A New and Fast Technique to Generate Offspring after Germ Cells Transplantation in Adult Fish: The Nile Tilapia (Oreochromis niloticus) Model

Background: Germ cell transplantation results in fertile recipients and is the only available approach to functionally investigate the spermatogonial stem cell biology in mammals and probably in other vertebrates. In the current study, we describe a novel non-surgical methodology for efficient spermatogonial transplantation into the testes of adult tilapia (O. niloticus), in which endogenous spermatogenesis had been depleted with the cytostatic drug busulfan. Methodology/Principal Findings: Using two different tilapia strains, the production of fertile spermatozoa with donor characteristics was demonstrated in adult recipient, which also sired progeny with the donor genotype. Also, after cryopreservation tilapia spermatogonial cells were able to differentiate to spermatozoa in the testes of recipient fishes. These findings indicate that injecting germ cells directly into adult testis facilitates and enable fast generation of donor spermatogenesis and offspring compared to previously described methods. Conclusion: Therefore, a new suitable methodology for biotechnological investigations in aquaculture was established, with a high potential to improve the production of commercially valuable fish, generate transgenic animals and preserv

Restriction site heteroplasmy in the mitochondrial DNA of Brycon opalinus (Cuvier, 1819) (Characiformes, Characidae, Bryconiae)

Homoplasmy is a feature usually found in the mtDNA of higher animal taxa. On the other hand, the presence of two classes of mtDNA in the same cell or organism is rare and may appear in length or site variation. Data from mtDNA RFLP analysis of Brycon opalinus populations (Cuvier, 1819; Characiformes, Characidae, Bryconinae) revealed site heteroplasmy from endonuclease Nhel digestion. Southem blotting hybridization was used to survey a total of 257 specimens with 24 restriction enzymes. Three different restriction fragment patterns of mtDNA were obtained from Nhel digestion. Two individuals from hatchery broodstock were found to have two of them. Nhel digests of heteroplasmic individuals yielded two fragments of approximately 1180 and 1260 bp. Despite the low frequency of this type of heteroplasmy in the whole B. opalinus population, the presence of site heteroplasmy in this species supports the evidence of this phenomenon in lower vertebrate groups.37330731

Mitochondrial DNA diversity in wild and cultured populations of Brycon opalinus (Cuvier, 1819) (Characiformes, Characidae, Bryconinae) from the Paraiba do Sul Basin, Brazil

Made available in DSpace on 2019-09-12T16:53:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2002RFLP analysis of mitochondrial DNA was carried out to investigate the population genetic structure of cultured and wild populations of Pirapitinga-do-sul-Brycon opalinus (Cuvier, 1819) (Characiformes, Characidae, Bryconinae) from the Paraiba do sul basin, Brazil. mtDNA samples were collected from 257 specimens sampled in seven rivers of the Paraiba basin and in a hatchery used for restocking. An initial screening with 24 restriction enzymes revealed six informative enzymes, which generated 27 haplotypes, Haplotype diversities were high both in the hatchery broodstock (h = 0.75) and in the samples from the wild (h = 0.60). Nucleotide diversity among the 27 B. opalinus haplotypes was 0.825%. Analysis of molecular variance (AMOVA) showed the highest variance within populations (70.48%) while 28.16% of the total diversity was due to interpopulation variance, suggesting the existence of genetic differentiation among B. opalinus populations. (C) 2002 Elsevier Science B.V. All rights reserved.Univ Sao Paulo, Inst Heart INCOR, Lab Genet & Mol Cardiol, BR-05403000 Sao Paulo, Brazil; Universidade de Taubaté (Unitau), Dept Agr Sci, BR-12020270 Sao Paulo, Brazil; Univ Estadual Campinas, Dept Genet & Evolut, BR-13083970 Campinas, SP, Brazil; Univ Estadual Campinas, Dept Physiol, BR-13081970 Campinas, SP, Brazi

Mitochondrial DNA diversity in wild and cultured populations of Brycon opalinus (Cuvier, 1819) (Characiformes, Characidae, Bryconinae) from the Paraiba do Sul Basin, Brazil

RFLP analysis of mitochondrial DNA was carried out to investigate the population genetic structure of cultured and wild populations of Pirapitinga-do-sul-Brycon opalinus (Cuvier, 1819) (Characiformes, Characidae, Bryconinae) from the Paraiba do sul basin, Brazil. mtDNA samples were collected from 257 specimens sampled in seven rivers of the Paraiba basin and in a hatchery used for restocking. An initial screening with 24 restriction enzymes revealed six informative enzymes, which generated 27 haplotypes, Haplotype diversities were high both in the hatchery broodstock (h = 0.75) and in the samples from the wild (h = 0.60). Nucleotide diversity among the 27 B. opalinus haplotypes was 0.825%. Analysis of molecular variance (AMOVA) showed the highest variance within populations (70.48%) while 28.16% of the total diversity was due to interpopulation variance, suggesting the existence of genetic differentiation among B. opalinus populations. (C) 2002 Elsevier Science B.V. All rights reserved.21441730819

Genetic evidence of population structuring in the neotropical freshwater fish Brycon hilarii (Valenciennes, 1850)

Brycon hilarii is a migratory fish widely distributed throughout the Paraguay River Basin. It is appreciated in sport fishing and for its superior meat quality. It is also the main species for tourist attraction in the Bonito region (State of Mato Grosso do Sul, Brazil). Considering the lack of information on the genetic structure of the fish of this species, the aim of the present study was to detect the genetic variability of Brycon hilarii through RAPD markers. A total of eighty specimens collected in different seasons at four sites of the Miranda River sub-basin (Paraguay River Basin, Brazil) were used for analysis. The results of genetic similarity, Shannon diversity, and AMOVA revealed differences between the sampling sites. Through AMOVA, differences between populations were more evident among the animals collected during the non-reproductive season, corresponding to a time of less movement of these fish. A population structuring model in which B. hilarii appears organized into genetically differentiated reproductive units that coexist and co-migrate through the studied system was suggested, contrasting the currently accepted idea that freshwater migratory fish form large panmictic populations in a determined hydrographic system. Despite the lack of a complete picture regarding the distribution of B. hilarii in the studied region, this initial idea on its population genetic structure could be an important contribution to providing aid for management and conservation programs of these fish