty). Phenotypic values and Genomic Estimated Breeding Values (GEBV) for growth, reproduction, and carcass traits were evaluated. Variance and discriminant multivariate analyses were performed to assess the effect of variables on early pregnancy. Significant statistical differences (P < 0.05) were observed between the groups of pregnant and empty females for live weight at the end of mating season (WF: 363.63±36.21 and 352.57±35.35 kg), rump fat thickness (RFT: 6.62±2.27 and 4.43±1.71 mm), and rump fat thickness gain during mating season (G:RFT: 0.04±0.01 and 0.02±0.02 mm). These traits showed significant discriminant power for early pregnancy. The GEBVs for probability of early calving and age at first calving were significant (P < 0.05) for discriminating early pregnancy, as well as the GEBV for rib eye area. Thus, heavier heifers with greater carcass finish at the end of mating season and genetic merit for sexual precocity determine the success of early pregnancy. Therefore, environmental conditions leading to greater fat deposition in the carcass and genetic selection for traits related to sexual precocity can be used as strategies to reduce puberty age and increase the rate of early pregnancy.

Genet. Mol. Res. 2024
DOI: 10.4238/gmr19273
Research Article

The Chromobacterium violaceum pqiB gene can be functionally expressed in plant cells and used for the development of paraquat-tolerant crops. Paraquat (1,1'-dimethyl-4,4'-bipyridinium dichloride) is a contact non-selective herbicide, widely used in agriculture in several countries. Proteins induced by paraquat have been the subject of great interest because of the possibility of conferring herbicide resistance when introduced into crops. In this work, we analyzed a paraquat-inducible B-like protein (cvpqiB) gene, isolated from Chromobacterium violaceum, for its capacity to confer tolerance to paraquat in transgenic tobacco. A DNA fragment containing the pqiB coding sequence was isolated from the C. violaceum ATCC12472 genome, inserted into the pCAMBIA1390 vector, under the control of the cauliflower mosaic virus (CaMV) 35S promoter, and used in Agrobacterium-mediated transformation of Nicotiana tabacum cv. Havana. Analysis of the regenerants revealed the incorporation of cvpqiB into the tobacco genome and its transmission in a Mendelian fashion to the progeny of transgenic plants. Sensitivity assays using tobacco leaves demonstrated that the transgenic plants were tolerant to paraquat with concentrations up to 50 µM, whereas the wild-type (WT) plants exhibited intolerance to concentrations higher than n1 µM of the herbicide. Paraquat-treated leaves of the transgenic plants also exhibited significantly reduced electrolyte leakage and their chlorophyll content was not impacted as observed in the WT plants. Besides, in contrast to the WT, negligible amounts of hydrogen peroxide were detected in paraquat-treated seedlings of the transgenic plants, as revealed by 3,3’-diaminobenzidine staining. Collectively, these results indicate that the cvpqiB gene is functional in plants and may be further used in the genetic engineering of crop plants aiming at paraquat tolerance.

Genet. Mol. Res. 2024
DOI: 10.4238/gmr19176
Research Article

Autogamous plant breeding programs require the advancement of many inbreeding generations to obtain a line with the most fixed loci. The time requested to obtain a new cultivar can be reduced through speed breeding protocols. This study aimed to evaluate the viability of soybean seeds at different phenological stages of development, at R6 (full developed seed) R7 (beginning of maturity) and R8 (full maturity); estimate genetic and phenotypic parameters associated with the physiological quality of immature soybean seeds; and study the feasibility of early harvesting as an alternative for soybean speed breeding protocol under tropical conditions. Thirty-two commercial and non-commercial soybean lines were utilized, sourced from cultivation and value-in-use trials within the soybean genetic improvement program at the Federal University of Lavras (UFLA). The plants were brought to the field, and the seeds were harvested at various phenological stages. After the plants in each plot reached the desired phenological stage, 10 plants were collected per plot at each evaluated phenological stage. Seed quality was assessed using the standard germination test on germitest paper, and seedling length and emergence tests were conducted in trays maintained in a plant growth chamber at a temperature of 25°C, with subsequent uniform irrigation as needed. The average percentage of cycle reduction gain with early harvest was 18.5% in the experiment aimed at precocity and 17% in the experiment targeting grain yield. The gain in days was 18 days for the early trials and 20 days for the yield trials. It is inferred that with the adoption of an early harvest, up to four generations of endogamy can be performed per year in soybean in a high-altitude tropical climate compared to one generation in the field or 2-3 generations in winter nurseries.

Genet. Mol. Res. 2024
DOI: 10.4238/gmr19232
Research Article

Two studies were undertaken with the aim of assessing the phenotypic stability and progression of ASR severity in soybean cultivars within a tropical altitude climate. In the first study, six commercial soybean cultivars containing the INOX® and a multiline cultivar were evaluated in 24 environments during the 2017/18 and 2018/19 growing seasons, assessing yield and full maturity. Stability was assessed using the ecovalence and Annicchiarico confidence index methods. To evaluate ASR progress in the second study, plants were maintained in a greenhouse and inoculated with Phakopsora pachyrhizi uredospores. Disease severity, area under the disease progress curve, above-ground biomass, number of pods, number seeds, number of seeds per pod, 100-seed weight, total grain weight, and harvest index were assessed. The multiline cultivar exhibited yield performance statistically similar to the higher-yielding INOX® cultivars, including the cultivar TMG 7067 IPRO, with the highest stability and lowest risk. In terms of ASR progression severity, the multiline cultivar exhibited statistically superior performance compared to M6410 IPRO, demonstrating enhanced responses for the variables SEV, AUDPC, NBS/P, 100SW, TGW and HI. It can be concluded that the use of resistant cultivars and multiline is effective in reducing the severity of ASR. The employment of multiline is a valuable strategy for the management of Asian soybean rust.

Genet. Mol. Res. 2024
DOI: 10.4238/gmr19230
Research Article

The Feline alphaherpesvirus 1 (FeAHV1) is commonly identified as the causative agent of respiratory and ocular disease in domestic cats. Studies on the expression of cytokine genes are relevant, as these genes can be used as molecular markers for the diagnosis of feline viral rhinotracheitis. In this sense, the aim of this study was to characterize, for the first time, gene expression profiles of cytokines in the blood of domestic cats infected with FeAHV-1 in Belem, state of Pará, Brazil from September 2020 to March 2021. Ocular secretion samples from 55 domestic cats (domiciled cats and shelter cats) were collected using sterile swabs, and subjected to deoxyribonucleic acid (DNA) extraction. These samples were evaluated using the conventional PCR technique to identify FeAHV1. Blood samples were also collected from 55 domestic cats for the expression study. After diagnosis of the virus, 12 blood samples were subjected to ribonucleic acid (RNA) extraction, of these samples, 6 were positive and 6 negative for FeAHV-1, subsequently the gene expression of six cytokines and the endogenous GAPDH gene was performed in these samples using the RT-PCR technique. The results revealed that of the 55 cats, nine cats were positive for FeHV-1 infection. The gene expression of cytokines performed in 12 samples showed that the cytokines TNF-α and IL-6 were significant, TNF-α showed higher expression in negative samples for the virus and IL-6 higher expression in positive samples for FeHV-1. Cytokines IL-1β, IFN-α, IFN-β and IFN-γ did not show significance. The present study provided data on the behavior of the immune system in cats infected with FeAHV-1 and may contribute to future research on new forms of treatment for feline viral rhinotracheitis.

 

Genet. Mol. Res. 2024
DOI: 10.4238/gmr19190
Research Article

Experimental classes may aid to develop scientific concepts and allow students to understand how to objectively approach their reality and develop solutions for complex problems, as environmental pollution and support for high schools and universities laboratories. In this work an electrophoresis box was made by students from and acrylic chocolate box, to verify DNA extracted and amplified from E. coli. Disposable cell phone power chargers of 12 V capacity were used as energy source. DNA fragments migrated during the electrophoresis process, demonstrating this artisanal box may be used for molecular biology experiments in schools and universities. Beside the possibility of using inexpensive laboratory material a reduction of environmental impacts, due to disposed materials such cell phone chargers and plastic containers, is also an advantage.

Genet. Mol. Res. 2024
DOI: 10.4238/gmr19156
Research Article

Beef fatty acid content and composition have an important effect on lipid metabolism; however, gene expression changes in response to their consumption have not been entirely explored. Thirteen candidate genes were selected according to its role in lipid metabolism and confirmed expression in PBMCs. They were studied to determine their gene expression effect in response to two types of beef: Wagyu-Cross beef characterized by a high concentration of total fat with higher concentration of monounsaturated fatty acids (MUFAs) especially oleic acid than Commercial beef. Both types of beef were consumed by two groups of volunteers (120 g commercial or Wagyu-Cross beef, three times per week) during a two-week clinical trial. The hypothesis of this work was: a dietary intervention involving the consumption of beef with different FA concentrations and compositions (Commercial and Wagyu-Cross beef) will lead to changes in the expression patterns of genes associated with total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein, and triglyceride concentrations in blood mononuclear cells obtained from both groups of consumers. Volunteers who consumed commercial beef showed a significant decrease in scavenger receptor class B member 1 (SCARB1), lactamase beta (LACTB), and sorting nexin 13 (SNX13). The expression of SNX13 was inversely correlated with the change that occurred in the volunteers’ LDL level (r= -0.398, P= 0.044) and had a significant predictive value for a decrease in LDL levels, with an area under the curve of 0.750 (P=0.009); thus, SNX13 is proposed as a candidate gene for evaluating changes in LDL concentrations. It is inferred that Wagyu-Cross beef produced a lower expression effect and favorable lipid profile on this consumer- group, due to the PUFAs-mediated SREBP transcription factor-nuclear abundance suppression, resulting in a reduction in cholesterol and FAs synthesis.

Genet. Mol. Res. 2024
DOI: 10.4238/gmr19169
Research Article

Inert surfaces favor the persistence of Staphylococcus aureus, as they are reservoirs and means of contamination in hospital and clinical environments. The pathogenicity of this bacterium is controlled by the accessory gene regulatory (agr) system. We examined virulence and toxin genes in isolated strains of S. aureus on inert surfaces and their relationship with the mecA gene, responsible for methicillin resistance (MRSA) in 59 S. aureus strains isolated from inert surfaces and stored in the molecular biology laboratory of the Catholic University of Cuenca, in which presence of toxin genes (lukS/lukF-PV,tst) and the mecA gene had been previously detected. Multiplex PCR was used to determine the agr types. Of the 59 S. aureus strains, 66.1% were positive for agrI, 8.5%, agrII, and 18.6%, agrIII; agrIV was not present in any of the strains. A significant relationship was found between agrI and MRSA. Molecular agr gene typing is important for monitoring the appearance, dissemination, and persistence of MRSA epidemic strains. In conclusion, the gene with the highest frequency was agrI followed by agrIII and agrII.

Genet. Mol. Res. 2024
DOI: 10.4238/gmr19203
Research Article

The aim of this paper is to describe in detail the development, over 30 years, of a large-size composite cattle population, destined for meat production in challenging environments in the tropical and sub-tropical regions of South America. Montana cattle were developed using crosses between Bos taurus and Bos indicus animals, and here we present details regarding the evolution of the breed, both numerically and in terms of the racial composition of the animals, and we assess the levels of heterosis and recombination and the genetic structure of the breed. Overall, given the continuous introduction of external germplasm, Montana Composite cattle have retained high levels of heterosis while maintaining inbreeding at very low levels.

Key words:
Genet. Mol. Res. 2024
DOI: 10.4238/gmr19252
Research Article
Authors:

The use of stress training induction is very important for psychology and neuroscience studies. It allows the researcher to manipulate the emotional activation of subjects to determine its effect on their behavior. This study was performed to explore the link between stress and heart rate variability (HRV) measures. HRV in the field of the nonlinear domain is also useful in determining the autonomic balance and is a more reliable marker of mortality and problems in patients with cardiovascular diseases.  These protocols let researchers examine the physiological paths of a stress reaction in physical condition and infection, which is crucial to stress research. This study aimed to support reliable information about psychological stress protocols and HRV measures during nonlinear measures. To conduct a systematic review of the evidence, a meta-analysis of the proof was carried out according to the inclusion criteria, performing a comprehensive search of electronic sources and a linear review of references. Once conference papers were removed, journal papers illustrating well-made studies analyzing HRV with healthy subjects were considered for inclusion if the stress-inducing protocols were the same. A total of 147 volunteers were enrolled in the four studies, which investigated 11 non-linear HRV measures. Mental Arithmetic Task is primarily used as a stress-inducing test, and three studies extracted SD1, SD2, and SD1/SD2 for HRV non-linear measurements. This study shows that induction of mental stress can increase the levels of cortisol in healthy subjects. In conclusion, the results showed that investigating nonlinear HRV measures for the duration of mental stress is still needed. Furthermore, the nonlinear HRV measures can be spread over to other fields where HRV has been shown to be clinically meaningful.

Genet. Mol. Res. 2024
DOI: 10.4238/gmr19038
Research Article

Globally, breast cancer a common disease affecting women. The epithelial cells lose their characteristic features and gain mesenchymal properties during disease progression. During transition, the intermediate filament changes status from keratin to cell-adhesive molecules. Vimentin, a glycoprotein constitutes an intermediate filament of mesenchymal cells to maintain tissue architecture. The role of a tumor suppressor gene (p53) and methylenetetrahydrofolatereductase (MTHFR C677T) polymorphism becomes essential to explore the mechanism of isoform expression of vimentin in circulating tumor cells (CTCs) of breast cancer patients. We examined the frequency of vimentin gene expression along with isoforms and their correlation with p53 and MTHFR C677 polymorphism in CTCs. Blood samples were collected from clinically diagnosed cases of breast cancer (n=38) and age matched controls. Short term lymphocyte cultures were prepared for isolation of CTCs. cDNA was synthesized followed by PCR. PCR products were separated with agarose gel electrophoresis. There was an additional 250bp band, besides a conventional band of 323bp, with differential expression in CTCs. Variable frequency of over-expression was observed in two different bands in 31.3% (323bp) and 18.8% in isoforms (250bp) of the CTCs. Similarly, down-regulation varying between 43.8% (323bp) and 25.05% (250bp), while 25% cases showed a mutation of 323bp in CTCs. Data was further analyzed to calculate an95% confidence interval with odds ratio varying from 10.85 to 0.62 and 3.95 to 0.76 for over and under expression, respectively showing significant differences with respect to controls. MTHFR polymorphism showed higher (Tm) values (6.36) in the cases, where the mutation was observed as compared to those cases showing isoforms (5.59). The p53 gene mutation (273bp) appeared in nineteen out of thirty eight cases of  breast cancer patients with a positive correlation between vimentin isoform expression and MTHFR polymorphism, suggesting a risk factor for this disease.

Genet. Mol. Res. 2024
DOI: 10.4238/gmr19195
Research Article

The objective of this study was to compare the performance of various Bayesian methods for genomic prediction of characteristics indicative of resistance to worms in Santa Inês sheep. Phenotypic records were collected from 271 animals belonging to six breeders in the states of Piauí and Maranhão, five from commercial herds and one from the conservation center of the research unit of Embrapa Central-North in Campo Maior, Piauí. Phenotypic records were collected from 271 animals of the Santa Inês sheep breed belonging to six breeders located Sub-região Centro-Norte do Brasil in the states of Piauí and Maranhão, five coming from commercial herds and one from herds at the conservation center of the federal research unit Embrapa Central-North (Campo Maior, Piauí). Phenotypic records of Strongyloides sp. eggs in the feces (STE), log transformed fecal egg count (LFEC), FAMACHA score of the ocular conjunctiva (FAM), and body condition score (BCS) were used. All animals were genotyped using the OvineSNP50 BeadChip (Illumina Inc.). After quality control, 44,548 SNP markers and all the DNA samples remained for further analyses. The following models were tested to estimate the effects of markers: Bayesian ridge regression (BRR), Bayes A, Bayes B, Bayes C, and Bayesian least absolute shrinkage and selection operator (BLASSO). The correlations between Genomic Breeding Values (GEBVs) and observed breeding values were calculated and used as indicators of prediction accuracy of the genomic models. We also calculated the accuracy of the pedigree-based BLUP for comparison. Variance components, heritability, and GEBvs were calculated using the BRR model. The BRR model was considered best, due to its prediction accuracy and because this model used the lowest number of parameters. Accuracy gains higher than 60% were obtained using Bayesian models in comparison to the pedigree-based model. The heritability estimates were 0.560, 0.242, 0.253, and 0.244 for STE, LFEC, FAM, and BCS, respectively. The Bayesian models showed similar performance for prediction accuracy and significantly outperformed the pedigree-based model. The BRR model is the most recommended for genomic selection for the traits evaluated.

Genet. Mol. Res. 2024
DOI: 10.4238/gmr19229
Research Article
Authors:

The leading japanese rice cultivar, Koshihikari, is in high demand globally due to its superior food quality. However, Koshihikari has had a reduction in yield and a loss of quality due to lodging and immature chalky grains, which has been linked to global warming and the changing climate. The semidwarf gene sd1 encoding a defective C20 oxidase in the gibberellin (GA) biosynthesis pathway (GA 20 oxidase, OsGA20ox2) was introduced into the Koshihikari genome through 14 backcrosses and the genome was surveyed with a next-generation sequencer. Trait investigation was conducted in six locations in japan for plant height, panicle numbers, yield, grain weight, quality, sensory taste, etc. The introgression of sd1 resulted in a semidwarf phenotype designated as Hikarishinseiki, which is 21.4 cm shorter than Koshihikari. Hikarishinseiki has the same genome as Koshihikari, except for the sd1 region. The taste and quality of Hikarishinseiki were equivalent to those of Koshihikari. Hikarishinseiki is registered under USDA Plant Variety Protection No. 201000072, as the first semidwarf isogenic Koshihikari using Jukkoku-derived sd1 in areas other than Japan.

Genet. Mol. Res. 2024
DOI: 10.4238/gmr19224
Research Article

Nitrogen via solid urea is easily lost by volatilization and leaching. This element, due to its easy absorption and translocation, shows the possibility of foliar supply. Knowledge of the dynamics of urea dissolved in water and foliar spraying on oats can improve use efficiency. The bjective of this study was to assess the urea dlution time under non-linearity of air temperature, and validate the technology of foliar application of urea dissolved in water in oat crops, considering different water volumes and urea (N) rates and the oat grain yield in different crop systems. The urea dissolution was carried out in laboratory, using a randomized block experimental design with four replications, in a 4×7 factorial arrangement, consisted of 4 water volumes (100, 200, 300, and 400 L ha-1) and 7 urea rates (0, 44, 88, 132, 164, 176, 220, and 264 kg ha-1). After determining the appropriate water volume for urea dissolution (300 L ha-1), a field experiment was carried out for foliar application, using a randomized block design with four replications, in a 2×7 factorial arrangement, consisted of application of two urea sources (solid and dissolved) and seven N rates (0, 20, 40, 60, 80, 100, and 120 kg ha-1). The water volume of 300 L ha-1 dissolves the rates of urea, resulting in the expected oat grain yield for the nitrogen rates. The use of high rates increases the urea dissolution time; high air temperature facilitates this dissolution. The use of the technology of urea dissolved in water for foliar application results in similar yields to those using applications to the soil, making it an alternative for supplying N to oat crop systems.

Genet. Mol. Res. 2024
DOI: 10.4238/gmr19171

Pages