A nondestructive,rapid, reliable and inexpensive method to sample,store and extract high‐quality DNA from fish body mucus and buccal cells

A rapid, nondestructive, reproducible and cheap DNA extraction method from body mucus and buccal cells of northern pike and brown trout is described. Buccal cells and body mucus were sampled on FTA Cards; the captured DNA was used directly for microsatellite and polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) analyses. A complete concordance with control DNA was found. The genotyping error rate for microsatellite ranged from 1.9% to 3.3% for the northern pike and brown trout, respectively. This methodology, using for the first time these materials as a fish DNA source, combines speed of sampling and processing, with a twofold to a threefold time and costs saving.     

Isolation and characterization of eight microsatellite loci in Leporinus macrocephalus (Characiformes: Anostomidae) and cross‐species amplification

Leporinus macrocephalus is a species endemic to the Paraguay River basin and an important fishery resource, as well as a valuable species in aquaculture programs. A total of eight polymorphic microsatellite loci were isolated and characterized. A population survey was conducted involving 45 specimens whereby a large number of alleles (range 5–17 among loci), a highly observed (0.1667–0.6129) and an expected (0.6967–0.9448) heterozygosity was detected, indicating its usefulness in population genetics studies. Cross‐species amplification was successful in eight Characiformes species.     

Isolation of polymorphic DNA microsatellites in the common sole Solea vulgaris

A microsatellite‐enriched genomic library was obtained from the common sole, Solea vulgaris, and seven polymorphic dinucleotide markers were successfully optimized. These markers showed levels of expected heterozygosity ranging from 0.55 to 0.83 and allele number ranging from eight to 12. Three of these markers were also found to successfully amplify in the closely related Solea senegalensis and can be employed to define population genetic structure of the two Solea species and for inferring stock origins.     

Deep biogeographical history and cytonuclear discordance in the black-tailed brush lizard (Urosaurus nigricaudus) of Baja California

Molecular tools help us deduce historical events such as vicariance, dispersal, gene flow and speciation. However, our inferences are inevitably linked to the nature of the characters that we use to infer history. For example, the difference in inheritance patterns of mitochondrial DNA (mtDNA) and nuclear DNA (non-recombining maternal vs. recombining biparental inheritance) may lead us to propose different intraspecific histories. The peninsula of Baja California of north-western Mexico, a region affected by a complex geological history involving temporary seaways, permits evaluation of differences between these character types. We sequenced 1966 bp of mtDNA to reconstruct the genealogical history of Urosaurus nigricaudus (black-tailed brush lizard) from samples spanning the entire peninsula. The genealogy revealed several deep divergences, congruent with temporary vicariance events in the mid-peninsular, Loreto and Cape regions, as well as a major split across the Isthmus of La Paz, possibly resulting from a late Miocene seaway. The results support an emerging picture of the historical biogeography of Baja California, which suggests that key vicariance events are older than commonly perceived. The maternal genealogy of U. nigricaudus sharply contrasts with variation in allozymes that suggests very little differentiation across mitochondrial breaks, consistent with a pattern of ongoing gene flow. We interpret this cytonuclear discordance in relation to the historical biogeography of the region.  © 2008 The Linnean Society of London, Biological Journal of the Linnean Society , 2008, 94 , 89–104.     

Antigenic Similarity Between the Coccidian Parasites Toxoplasma gondii and Hammondia hammondi1

The antigens that are present in the coccidian parasites Toxoplasma gondii and Hammondia hammondi were demonstrated and defined by using SDS-PAGE and immunoenzymatic techniques with ¹²⁵I-labeled and unlabeled antigens of T. gondii and sera of mice infected orally or intraperitoneally with H. hammondi. All cell surface antigens of T. gondii that were labeled with ¹²⁵I were recognized by antibodies in the sera of the mice infected with H. hammondi except the antigen of approximate molecular weight of 21.5 Kd. This suggests that this antigen is specific for T. gondii. Various antigens in the T. gondii-lysed antigen preparations were recognized by antibodies to H. hammondi. The number of recognized antigens increased as the infection of the mice with H. hammondi progressed. Oral infection with H. hammondi appeared to induce the formation of antibodies that recognized more T. gondii antigens than infection by intraperitoneal inoculation.     

Binding of Lectins to the Cell Surface of Trypanosoma cruzi*

SYNOPSIS. Differences in the composition and distribution of cell membrane carbohydrates were demonstrated in the 3 life cycle forms of 3 Trypanosoma cruzi strains by using lectins with different specificities. The results suggest that lectin binding may be useful in characterization of the parasite strains.     

Isolation and characterization of microsatellite loci in Pseudoplatystoma corruscans (Siluriformes: Pimelodidae) and cross‐species amplification

A total of five polymorphic microsatellites loci from Pseudoplatystoma corruscans were isolated and characterized. A population survey involving 43 specimens resolved a large number of alleles (range seven to eight among loci) and high observed heterozygosity (0.500–0.615), indicating its usefulness in population genetics studies. Cross‐species amplification was successful in four other Pimelodidae species.