Developmental biology, polymorphism and ecological aspects of Stiretrus decemguttatus (Hemiptera, Pentatomidae), an important predator of cassidine beetles

Developmental biology, polymorphism and ecological aspects of Stiretrus decemguttatus (Hemiptera, Pentatomidae), an important predator of cassidine beetles. Stiretrus decemguttatus is an important predator of two species of cassidine beetles, Botanochara sedecimpustulata (Fabricius, 1781) and Zatrephina lineata (Fabricius, 1787) (Coleoptera, Cassidinae), on the Marajó Island, Brazil. It attacks individuals in all development stages, but preys preferentially on late-instar larvae. Its life cycle in the laboratory was 43.70 ± 1.09 days, with an egg incubation period of six days and duration from nymph and adult stages of 16.31 ± 0.11 and 22.10 ± 1.67 days, respectively. The duration of one generation (T) was 12.65 days and the intrinsic population growth rate (r) 0.25. These data reveal the adjustment of the life cycle of S. decemgutattus with those of the two preys, but suggest greater impact on Z. lineata. However, no preference over cassidine species was shown in the laboratory. Up to 17 different color patterns can be found in adults of S. decemguttatus, based on combinations of three basic sets of color markings. Some of them resemble the markings of chrysomelids associated with Ipomoea asarifolia (Convolvulaceae) and are possibly a mimetic ring. Three color patterns were identified in nymphs, none of which was associated with any specific adult color pattern.

Caste polymorphism of apterous line of the Neotropical termite Nasutitermes corniger (Motschulsky) (Isoptera, Termitidae)

Termite societies are structured by individuals that can be grouped into castes and instars. The development of these instars in most species occurs in irregular patterns and sometimes is distinguished subcastes in physical systems that originate polymorphic soldiers and workers. In this study, we characterized the morphological diversity of castes of apterous in Nasutitermes corniger. We collected four colonies of N. corniger, one every three months between May 2011 and February 2012. Individuals of the nest were separated into groups: larval stages, workers and presoldiers and soldiers. A morphometric analysis was performed on individuals from each group based on head width, metatibia, antenna, and thorax length. The data were submitted to discriminant analysis to confirm different morphological types inside these groups. The apterous line of N. corniger is composed of one first larval instar and two second larval instar. The workers caste has two lines of development with four instars in a larger line and three instars in a lower line. Two morphological types were identified in presoldiers and soldiers. The pattern of castes was similar to other species of the genus, in which bifurcation into two lines of workers, one smaller and one larger occurs after the first molt.

Genetic structure of populations of Pissodes castaneus (De Geer) (Coleoptera, Curculionidae) using amplified fragment length polymorphism

Genetic structure of populations of Pissodes castaneus (De Geer) (Coleoptera, Curculionidae) using amplified fragment length polymorphism. The objective of this study was to determine the genetic structure of populations of Pissodes castaneus from different areas and on different species of Pinus using the PCR-AFLP technique. Twenty samples were analyzed, representing 19 populations from Brazil and one from Florence, Italy, which is the region of origin of P. castaneus. The four combinations of primers generated a total of 367 fragments of DNA, and 100% of polymorphic loci, indicating high degree of molecular polymorphism. The dendrogram did not reveal trends for grouping the populations in relation to origin. The low genetic similarity (0.11 between the most distant groups) and genetic distances of 0.13 and 0.44 for 10 out of the 20 samples may indicate several founding events or multiple introductions of heterogeneous strains into Brazil. The allelic fixation index (Fst) was 0.3851, considered high, and the number of migrants (Nm) was 0.3991, indicating low gene flow among populations. The highest genetic distances were between the population from Irani, SC and Cambará do Sul, RS and Bituruna, PR, indicating an independent founding event or a particular allelic fixation in the former location. The high genetic diversity among populations points out that the populations are genetically heterogeneous with a diverse gene pool in the surveyed areas, what makes them to respond differently to control measures.

Polymorphism of the grasshopper Rhammatocerus schistocercoides populations revealed by RAPD

The objective of this work was to study the genetic variability of the grasshopper Rhammatocerus schistocercoides (Orthoptera: Acrididae) using RAPD analysis among individuals from three populations, one from Colombia and two from Brazil (Goiás and Mato Grosso States). Ninety scorable binary markers were obtained by fingerprinting with 11 oligonucleotide primers. Most of the polymorphism was attributed to 42 markers with variable frequency among the different populations. Although the existence of significant difference among populations (P<0.0001), most of the genetic variability was found within populations (87.7% of total variation). Pairwise distances between Colombian and Brazilian populations were 0.12 (P<0.0001) and 0.18 (P<0.0001) for Goiás and Mato Grosso, respectively. The pairwise distance between Goiás and Mato Grosso populations was 0.06 (P<0.0001). These data indicated that the phenotypic differences among populations are associated mainly with the geographical distances between the Brazilian and Colombian populations.

Alternative genotyping method for the single nucleotide polymorphism A2959G (AF159246) of the bovine CAST gene

The objective of this work was to genotype the single nucleotide polymorphism (SNP) A2959G (AF159246) of bovine CAST gene by PCR-RFLP technique, and to report its use for the first time. For this, 147 Bos indicus and Bos taurus x Bos indicus animals were genotyped. The accuracy of the method was confirmed through the direct sequencing of PCR products of nine individuals. The lowest frequency of the meat tenderness favorable allele (A) in Bos indicus was confirmed. The use of PCR-RFLP for the genotyping of the bovine CAST gene SNP was shown to be robust and inexpensive, which will greatly facilitate its analysis by laboratories with basic structure.

Esterase polymorphism in remanant populations of Aspidosperma polyneuron Müll.Arg. (Apocynaceae)

The population genetic structure of the endangered tree species Aspidosperma polyneuron Mull.Arg. (Apocynaceae) was reported based on analysis of esterase polymorphism in two remanant populations. Allelic variation was detected at three isoesterase loci (Est-3, Est-9, and Est-10). The proportion of polymorphic loci for both populations was 30% and deviation from Hardy-Weinberg equilibrium was observed for the Est-3 locus observed in the northern population. Segregation distortion and the lower level of observed and expected heterozygosity in this population were attributed to founder genotype. The high genetic identity values for northern and northwestern populations are in accordance with the low levels of interpopulation genetic divergence demonstrated by the F(ST) (0.03) value. The F(IS) value (0.23) indicated moderate levels of inbreeding. A. polyneuron can be indicated as an example of endangered species suggesting high genetic variation in contrast to the low genetic variation reported for endangered species. The esterase isozymes may be a good genetic marker for studies of natural A. polyneuron populations.

CFH Y402H polymorphism and response to intravitreal Ranibizumab in brazilian patients with neovascular age-related macular degeneration

Objective: To investigate the association between CFH gene polymorphism and response to ranibizumab in Brazilian patients with neovascular age-related macular degeneration (AMD).Methods: 95 patients were genotyped for the CFH rs1061170 (Y402H) single nucleotide polymorphism. Patients with neovascular AMD initially received intravitreal ranibizumab injections for three months and were retreated as needed. Visual acuity (VA) and central retinal thickness (CRT) were measured before treatment and at 1, 3, 6, and 12 months post-treatment.Results: For patients with the TT and TC genotypes, paired comparisons of VA showed a statistically significant improvement when the data obtained at all visits were compared with baseline. Patients homozygous for the risk genotype (CC) did not show a statistically significant improvement when VA obtained at visits 1, 3, 6 and 12 were compared with baseline. For all genotypes, paired comparisons of CRT showed a statistically significant improvement when the data obtained at visits 1, 3, 6 and 12 were compared with baseline.Conclusion: Patients with the CC genotype showed poorer long-term functional response to intravitreal ranibizumab.

Polymorphism in the lymphotoxin-alpha gene, position +252 (rs909253), is not associated with preeclampsia development in Brazilian women

PURPOSE: To investigate the frequencies of polymorphic allele and genotypes for the LT-α gene, position +252 (rs909253), in Brazilian women with preeclampsia.METHODS: This is a case-control study, in which 30 women with preeclampsia, classified according to the criteria of the National High Blood Pressure Education Program, and 115 women in the control group, with at least two healthy pregnancies, were selected. Peripheral blood was collected, and DNA was extracted, followed by genotyping, using specific primers and restriction analysis. The genotypes obtained were AA, AG and GG. Statistical analysis was performed using the χ2association test. The Hardy-Weinberg Equilibrium was tested using the Haploview Program.RESULTS: The results showed no association between genotypes and preeclampsia development (χ2=2.0; p=0.4). When the AG and GG genotypes were grouped according to allele G presence or absence (genotype AA), the data showed that the presence of allele G was not significantly different between cases (women with preeclampsia) and controls (χ2=0.0; p=1.0). The LT-α gene polymorphism, position +252 (rs909253), seems not to be an important candidate for the development of preeclampsia. Other inflammatory genes should be researched, and studies involving gene-environment interactions should be performed, in order to reach a better understanding of the etiology of the preeclampsia.

Genetic polymorphism of fifteen microsatellite loci in Brazilian (blue-egg Caipira) chickens

The purpose of this study was to investigate the genetic polymorphism of fifteen microsatellites loci in Brazilian (blue-egg Caipira) chickens. Samples were collected from 100 blue eggs of Caipira chickens from rural properties in the city of Dois Lajeados, RS. After DNA extraction, the fragments related to molecular markers LEI0248, LEI0221, LEI0214, LEI0192, LEI0217, LEI0254, LEI0194, LEI0212, MCW0371, ADL0278, LEI0234, MCW0183, MCW0216, MCW0330 and MCW0081 were obtained by polymerase chain reaction (PCR). The statistical analysis were carried out with the softwares ARLEQUIN 3.5 version and CERVUS 3.0.3 version. The allelic and genotypic frequencies, deviations from Hardy-Weinberg equilibrium, estimates of observed (HO) and expected (HE) heterozygosity and polymorphic information content (PIC) were obtained for each marker locus. A total of 186 alleles from 15 loci were obtained, with sizes ranging of 83 to 490 base pairs. The medium number of alleles was 12.4, the HE was 0.76±0.14 and HO was 0.49±0.21 and PIC was 0.706. The first conclusion is that the microsatellites used are polymorphic and can be used to genetic studies in chickens. The second is that the "Caipira" chicken (blue eggs) population investigated has a great genic variability, which makes than an important source of genetic resources for future animal breeding programs.

Assessment of silver-stained AFLP markers for studying DNA polymorphism in proso millet (Panicum miliaceum L.)

Proso millet (Panicum miliaceum L.) is a serious weed in North America. A high number of wild proso millet biotypes are known but the genetic basis of its phenotypic variation is poorly understood. In the present study, a non-radioactive silver staining method for PCR-Amplified Fragment Length Polymorphism (AFLP) was evaluated for studying genetic polymorphism in American proso millet biotypes. Twelve biotypes and eight primer combinations with two/three and three/three selective nucleotides were used. Pair of primers with two/three selective nucleotides produced the highest number of amplified DNA fragments, while pair of primers with three/three selective nucleotides were more effective for revealing more polymorphic DNA fragments. The two better primer combinations were EcoR-AAC/Mse-CTT and EcoR-ACT/Mse-CAA with seven and eleven polymorphic DNA fragments, respectively. In a total of 450 amplified fragments, at least 339 appeared well separated in a silver stained acrylamide gel and 39 polymorphic DNA bands were scored. The level of polymorphic DNA (11.5%) using only eight pairs of primers were effective for grouping proso millet biotypes in two clusters but insufficient for separating hybrid biotypes from wild and crop. Nevertheless, the present result indicates that silver stained AFLP markers could be a cheap and important tool for studying genetic relationships in proso millet.

Transferrin polymorphism in Amazon turtle (Podocnemis expansa) stocks

The transferrin gene locus (Tf) was investigated in five populations of the Amazon turtle (Podocnemis expansa) sampled from five geographical areas in the Amazon region. This locus was polymorphic, showing three genotypes (Tfª Tfª, Tfª Tf b and Tf b Tf b), presumably encoded by two co-dominant alleles, Tfª and Tf b. All populations showed good genetic balance according to Hardy-Weinberg expectations, and may sustain the hypothesis of a single stock in the area investigated. The data are consistent with free flow of genes among the population samples examined.

Chromosome polymorphism in Ctenomys minutus (Rodentia-Octodontidae)

A sample of 101 specimens of Ctenomys minutus was collected along its geographic range. Eight karyotypes (2n = 42, 45, 46a, 46b, 47, 48, 49 and 50) were found. The chromosome polymorphisms were due to Robertsonian rearrangements and tandem fusions. The distribution of polymorphisms indicated three population blocks: northern (2n = 49 and 50), central (2n = 46a, 47, and 48) and southern (2n = 42, 45, and 46b). These findings suggest that this species is undergoing a speciation process due to geographic isolation.

Chromosomal polymorphism in urban populations of Drosophila paulistorum

Drosophila paulistorum populations colonizing the urban area of Porto Alegre, southern Brazil, were studied with the objective of characterizing their chromosomal polymorphism in this new environment. Despite being geographically and ecologically marginal and the fact that the colonization of the urban area seems to be a recent event, the populations showed a large number of inversions on all chromosome arms. Differences regarding inversion frequencies and percentage of heterozygosis were found when we compared the samples with respect to geographical, microenvironmental and temporal aspects. Such differences, however, could be attributed to both selective and stochastic factors

A novel polymorphism in the coding region of the vasopressin type 2 receptor gene

Nephrogenic diabetes insipidus (NDI) is a rare disease characterized by renal inability to respond properly to arginine vasopressin due to mutations in the vasopressin type 2 receptor (V2(R)) gene in affected kindreds. In most kindreds thus far reported, the mode of inheritance follows an X chromosome-linked recessive pattern although autosomal-dominant and autosomal-recessive modes of inheritance have also been described. Studies demonstrating mutations in the V2(R) gene in affected kindreds that modify the receptor structure, resulting in a dys- or nonfunctional receptor have been described, but phenotypically indistinguishable NDI patients with a structurally normal V2(R) gene have also been reported. In the present study, we analyzed exon 3 of the V2(R) gene in 20 unrelated individuals by direct sequencing. A C®T alteration in the third position of codon 331 (AGC®AGT), which did not alter the encoded amino acid, was found in nine individuals, including two unrelated patients with NDI. Taken together, these observations emphasize the molecular heterogeneity of a phenotypically homogeneous syndrome

Fractures of the proximal femur: correlation with vitamin D receptor gene polymorphism

Fractures are the feared consequences of osteoporosis and fractures of the proximal femur (FPF) are those that involve the highest morbidity and mortality. Thus far, evaluation of bone mineral density (BMD) is the best way to determine the risk of fracture. Genetic inheritance, in turn, is one of the major determinants of BMD. A correlation between different genotypes of the vitamin D receptor (VDR) and BMD has been recently reported. On this basis, we decided to determine the importance of the determination of VDR genotype in the presence of an osteoporotic FPF in a Brazilian population. We studied three groups: group I consisted of 73 elderly subjects older than 65 years (78.5 ± 7.2 years) hospitalized for nonpathological FPF; group II consisted of 50 individuals older than 65 years (72.9 ± 5.2 years) without FPF and group III consisted of 98 young normal Brazilian individuals aged 32.6 ± 6.6 years (mean ± SD). Analysis of VDR gene polymorphism by restriction fragment length polymorphism (RFLP) was performed by PCR amplification followed by BsmI digestion of DNA isolated from peripheral leukocytes. The genotype distribution in group I was 20.5% BB, 42.5% Bb and 37% bb and did not differ significantly from the values obtained for group II (16% BB, 36% Bb and 48% bb) or for group III (10.2% BB, 47.6% Bb and 41.8% bb). No differences in genotype distribution were observed between sexes or between the young and elderly groups. We conclude that determination of VDR polymorphism is of no practical use for the prediction of FPF. Other nongenetic factors probably start to affect bone mass, the risk to fall and consequently the occurrence of osteoporotic fractures with advancing age.