Current issues

Table of contents: 2019

Research Article

With the advent of the Brazilian Government Biodiesel Program and the increasing demand for vegetable oils, Jatropha curcas has been emphasized as an alternative raw material. Given the known water stress tolerance of this species, we evaluated the plasticity of photosynthetic metabolism in nine genotypes of J. curcas under water stress (WS). The hypotheses that (1) the photosynthetic metabolism of J. curcas is plastic and changes towards crassulacean acid metabolism  (CAM)  according to water availability and (2) the plasticity of the metabolic alteration is variable among the different genotypes and is related to physiological adjustments, were tested. Water deficit led to 167 and 187% increase in phosphoenolpyruvate carboxylase (PEPC) activity in leaves collected at 4 and 16 h,, respectively, when compared to control plants. The accumulation of organic acids (malate and citrate) differed among genotypes and WS treatments. There was an average increase of 270% for plants submitted to WS, when citrate was compared to malate. There was an increase of 62% in total soluble sugar content and a decrease of 27% in starch content in plants under WS when compared to controls. Significant effects of genotype and watering regime were detected for carbon isotope composition of leaf biomass. We detected changes in photosynthetic metabolism towards low CAM levels, thus explaining the maintenance of efficiency of water use under water deficit.

 

Genet. Mol. Res. 18(2): GMR18228
DOI: 10.4238/gmr18228
Research Article

In passion-fruit breeding programs, characterizing genotypes developed through morpho-agronomic descriptors helps quantify genetic diversity and identify individuals with desirable qualities. We examined the discriminatory ability of passion-fruit descriptors and determined their relative importance in the characterization of 91 genotypes from a breeding program for resistance to Cowpea aphid-borne mosaic virus. Twenty-four quantitative and 14 multi-category qualitative descriptors related to plant, leaf, flower, and fruit characteristics were used. The quantitative descriptors were subjected to correlation and principal-component analyses and selected based on direct selection and the Singh method. The traits were used to obtain a distance matrix, based on Gower’s algorithm, and a comparative clustering between the dendrograms for the morpho-agronomic variables was obtained using the unweighted pair group method with arithmetic mean procedure. Based on the principal components method, the traits that most contributed to genetic variability were number of seeds (23.241%), petiole length (19.438%), and petal width (10.440%). In its turn by the Singh method, the traits androgynophore length (6.68%), followed by flower length (5.47%), area under the disease progress curve (5.27%), and peduncle length (5.17%) were those which most contributed to the differentiation of genotypes. Although seven descriptors (leaf length, bract width, corona long filament length, sepal length, fruit width, fruit mass, and mass of fruit pulp) showed little contribution to the characterization of genotypes, their discard is not suggested, as they significantly contribute to the discrimination of genetic divergence in the population. Comparative analysis between the dendrogram containing all descriptors and the dendrogram containing only flower, leaf, or fruit descriptors evidenced the need for using a large number of descriptors in the characterization of genetic diversity in Passiflora. The use of all 38 descriptors increased the efficiency in the discrimination of groups.

Genet. Mol. Res. 18(2): GMR18255
DOI: 10.4238/gmr18255
Research Article

The black rhino sanctuaries system has played a key role in repopulating and starting new subpopulations in Kenya. If this system is efficiently managed it may save the black rhinoceros from local extinction. Understanding the genetic status of endangered species is the most elemental sine qua non of animal breeding and conservation. It is therefore important to determine the genetic diversity of black rhino populations, especially of nucleus breeding populations that are used as a source of individuals for translocation and supplementation programs. We assessed the genetic diversity of one of the pioneer breeding subpopulations of the black rhino Diceros bicornis in Kenya using a mitochondrial DNA D-loop region. We then compared this subpopulation with the entire Kenyan population to determine its status vis-à-vis the Kenya pooled population and determine the possible sources/relationships of the founder individuals. In the 469-bp D-loop region we analyzed, 7.11% of the sites were variants, contributing to 18 distinct haplotypes. Estimates of genetic diversity using haplotype and nucleotide diversity metrics showed that the Lake Nakuru National Park subpopulation has a slightly lower genetic diversity when compared with that of the pooled Kenya population.  The phylogenetic tree revealed that Lake Nakuru National Park founder individuals were probably sourced from multiple subpopulations. The dendrogram and the principal coordinate analysis plot indicated that the Maasai Mara subpopulation is not a distinct subpopulation, as had been suggested previously. Our results provide baseline genetic data for the Lake Nakuru National Park breeding subpopulation and valuable information for translocation/supplementation programs.

Genet. Mol. Res. 18(2): GMR18203
DOI: 10.4238/gmr18203
Research Article

Human leukocyte antigen (HLA) G, a non-classical HLA class I (MHC class I) molecule, is characterized by a low degree of polymorphism, unlike classical MHC-I. The 14-base pair insertion/deletion (indel) polymorphism (rs16375) in exon 8 of the 3′ untranslated region has been reported to control HLA-G expression transcriptionally and post-transcriptionally. We evaluated a possible association between the 14-bp indel polymorphism of HLA-G and the level of this protein in serum [sHLA-G1] and in primary-tumor tissue in colorectal cancer (CRC) of a Saudi population. A total of 105 patients with CRC and 105 healthy controls were analyzed for the 14-bp indel polymorphism. sHLA-G1; histological presence of HLA-G was also investigated for association with CRC. Lower prevalence of the heterozygous genotype of the 14-bp indel polymorphism was observed among the patients with CRC, though the difference was not quite significant (P = 0.052). In addition, the sHLA-G1 pattern did not show a significant difference between the patients with CRC and the controls. However, the expression pattern of HLA-G in colorectal tissue showed a heterogeneous profile, marked by a lack of expression in colorectal adenocarcinoma and normal cells and focal expression of the protein in the transition zone.

 

Genet. Mol. Res. 18(2): GMR18324
DOI: 10.4238/gmr18324
Research Article

Glioblastomas are the most common primary malignant brain tumors, and despite current advances in therapy, they are still extremely resistant to treatment. The tumorigenic potential of glioblastomas is due to a subpopulation of neoplastic cells, called cancer stem cells (CSCs), which in culture form a suspension cluster called neurospheres. Their properties include tumorigenesis, chemoresistance, and radioresistance. Several miRNAs exhibit altered expression levels during gliomagenesis; thus they constitute one of the key mechanisms for CSC regulation. We evaluated whether temozolomide and ionizing radiation modulate the expression of the tumor suppressor microRNAs-15, -16 and of the oncogenic miR-21 in neurospheres and attached cells in a glioblastoma cell line culture (U343-MG). The methods included staining with Trypan blue to verify cell viability and real time PCR to quantify the expression of microRNAs after exposure to  treatments. We observed that miR-16 was more highly expressed in neurospheres than in attached cells 48h after treatment with temozolomide, and miR-21 was highly expressed in attached cells compared to neurospheres treated with temozolomide at time 0 h (30 min after treatment); at 48 h this microRNA was highly expressed in neurospheres treated with temozolomide in association with ionizing radiation. We concluded that the microRNAs were differentially expressed when comparing the different cell types and treatment modalities. The higher expression of miR-21 in neurospheres at time 48 h may suggest a pathway of CSC radioresistance and chemoresistance, with further rapid tumor growth and recurrence or resistance to other treatment modalities.

 

Genet. Mol. Res. 18(2): GMR18095
DOI: 10.4238/gmr18095
Research Article

We evaluated correlations between yield, meteorological and bromatological characters in five genotypes of dual-purpose wheat submitted to different cutting management systems. The experiments were carried out in 2014 and 2015. The experimental design was a randomized block, organized in a factorial scheme, with five genotypes of dual purpose wheat (BRS Tarumã, BRS Umbu, BRS Figueira, BRS Guatambu and BRS 277), three cutting managements (one, two and three cuts), with three replicates. The data of each cut management were submitted to linear correlation analysis, canonical correlations and stepwise predictions . We conclude that yield and bromatological components of the forage are closely related to the meteorological attributes and cut management. Neutral and acid detergent fiber, hemicellulose, mineral matter and total carbohydrates are influenced by maximum and minimum air temperature, as well as by incident solar radiation. The canonical interrelationships and the predictive models developed for the morphological, bromatological and grain yield attributes are specifically dependent on cut management in dual purpose wheat.

Genet. Mol. Res. 18(2): GMR18204
DOI: 10.4238/gmr18204
Research Article

Commercial whaling has been banned since the moratorium of the International Whaling Commission in 1986. However, domestic sale of cetaceans that are caught as bycatch is still allowed in South Korea. Although whale meat is not very popular in South Korea, it is consumed in certain areas. To identify the species composition of whale meat in South Korean markets, we collected 54 samples that were sold as minke whale meat at restaurants and markets of four cities: Seoul, Ulsan, Busan, and Pohang. Of the 54 whale meat samples, 51 were successfully identified using the partial mitochondrial cytochrome b gene (806–1,140 bp) amplified for species identification. Molecular species identification revealed three species among the samples: minke whale (52%), common dolphin (22%), and narrow-ridged finless porpoise (26%). We also gathered data for cetacean bycatch in South Korea. In total, 19 species were confirmed to be incidentally caught in South Korea over the past 13 years, and minke whale (13%), common dolphin (30%), and narrow-ridged finless porpoise (45%) were recorded as the most frequently caught species. The sale of “fake” minke meat in the markets may have been due to a lack of availability of minke meat, as well as the difference in market values of meat from baleen and toothed whales. These factors that lead to the sale of “fake” minke meat are thought to be contributing causes of the illegal, unregulated, and unreported exploitation of small cetaceans. To prevent such exploitation, it is necessary to continuously monitor whale meat using molecular species identification. Our study improves the understanding of which species of whales (meat) are sold in South Korea and proposes a management policy for the conservation of small cetaceans in South Korea

Genet. Mol. Res. 18(2): GMR18171
DOI: 10.4238/gmr18171
Research Article

Francisella noatunensis subsp. orientalis (Fno) is a Gram-negative bacterium that causes granulomatous infections in fish reared at low water temperatures; it has been responsible for a large number of deaths in tilapia fish farms. Fno has been reported in many countries in the last decade. Studies on phylogenomic relationships among isolates are needed because of the increasing importance of this disease. Here, we present the complete genome of the Fno F1 strain isolated in 2015 from a tilapia farm in São Paulo state, Brazil. The genome is a circular chromosome with a length of 1,854,333 bp, containing 32.26% G+C DNA content, 1,448 protein-coding genes and 393 pseudogenes. In addition, a prediction of conserved vaccine targets was made between the two subspecies of F. noatunensis that cause disease in tropical and cold-water fish species. Five proteins conserved between Fno and Francisella noatunensis subsp. noatunensis were predicted to be good vaccine candidates for the development of a recombinant vaccine against francisellosis. This genome also provides useful data to help understand the pathogen evolution and epidemiology of this disease in Brazil.

Genet. Mol. Res. 18(2): GMR18302
DOI: 10.4238/gmr18302
Research Article

The estimation of genetic variability in germplasm banks is important not only for the conservation of genetic resources, but also for their use in plant breeding. However, a large number of traits from different categories (qualitative and quantitative) can make the analysis and interpretation of the results difficult, often resulting in an incomplete distinction among accessions. We characterized 45 accessions of food-type soybean (Glycine max) from the Soybean Germplasm Bank of Londrina State University based on morphoagronomic traits. The experiment was carried out in the university farm using a randomized block design with three replicates. Twelve traits were evaluated: flower color, pubescence color, tegument color, hilum color, days until flowering, days until maturation, plant height, height of insertion of  the first pod, mass of 100 grains, grain yield per plot, agronomic value, and lodging index. The quantitative trait data were submitted to deviance analysis. The genetic divergence among the accessions was examined by Gower's distance and clustering of the accessions was made based on Ward's hierarchical method. Morphoagronomic descriptors proved efficient in detecting the levels of genetic variability among the accessions maintained in the germplasm collection. Gower's distance was efficient in the discrimination of accessions, showing that simultaneous analysis of quantitative and qualitative traits is useful to evaluate the variability in a germoplasm bank. These results can be used as an additional source of information to be exploited in food-type soybean breeding programs.

Genet. Mol. Res. 18(2): GMR18298
DOI: 10.4238/gmr18298
Research Article

We evaluated the association of glutathione S-transferase polymorphisms (GSTT1 and GSTM1) and oxidative stress biomarkers in patients with schizophrenia. A total of 162 subjects were studied: 53 had schizophrenia (Total Study Group-TSG), and 109 without the disorder (Total Control Group-TCG). To analyze oxidative stress, TSG was distributed into treatment-responsive schizophrenia (N = 26) and treatment-resistant (N = 27) versus control group (N = 36). Peripheral blood collection for analysis of polymorphisms, malondialdehyde (MDA) and trolox equivalent antioxidant capacity (TEAC); a questionnaire or a medical record for clinical profile and lifestyle was also applied. Frequency of genotypes did not differ significantly between the groups. The patients had a significantly reduced frequency of the combination GSTT1-null/GSTM1-present (13 versus 30%) and significantly higher plasma MDA levels, but similar TEAC values. Smoking, diabetes mellitus (DM), systemic arterial hypertension (SAH) and family history (FH) significantly prevailed in patients (TSG) compared to controls (TCG). High sensitivity and specificity values for MDA (area under the curve >0.90) were observed. Reduced frequency of the combination GSTT1-null/GSTM1-present in patients suggests exposure to oxidative stress, represented by increased MDA and mainly aggravated by smoking, SAH, DM and FH. High sensitivity and specificity identifies the potential of MDA as a marker of oxidative stress in schizophrenia.

 

Genet. Mol. Res. 18(2): GMR18259
DOI: 10.4238/gmr18259
Research Article

Marker-assisted selection has been widely used in breeding programs. The use of single nucleotide polymorphisms (SNPs) as genetic markers enables identification of genotypes that best contribute to quantitative characteristics. We evaluated a possible association between the DdeI growth hormone gene polymorphism and meat and carcass traits. A total of 476 halothane-free animals were genotyped. Animals originated from the crossing of an AGIPIC®415 male with Large White (LW) x Landrace (LD) females. Males were castrated when young and males and females were slaughtered between 150 and 180 days old. Hot carcass weight, carcass length, pH 45 min , and pH 16 postmortem of Longissimus cervicis, Longissimus dorsi, and Semimembranosus muscles, backfat thickness, Longissimus dorsi muscle depth, and color by the CIELAB system were measured and the percentage of lean meat was calculated. Water holding capacity was determined by the filter paper method in the Semimembranosus muscle. A 605-base pair (bp) amplicon was obtained by PCR and a DdeI polymorphism was genotyped and two alleles identified, D1 with 335, 148, and 122 bp and D2 allele with 457 and 148 bp. Allele frequencies were 0.43 for D1 and 0.57 for D2. Genotypic frequencies were as follows: D1D1 (22.1%), D1D2 (49.8%), and D2D2 (28.1%). The Chi-Square test showed that the population was in Hardy-Weinberg equilibrium. The results of hot carcass weight, carcass length, pH 16 postmortem of Longissimus cervicis, Longissimus dorsi, and Semimembranosus muscles, backfat thickness, Longissimus dorsi muscle depth, color and water holding capacity did not differ significantly among the genotypes. The DdeI SNP was associated with lean meat percentage and pH at 45 min posmortem in the Longissimus cervicis muscle; properties that are important for the commercialization of fresh meat as well as processed products.

 

Genet. Mol. Res. 18(2): GMR18257
DOI: 10.4238/gmr18257
Research Article

Raspberry is a berry crop of great economic importance, and its cultivation has expanded worldwide. Information on the genetic parameters of raspberry for use in breeding programs is currently limited. We used Restricted Maximum Likelihood (REML) and Best Linear Unbiased Prediction (BLUP) to estimate variance components and predict genetic parameters for morphological, phytochemical, and mineral components in primocane-fruiting raspberries in southern Brazil. The experimental design was randomized blocks in a factorial scheme, with two production cycles (fall and spring) x three cultivars (‘Alemãzinha’, ‘Heritage’ and, ‘Fallgold’), with eight replicates. A total of 27 traits were evaluated, out of which only the traits beginning of fruit harvest, plant height, dry mass of pruning, average fruit weight, total phenolic compounds, anthocyanins, antioxidant activity, Ca, Mg, Cu, Fe, Mn, Zn, and titratable acidity showed significant differences. The anthocyanins presented 87% of broad sense heritability, and this high value indicates that this trait can be improved through selection. Plant height, fruit weight, total phenolic compounds, Mg and Fe had moderate broad sense heritability (46, 58, 58, 51, and 66%, respectively); and the traits beginning of fruit harvest, dry mass of pruning, antioxidant activity, Ca, Cu, Mn, Zn, and titratable acidity are strongly influenced by production cycle effects. Greater genetic variance contribution in the interaction between genotypes × production cycle was observed for plant height, fruit weight, total phenolic compounds, anthocyanins, antioxidant activity, Mg and Fe. The genotype ‘Alemãzinha’ was superior for beginning of fruit harvest, plant height, anthocyanins, titratable acidity, and several minerals. Five inheritable profiles were found; the profile IV, including plant height, fruit weight, Mg, Fe, and total phenols had moderate broad sense heritability. Only profile V, composed of anthocianins, presented high heritability.

Genet. Mol. Res. 18(2): GMR18254
DOI: 10.4238/gmr18254
Research Article

In order to facilitate corn production, herbicides such as nicosulfuron and topramezone are commonly used. Though they offer great advantages, they can affect crop productivity and induce DNA damage. The genotoxic activity of nicosulfuron was evaluated at two concentrations (40,000 and 80,000 ppm) and topramezone at four concentrations (1480, 148, 14.8 and 1.48 ppm) respectively, in sweet corn and hybrid accessions from Mexico and South America using a comet assay system. Sweet corn apical meristematic cell nuclei were tested in 113 accessions from Mexico and South America and five commercial hybrids for nicosulfuron and nine accessions and a hybrid for topramezone. Both nicosulfuron concentrations induced significant genetic damage to sweet corn and normal hybrids. Topramezone showed significant genotoxic activity in both sweet corn and normal hybrids. Normal hybrid corn was subject to genetic damage caused by the herbicides, and all showed significant genetic damage compared to their corresponding untreated controls. Genotoxic activity of nicosulfuron and topramezone was evident; additionally, the comet assay study demonstrated that corn can be used as a biomonitor for genotoxicity assessment.

 

Genet. Mol. Res. 18(2): GMR18159
DOI: 10.4238/gmr18159
Research Article

Genetic diversity is the basis for genetic improvement as it can provide the basis for new cultivars. Stylosanthes scabra is a grasslands legume that presents potential economic importance in tropical and subtropical regions. Plants of the genus Stylosanthes naturally occur in semiarid native pastures in northeastern Brazil and are highly favored by grazing animals; therefore Brazil's Northeast stands out as an center of this genus. We evaluated the genetic diversity of S. scabra using ISSR molecular markers; naturally occurring samples were harvested from Santa Cruz do Capibaribe, Floresta, Sertânia and Petrolina in Pernambuco state, Brazil. We selected seven ISSR primers for amplification and analyzed 75 individuals, obtaining 88 bands, which amplified with 95% polymorphism at the species level. The AMOVA test revealed that 40% of the total genetic variation occurs within populations and 60% among populations. Population differentiation was 0.332 and the migrant number per generation was 0.5. Grouping analysis confirmed a high level of differentiation among populations and that the greatest variability was in Santa Cruz do Capibaribe and Petrolina regions. The ISSR markers were efficient for genetic diversity quantification in S. scabra, which presented greater variability among populations than within them. Overall, the population variability found will be useful for breeding programs for this species.

 

Genet. Mol. Res. 18(2): GMR18219
DOI: 10.4238/gmr18219
Research Article

Coffea canephora shows considerable variability for several agronomic traits, including nutritional efficiency. Beside the intrinsic nutritional efficiency of a genotype, the availability of water in the soil is another factor that can cause different responses, which suggests the possibility of selection of genotypes to enhance the nutritional efficiency under different scenarios, such as plantings in areas with low natural fertility or subjected to drought. We evaluated the genetic diversity of genotypes of C. canephora that compose the cultivar “BRS Ouro Preto”, the first available clonal cultivar recommended for Rondonia State, based on parameters of nutritional status of the plants subjected to cultivation under conditions of abundant water supply or subjected to water deficit. To this end, the experiment was developed with two trials where the 15 genotypes of this cultivar were cultivated in a greenhouse, under conditions of abundant water supply or subjected to water deficit. The trials followed a completely randomized design, with four replications and the mineral status of the plants was evaluated based on the content of N, P, K, Ca, Mg and S of their green tissues. The genotypes presented high variability for these nutritional parameters, making it possible to identify distinct patterns and to group them according to their nutritional status. Variability was affected by drought, showing that the water supply can cause changes in patterns of nutritional status and affect the clustering of genotypes. The genotypic effect surpassed the environmental influence for most mineral parameters, resulting in a desirable scenario for a possible selection to enhance nutritional efficiency, for both irrigated and rainfed systems, within the group of genotypes that already present high yield in Rondonia state.

 

Genet. Mol. Res. 18(2): GMR18300
DOI: 10.4238/gmr18300

Pages