ABSTRACT
The genus Bryconcomprises fish species of significant socioeconomic and biological importance in Brazil. Despite that, the genetic knowledge about these species is scarce, especially regardingBrycon falcatus. Thus, the objective of this study was to evaluate the transferability of heterologous microsatellite primers inB. falcatus for the first time. Heterologous primers obtained from B. opalinus, B. hilarii, B. insignis, B. orbignyanus, B. amazonicus, Prochilodus argenteus, Prochilodus lineatus, Piaractus mesopotamicus, and Colossoma macropomum were evaluated. The primers that showed the best amplification patterns were applied to a sample of 22 individuals and the genetic parameters were calculated. Nine primers displayed satisfactory cross-amplification withB. falcatus: BoM5 (Brycon opalinus); Bh8, Bh13 and Bh16 (B. hilarii); Borg59 (B. orbignyanus); Bag22 (B. amazonicus); Par12 and Par80 (P. argenteus), and Cm1A8 (C. macropomum). The genetic parameters (number of alleles, effective alleles, allele richness, and expected and observed heterozygosity) and the polymorphic information content (PIC) confirmed the viability of these primers for population genetics analyses. Our study demonstrates the potential of transferability of microsatellite markers from related species and even different genera to B. falcatus, providing usefull tools for future population genetic studies in this species. (AU)
Subject(s)
Genetic Variation , Microsatellite Repeats , /classification , Genetics, PopulationABSTRACT
Being an economical and nutritional crop, Capsicum appeases people’s peppery taste and is found to bewidely distributed all over the world having vast diversity. In the present study, genetic polymorphism, cross transferability (CT) and genetic diversity were examined among the 54 different accessions of Capsicum species including 49 of Capsicum annuum, three of C. baccatum and two of C. frutescens, using a set of 36 start codon targeted (SCoT) primers. Of the total, 35 SCoT markers showed successful amplification profile among chilli germplasms and an average primer polymorphism was reported as 81.52% which ranged from 50% (SCoT-6) to 100% (SCoT-11). A total of 365 amplicons were obtained with an average of 10.43 bands per primer and the length of the bands ranged from 150 bp to 1.2 kb. Further, polymorphic information content value of SCoT markers ranged from 0.42 (for SCoT-25) to 0.86 (SCoT-27) with an average of 0.78. The average value of CT of SCoT markers was 44.08% ranged from 14.25% to 57.26% among different chilli accessions. A dendrogram was constructed and established genetic relationship among 54 capsicum species, with the help of translation initiation codon polymorphisms or SCoT primer amplification. This study suggests the effectiveness of SCoT marker system for characterizing and assessing genetic diversity of Capsicum germplasm, which can be used for evolutionary studies and to identify agronomically important traits.
ABSTRACT
ABSTRACT: Brycon gouldingi is a species of neotropical fish of socioeconomic and environmental importance in the Tocantins-Araguaia Basin. Genetic studies on this species are still limited, making it difficult to evaluate the population structure and genetic diversity in natural and captive stocks. Here, we aimed to evaluate the transferability of heterologous microsatellite primers in B. gouldingi. A total of 30 primers for eight species were evaluated: Brycon hilarii, Brycon opalinus, Brycon cephalus, Brycon orbignyanus, Prochilodus lineatus, Prochilodus argenteus, Piaractus mesopotamicus, and Colossoma macropomum. The primers that showed the best amplification patterns were applied to 20 specimens of B. gouldingi, and their genetic parameters were assessed. Among the 30 primers, seven showed satisfactory transferability, six of which belonged to the genus Brycon: Bh13 (B. hilarii), BoM5, BoM13 (B. opalinus), Borg9, Borg13, and Borg59 (B. orbignyanus), and one belonged to P. argenteus (Par80). The primers for the other species tested showed non-specificity or monomorphism; and were therefore, excluded from the analyses. The number of alleles ranged between two (Borg13 and Borg59) and three (Bh13, BoM5, BoM13, Borg9 and Par80), with sizes varying between 103 bp (BoM5) and 430 bp (Borg9). Four primers showed evidence of null alleles (BoM13, Borg9, Borg13, and Par80), which could probably be attributed to the respective Hardy-Weinberg deviation. Thus, seven primers were validated for cross-amplification in B. gouldingi, which may be used in future studies involving this species.
RESUMO: Brycon gouldingi é uma espécie de peixe neotropical com importância socioeconômica e ambiental na Bacia do Tocantins-Araguaia. Estudos genéticos nessa espécie ainda são escassos, dificultando o conhecimento sobre a estrutura populacional e a diversidade genética nos estoques naturais e em cativeiro. O objetivo do presente estudo foi avaliar a transferibilidade de primers microssatélites heterólogos em B. gouldingi. Foram avaliados um total de 30 primers de oito espécies: Brycon hilarii, Brycon opalinus, Brycon cephalus, Brycon orbignyanus, Prochilodus lineatus, Prochilodus argenteus, Piaractus mesopotamicus e Colossoma macropomum. Os primers que demonstraram melhores padrões de amplificação foram aplicados em 20 espécimes de B. gouldingi para os cálculos dos parâmetros genéticos. Sete dos 30 primers apresentaram resultados satisfatórios de transferibilidade, sendo seis oriundos do gênero Brycon: Bh13 (B. hilarii), BoM5, BoM13 (B. opalinus), Borg9, Borg13 e Borg59 (B. orbignyanus), e um oriundo de P. argenteus (Par80). Os primer das outras espécies testados mostraram inespecificidade ou monomorfismo, sendo excluídos das análises. O número de alelos variou de dois (Borg13 e Borg59) a três (Bh13, BoM5, BoM13, Borg9 e Par80), com tamanhos entre 103 pb (BoM5) e 430 pb (Borg9). Quatro primers apresentaram evidências de alelos nulos (BoM13, Borg9, Borg13 e Par80), o que provavelmente inferiu sobre o desvio de Hardy-Weinberg nos mesmos. Concluindo, sete primers foram validados para a amplificação cruzada em B. gouldingi e poderão ser utilizados em futuros estudos com essa espécie.
ABSTRACT
Citrus Huanglongbing (HLB) also known as citrus greening is one of the most devastating diseases of citrus worldwide. The disease is caused by Candidatus Liberibacter bacterium, vectored by the psyllid Diaphorina citri Kuwayama and Trioza erytreae Del Guercio. Citrus plants infected by the HLB bacterium may not show visible symptoms sometimes for years following infection. The aim of this study was to develop effective gene-specific primer pairs for polymerase chain reaction based method for quick screening of HLB disease. Thirty-two different gene-specific primer pairs, across the Ca. Liberibacter asiaticus genome, were successfully developed. The possibility of these primer pairs for cross-genome amplification across ‘Ca. Liberibacter africanus’ and ‘Ca. Liberibacter americanus’ were tested. The applicability of these primer pairs for detection and differentiation of Ca Liberibacter spp. is discussed.
ABSTRACT
Cross-amplification was tested and variability in microsatellite primers (designed for Neotropical parrots) compared, in five macaw species, viz., three endangered blue macaws (Cyanopsitta spixii [extinct in the wild], Anodorhynchus leari [endangered] and Anodorhynchus hyacinthinus [vulnerable]), and two unthreatened red macaws (Ara chloropterus and Ara macao). Among the primers tested, 84.6 percent successfully amplified products in C. spixii, 83.3 percent in A. leari, 76.4 percent in A. hyacinthinus, 78.6 percent in A. chloropterus and 71.4 percent in A. macao. The mean expected heterozygosity estimated for each species, and based on loci analyzed in all the five, ranged from 0.33 (A. hyacinthinus) to 0.85 (A. macao). As expected, the results revealed lower levels of genetic variability in threatened macaw species than in unthreatened. The low combined probability of genetic identity and the moderate to high potential for paternity exclusion, indicate the utility of the microsatellite loci set selected for each macaw species in kinship and population studies, thus constituting an aid in planning in-situ and ex-situ conservation.
ABSTRACT
La familia Myrtaceae ha evolucionado desde las formas más primitivas en los bosques húmedos y lluviosos hasta formas especializadas en regiones semiáridas, muy secas y altamente influenciadas por los cambios estacionales. Aunque los botánicos han estado describiendo estas especies desde hace 200 años, la clasificación de las mismas no está completamente esclarecida. Las Secuencias Simples Repetidas (SSR), conocidas comúnmente como microsatélites, representan una porción significativa del genoma eucariótico y pueden ser de gran utilidad para estos fines. El objetivo del presente trabajo fue utilizar cebadores SSR, diseñados previamente para guayabo, en la identificación de accesiones y en el estudio de diversidad en Myrtaceae. Para este propósito se emplearon cuatro combinaciones de cebadores SSR siguiendo los protocolos establecidos en la literatura. Se realizó el análisis de los resultados atendiendo a la potencialidad de amplificación cruzada, la detección de diferentes alelos, la utilidad para la identificación de accesiones y el estudio de la diversidad y la determinación de las relaciones existentes entre las especies y cultivares en estudio. El alto nivel de polimorfismo detectado por los microsatélites evaluados, el cual se refleja en los valores de los índices relacionados con el nivel de polimorfismo y la capacidad de discriminación calculados, indica las potencialidades de los SSR para la identificación de accesiones en otros representantes de la familia Myrtaceae. Además, representan una herramienta de gran utilidad para estudios de diversidad en esta familia; así como para la estimación de las relaciones de parentesco entre los genotipos analizados, análisis taxonómico y de filogenia.
Myrtaceae family has evolved from primitive forms in rainy and humid forest to specialized forms in semiarid and very dry regions, highly influenced by seasonal changes. Although botanist have been describing Myrtaceae family species over 200 years, classification is far from be completely clarify. Simple Sequences Repeats (SSR), usually known as microsatellites, represent a significant portion of eukaryotic genome and can be of great utility for these purposes. The objective of the present work was to utilize SSR primers, previously designed in guava, for accessions identification and diversity studies of other Myrtaceae members. For this purpose, four SSR primer combinations were utilized following the protocols established in the literature. The results were analyzed attending to cross amplification potentiality, detection of different alleles, utility for accessions identification and diversity studies and relationships determination between the studied species and cultivars. The high level of polymorphism detected by the evaluated microsatellites, which is reflected in the values of each index related with polymorphism and calculated discriminating capacity, indicates the potentials of SSR for accessions identification in other Myrtaceae family members. Also, represents a great utility tool for diversity studies in this family, as well as for the estimation of parentage relationship between the genotypes investigated and the taxonomic and phylogenetic analysis.
Subject(s)
Psidium/genetics , Psidium/microbiology , Psidium/chemistry , PhylogenyABSTRACT
In this study we tested the cross-amplification of 33 microsatellite loci previously developed for two closely related Neotropical orchid genera (Epidendrum and Laelia). A set of ten loci were polymorphic across five examined species (20 individuals each) with 2 to 15 alleles per locus. The mean expected and observed heterozygosity (average across species) ranged from 0.34 to 0.82 and from 0.27 to 0.85, respectively. In addition we tested all loci in 35 species representative of the genus Epidendrum. Of these, 26 loci showed successful amplification. Cross-application of these loci represent a potential source of co-dominant markers for evolutionary, ecological and conservation studies in this important orchid genus.
ABSTRACT
The maned wolf (Chrysocyon brachyurus) is the largest South American canid. Habitat loss and fragmentation, due to agricultural expansion and predatory hunting, are the main threats to this species. It is included in the official list of threatened wildlife species in Brazil, and is also protected by IUCN and CITES. Highly variable genetic markers such as microsatellites have the potential to resolve genetic relationships at all levels of the population structure (among individuals, demes or metapopulations) and also to identify the evolutionary unit for strategies for the conservation of the species. Tests were carried out to verify whether a class of highly polymorphic tetranucleotide repeats described for the domestic dog effectively amplifies DNA in the maned wolf. All five loci studied were amplified; however, one of these, was shown to be monomorphic in 69 maned wolf samples. The average allele number and estimated heterozygosity per polymorphic locus were 4.3 and 67%, respectively. The genetic variability found for this species, which is considered threatened with extinction, showed similar results when compared to studies of other canids.
Subject(s)
Animals , Dogs , Genetic Variation , Genetic Markers , Microsatellite Repeats , Alleles , Brazil , Species Specificity , Genetics, Population , Geography , Wolves , Polymorphism, GeneticABSTRACT
The maned wolf (Chrysocyon brachyurus) and the crab-eating fox (Cerdocyon thous) are two wild-canid species found in the Brazilian Cerrado. We tested cross-amplification and transferability of 29 short tandem repeat primers originally developed for cattle and domestic dogs and cats on 38 individuals of each of these two species, collected in the Emas National Park, which is the largest national park in the Cerrado region. Six of these primers were successfully transferred (CSSM-038, PEZ-05, PEZ-12, LOCO-13, LOCO-15, and PEZ-20); five of which were found to be polymorphic. Genetic parameter values (number of alleles per locus, observed and expected heterozygosities, and fixation indices) were within the expected range reported for canid populations worldwide.