scholarly journals Genetic diversity of Tambaqui (Teleostei - Characidae) broodstocks from Northern region of Brazil using microsatellite markers

2020 ◽  
Vol 41 (6supl2) ◽  
pp. 3249-3258
Author(s):  
Angela Maria Urrea-Rojas ◽  
◽  
Felipe Pinheiro de Souza ◽  
Ed Christian Suzuki de Lima ◽  
Andrei Lincoln Yamachita ◽  
...  

The Amazonian fish Tambaqui (Colossoma macropomum) is the most common native species in Brazil. This species has the highest production rate in the Northern region, especially in the State of Rondônia. The genetic evaluation of Tambaqui is an extremely important to increase productivity in fish farms or improve the adaptability in restocking natural populations. The objective of this study was to evaluate the genetic diversity of three Tambaqui broodstocks in Rondônia, Brazil. Six microsatellite markers were used to analyze a total of 89 breeders collected from three fish farms located in Ji-Paraná (JP), Ouro Preto do Oeste (OP) and Presidente Médici (PM). A total of 37 alleles between 140 and 310 bp were found, including the presence of exclusive and low frequency alleles in the three broodstocks. The average values of observed heterozygosity ranged from 0.404 (PM) to 0.499 (JP). The FIS coefficient values were positive for the three broodstocks, demonstrating a deficit of heterozygotes. The Molecular Variance Analysis (AMOVA) showed greater variation within the stocks than between them. The genetic differentiation was moderate and significant between the stocks, with higher differentiation between JP x PM and lower between OP x PM. The Bayesian analysis designated an optimal value of K = 3 groupings. Although there is moderate genetic diversity between broodstocks, the high FIS indicates a possible decline of diversity in the next generations, and therefore, the incorporation of new breeders is suggested to increase the genetic diversity in the three stocks.

2008 ◽  
Vol 17 (17) ◽  
pp. 3808-3817 ◽  
Author(s):  
ÜLO VÄLI ◽  
ANNIKA EINARSSON ◽  
LISETTE WAITS ◽  
HANS ELLEGREN

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e2936 ◽  
Author(s):  
Caroline E. Dubé ◽  
Serge Planes ◽  
Yuxiang Zhou ◽  
Véronique Berteaux-Lecellier ◽  
Emilie Boissin

Quantifying the genetic diversity in natural populations is crucial to address ecological and evolutionary questions. Despite recent advances in whole-genome sequencing, microsatellite markers have remained one of the most powerful tools for a myriad of population genetic approaches. Here, we used the 454 sequencing technique to develop microsatellite loci in the fire coralMillepora platyphylla, an important reef-builder of Indo-Pacific reefs.We tested the cross-species amplification of these loci in five other species of the genusMilleporaand analysed its success in correlation with the genetic distances between species using mitochondrial 16S sequences. We succeeded in discovering fifteen microsatellite loci in our target speciesM. platyphylla,among which twelve were polymorphic with 2–13 alleles and a mean observed heterozygosity of 0.411. Cross-species amplification in the five otherMilleporaspecies revealed a high probability of amplification success (71%) and polymorphism (59%) of the loci. Our results show no evidence of decreased heterozygosity with increasing genetic distance. However, only one locus enabled measures of genetic diversity in the Caribbean speciesM. complanatadue to high proportions of null alleles for most of the microsatellites. This result indicates that our novel markers may only be useful for the Indo-Pacific species ofMillepora.Measures of genetic diversity revealed significant linkage disequilibrium, moderate levels of observed heterozygosity (0.323–0.496) and heterozygote deficiencies for the Indo-Pacific species. The accessibility to new polymorphic microsatellite markers for hydrozoanMilleporaspecies creates new opportunities for future research on processes driving the complexity of their colonisation success on many Indo-Pacific reefs.


Parasitology ◽  
2002 ◽  
Vol 125 (7) ◽  
pp. S51-S59 ◽  
Author(s):  
J. CURTIS ◽  
R. E. SORENSEN ◽  
D. J. MINCHELLA

Blood flukes in the genus Schistosoma are important human parasites in tropical regions. A substantial amount of genetic diversity has been described in populations of these parasites using molecular markers. We first consider the extent of genetic variation found in Schistosoma mansoni and some factors that may be contributing to this variation. Recently, though, attempts have been made to analyze not only the genetic diversity but how that diversity is partitioned within natural populations of schistosomes. Studies with non-allelic molecular markers (e.g. RAPDs and mtVNTRs) have indicated that schistosome populations exhibit varying levels of gene flow among component subpopulations. The recent characterization of microsatellite markers for S. mansoni provided an opportunity to study schistosome population structure within a population of schistosomes from a single Brazilian village using allelic markers. Whereas the detection of population structure depends strongly on the type of analysis with a mitochondrial marker, analyses with a set of seven microsatellite loci consistently revealed moderate genetic differentiation when village boroughs were used to define parasite subpopulations and greater subdivision when human hosts defined subpopulations. Finally, we discuss the implications that such strong population structure might have on schistosome epidemiology.


2021 ◽  
Author(s):  
Rafael Oliveira Moreira ◽  
Eduardo de Andrade Bressan ◽  
Horst Bremer Neto ◽  
Angelo Pedro Jacomino ◽  
Antonio Figueira ◽  
...  

Abstract Campomanesia phaea (Myrtaceae), known as cambuci, is a native species from the Brazilian Atlantic Forest with great potential to be developed as a new fruit crop. Microsatellite markers were developed for cambuci to characterize the genetic diversity and to investigate the genetic structure of a group of accessions originally collected at the presumed center of diversity of the species. The work involved the collection of 145 accessions from five regional groups (Juquitiba, Paraibuna, Mogi das Cruzes, Ribeirão Pires, and Salesópolis) in São Paulo state, Brazil. Fourteen loci were identified in an enriched genomic library developed from one of these accessions. Six out of 14 loci revealed to be polymorphic, disclosing 26 alleles. Based on the allele frequencies, the calculated genetic parameters of the five groups indicated an average allele number per loci (A) of 3.83, with the expected heterozygosity (He) of 0.57 and the observed heterozygosity (Ho) of 0.54. The analysis of the genetic structure indicated that most of the genetic diversity is found within each population (HS = 0.57), whereas the genetic diversity among populations was low (GST = 0.19). The genetic diversity parameter of Nei was considered low for the cambuci analyzed populations, with no evidence of inbreeding. Based on Darwin analysis, we chose 18 accessions from the five regional populations to compose a core collection that includes most of the genetic diversity found in this study. Our findings may contribute to define better conservation strategies and genetic breeding approaches for this native species in Brazil.


Rodriguésia ◽  
2021 ◽  
Vol 72 ◽  
Author(s):  
Micheli Sossai Spadeto ◽  
Thais Lazarino Maciel ◽  
Tatiana Tavares Carrijo ◽  
Marcia Flores da Silva Ferreira ◽  
Milene Miranda Praça Fontes

Abstract The investigation of genetic diversity in natural populations of species that show potential for use in reforestation programs is a key step in making management decisions. However, reforestation programs with native species in Brazil are still rarely based on a genetic understanding of the seed matrices used for seedling production. This is also the case for Myrsine umbellata, a dioecious shrub within the family Primulaceae that has been used in reforestation programs in Brazil, mainly due to its high production capacity of fruits attractive to the avifauna. The goal of this study was to measure intra- and interpopulational genetic diversity in natural populations of M. umbellata in six forest remnants of the Atlantic Forest using ISSR markers. The results revealed that the intrapopulational genetic diversity was greater than the genetic diversity among the studied populations. For this reason, the cultivation of seedlings from seeds obtained in more than one population seems the most appropriate strategy for reforestation purposes. Even though the most isolated populations are also the ones with highest genetic structure, all populations of M. umbellata included in this study revealed to be an important germplasm bank conserved in situ.


2018 ◽  
Vol 46 (1) ◽  
pp. 59-66 ◽  
Author(s):  
Cintia P. Souto ◽  
Mariana Tadey

SummaryGenetic diversity is the raw material for species’ persistence over time, providing the potential to survive stochastic events, as well as climate and/or human-induced environmental changes. Biodiversity in dry rangelands is decreasing due to intensification of livestock production, but its effects on the genetic diversity of the consumed biota have seldom been assessed. We examined livestock effects on the genetic diversity of two dominant creosote species of the Patagonian Monte Desert, Larrea divaricata and Larrea cuneifolia. We deployed competing hierarchical regression models to assess the relationship between genetic variation within natural populations as a function of increasing stocking rates on ten arid rangelands. These species exhibit similar levels and patterns of genetic structure, with high levels of both inbreeding and divergence among locations. We found that increased stocking reduces genetic variation and increases genetic subdivision between populations. Our results indicate that grazing pressures are impoverishing the gene pool of these dominant native species of the Monte Desert, decreasing the evolutionary potential of the primary plant producers and increasing the desertification risk for a vulnerable habitat. We highlight the importance of considering livestock as a major driver of genetic losses in dry rangelands under overgrazing pressure, especially given current forecasts of climate change.


2017 ◽  
Vol 38 (3) ◽  
pp. 1665
Author(s):  
Americo Moraes Neto ◽  
Denise Rocha Ayres ◽  
Danilo Pedro Streit Junior ◽  
Nelson Mauricio Lopera-Barrero ◽  
Paulo Bahiense Ferraz Filho ◽  
...  

Natural populations of tambaqui (Colossoma macropomum) have significantly decreased in recent decades especially due to human extraction activities. So that the environmental impact may be reduced, the restocking of fish and increase in fish production are enhanced. Genetic evaluations using molecular markers are essential for this purpose. Current study evaluates the genetic variability of two tambaqui broodstocks used in restocking programs. Sixty-five samples (33 samples from broodstock A and 32 samples from broodstock B) were collected. DNA was extracted from caudal fin samples, with the amplification of four microsatellite loci: Cm1A11 (EU685307) Cm1C8 (EU685308) Cm1F4 (EU685311) and Cm1H8 (EU685315). Fourteen alleles in the stock of broodstock A were produced, five alleles for Cm1A11 locus (230, 255, 260, 270 and 276 bp), three alleles Cm1C8 (239, 260, and 273 bp), two alleles Cm1F4 (211 and 245 bp), four alleles for Cm1H8 (275, 290, 320 and 331 bp) and two unique alleles were found for Cm1A11 loci (alleles 270 and 276 bp) and Cm1H8 (alleles 275 and 331 bp). In broodstock B, ten alleles were produced, the same alleles of the first stock except for alleles 270 and 276 bp in Cm1A11 locus and 275 and 331 bp in Cm1H8 locus. Broodstock A revealed low frequency alleles in Cm1A11 loci, Cm1C8, Cm1F4 and Cm1H8, whereas broodstock B had no locus with low allelic frequency. Loci Cm1A11, Cm1C8 and Cm1H8 exhibited significant deficit of heterozygotes in both broodstocks, revealing changes in Hardy-Weinberg equilibrium. Genetic diversity between stocks was 0.1120, whilst genetic similarity was 0.894, with FST rate = 0.05, and Nm = 3.93, indicating gene flow between the two broodstocks. Results show that broodstocks are genetically closely related, with no great genetic variability. Strategies such as a previous genetic analysis of breeding with its marking, use of a large Ne crossing between the most genetically divergent specimens, and the introduction of new genetic material to broodstocks may maximize genetic diversity and minimize inbreeding within the next generation.


2011 ◽  
Vol 60 (1-6) ◽  
pp. 285-288 ◽  
Author(s):  
G. Marconi ◽  
M. A. Martín ◽  
M. Cherubini ◽  
L. Raggi ◽  
F. Drake ◽  
...  

Abstract Araucaria araucana (Mol.) K. Koch is one of the most important native species of Chile and Argentina, and also one of the most endangered. In this study, we report the development and characterization of a set of microsatellite markers in the species by means of the microsatellite-AFLP (M-AFLP) technique. A total of 25 M-AFLP derived bands, showing a typical microsatellite pattern, were selected and sequenced. Of these, 12 that contained microsatellite sequences, were used for primer extension. Six of the resulting SSR markers provided easily interpretable patterns and were used to investigate the level of genetic diversity in two populations of A. araucana. A total of 43 alleles were amplified. The mean overall loci of observed and expected heterozygosities for the Conguillio and Villa Araucaria populations were 0.322 and 0.443, respectively. The primers presented in this study may provide useful information for the establishment of a conservation strategy in the species.


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