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Wild Individuals (wild + individual)
Selected AbstractsRearing Environment Affects the Brain Size of Guppies: Lab-Reared Guppies have Smaller Brains than Wild-Caught GuppiesETHOLOGY, Issue 2 2009James G. Burns Animals bred for captivity often have smaller brains and behave differently than their wild counterparts. These differences in brain size have been attributed to genetic changes resulting from, for example, inbreeding depression and pleiotropic effects of artificial selection for traits such as docility. A critical question, though, is whether these differences in brain size are due to plastic responses to the environment, not just genetic changes. We observed a large reduction in brain size in first generation, lab-reared female guppies compared with wild-caught ones (19% smaller telencephalon, 17% smaller optic tectum). We then reared first-generation, lab-born guppies in environments varying in spatial complexity and size in an attempt to isolate factors that might increase brain size and change temperament, but no significant differences in phenotype were observed. The results of these experiments show that, although the environmental factors responsible for the effect have not been found, even first generation lab-reared individuals can have smaller brains than wild individuals. [source] Reversible introduction of transgenes in natural populations of insectsINSECT MOLECULAR BIOLOGY, Issue 2 2006A. Le Rouzic Abstract The most serious challenge concerning genetically modified insects remains their invasion ability. Indeed, transgenic insects often show lower fitness than wild individuals, and the transgene does not seem able to spread through a natural population without a driving system. The use of remobilizable vectors, based on the invading properties of transposable elements, has been frequently suggested. Simulations show that this strategy can be efficient. Moreover, if the transgene is designed to use transposition machinery already present in the genome, the transgene invasion appears to be potentially reversible after a few hundred generations, leading to new experimental perspectives. [source] New polymorphic microsatellite markers for the limpet Patella rustica and cross-priming testing in four Patella speciesMOLECULAR ECOLOGY RESOURCES, Issue 4 2008M. PÉREZ Abstract Eighteen microsatellite markers have been characterized from the Patella rustica genome. An average of 10 alleles per locus and an expected heterozygosity ranging from 0.054 to 0.937 were observed in a sample of 32 wild individuals from Viana do Castelo, Portugal. Distinct cross-priming amplification rates were recovered on four additional Patella species. Three monomorphic P. rustica loci were polymorphic in other Patella species. The microsatellites developed herein could be a useful intraspecific genetic tool to undertake fine population studies in the genus Patella. [source] PRIMER NOTE: Isolation and characterization of polymorphic microsatellite markers for the endangered Korean freshwater fish Hemibarbus mylodonMOLECULAR ECOLOGY RESOURCES, Issue 3 2007WOO-JIN KIM Abstract Korean barbel, Hemibarbus mylodon, is an endangered freshwater species endemic to Korea. In order to undertake a conservation program for this species in Korea, it is essential to evaluate its genetic diversity and population structure. For this purpose, we developed 10 polymorphic microsatellite markers and examined their allelic variation using a total of 60 wild individuals collected from three different localities. The number of alleles per locus ranged from three to 26. The expected and observed heterozygosities per locus ranged from 0.19 to 0.94 and from 0.20 to 0.98, respectively. Significant departures from Hardy,Weinberg equilibrium expectations occurred in four loci. These markers will be useful for the assessment of genetic diversity for this species. [source] Wild grapevine: silvestris, hybrids or cultivars that escaped from vineyards?PLANT BIOLOGY, Issue 3 2010Molecular evidence in Sardinia Abstract Vitis vinifera ssp. silvestris, the spontaneous subspecies of V. vinifera L., is believed to be the ancestor of present grapevine cultivars. In this work, polymorphism at 13 SSR loci was investigated to answer the following key question: are wild plants (i) true silvestris, (ii) hybrids between wild and cultivated plants or (iii) or ,escapes' from vineyards? In particular, the objective of the present study was to identify truly wild individuals and to search for possible hybridization events. The study was performed in Sardinia, the second largest island in the Mediterranean Sea, which is characterized by a large and well-described number of both grape cultivars and wild populations. This region was ideal for the study because of its spatial isolation and, consequently, limited contamination from outside material. The results of this study show that domesticated and wild grapevine germplasms are genetically divergent and thus are real silvestris. Pure lineages (both domesticated and wild) show very high average posterior probabilities of assignment to their own clusters, with a low level of introgression. [source] High levels of nucleotide diversity in the European rabbit (Oryctolagus cuniculus) SRY geneANIMAL GENETICS, Issue 4 2005A. Geraldes Summary We have sequenced 2388 bp of the European rabbit sex determining region Y (SRY) gene. These data provide a 10-fold increase in the coverage of the Y chromosome in this species, including the entire open reading frame of the SRY, the polyadenylation signal, and two repetitive sequences in the 5, -region. A survey of 2021 bp of this gene in eight domestic breeds and four wild individuals revealed a total of nine single nucleotide polymorphisms and one indel, defining two deeply divergent lineages. The resulting estimation of nucleotide diversity (, = 1.34 × 10,3) is very high when compared with other species, but no variability was detected among the domestic breeds. This study represents a first step in the characterization of the European rabbit Y chromosome and its variability. These sequences can be used in additional phylogeographical analyses of the European rabbit and other Leporid species, as well as in evolutionary studies of sex determination and the Y chromosome in wild species. [source] Heterochronic differences in fin development between latitudinal populations of the medaka Oryzias latipes (Actinopterygii: Adrianichthyidae)BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 3 2009MAIKO KAWAJIRI Heterochrony is believed to have played important roles in macroevolutionary morphological changes. However, few studies have focused on intraspecific heterochrony, although interspecific differences ultimately originated from variation within ancestral species. We have demonstrated heterochrony in fin development between two latitudinal populations of the medaka, Oryzias latipes. Comparisons of fin length (anal and dorsal) among wild individuals revealed that fins are shorter with respect to body length in the northern population, indicating that they are ,paedomorphic' compared with the southern population. Observations of fin ray formation and subsequent fin growth in the laboratory revealed that the timing of pterygiophore development occurs later, and that fins start to elongate later with respect to body length in the northern fish, indicating that fin growth is ,post-displaced' compared with the southern population. In addition, the rate of fin growth with respect to body length was lower in the northern males, indicating ,neoteny'. Given that all Oryzias except O. latipes are distributed in the tropics, it is likely that higher-latitude fish have evolved post-displacement and neoteny during northern extension of their geographic range. The delayed development in higher-latitude fish is probably a trade-off for faster body growth, which has evolved as an adaptation to seasonally time-constrained environments. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 97, 571,580. [source] | ||||||||||