Current issues

Table of contents: 2020

Research Article

Ningxia Tan sheep meat is tender, has no strong smell, a delicious taste, and even fat distribution. Intramuscular fat (IMF) content and the composition of fatty acid (FA) both are important factors associated with meat quality, and are also important for meat tenderness and flavor assessment. We examined the correlation of candidate genes expression with these factors in four muscle tissues, including longissimus dorsi, triceps, biceps and supraspinatus from Tan sheep. The IMF and FA composition in the different muscle tissues were measured and associated with mRNA expression of related genes (PPARγ, C/EBPα, FAS, LPL, FABP4, and ACC). IMF content in longissimus dorsi muscle was 45.4% higher than that in triceps brachii (P < 0.05), 48.4% higher than that in biceps femoris, and 20.1% higher than that in supraspinatus. PPARγ, C/EBPα, FAS and LPL mRNA levels in supraspinatus were significantly different among longissimus dorsi muscle, biceps femoris and triceps brachii. There was significant positive correlation between IMF content and the relative mRNA expression of PPARγ, C/EBPα, FAS, LPL, FABP4 and ACC in longissimus dorsi muscle. The ratio of polyunsaturated fatty acids to saturated fatty acid was positively and significantly correlated with C/EBPα and ACC mRNA levels, and negatively and significantly correlated with FAS and FABP4 mRNA levels. Omega-6 fatty acid (ω6)/omega-3 fatty acid (ω3) ratio was positively and significantly correlated with C/EBPα, FAS and LPL mRNA levels, but negatively and significantly correlated with FAS and PPARγ mRNA levels. These correlations indicate that PPARγ, C/EBPα, FAS, LPL, FABP4, and ACC are key candidate genes for fatty deposits and the components and contents of FA in sheep, and the evaluation and functional verification of these genes may be useful for improving the meat quality of Tan sheep.

Genet. Mol. Res. 19(4): GMR18550
DOI: 10.4238/gmr18550
Research Article

The development of oral cancer results from interactions between genetic and environmental factors. Glutathione-S-transferase gene null polymorphisms have a strong impact on the detoxification of carcinogens; therefore they are expected to be related to oncogenic risk, including oral cancer. Various studies have evaluated a possible association of GSTT1 and GSTM1 null genotypes with oral cancer, including their relationship with tobacco smoking; though the findings have been inconsistent. We analyzed the available publications concerning association of tobacco smoking and GSTT1 and GSTM1 null polymorphisms and how they relate to the risk of developing oral cancer. A systematic review of the literature was conducted in the PubMed database using combinations of the following descriptors and Boolean operators ‘GSTM1 and GSTT1’, [AND] ‘oral cancer’, [AND] ‘polymorphism’. A meta-analysis of GSTT1 and GSTM1 null polymorphisms in patients with oral cancer (cases) and cancer-free individuals (controls) from each of the studies was performed. The data of each study were analyzed, and the odds ratio, the 95% confidence interval, and the number of patients were determined for each study and for all studies combined. The number of individuals analyzed was 7,839, 44.3% presenting with oral cancer and 55.7% healthy controls. The meta-analysis showed that GSTT1 and GSTM1 were associated with protection against oral cancer. A significant association of GSTT1 and GSTM1 null polymorphisms with an increased risk of developing oral cancer was observed. These findings point to a synergistic relationship between environmental and genetic factors in the development of oral cancer tumors.

Genet. Mol. Res. 19(4): GMR18712
DOI: 10.4238/gmr18712
Research Article

Microsatellite markers, also known as single sequence repeats (SSRs), are highly polymorphic, fast evolving, and regarded as neutral markers. Due to these traits, they have been widely used in population studies. The development of SSRs for a given species opens possibilities for their application in population studies of other species that are phylogenetically related. We tested 16 primer pairs developed for Drosophila sturtevanti and the transferability test of them in 14 species of the saltans group of Drosophila. The optimal amplification conditions were established using the DNA of 15 D. sturtevanti males. Among the primers pairs developed, 13 have successful in the amplification for D. sturtevanti. And in the transferability test, the total percentage of transfer was nearly 50%. The species with the highest success rates of heterologous amplification were in the sturtevanti subgroup. Two microsatellite markers amplified in all the species, while one would not amplify for any of the saltans group species. These data demonstrate the usefulness of testing transferability of genetic markers, which may be used in studies of genetic diversity and population structure of D. sturtevanti and other species of the saltans group of Drosophila.

Genet. Mol. Res. 19(4): GMR18700
DOI: 10.4238/gmr18700
Research Article

Analysis of the relationship of oat grain chemical components with productivity can yield information that determines crop production strategies. The market values high protein grain, but production and other nutritional components may be affected in the effort to increase protein levels. The objective of this study was to determine how the dynamics of the components of oat grain chemical composition relate to productivity when adding nitrogen to the soil, in order to develop nutrient management strategies that can combine productivity with grain quality.  The study was conducted from 2011 to 2016 in Augusto Pestana, Brazil, in a randomized block design with four replications in a 4x2 factorial design for nitrogen rates (0, 30, 60 and 120 kg.ha-1) and standard biotype oat cultivars used on a commercial scale (Barbarasul and Brisasul) in two succession systems soybean/oat and corn/oat, totaling 64 experimental units. The nitrogen doses were applied at the phenological stage of expanded fourth leaf using urea. The increase of nitrogen fertilization for topdressing promoted increase of the total protein of oat grains and reduction of the total fiber in both soybean/oat and corn/oat systems. Higher levels of grain protein due to nitrogen fertilization reduced grain production, regardless of the cropping system.

Genet. Mol. Res. 19(4): GMR18569
DOI: 10.4238/gmr18569
Research Article

Annona sylvatica (Annonaceae) is a common medicinal plant used in folk medicine for fever and cough; it is found in several Brazilian states, including Mato Grosso do Sul. The local population uses A. sylvatica leaves for treating fever and cough; however, how this medicinal plant affects the patients is little understood. We evaluated the anti-inflammatory and anti-allergic properties of a methanolic extract of A. sylvatica (MEAS) leaves in mouse models of inflammation and allergy. The study employed male C57bL/6 mice for allergy models and male Swiss mice for the inflammation study. Oral treatments with MEAS (30 to 150 mg/kg) significantly inhibited the carrageenan-induced leukocyte migration and protein extravasation to the cavity in an air pouch model. In the allergic animal models, oral treatment with MEAS (150 mg/kg) significantly reduced histamine- and ovalbumin (OVA)-induced paw edema. Moreover, in the OVA-induced allergic lung inflammation model, oral treatment with MEAS (150 mg/kg) significantly inhibited neutrophil, eosinophil, and mononuclear cells migration to the lung. Pretreatment of neutrophils with MEAS (3, 150, 300 µg/mL) significantly reduced neutrophil chemotaxis induced by N-Formyl-Met-Leu-Ph (fMLP) and complement 5a (C5a, in a concentration-dependent manner. We conclude that A. sylvatica has anti-inflammatory and anti-allergic properties. Flavonoids and acetogenins, compounds found in the MEAS, could be responsible for these anti-inflammatory and anti-allergic effects.

Genet. Mol. Res. 19(3): GMR18661
DOI: 10.4238/gmr18661
Research Article

Winter squash (Cucurbita moschata) has great importance as a food. Brazil has a wide genetic variability of squash; most of this is conserved in germplasm banks. The Vegetable Germplasm Bank of the Federal University of Viçosa (BGH-UFV) includes more than 350 accessions of squash; however, this germplasm is still little used. Characterization of accessions requires time, labor, and financial resources. Image-based, high-quality and large-scale phenotyping is a promising alternative tool. We propose digital phenotyping of C. moschata germplasm fruit. To achieve this, we evaluated 466 fruits from 148 accessions of squash from BGH-UFV and four checks. After longitudinal cutting, the fruits were evaluated on the basis of their length, diameter, and internal cavity dimensions. An image of every fruit was also obtained. Digital measurements were made using the software FENOM. The comparison between manual and digital forms of fruit evaluation was carried out with the software GENES. The comparisons were based on the analyses of simple linear regression, bias, the coefficient of Pearson correlation, the index of concordance, the index of performance, the efficiency of the method, the absolute average error, and the absolute maximum error. The evaluations based on images had high concordance (>0.93), almost perfect correlation (>0.99), and a performance classified as excellent (>0.92), in the evaluation of all the descriptors, when compared to manual measurements. We conclude that phenotyping of winter squash fruits based on digital images is promising for the characterization of C. moschata accessions, resulting in an efficient evaluation.

Genet. Mol. Res. 19(3): GMR18646
DOI: 10.4238/gmr18646
Short Communication

Genome size and chromosome number are basic biological characteristics that reveal a wide diversity in plants. The most widely used method to estimate genome size is flow cytometry; however, genomic estimation is only available for a small number of species. In this context, the DNA content of plants distributed in areas rich in species and endemism, such as the Brazilian Cerrado, remains little known. We examined genome size and number of chromosomes for the legume Dipteryx alata (popularly known as “baru”), a tree used for food, medicine, forage, recovery of degraded areas, landscaping and wood extraction. Dipteryx alata showed 2n = 16, with small chromosomes.  Genome size or C-value was estimated at 1C = 0.825 pg which corresponds to 807.2 Megabases. This species is an important genetic resource, though it has a very small genome. In addition, this species is phylogenetically positioned in the first diverging lineage of Papilionoideae. Therefore, D. alata is a strong candidate among the tree species of the Brazilian Cerrado to be a model species in studies of comparative genomics of Leguminosae.

Genet. Mol. Res. 19(3): GMR18640
DOI: 10.4238/gmr18640
Research Article

Chronic periodontal disease (CPD) is described as a recurrent inflammatory condition of tooth supporting tissues, caused by bacterial infections and self-destructive processes of immune activity mediated by pro-inflammatory cytokines, of which the interleukins 1β, 6 and 8 stand out; together with other biomolecules these cytokines mediate innate immunity. These molecules may have variations in their genes, such as single nucleotide polymorphisms, which together with environmental factors, can affect susceptibility to this disease condition. We investigated how polymorphisms of the IL1B, IL6 and CXCL8 genes, as well as sociodemographic and lifestyle aspects, affect susceptibility to chronic periodontal disease in a group of volunteers in Goiânia city. Peripheral blood samples from 152 volunteers were obtained via venipuncture and grouped into controls and a case group (CPD), according to the result of the periogram, previously elaborated, together with a questionnaire concerning habits and life style. The DNA of the samples was genotyped using PCR-RFLP and qPCR, for each molecular marker. A significant trend to develop CPD was detected for individuals who brush their teeth less than twice a day. The allele of minor frequency of the variants rs1143634, rs1800796, and rs2227539 were associated with CPD, revealing a significant predictive effect (P < 0.05). The most significant findings involved the T (rs1143634) and C (rs1800796) alleles, which were associated with increased risk, when examined individually and together. We concluded that this is a multifactorial disease, although the the genetic influence was predominant.

Genet. Mol. Res. 19(3): GMR18568
DOI: 10.4238/gmr18568
Research Article

In Brazil, most sheep are of the Santa Inês breed, which shows rusticity in breeding and grazing systems, being able to offer better adaptation characteristics for animals with meat production ability, such as the Texel and Dorper sheep. They can also improve meat production in animals that have better characteristics for milk production, such as Lacaune and East Friesian breeds. We investigated the polymorphisms of calpastatin (CAST) and myostatin (GDF8) genes and their association with meat quality parameters of 84 lambs, including: 14 purebred Santa Inês and 70 crossbred animals of five genetic groups: 16 animals (½ Santa Inês x ½ Black Dorper); 12 animals (½ Santa Inês x ½ White Dorper); 19 animals (½ Santa Inês x ½ Texel); 14 animals (½ Santa Inês x ½ Lacaune); and 9 animals (½ Santa Inês x ½ East Friesian). To evaluate the polymorphism of the genes we used PCR and Simple Chain Conformation Polymorphism (SSCP) with DNA sequencing to determine where base exchange occurred in the gene sequences. The PCR-SSCP technique detected four bands of the CAST gene and three of the GDF-8 gene. In meat quality of sheep there was only one different breed group by Shear force with less value than Santa Ines breed group. The CAST gene had four genotypes with two single nucleotide polymorphisms (SNPs) (c.679A> G; c.383A> G), which resulted in the exchange of glutamic acid by glycine and threonine by alanine, which impacted pH values. Reduced pH values for BB and AB genotypes, and increased pH value in the AA genotype were found.  Three genotypes of the DGF-8 gene with three SNPs were identified with changes of A-T, A-G, and T-G, influencing color hue angle (h*). After 10 days post mortem, there was an increase in hue angle the highest values were found for genotypes DF and DE. The polymorphisms of the CAST gene and in the promoter region of the GDF-8 gene influence meat color and final pH, affecting meat quality in various of the sheep breed groups.

Genet. Mol. Res. 19(3): GMR18325
DOI: 10.4238/gmr18325
Research Article

One of the main global causes of mortality is cerebral ischemia. Studies report that alcohol abuse causes health problems, aggravating the conditions of neurological diseases. The role of microRNAs has been highlighted in the literature as biomarkers in various types of diseases, including neurological disorders. Evidence of dysregulation of serum miRNAs related to apoptosis in experimental brain ischemia associated with alcoholism is scarce. We evaluated the gene expression of miRNA-15b and 16 (apoptotic) and miRNA-21, -221 and -222 (anti-apoptotic) in the blood after experimental induction of temporary focal ischemia (90 minutes) by occlusion of the middle cerebral artery in rats, followed by reperfusion for 48 hours, associated with  a  chronic alcoholism model. Fifty-six rats were randomly divided into seven experimental groups: Control (C); Sham (S); Ischemic (I); Ischemia-reperfusion (IR), Alcoholic (A); Alcoholic and ischemic (I + A); Ischemia-reperfusion and Alcoholic (IR+A). The blood samples were collected for gene expression analysis of some serum miRNAs by PCR in real time. The serum expression of miRNA-16 was higher in the IR group compared to C and S groups (P < 0.05) but no association with chronic alcoholism was found. The serum expressions of miRNA-21, -221 and -222 were low in all groups and were not correlated with ischemic injury and/or chronic alcoholism. The serum expressions of miRNA-15b, -21, -221 and -222 were similar among the experimental groups, with no correlation with ischemia, with or without reperfusion, and/or alcoholism. The overexpression of miRNA-16 in the blood of I and IR groups demonstrated a correlation with the ischemic process, mainly after reperfusion for 48 hours, associated or not with alcoholism.

Genet. Mol. Res. 19(3): GMR18637
DOI: 10.4238/gmr18637
Research Article

Myrica rubra has been cultivated for more than 2000 years it is one of most popular fruits in south China. We compared three M. rubra cultivars, "Muye" (MY), "DongKui" (DK), and "Zao Jia" (ZJ) to determine the causes of the differences in fruit color. We found changes in the anthocyanin and carotenoid contents during the fruit coloring and maturity phases. The anthocyanin contents of the three cultivars increased from the initial fruit coloring phase to the maturity phase. During this period, the total contents of anthocyanin and cyanidin in MY were higher than those in ZJ by 8.57 and 26.45% and higher than those in DK by 80.16 and 129.37%, respectively. RNA-Seq based transcriptome analysis of veraison and mature berries of the three M. rubra cultivars was conducted. The total numbers of genes and N50 lengths were 33,033 and 1,426 for MY, 35,166 and 1,145 for DK, and 31,374 and 476 for ZJ, respectively From the initial color-turning phase to the maturity phase, there were three up-regulated and three down-regulated genes in MY, while there were 3,058 up-regulated and 65 down-regulated genes in DK and 1,484 up-regulated and 1,169 down-regulated genes in ZJ. Based on functional insight of the differentially expressed genes, 3-Amino-1,2,4-triazole (3AT) would be the key gene responsible for color variation in these three cultivars. We concluded that the 3AT gene controls M. rubra berry color. Based on qRT-PCR, we found that expression of 3AT was much higher in MY and ZJ. This result was consistent with our RNA-Seq analysis. In conclusion, cy-3glu and peonidin are pigments that have a significant effect on the color of M. rubra fruit, and 3AT is a functional gene that regulates these pigments. These results could have practical significance for M. rubra selection strategies.

Genet. Mol. Res. 19(3): GMR18371
DOI: 10.4238/gmr18371
Research Article

Understanding the genetic control of internode length is essential to develop more compact winter squash genotypes. Our objective was to elucidate the genetic control of internode length before and after emergence of the first female flower in winter squash, Cucurbita moschata. This was done by estimating the linear and quadratic genetic components and using the maximum likelihood estimation function. The parents used were the long-vined accession BGH 7319 (P1) and the compact cultivar ‘Tronco Verde’ (P2). The F1 plants from this cross were self-fertilized to obtain the F2 generation, and then they were backcrossed with P1 and P2 to obtain generations BC1 and BC2, respectively. By examining the linear and quadratic genetic components of variations in internode length, we found evidence of dominance effects both before and after flowering, with a reversal in dominance after flowering. Using maximum likelihood, we observed that the internode length before flowering was controlled by one major gene with additive and dominance effects, while the internode length after flowering was controlled by multiple genes with additive and dominance effects, plus environmental effects. Based on these results, strategies using backcrosses for introgression of the major gene controlling this trait before flowering and recurrent selection for introgression of the polygenes involved in trait control after flowering are recommended.

Genet. Mol. Res. 19(3): GMR18660
DOI: 10.4238/gmr18660
Research Article

Rice (Oryza sativa) is crop that adapts well to diverse soil and climate conditions; breeding programs have generally been committed to identifying and selecting genotypes that are stable and have high productivity in various environments. In this sense, studies of adaptability and stability are of paramount importance to aid in the recommendation of cultivars, since it allows growers to obtain detailed information about the behavior of the genotypes in each region. We evaluatde the adaptability and stability of irrigated rice genotypes grown with continuous flooding, for the selection and recommendation of cultivars for crops or breeding programs. Eighteen genotypes were evaluated for grain yield in four agricultural years at three sites, covering 12 environments. The adaptability and stability were assessed by the methods of Eberhart and Russell, multiple centroids and GGE biplot. Genotypes behaved differently regarding stability and adaptability in the different environments. Both methodologies identified BRA 02691 and MGI 0607-1 as promising to be released as cultivars; however, classification inconsistencies occurred, such as for the line BRA 031001. Multiple centroid and GGE biplot methods demonstrated greater sensitivity than the Eberhart and Russell method. Using the methods simultaneously provides an innovative approach to the interpretation of GxE interactions and is a viable alternative for genotype classification. The genotype MGI 0607-1 showed promising behavior independent of the methodology used.

Genet. Mol. Res. 19(3): GMR18434
DOI: 10.4238/gmr18434
Research Article

We compared three Pi-efficient (ATF-14B, ATF-53B, 101B) and four Pi-inefficient (ATF-16B, 116R, 136B, 187R) sorghum genotypes under different Pi concentrations. There were no significant differences between the groups in Pi-use efficiency under Pi-deprivation for anthocyanin accumulation, dry-weight matter, acid phosphatase activity (APA), and aerenchyma formation. However, both groups showed anthocyanin accumulation under Pi-deprivation. Under Pi-deficiency, there was a significant reduction of dry weight in both groups, with no significant differences between contrasting genotypes. All genotypes exhibited a significant increase in root/shoot ratios during Pi-deficiency, and these changes were not related to Pi-use efficiency. The total Pi content in roots and shoots in all genotypes was similar and represented less than 0.2 % of the total dry weight. For all genotypes, the Pi content in P+ treatment resulted in a significant variation ranging from 0.45 to 0.85% and 0.41 to 0.66% in roots and shoots, respectively. The genotype 187R had the highest P content in roots and shoots. APA activity showed increased activity only in the roots of both groups. The development of aerenchyma was conspicuous in the basal and in the middle root sections of all genotypes grown under different Pi levels. Two sorghum Pi-transporter genes were strongly overexpressed in the middle part of Pi-deprived roots of 136B genotype. We did not find differences that explain the Pi-use efficiency between efficient and inefficient genotypes. More studies are needed to elucidate the complex mechanism of P-utilization by sorghum plants.

Genet. Mol. Res. 19(3): GMR18469
Research Article

Pyemotidae mites are ectoparasites of a large number of arthropods, and Pyemotes tritici (Acari: Pyemotidae) is often found parasitizing insects in various habitats, including in the laboratory. Here we report widespread infestation of P. tritici in laboratory colonies of various species of stored-products insects. P. tritici infestations were observed in laboratory colonies (MIPGrains/UFV) of Sitophilus zeamais (Coleoptera: Curculionidae), Alphitobius diaperinus (Coleoptera: Tenebrionidae), Lasioderma serricorne (Coleoptera: Anobiidae), Acanthoscelides obtectus (Coleoptera: Bruchidae), Rhyzopertha dominica (Coleoptera: Bostrichidae), Ephestia sp. (Lepidoptera: Pyralidae), and Tribolium castaneum (Coleoptera: Tenebrionidae). The widespread infestation of P. tritici in laboratory colonies of these species is a serious problem. This mite can substantially reduce insect populations or even kill them, making it impossible to rear the insects, as observed in this research. This ectoparasite is not recommended as a biological control agent in integrated pest management of stored-product pests because P. tritici can attack bees, mammals, and other animals and cause dermatitis in humans. In consideration of the above, the widespread infestation of P. tritici in colonies of S. zeamais, A. diaperinus, L. serricorne, A. obtectus, R. dominica, Ephestia sp., and T. castaneum indicates that this mite should be monitored when raising stored-products insects to ensure the development of the insect populations and ensure that the laboratory environment is safe.

Genet. Mol. Res. 19(3): GMR18548
DOI: 10.4238/gmr18548