Analysis of genetic variability in three species of Pimelodidae (Ostariophysi - Siluriformes)

Genetic variability of three Pimelodidae species, Pimelodus maculatus, Iheringichthys labrosus, and Pinirampus pirinampu, collected at one site in the Tibagi River, was comparatively analyzed using protein data for six systems which code 15 loci in liver, muscle, and heart. The proportion of polymorphic loci (<img src="http:/img/fbpe/gmb/v21n4/21n4a14.jpg" alt="21n4a14.jpg (768 bytes)" align="middle">) for P. maculatus, I. labrosus, and P. pirinampu was 13.33, 20, and 6.67%, respectively, and mean heterozigosity was 6, 8.3, and 4.3%. The genetic identity value (I) was 0.32 between P. maculatus and I. labrosus, 0.37 between P. maculatus and P. pirinampu, and 0.58 between I. labrosus and P. pirinampu. This value suggests that these two latter species are congeneric. However, morphological characteristics place these species in distinct genera

Genetic diversity of Hypostomus ancistroides (Teleostei, Loricariidae) from an urban stream

In this study, random amplified polymorphic DNA (RAPD) markers were applied to analyze the genetic diversity of samples of the Neotropical catfish Hypostomus ancistroides, collected from four sites (S1, S2, S3 and S4) along an urban stream in Southern Brazil. The 11 primers used in RAPD analysis amplified 147 loci, 76 (51.7%) of which were polymorphic. The proportions of polymorphic loci observed in the four samples were: 29.93% (S1), 31.97% (S2), 23.81% (S3) and 38.77% (S4). The average heterozygosity within sampling localities ranged from 0.1230 to 0.1526 and unbiased genetic distances ranged from 0.0253 to 0.0445. AMOVA partitioned 90.85% of the total variation within samples and 9.15% among samples. Excepting for the sample pair S1-S2 (phiST = 0.02784; p > 0.05), all others pairwise phiST values were significantly greater than zero, indicating moderate genetic differentiation among catfish samples from four localities. The relative low levels of genetic variation detected in all groups studied could be related to different factors, including the sedentary habit of these fish, which can be eroding the genetic variation of H. ancistroides from each locality

Genetic structure analysis of Eufriesea violacea (Hymenoptera, Apidae) populations from southern Brazilian Atlantic rainforest remnants

Random amplified polymorphic DNA (RAPD) markers were used to analyze the genetic structure of Eufriesea violacea populations in three fragments (85.47, 832.58 and 2800 ha) of Atlantic rainforest located in the north of the Brazilian state of Paraná. A total of twelve primers produced 206 loci, of which 129 were polymorphic (95% criterion). The proportions of polymorphic loci in each population ranged from 57.28% to 59.2%, revealing very similar levels of genetic variability in the groups of bees from each fragment. Unbiased genetic distances between groups ranged from 0.0171 to 0.0284, the smallest genetic distance occurring between bees from the two larger fragments. These results suggest that the E. violacea populations from the three fragments have maintained themselves genetically similar to native populations of this species originally present in northern Paraná