Table of Contents | Genet. Mol. Res. 2023 (2)
The development of common bean plants with an improved root system can be a strategy for water and nutrient absorption in limiting environmental conditions. The objective of this study was to understand the influence of root phenotyping methods and phenological stages of evaluation on the selection of common bean genotypes for a highly branched root system. In the 2021/22 growing season, this study was initiated with 36 field treatments, consisting of the combination of three genotypes, two parents (Mesoamerican and Andean gene pools) and one progeny, two methods of root phenotyping (Shovelomics and WinRHIZO) and six growth stages (R1-6: four and eight trifoliate leaves, flower bud, full flowering, pod formation and grain filling). The field treatments were randomized in a simple lattice design. Five plants from each experimental unit were evaluated, considering the genotype and phenotyping methods in each developmental stage. The genotype x method x stage interaction was significant. The partitioning of the simple effects of the factors indicated that the root system variables of the parents could be distinguished from those of the progeny at R6. At this stage, the recommended phenotyping method differs according to the genetic origin of the genotypes. Plotting of the standardized canonical scores for the triple interaction showed that the Shovelomics and WinRHIZO phenotyping methods are adequate for the Andean and Mesoamerican genotypes, respectively, in view of their high scores with high discriminative power, allowing treatment discrimination. Specific phenotyping methods were indicated for Mesoamerican versus Andean genotypes in view of the root development trait intrinsic to each gene pool. We conclude that improving root phenotyping for the development of cultivars with a finely branched root system is a useful strategy to maintain common bean yields in environments under stressful conditions.
Insertion of nucleic acids into cells unlocks the possibility of modulating gene expression; however, some cells such as primary cells and those that grow in suspension are hard-to-transfect. New therapies for cancer and possible autoimmune diseases, such as those that involve chimeric antigen receptor T cells, rely on the insertion of plasmids into lymphocytes, which fit into the hard-to-transfect category. In such cases virus-based transduction is usually applied, but the carrier vector tends to be incorporated into the cell’s own DNA in a stable manner, with unpredictable consequences. Thus, highly efficient non-viral gene/plasmid delivery is a sought-after technology. We evaluated several commercially available chemical transfection methods as well as electroporation in difficult-to-transfect cells, including a human lymphocyte cell-line (Jurkat) and fresh peripheral blood mononuclear cells (PBMCs), both grown in suspension. The cell-toxicity of the methods was also evaluated. Twenty-four hours after transfection of the plasmid pCMV-GFP, the proportion of GFP positive (GFP+) cells was evaluated by cytometry. The cationic polymer TurboFect yielded ~7.8% of GFP+ Jurkat cells on average, while the other reagents (Lipofectamine 3000, FuGENE HD and X-tremeGENE HP) presented <3% of GFP+ cells. In PBMCs, none of the chemical reagents yielded >3% transfected cells. Electroporation was more efficient, with ~45% of GFP+ in Jurkat and ~15.7% GFP+ in PBMCs. However, it proved to be highly toxic, with ~80% of the cells considered non-viable 24h after the procedure, while TurboFect showed little-to-no toxicity. In conclusion, it was found that despite its high toxicity electroporation was the only method with applicable transfection efficiency in PBMCs, while in Jurkat the reagent TurboFect can be applied with acceptable results. The strategy for insertion of nucleic acids needs to be fine-tuned for each target cell type and experimental condition.
The largemouth bass (belonging to the genus Micropterus) is one of the most important freshwater fish for sport fishing; the native range of Micropterus salmoides extends into the northeastern Mexican drainages, providing important economic benefits for communities with thriving bass populations. However, the genetic diversity of this species is progressively declining due to various factors, including direct human impacts and alteration of natural ecosystems. In this study, the genetic diversity and structure of largemouth bass from the main reservoirs of northeastern Mexico were assessed. A total of 350 Micropterus spp. dorsal fin samples collected from seven reservoirs were genotyped using a panel of 10 microsatellite markers. The individual samples were genotyped and the different genetic diversity parameters and population structure analysis were evaluated. The microsatellite markers used in this study were highly informative. All the populations exhibited Hardy Weinberg disequilibrium, with some degree of inbreeding within populations. The populations showed moderate genetic differentiation, allowing the establishment of three genetic clusters. Structure analysis indicated that four ancestral populations is most likely. The populations are characterized by low genetic diversity, reduced effective population sizes and a high probability of inbreeding. This study highlights the importance of genetic diversity studies to manage native largemouth bass in the main reservoirs of northeastern Mexico.
Approximately 60% of all cases of congenital bilateral sensorineural hearing impairment are due to genetic factors, and about 50% of hearing impairment cases at a later stage are caused by a mutation in a single gene. Because of the high frequency of gap junction beta-2 protein gene (GJB2) mutations, mutation analysis of this gene is widely used in hearing impairment research and diagnosis. This study aimed to determine the prevalence of common GJB2 mutations in patients with profound non-syndromic sensorineural hearing impairment. Sixty-one patients (32 male and 29 female) included in this study had above 90 decibels of bilateral sensorineural hearing impairment. Patient DNA was isolated from buccal cells. The 1st and 2nd exons of the GJB2 gene were amplified with specific primers after gel purification of both regions. Sanger DNA sequencing analysis was used for investigation of changes in these gene regions. The pathological variant was found in nine patients (15%). This variation involved a frameshift mutation in GJB2 (homozygous 35delG) of the 2nd exon; no mutation was detected in the 1st exon. This study is the first report of a genetic investigation of hearing impairment in the Kurdish population in Sulaimani province, northeastern Iraq, near the Iraq-Iran border. The results show that 35delG mutation has a high prevalence in patients with non-syndromic sensorineural hearing impairment.