ABSTRACT
Identifying genome regions subject to selection in local breeds of Brazil is an opportunity to elucidate the C. hircus genome plasticity, flowing the colonization history of the country. Using SNP Bead Chip Illumina 50K genotyping of Brazilian Anglo-Nubian (standardized breed) and Marota (local endangered population from the semiarid area of Brazil) to show outliers loci in genome regions subject to selection. After applying data quality control, 45,600 SNPs were included in this investigation. Principal component analysis (PCAdapt) and FDIST2 analysis signalized 14 genomic regions more affected by selection in the Brazilian dry zone environment. The genome study signalized regions that are close to the sequences of genes related to growth and embryonic skeletal development (FGF12, AMPD2, OSTN). In addition, flagged regions close to the genes UTSB2 and SLC5A2 contribute to research on functional adaptation with low water needs and poor nutritive diet to survive. Both genes encode proteins that act on osmotic pathways and avoid cell flooding on stress cell responses. Further studies on the genetic role and involvement of these outliers' genomic regions, building a robust conceptual high-resolution map of natural selection drives, help to achieve hardiness candidate genes linked to the evolutionary history of Capra hircus in the semiarid area of Brazil.
ABSTRACT
Fusarium oxysporum f. sp. phaseoli (Fop) J.B. Kendrich & W.C. Snyder is the causal agent of Fusarium wilt of common bean (Phaseolus vulgaris L.). The objective of this study was to develop microsatellite markers (SSRs) to characterize the genetic diversity of Fop. Two libraries enriched with SSRs were developed and a total of 40 pairs of SSRs were characterized. Out of these, 15 SSRs were polymorphic for 42 Fop isolates. The number of alleles varied from two to ten, with an average of four alleles per locus and an average PIC (Polymorphic Information Content) of 0.38. The genetic diversity assessed by microsatellites for Fop was low, as expected for an asexual fungus, and not associated with geographic origin, but they were able to detect enough genetic variability among isolates in order to differentiate them. Microsatellites are a robust tool widely used for genetic fingerprinting and population structure analyses. SSRs for Fop may be an efficient tool for a better understanding of the ecology, epidemiology and evolution of this pathogen.
ABSTRACT
The hard tick Amblyomma aureolatum (Pallas) is a vector of the bacterium Rickettsia rickettsii, the etiologic agent of Brazilian spotted fever (BSF) in parts of Brazil. Despite its wide distribution in southeastern South America and its public health importance, there is no information about genetic variation of this species that might help to understand the epidemiology of BSF. Using data from eight microsatellite markers and ticks from six localities, we used a population genetics approach to test the hypothesis that tick populations from areas with the presence of R. rickettsii are genetically different from ticks from areas without R. rickettsii Contrary to expectations, we found low genetic structure between studied regions. Thus, the presence of R. rickettsii in the specific area is more likely correlated with ecological and the environmental conditions or due to unknown gene coding regions of A. aureolatum genome that would be related to R. rickettsii infection resistance.
Subject(s)
Genetic Variation , Ixodidae/physiology , Microsatellite Repeats , Animals , Brazil , Ixodidae/genetics , Ixodidae/microbiology , Population Dynamics , Rickettsia rickettsii/physiologyABSTRACT
PREMISE OF THE STUDY: Baccharis dracunculifolia (Asteraceae) is a native plant of the Atlantic Forest that is used for the production of essential oil. Microsatellite markers were developed for this species to investigate the genetic diversity of three natural populations. METHODS AND RESULTS: Seventeen out of 27 microsatellite loci identified in a genomic library used for the characterization of 315 individuals derived from three natural populations of B. dracunculifolia resulted in successful amplifications. Eleven polymorphic loci, ranging from two to seven alleles per locus, were obtained with expected and observed heterozygosity values ranging between 0.068 and 0.775 and 0.046 and 0.667, respectively. CONCLUSIONS: The microsatellite loci described in this study are tools that can be used for further studies of population genetics of B. dracunculifolia with a focus on deforested areas and conservation of natural populations.
ABSTRACT
PREMISE OF THE STUDY: Microsatellite primers were designed for the submersed aquatic plant Cabomba aquatica s.l. (Cabombaceae) and characterized to estimate genetic diversity parameters. METHODS AND RESULTS: Using a selective hybridization method, we designed and tested 30 simple sequence repeat loci using two natural populations of C. aquatica s.l., resulting in 13 amplifiable loci. Twelve loci were polymorphic, and alleles per locus ranged from two to four across the 49 C. aquatica s.l. individuals. Observed heterozygosity, expected heterozygosity, and fixation index varied from 0.0 to 1.0, 0.0 to 0.5, and -1.0 to -0.0667, respectively, for the Manaus population and from 0.0 to 1.0, 0.0 to 0.6, and -1.0 to 0.4643 for the Viruá population. CONCLUSIONS: The developed markers will be used in further taxonomic and population studies within Cabomba. This set of microsatellite primers represents the first report on rapid molecular markers in the genus.
ABSTRACT
UNLABELLED: ⢠PREMISE OF THE STUDY: We developed and validated microsatellite primers for Vellozia squamata (Velloziaceae), an endemic species of the cerrado (Brazilian savannas), to investigate the influence of different fire regimes on its genetic diversity and population structure. ⢠METHODS AND RESULTS: Using a selective hybridization method, we tested 51 SSR loci using a natural population of V. squamata and obtained 47 amplifiable loci. Among these, 26 loci were polymorphic and the average values of genetic diversity were: average number of alleles per locus ([Formula: see text]) = 6.54, average number of alleles per polymorphic locus ([Formula: see text]) = 7.13, average observed heterozygosity [Formula: see text] = 0.22, average expected heterozygosity [Formula: see text] = 0.49, and average fixation index [Formula: see text] = 0.55. ⢠CONCLUSIONS: These 26 loci allowed us to assess the effects of distinct fire regimes on the genetic structure of V. squamata populations with the aim of establishing strategies for the conservation of this endemic species. The markers can also be useful for future pharmaceutical studies, as the species has great potential for medicinal and cosmetic applications.
ABSTRACT
UNLABELLED: ⢠PREMISE OF THE STUDY: Microsatellite primers were designed for Piptadenia gonoacantha (Fabaceae) and characterized to estimate genetic diversity parameters. The species is a native tree from the Atlantic Forest biome commonly used in forest restoration; it has medicinal potential and the wood is economically useful. ⢠METHODS AND RESULTS: Twenty-eight microsatellite loci were identified from an enriched genomic library. Fifteen loci resulted in successful amplifications and were characterized in a natural population of 94 individuals. Twelve loci were polymorphic, with allele numbers ranging from three to 15 per locus, and expected and observed heterozygosities ranging from 0.2142 to 0.8325 and 0.190 to 0.769, respectively. ⢠CONCLUSIONS: The developed markers will be used in further studies of population genetics of P. gonoacantha, aimed at conservation and management of the species in natural populations and in forest restoration projects.
ABSTRACT
This study aimed to present information about the sarsaparilla sold in establishments in the state of São Paulo, Brazil, assess the genetic diversity of Smilax brasiliensis Spreng., Smilacaceae, and examine the growing conditions and productivity of five species of Smilax. The amount of sarsaparilla sold per month at most pharmacies was 0.4 kg on average. Herbal stores and markets sold averages of 9 kg and 8 kg per month, respectively. The weight of the underground biomass of S. fluminensis (188.3 g) is significantly higher than those of other species (28.3-79.6 g). The study demonstrated that high genetic diversity among the Smilax brasiliensis plants belonging to the CPQBA germplasm bank, which was confirmed by the results of the genotyping study that used a SSR marker on S. brasiliensis. The high consumption of sarsaparilla and the low yield of young plants cultivated from seeds with high genetic variability reinforce the need for further studies on the production of Smilax species.
ABSTRACT
PREMISE OF THE STUDY: A new set of microsatellite or simple sequence repeat (SSR) markers were developed for Smilax brasiliensis, which is popularly known as sarsaparilla and used in folk medicine as a tonic, antirheumatic, and antisyphilitic. Smilax brasiliensis is sold in Brazilian pharmacies, and its origin and effectiveness are not subject to quality control. ⢠METHODS AND RESULTS: Using a protocol for genomic library enrichment, primer pairs were developed for 26 microsatellite loci and validated in 17 accessions of S. brasiliensis. Thirteen loci were polymorphic and four were monomorphic. The primers successfully amplified alleles in the congeners S. campestris, S. cissoides, S. fluminensis, S. goyazana, S. polyantha, S. quinquenervia, S. rufescens, S. subsessiliflora, and S. syphilitica. ⢠CONCLUSIONS: The new SSR markers described herein are informative tools for genetic diversity and gene flow studies in S. brasiliensis and several congeners.
