The increased population of the Wild Boar (Sus scrofa L.) in Europe

In this paper the recent population changes of the Wild Boar in different European countries is analysed through the study of hunting statistics. A simultaneous increase in numbers is observed throughout the whole area during the period 1965–1975. From 1975 onwards the population stabilizes itself apart from in peripheral areas like Finland. Potentially favourable factors which play a part in this process are discussed and certain reproductive and dispersive characteristics which favour its invasive behaviour are discussed.     

Spauligodon loboi n. sp. (Nematoda: Pharyngodonidae) parasite of Liolaemus spp. (Iguania: Liolaemidae) from northwestern Argentina

Three-hundred and forty-nine specimens of Spauligodon loboi n. sp. (Nematoda, Pharyngodonidae) were found in the large intestines of 55 of 225 adult specimens representing 5 species of Liolaemus collected in 11 localities of northwestern Argentina. Prevalence of infection was 24% (mean intensity = 6.3 +/- 3.4, range = 2-28). Spauligodon loboi n. sp. differs from other neotropical species in that the filamentous portion of the tail of males is spiny, whereas that of females is smooth. A key to the species of Spauligodon in the Neotropical Realm is provided.     

A Highlights from MBoC Selection: Spatial distribution of cell–cell and cell–ECM adhesions regulates force balance while main-taining E-cadherin molecular tension in cell pairs

Mechanical linkage between cell–cell and cell–extracellular matrix (ECM) adhesions regulates cell shape changes during embryonic development and tissue homoeostasis. We examined how the force balance between cell–cell and cell–ECM adhesions changes with cell spread area and aspect ratio in pairs of MDCK cells. We used ECM micropatterning to drive different cytoskeleton strain energy states and cell-generated traction forces and used a Förster resonance energy transfer tension biosensor to ask whether changes in forces across cell–cell junctions correlated with E-cadherin molecular tension. We found that continuous peripheral ECM adhesions resulted in increased cell–cell and cell–ECM forces with increasing spread area. In contrast, confining ECM adhesions to the distal ends of cell–cell pairs resulted in shorter junction lengths and constant cell–cell forces. Of interest, each cell within a cell pair generated higher strain energies than isolated single cells of the same spread area. Surprisingly, E-cadherin molecular tension remained constant regardless of changes in cell–cell forces and was evenly distributed along cell–cell junctions independent of cell spread area and total traction forces. Taken together, our results showed that cell pairs maintained constant E-cadherin molecular tension and regulated total forces relative to cell spread area and shape but independently of total focal adhesion area.     

Observations on two Rhabdochona species (Nematoda: Rhabdochonidae) from freshwater fishes in Argentina, including description of Rhabdochona fabianae n. sp

Helminthological examination of specimens of the freshwater fishes Bryconamericus iheringi Boulenger, 1887 (Characidae) and Jenynsia multidentata (Jenyns, 1842) (Anablepidae), collected from Medina River, Province of Tucuman, Argentina, revealed the presence of 2 species of parasitic nematodes, Rhabdochona fabianae n. sp. and Rhabdochona acuminata (Molin, 1860) (Rhabdochonidae). Rhabdochona fabianae n. sp. was characterized by the presence of 16 anterior teeth in the prostom and filamented eggs in females. Rhabdochona acuminata was recorded for the first time in the north of Argentina.     

Chromosome numbers in Brazilian species of Crotalaria (Leguminosae, Papilionoideae) and their taxonomic significance

Chromosome numbers were counted for 23 species of Crotalaria native to Brazil. Among these data there were new counts for 15 taxa, and some confirmed previous reports or represented numbers that were different from those cited previously. The chromosome numbers most frequently found were 2 n  = 16 and 2 n  = 32. Only C. incana L. had 2 n  = 14 and C. tweediana Benth. had 2 n  = 54. The counts 2 n  = 32 and 54 were found in species of section Calycinae and 2 n  = 16 and 14 in species of section Chrysocalycinae . The data revealed the importance of chromosomal parameters in the characterization of sections Calycinae and Chrysocalycinae in Brazil. We discuss the systematic significance and evolutionary aspects for the genus, comparing the results with the two sections that are native in Brazil.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 271–277.     

Chromosome numbers and meiotic analysis in the pre-breeding of <Emphasis Type="BoldItalic">Brachiaria decumbens</Emphasis> (Poaceae)

A total of 44 accessions of Brachiaria decumbens were analysed for chromosome count and meiotic behaviour in order to identify potential progenitors for crosses. Among them, 15 accessions presented 2n = 18; 27 accessions, 2n = 36; and 2 accessions, 2n = 45 chromosomes. Among the diploid accessions, the rate of meiotic abnormalities was low, ranging from 0.82% to 7.93%. In the 27 tetraploid accessions, the rate of meiotic abnormalities ranged from 18.41% to 65.83%. The most common meiotic abnormalities were related to irregular chromosome segregation, but chromosome stickiness and abnormal cytokinesis were observed in low frequency. All abnormalities can compromise pollen viability by generating unbalanced gametes. Based on the chromosome number and meiotic stability, the present study indicates the apomictic tetraploid accessions that can act as male genitor to produce interspecific hybrids with B. ruziziensis or intraspecific hybrids with recently artificially tetraploidized accessions.     

Patterns of genetic variability at individual minisatellite loci in minke whale Balaenoptera acutorostrata populations from three different oceans

The genetic variability at six cloned minisatellite loci was analyzed in minke whale populations from the North Atlantic, North Pacific, and Antarctic Oceans. Three loci displayed only a few different alleles in each of the three populations, with heterozygosity ranging from 0.00 to 0.47, and three loci revealed many different alleles in at least two fo the three populations, with heterozygosity ranging up to 0.98. Using small sample sizes, samples from two adjacent Antarctic Management Areas were not found to differ significantly in allele frequencies at any of the six loci. The use of principal coordinate analysis to detect multilocus disequilibria was explored. No significant evidence was found of intrapopulation heterogeneity within the pooled Antarctic sample. Pronounced interoceanic differences were observed at every locus, confirming the existence of genetic isolation found earlier using more conventional marker systems. The populations from the three oceans appear to have diverged to such a degree that the hypervariable loci have had time to evolve independently and arrive at different evolutionary stages in different populations. The frequency of undetected "null" alleles is remarkably high in minke whale populations compared to human populations and is probably a result of the cloning protocol used. Minisatellite loci are shown to provide a powerful population genetic tool, supplying levels of resolution appropriate to different degrees of evolutionary divergence.