RESUMO
Fluctuating asymmetry (FA), used as an indicator of developmental stability, has long been hypothesized to be negatively correlated with genetic variability as a consequence of more variable organisms being better suited to buffer developmental pathways against environmental stress. However, it is still a matter of debate if this is due to metabolic properties of enzymes encoded by certain key loci or rather to overall genomic heterozygosity. Previous analyses suggest that there might be a general difference between homeo- and poikilotherms in that only the latter tend to exhibit the negative correlation predicted by theory. In the present study, we addressed these questions by analysing roe deer (Capreolus capreolus) from five German populations with regard to FA in metric and non-metric skull and mandible traits as well as variability at eight microsatellite loci. Genetic variability was quantified by heterozygosity and mean d2 parameters, and although the latter did not show any relationship with FA, we found for the first time a statistically significant negative correlation of microsatellite heterozygosity and non-metric FA among populations. Because microsatellites are non-coding markers, this may be interpreted as evidence for the role of overall genomic heterozygosity in determining developmental stability. To test if the threshold character of non-metric traits is responsible for the metric vs non-metric difference we also carried out calculations where we treated our metric traits as threshold values. This, however, did not yield significant correlations between FA and genetic variability either.
Assuntos
Cervos/genética , Variação Genética , Genética Populacional/métodos , Repetições de Microssatélites , Modelos Genéticos , Animais , Alemanha , Mamíferos/genética , Mandíbula/anatomia & histologia , Modelos Biológicos , Fenótipo , Crescimento Demográfico , Característica Quantitativa Herdável , Crânio/anatomia & histologiaRESUMO
The possibly distinct Carpathian red deer was compared genetically to other European populations. We screened 120 red deer specimens from Serbia, the Romanian lowland and the Romanian Carpathians for genetic variability using 582 bp of the mitochondrial control region and nine polymorphic nuclear microsatellite loci. The study aimed at a population genetic characterization of the Carpathian red deer, which are often treated as a distinct subspecies (Cervus elaphus montanus). The genetic integrity of the Carpathian populations was confirmed through the haplotype distribution, private alleles and genetic distances. The Carpathian red deer are thus identified as one of the few remaining natural populations of this species, deserving special attention among game and conservation biologists. The history of the populations studied, in particular the introduction of Carpathian red deer into Romanian lowland areas in the 20th century, was reflected by the genetic data.
Assuntos
DNA Mitocondrial/genética , Cervos/genética , Repetições de Microssatélites/genética , Animais , Cervos/classificação , Variação Genética/genética , Genética Populacional , Haplótipos/genética , FilogeniaRESUMO
To add genetic information to the international conservation efforts on European otters Lutra lutra, we investigated the genetic population structure in and around a known "source" population of the otter, the Oberlausitz (OL) in eastern Germany. This was complemented by a first survey of genetic variation levels in the Central European otter population. Sequence analysis of 300bp of the mitochondrial control region in 76 specimens from the eastern German study region and 53 individuals from several other European populations revealed a low level of genetic variation, with only 5 haplotypes present and nucleotide diversities within populations ranging from 0.00% to 0.17%. Apart from eastern Germany, one haplotype was by far the most abundant one, from which other, only locally occurring types, could be derived by a single point mutation. This suggests a single Pleistocene refugium from which the analyzed European regions have been reinvaded after the glaciations. Within eastern Germany, two abundant haplotypes were found. Their occurrence differed significantly among subregions of eastern Germany. The uneven distribution of a locally restricted but abundant haplotype could be explained by isolation-by-distance and might reflect emigration from the OL source population to surrounding regions. This suggests that vital local populations can indeed serve as "sources" for the invasion of surrounding areas. Given a suitable genetic marker, we suggest a spatial autocorrelation analysis to monitor the genetic effect of such an emigration from a source population.
Assuntos
DNA Mitocondrial/genética , Variação Genética , Lontras/genética , Animais , Europa (Continente) , Reação em Cadeia da Polimerase , Análise de Sequência de DNARESUMO
Data from an extensive research project on lagomorphs were compiled and re-analyzed from a synoptical point of view for examining the indicative function of allozymic variation. Empirical data suggested the Shannon-Weaver information index to be a better indicator of allelic diversity than expected average heterozygosity. There were differences in polymorphism among various structural and physiological classes of enzymes. Reliable estimates of gene diversity and genetic distances can be obtained only if more than 30 loci are examined. At the population level, allozymic diversity was not related to morphological variation. It was, however, indicative of increased developmental homeostasis as assessed by overall fluctuating asymmetry in non-metric morphological traits. Allozymes served well for fully resolving genetic differentiation among populations and for assessing levels of migration, whereas mtDNA and morphological data provided only additional information. The results are discussed with respect to data from other mammalian taxa.
Assuntos
Marcadores Genéticos/genética , Genética Populacional , Isoenzimas/genética , Filogenia , Animais , Variação Genética/genética , Mamíferos/genética , Coelhos/genéticaRESUMO
Genetic polymorphism in transferrin (TF) and in the haemoglobin alpha chain (HBA) was detected in the brown hare (Lepus europaeus) from Austria and Czechoslovakia by means of horizontal agarose and starch gel electrophoresis, respectively. Genetic analyses of complete families suggest that the TF and the HBA systems are each controlled by one autosomal gene locus with two codominant alleles. The distribution of both polymorphisms among some free-ranging Austrian brown hare populations was examined and the observed genotypes were in good agreement with the Hardy-Weinberg expectations. A comparison between the brown hare and the rabbit revealed no bands in common. The HB beta-chain was monomorphic in all specimens investigated.
Assuntos
Hemoglobinas/genética , Lagomorpha/sangue , Lagomorpha/genética , Polimorfismo Genético , Transferrina/genética , Alelos , Animais , Eletroforese em Gel de Amido , Frequência do Gene , Coelhos/sangue , Coelhos/genética , Especificidade da EspécieRESUMO
Morphological characters in red deer (Cervus elaphus), which serve as criteria for selective hunting, were examined in relation to electrophoretic variation in three populations from the Vosges in eastern France. From the polymorphic loci examined, certain alleles at Idh-2, Me-1 and Acp-1 showed significant associations with a special development of body and antler characters selected for by hunters. Idh-2(125) was associated with larger hind foot length in females and a higher number of antler points in males. Me-1(90) and Acp-1(100) were associated with small spikes. The populations studied differed from one another in the duration and intensity of selective hunting and the increase or decrease in the respective allele frequencies could be explained by selection for large body size, a high number of antler points and against small spikes in yearlings, rather than by genetic drift. Among other morphological characters examined, the length of the main beam was significantly associated with the allele Acp-2(100). In contrast, no associations could be detected between overall heterozygosity and the development or the degree of asymmetry (in paired structures) of any of the morphological traits in question. Although no obvious differences in the overall values of polymorphism or heterozygosity were found between the populations, selective hunting leads towards a change in allele frequencies and eventually to the loss of one or the other rare allele.
Assuntos
Cervos/genética , Frequência do Gene , Variação Genética , Heterozigoto , Isoenzimas/genética , Seleção Genética , Esportes , Alelos , Animais , FrançaRESUMO
A genetic polymorphism of sorbitol dehydrogenase (SDH; EC 1.1.1.14) for two allozymes is demonstrated in the brown hare (Lepus europaeus) by means of horizontal starch gel electrophoresis. Segregation analysis was performed in a sample of four matings with 12 offspring and confirmed the genetic hypothesis: two alleles at an autosomal locus. The calculated gene frequencies in the brown hare breed studied are Sdha = 0.712 and Sdhb = 0.288. The distribution of the polymorphism in free-ranging brown hare populations from Austria, Czechoslovakia, Hungary, and Poland is described.
Assuntos
L-Iditol 2-Desidrogenase/genética , Coelhos/genética , Alelos , Animais , Áustria , Eletroforese em Gel de Amido , Europa Oriental , Frequência do Gene , Variação Genética , Polimorfismo Genético , Coelhos/metabolismoRESUMO
Tissue samples from 161 roe deer (Capreolus capreolus L.) from 5 populations in Austria were screened for allelic variation at 41 presumptive genetic loci by means of horizontal starch gel electrophoresis. The proportion of polymorphic loci ranged from 14.6 per cent to 19.5 per cent, the values for expected average heterozygosity from 3.5 per cent to 7.9 per cent. These values are among the highest ones yet found among deer species. The relationship between biochemical genetic variation, body size and ecological strategy of adaptation is discussed.
Assuntos
Cervos/genética , Variação Genética , Adaptação Fisiológica , Animais , Áustria , Cervos/fisiologia , Ecologia , Frequência do Gene , Heterozigoto , Isoenzimas/genética , Polimorfismo GenéticoRESUMO
Twelve blood proteins and enzymes were tested for polymorphism in a herd of fallow deer, Dama dama L., bred for meat production in Western Germany, to investigate the genetic constitution of the population. Although an enzyme polymorphism was detected (Catalase) for the first time in this species, electrophoretic variation is very low in comparison to other large ungulates. Possible explanations for this finding, such as recent inbreeding and a past genetic bottleneck, are given. The relationship between low genetic variation in biochemical marker systems and fitness is discussed.