Allozymes

Physalaemus pustulosus, a small leptodactylid frog with South American affinities, ranges across northern South America through Middle America to southern Mexico. To investi-gate its geographic variation and evolutionary origins, we analysed the presumptive gene products of 14 allozyme loci and sequenced a portion of the mitochondrial COI gene from individuals sampled throughout the distribution. Generally, allozyme dissimilarities and sequence divergences are correlated with each other and with geographic proximity. The greatest discontinuity in genetic variation was found between populations in Middle America vs. South America + Panama. Based on two Bayesian MCMC (Markov chain Monte Carlo) divergence time estimates involving two independent temporal constraints, the timing of the separation of northern and southern túngara frog lineages is significantly older than the time since completion of the current Panama land bridge. P

We combined reproductive and allozyme data to assess the levels and structuring of genetic variation and propose conservation guidelines in Limonium dendroides, a critically endangered Canarian endemic Plumbaginaceae featuring the floral and pollen pap/cob dimorphisms associated with the heteromorphic diallelic self-incompatibility system described for this family. Although seed germination has been reported in greenhouse conditions, the detection of individuals of only one morph in all wild subpopulations surveyed explains the extremely limited seed production and recruitment in nature. The geographical proximity and genetic closeness between some subpopulations, together with absence of inbreeding depression symptoms, and a higher allozyme variation in the cultured or reintroduced offspring than in their parental wild subpopulations indicate the viability of occasional compatible matings, thereby suggesting that even low levels of gene flow could mitigate the deleterious effects o...

ABSTRACT Iphigenia brasiliensis (Lamarck, 1818) is a species of bivalve of the family Donacidae Fleming, 1828 which inhabits unconsolidated substrata and occurs in Brazil between 0°07ʹ04ʺS, 49°23ʹ17ʺW and 29º19ʹ46ʺS, 49º42ʹ39ʺW, and is also found in Florida (USA), Suriname and parts of the Caribbean sea. As an estuarine species it is subject to a wide range of environmental variables usually presenting considerable variation in morphological traits and genetic composition. In this paper, the presence and type of asymmetry in the species was inferred based on measures from left and right valves and genetic variation was assessed by means of allozymes electrophoresis. The assessment of levels of asymmetry and genetic variation was done in three different localities and two environments (Channel and Mangrove). The results indicate the generalized presence of asymmetry, which varied between directional (DA) and fluctuating (FA) depending on the environment. Associations between FA and genetic variation were statistically significant on the dependence of the measure assessed. Thus, we present information on the levels of asymmetry and genetic variation of natural populations of I. brasiliensis which may be useful to research and management of this species.

Acorus calamus is a highly valued medicinal plant with global distribution used in several drugs of health care systems. We evaluated the genetic diversity and population structure of 50 populations of A. calamus from different geographical regions in India through RAPD and chloroplast microsatellite markers. From the total screened 82 RAPD primers and 18 cpSSR primers, 10 RAPD and nine

Random amplified polymorphic DNA (RAPD) and quantitative trait variation of the widespread and ephemeral Senecio gallicus were surveyed in 11 populations sampled from the Iberian Peninsula and southern France. The aim of the study was to compare population relationships and levels of geographical differentiation with chloroplast (cp) DNA and allozyme variation assessed previously in the same populations. Employing multivariate statistics, a moderate level of intraspecific differentiation was observed among populations from Iberian coastal and inland regions for both RAPDs and quantitative traits. However, RAPDs provided greater resolution in identifying additional population structure within the hypothesized, Pleistocene refugial source area of the species in coastal Iberia. A major part of the geographical subdivision in RAPD and quantitative traits was concordant with the coastal vs. inland divergence as previously inferred from cpDNA haplotype frequencies, but strongly contrasted...

To determine the genetic relationship of anadromous and resident life-history types within and among drainages, and compare several hatchery strains to their progenitor populations, brook charr Salvelinus fontinalis were examined for allozyme and mitochondrial DNA variation. Greater genetic similarity of sympatric anadromous and resident charr was found compared to similar life-history forms allopatrically, suggesting the two life-history types are not reproductively isolated. Low divergence among the mtDNA haplotypes suggests that the two life-history types are members of the same evolutionary lineage. Population differentiation from mtDNA data exceeded that from estimates based on allozymes. Genetic deviations from expectations suggest that the hatchery strains were derived from few individuals.

... Author , Rachid Cheddadi b , Jacques-Louis de Beaulieu c , Bruno Fady d , Dušan Gömöry e , Erwin Hussendörfer f , Monika Konnert g ... and routes of range expansion, and regarding contact zones of the different refugial lineages within the modern range ([Kral, 1974], [Kral ...

Abstract. Allozymes were assessed by starch gel electrophoresis in 3 populations of a eutar-digrade, Richtersius coronifer, with different reproductive modes. One population from Italy (with 2 sub-populations) was amphimictic and 2 populations (1 from Italy and 1 from Sweden) ...

Geographic differentiation in skull morphological characters in the subterranean rodent Ctenomys australis (Rodentia: Ctenomyidae). We assess geographical morphological differentiation in the subterranean rodent Ctenomys australis, which is distributed in the first line of coastal sand dunes between the localities of Necochea and Punta Alta, province of Buenos Aires, Argentina. Using a multivariate Discriminant Function Analysis (DFA), we evaluate geographic variation as congruent with an isolation by distance model and its correspondence with the pattern of differentiation reported for molecular markers like mitochondrial DNA (apparently neutral) and allozymes. Drift in conjunction with both low rates of migration and the isola - tion among localities are expected to be the main factor to explain an important fraction of the morphological variation at the geographic level. This general prediction of isolation by distance does not rule out the presence of adaptive or environmentally...

Allozyme diversity of natural and introduced cypress stands in Morocco: consequences for management of genetic resources. For the purpose of managing Cupressus atlantica natural genetic resources in Morocco, diversity among 9 provenances from 3 cypress species (Cupressus atlantica and 2 introduced species: C. sempervirens and C. arizonica) was studied using seven enzymatic systems. Mean allele number per locus (A) ranged from 2.0 in C. atlantica and C. arizonica to 1.7 in C. sempervirens. Genetic diversity was high (He = 0.29 in C. atlantica; 0.27 in C. sempervirens and 0.33 in C. arizonica) but heterozygote deficiencies were observed. C. atlantica provenances exhibited a low differentiation (GST = 0.013). The high interspecific differentiation (GST = 0.279) was due to the distance between the 2 Mediterranean cypresses (C. atlantica and C. sempervirens) and the Arizonica cypress. Two enzymatic systems (GOT et SOD) strictly differentiated these 2 origins and could be used for introgr...