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1.
A maximum parsimony phylogeny of 14 Caucasian species of rock lizards, genus Ijicerta , subgenus Archaeolacerta , was constructed from mitochondrial cytochrome b and ATPase 6 partial gene sequences. Congruence analyses were carried out between the two genes. A synthesis of the data sets reveals three well supported monophyletic groups: (1) the caucasica group including ( Lacerta derjugini (( Lalpina, L. clarkorum ) ( L. caucasica, L. daghestanica ))); (2) the rudis group including ( L. parvula ( L. portschinskii ( L. vakntini, L. rudis ))); and (3) the saxicola group including ( L. mixta ( L. nairensis ( L. saxicola, L. raddeijj ). Despite the diagnosis of three groups, the placement of L. praticola as a basal taxon is uncertain, as are the relationships among the three groups. The mitochondrial DNA sequence data suggested prior hybridization between L. mixta and L. alpina and possibly between L. saxicola and L. nairensis. Lacerta raddei was resolved as a paraphyletic species on the mtDNA tree; this may result from either hybridization or random gene sorting.  相似文献   

2.
To characterize the molecular genetic diversity of the genus Darevskia, several populations were examined by the inter-SINE-PCR method, reporting the number and sizes of the spacers between individual copies of SINE-like interspersed repeats. Examination of 17 D. raddei geographical populations and several reference species revealed unequal genetic differences, measured as Nei and Li’s genetic distances (DNL), for different groups of samples. The highest homogeneity was observed for the apparently panmictic D. raddei nairensis population from the basin of the Hrazdan River: genetic differences within each of the five samples and between them were similarly low (less than 0.1). The difference between ten samples of D. raddei raddei from Armenia and Karabakh (0.2–0.3) was somewhat higher than the interindividual difference within each sample (0.1–0.2), indicating that the samples belonged to different populations. The assumption was supported by the phylogenetic tree topology and multidimensional scaling. The differences between samples from the morphological subspecies D. raddei raddei and D. raddei nairensis ranged 0.3–0.4. The difference of two D. raddei raddei samples of Talysh (Azerbaijan) from other samples of the same subspecies corresponded to the subspecific level. The genetic distances between the good species D. raddei and D. rudis was 0.6–0.7. In terms of DNL, a questionable population from northwestern Turkey (“D. tristis”) was closer to D. rudis (DNL = 0.45), probably representing its subspecies. The phylogeography of D. raddei is discussed.  相似文献   

3.
Satellite DNA repeats were studied in Caucasian populations of 18 rock lizard species of the genus Darevskia. Four subfamilies (Caucasian Lacerta satellites (CLsat)I-IV) were identified, which shared 70%-75% sequence similarity. The distribution of CLsat subfamilies among the species was studied. All the species could be divided into at least 3 clades, depending on the content of CLsat subfamilies in each genome: "saxicola", "rudis", and "mixta" lizards. CLsatI was found in all studied species, but in very different quantities; the "saxicola" group contained this subfamily predominantly. The "rudis" group also contained CLsatIII, and the "mixta" group carried considerable amounts of CLsatII. The highest concentrations of CLsatI and CLsatII were detected in 2 ground lizards--D. derjugini and D. praticola, respectively. D. parvula predominantly carried CLsatIII. CLsatIV was found only in the Crimean species D. lindholmi. The distribution patterns of satellite subfamilies show possible postglacial speciation within the genus Darevskia. A hybrid origin of species that possess 2 or 3 CLsat subfamilies and important clarifications to the systematics of the genus are proposed.  相似文献   

4.
A phylogeny of Caucasian rock lizards (genus Darevskia , formerly Lacerta ) was reconstructed using mitochondrial DNA sequence and allozyme data. All 15 bisexual species grouped into three major clades: the caucasica, saxicola and rudis clades. Unisexual Darevskia originate from inter-clade hybridization, never from within clades. Only two clades, the caucasica clade and the rudis clade, were involved in forming unisexuals; the saxicola clade was never involved. Furthermore, the hybridization is directional in that the caucasica clade contributed only maternal parents and the rudis clade only paternal parents. The formation of unisexual species is best explained by sexually directional phylogenetic constraints. We hypothesize that the causative agents are likely to be genes linked with the sex chromosomes within the parental sexual species.  相似文献   

5.
The article presents the genetic parameters of the populations of lizards of the Darevskia raddei complex (D. raddei nairensis and D. raddei raddei) and the populations of D. valentini calculated on the basis of the analysis of variability of 50 allelic variants of the three nuclear genome microsatellite-containing loci of 83 individuals. It was demonstrated that the Fst genetic distances between the populations of D. raddei nairensis and D. raddei raddei were not statistically significantly different from the Fst genetic distances between the populations of different species, D. raddei and D. valentini. At the same time, these distances were statistically significantly higher than the Fst distances between the populations belonging to one species within the genus Darevskia. These data suggest deep divergence between the populations of D. raddei raddei and D. raddei nairensis of the D. raddei complex and there arises the question on considering them as separate species.  相似文献   

6.
Parts of the mitochondrial genes coding for 12SrRNA and 16SrRNA (together about 960 bp) were sequenced for all Mediterranean species of 'Mountain lizards' of the genera Archaeolacerta ( sensu lato ) and Iberolacerta . All subspecies of the Iberian species Iberolacerta cyreni and I. monticola were included in this study. In addition, samples of Apathya cappadocica and Darevskia rudis were analysed to elucidate the relationships of the European 'Mountain lizards' to their possible relatives in the Near East. Maximum parsimony and neighbour joining analyses lead to the following major conclusions: (i) the monophyly of the genus Iberolacerta is very well supported; (ii) Archaeolacerta bedriagae (the type species of the genus) is most basal with respect to the ingroup taxa. If we accept Iberolacerta as a genus, Archaeolacerta becames paraphyletic. Therefore, we propose to restrict Archaeolacerta to the type species and to treat A. mosorensis and A. oxycephala provisionally as members of the collective genus Lacerta ; (iii) within the genus Iberolacerta three groups were found: a Pyrenean group, an Iberian group and I. horvathi . The relationships among these groups remain unresolved; and (iv) the Peña de Francia lizards, described originally as a subspecies of I. cyreni , are in fact more closely related to I. monticola .  相似文献   

7.
Populations of parthenogenetic lizards of the genus Darevskia consist of genetically identical animals, and represent a unique model for studying the molecular mechanisms underlying the variability and evolution of hypervariable DNA repeats. As unisexual lineages, parthenogenetic lizards are characterized by some level of genetic diversity at microsatellite loci. We cloned and sequenced a number of (GATA)n microsatellite loci of Darevskia unisexualis. PCR products from these loci were also sequenced and the degree of intraspecific polymorphism was assessed. Among the five (GATA)n loci analysed, two (Du215 and Du281) were polymorphic. Cross-species analysis of Du215 and Du281 indicate that the priming sites at the D. unisexualis loci are conserved in the bisexual parental species, D. raddei and D. valentini. Sequencing the PCR products amplified from Du215 and Du281 and from monomorphic Du323 showed that allelic differences at the polymorphic loci are caused by microsatellite mutations and by point mutations in the flanking regions. The haplotypes identified among the allelic variants of Du281 and among its orthologues in the parental species provide new evidence of the cross-species origin of D. unisexualis. To our knowledge, these data are the first to characterize the nucleotide sequences of allelic variants at microsatellite loci within parthenogenetic vertebrate animals.  相似文献   

8.
The genesis of mini- and microsatellite loci, which is under extensive study in humans and some other bisexual species, have been virtually overlooked in species with clonal mode of reproduction. Earlier, using multilocus DNA fingerprinting, we have examined variability of some mini- and microsatellite DNA markers in parthenogenetic lizards from the genus Darevskia. In particular, mutant (GATA)n-restrictive DNA fragments were found in Darevskia unisexualis. In the present study, we examined intraspecific polymorphism of three cloned loci of D. unisexualis--Du323, Du215, and Du281--containing (GATA)7GAT(GATA)2, GAT(GATA)9, and (GATA)10TA(GATA) microsatellite clusters, respectively. Different levels of intrapopulation and interpopulation variability of these loci were found. Locus Du281 showed the highest polymorphism--six allelic variants (in the sample of 68 DNA specimens). Three alleles were found for locus Du215. The Du325 locus was electrophoretically invariant. The primers chosen for loci Du323, Du215, and Du281 were also used for PCR analysis of homologous loci in two presumptive parental bisexual species, D. valentini and D. nairensis. The PCR products of the corresponding loci of the parental species had approximately the same size (approximately 200 bp) as their counterparts in D. unisexualis, but the polymorphism levels of the paternal, maternal, and hybrid species were shown to be somewhat different. These data on the structure of the D. unisexualis loci provide a possibility to study genetic diversity in the parthenogenetic species D. unisexualis and other related unisexual and bisexual species of this genus, which can provide new information on the origin of parthenogenetic species and on the phylogenetic relationships in the genus Darevskia. These data can also be used for resolving problems of marking the lizard genome, which is still poorly studied.  相似文献   

9.
Chobanu DG  Grechko VV  Darevskiĭ IS 《Genetika》2003,39(11):1527-1541
The structure and evolution of a satellite DNA family was examined in lizards from the genus Darevskia (family Lacertidae). Comparison of tandem units of repeated DNA (satDNA), CLsat, in all species from the genus Darevskia has shown that their variability is largely based on single-nucleotide substitutions, which constitute about 50 diagnostic positions underlying classification of the family into three subfamilies. Maximum differences between the subfamilies reached 25%. At this level of tandem unit divergence between the subfamilies, no cross-hybridization between them was observed (at 65 degrees C). The individual variability of one subfamily within the species was on average 5% while the variability between species consensuses within a subfamily was 10%. The presence of highly conserved regions in all monomers and some features of their organization show that satellites of all Darevskia species belong to one satDNA family. The organization of unit sequences of satellites CLsat and Agi also detected by us in another lizard genus, Lacerts s. str. was compared. Similarity that was found between these satellites suggests their relatedness and common origin. A possible pathway of evolution of these two satDNA families is proposed. The distribution and content of CLsat repeat subfamilies in all species of the genus was examined by Southern blotting hybridization. Seven species had mainly CLsatI (83 to 96%); three species, approximately equal amounts of CLsatI and CLsatIII (the admixture of CLsatII was 2-3%); and five species, a combination of all three subfamilies in highly varying proportions. Based on these results as well as on zoogeographic views on phylogeny and taxonomy of the Darevskia species, hypotheses on the evolution of molecular-genetic relationships within this genus are advanced.  相似文献   

10.
11.
Population and family samples of two morphological forms (mutant and normal with respect to dorsal color) of pathogenetic lizard Darevskia armeniaca were examined by means of DNA fingerprinting using M13 mini- and (GATA)n and (TCC)n microsatellite DNA markers. The morphological forms examined were characterized by clonally inherited, species-specific patterns of the DNA markers, which were different from the species-specific DNA fingerprints of the other parthenogenetic species of the genus Darevskia (D. dahli. D. unisexualis, and D. rostombekovi). The mean index of similarity (S) obtained for a sample of 36 individuals from three isolated populations using three types of DNA markers was 0.966. This was similar to the variability level observed in D. dahli (0.962) (P > 0.05), but higher than that in D. unisexualis (0.950) (P < 0.05) and D. rostombekovi (0.875) (P < 0.01). Inheritance of M13 minisatellite and (TCC)n microsatellite DNA markers in the F1 offspring of parthenogenetic lizards was examined. It was shown that variability and clonal diversity of the fingerprint phenotypes observed in the populations and families of D. armeniaca could be at least partly explained by RFLP mutations in microsatellite repeats.  相似文献   

12.
Using multilocus DNA fingerprinting with microsatellite probes (CAC)5, (GACA)4, (GGCA)4 and (GATA)4, intraspecific variation of the Southeast Asian lizards belonging to the genus Leiolepis (bisexual species Leiolepis reevesii and triploid parthenogenetic species Leiolepis guentherpetersi) was first examined. The L. guentherpetersi lizards were characterized by monophyletic DNA fingerprint profiles for the loci detected by the (GACA)4, (GGCA)4, and (CAC)5 probes, in terms of intrapopulation similarity index constituting S = 0.96. This was different from the individual-specific profiles of the lizards from bisexual, presumably parental species, L. reevesii (S = 0.6; P < 0.001). Genetic homogeneity of triploid L. guentherpetersi lizards at the loci examined serves as one of the arguments for the parthenogenetic nature of this species. Genetic variability of triploid parthenogenetic species L. guentherpetersi appeared to be comparable with that reported earlier for the Caucasian rock lizards of the genus Darevskia, namely, D. dahlia, D. armeniaca, and D. unisexualis (P > 0.05). The results of DNA fingerprinting analysis of the same L. guentherpetersi samples with the (GATA)4 hybridization probe were unexpected. Variability of parthenogenetic species L. guentherpetersi at the (GATA)n markers was remarkably higher than that at other DNA markers (S = 0.35; P = 3.08 x 10(-11)), being comparable to the variation of the (GATA)n DNA markers in bisexual species L. reevesii (P = 0.74). The reasons for high polymorphism of the (GATA)n-containing loci in L. guentherpetersi still remain unclear. This polymorhism is probably associated with high instability of the loci, which can be revealed by means of family analysis of parthenogenetic offspring.  相似文献   

13.
The molecular structure of the allelic variants of (AAT) n of the Du47D microsatellite locus was determined in parthenogenetic lizards Darevskia dahli, D. armeniaca, and D. rostombekovi. Comparative analysis of these alleles showed that they were characterized by perfect structure of microsatellite cluster, and were different in the number of (AAT) monomeric units, as well as in the combinations of species-specific substitutions and deletions in the microsatellite flanking regions. Molecular structure of microsatellite cluster, species-specific single nucleotide polymorphism (SNP), and different representation of alleles Du47 in the samples of parthenogenetic species examined point to the origin of the alleles from different bisexual species, which is consistent with the hybrid nature of unisexual species of the genus Darevskia. In addition, these data reflect different combination patterns of interspecific hybridization events with the participation of the same bisexual species upon the formation of hybrid genomes of parthenogenetic species. Possible application of the allelic variants of microsatellite loci of parthenogenetic lizards as the genetic markers for the analysis of the genomes of parthenogenetic species in the light of evolution, ecology, and parthenogenetic type of reproduction in vertebrates is discussed.  相似文献   

14.
Methods of estimating within- and between-population gene diversity in parthenogenetic species using mini- and microsatellite DNA markers and modified Wright's FST statistic are presented with special reference to model populations of lizards of the genus Darevskia (D. dahli, D. armeniaca, D. unisexualis). We used DNA fingerprinting data for several populations of these species examined earlier. The effects of variation in M13, minisatellite, (GACA)n and (TCC)n microsatellite loci on the formation of within-population gene diversity in parthenogenetic species D. dahli and D. armeniaca were shown to be different. The equality of the realized gene diversity H and its maximum possible value Hmax in two populations of D. dahli (Hmax = 0.032, H = 0.031, P < < 0.0431; Hmax = 0.024, H = 0.027, P = 0.09) and D. armeniaca (Hmax = 0.05, H = 0.053, P = 0.03; Hmax = 0.054, H = 0.055, P = 0.02) suggests that variation in (GACA)n loci substantially contributes to the maintenance of within-population genetic diversity. Analysis of between-population genetic diversity using loci M13, (GACA)n, and (TCC)n showed differentiation of D. dahli populations from northeastern and northwestern Armenia (FST = 0.0272, P = 3 x 10(-13)) and genetic homogeneity of the Armenian and Introduced to the Ukraine populations of D. armeniaca characteristic of one clone (FST = 0, P = 1).  相似文献   

15.
Using multilocus DNA fingerprinting, we have examined variability of (TCT)n microsatellite and M13 minisatellite DNA repeats in populations, families, and tissues of Caucasian parthenogenetic rock lizards Darevskia unisexualis (Lacertidae). It has been shown for the first time that population and family DNA samples of D. unisexualis (75 samples in total) have individually specific DNA fingerprinting patterns of (TCT)n fragments. Analysis of inheritance of (TCT)n microsatellites in 46 first-generation progeny in 17 parthenogenetic D. unisexualis families revealed their extremely high instability. Mutant TCT fingerprint phenotypes were found in virtually each animal of the progeny. Moreover, varying fragments in the progeny and their original variants in the mothers were shown to simultaneously contain (TCT)n and (TCC)n polypyrimidine clusters. At the same time, no variability of (TCT)n fragments has been detected in the tissues and organs of mature parthenogenetic lizards and in the analogous tissues of the two-week-old progeny of this year. This suggests the absence of somatic mosaicism and methylation of the corresponding loci in the samples. Along with the hyperinstability of (TCT/TCC)n polypyrimidine clusters, we have shown that the population and family DNA fingerprinting patterns of M13 minisatellites were invariable and monomorphic in the same DNA samples of D. unisexualis. Our results indicate that mutations at loci containing polypyrimidine microsatellites significantly contribute to the total genomic variability of parthenogenetic lizards D. unisexualis.  相似文献   

16.
To study the molecular genetic relationships and correlate them with the taxonomy within the complex of lacertid lizards of the genus Darevskia, the locus analysis of the copies of the SINE-type repeat (Squam1) specific for the order Squamata was used. It was demonstrated that one of the loci (No. 34) contained the Squam1 copy insert in all species and subspecies of the examined genus. SINE allelic copies in some of the loci contained large indels and specific sets of mutations. The allelic variant M (medium, about 340 bp) was found most frequently; it was detected in all subspecies of D. saxicola (saxicola, darevskii, szczerbaki, lindholmi) and in most of the other species of the genus. Two species, D. derjugini and D. praticola, differed from the other species in the presence of long (L) and short (S) alleles. The longest allele was characteristic of the D. derjugini population from the Northern Caucasus (L, 379 bp, ssp. silvatica), while the shortest allele (97 bp) united the derjugini and barani subspecies. The second allele S (279 bp) characterizes the subspecies D. praticola praticola, some individuals of which also carry allele M. The second subspecies, D. p. pontica, contains allele L2, which differs from all other medium alleles in the presence of strictly specific short indel. In addition to apomorphic indels, the specificity and mutation distribution patterns among the Squam1 alleles were also examined. An analysis of the NJ tree indicated the concordance between morphological and molecular genetic characters of the species derjugini, praticola, and saxicola. Furthermore, four subspecies of D. saxicola were much closer to each other than the subspecies within the first two species; D. d. silvatica and the group of D. d. derjugini + barani were clearly separated. It cannot be excluded that populations from Azerbaijan and Serbia can be treated as the independent subspecies of D. praticola.  相似文献   

17.
The genesis of mini- and microsatellite loci, which is under extensive study in humans and some other bisexual species, has been virtually overlooked in species with clonal mode of reproduction. Earlier, using multilocus DNA fingerprinting, we have examined variability of some mini- and microsatellite DNA markers in parthenogenetic lizards from the genus Darevskia. In particular, mutant (GATA)n-restriction DNA fragments were found in Darevskia unisexualis. In the present study, we examined intraspecific polymorphism of three cloned loci of D. unisexualisDu323, Du215, and Du281—containing (GATA)7GAT(GATA)2, GAT(GATA)9, and (GATA)10TA(GATA) microsatellite clusters, respectively. Different levels of intrapopulation and interpopulation variability of these loci were found. Locus Du281 showed the highest polymorphism—(six allelic variants in the sample of 68 DNA specimens). Three alleles were found for locus Du215. The Du323 locus was electrophoretically invariant. The primers chosen for loci Du323, Du215, and Du281 were also used for PCR analysis of homologous loci in two presumptive parental bisexual species, D. valentini and D. nairensis. The PCR products of the corresponding loci of the parental species had approximately the same size (200 bp) as their counterparts in D. unisexualis, but the polymorphism levels of the paternal, maternal, and hybrid species were shown to be somewhat different. These data on the structure of the D. unisexualis loci provide a possibility to study genetic diversity in the parthenogenetic species D. unisexualis and other related unisexual and bisexual species of this genus, which can provide new information on the origin of parthenogenetic species and on the phylogenetic relationships in the genus Darevskia. These data can also be used for resolving problems of marking the lizard genome, which is still poorly studied.  相似文献   

18.
Four types of nuclear DNA markers identified by the taxonprint, RAPD, and IMP (Inter-MIR-PCR) methods, and the nucleotide sequences of satellite DNA monomers have been used to analyze the molecular genetic similarity between some populations, subspecies, and species of lizards combined into the group Lacerta s. str., as well as representatives of some other genera. The notions on the systematics and phylogeny of this group based on morphological and zoogeographic criteria have been compared to the conclusions based on molecular genetic data. The genus and species subdivisions of populations based on nuclear molecular markers and morphological characters generally agree with each other, the degree of genetic differences being correlated with the taxonomy suggested by zoomorphologists. The degree of differences between the subspecies of one of the species studied, Lacerta agilis, varies depending on the molecular markers used: according to the results of RAPD analysis, all subspecies substantially differ from one another, the variation within populations being small; with respect to other markers, the differences are smaller and not equivalent. The existence of the so-called eastern and western clades of this species earlier assumed by other researchers on the basis of mtDNA and morphological data has been confirmed. There are no distinct gradations exceeding individual variation in 14 populations of L. agilis exigua (the eastern clade) with respect to IMP markers, although these populations inhabit a vast area from the Ural Mountains to the Kabardino-Balkar Republic (the Caucasus). These data suggest that the subspecies has been rapidly spreading northwards since the Pleistocene glaciation (about 15,000 years ago).  相似文献   

19.
Individual and geographical variability of male conscutum pattern in five closely related species of the Dermacentor marginatus complex (D. marginatus, D. ushakovae, D. niveus, D. silvarum, D. nuttalli) has been examined. The pattern has been examined in three to six geographical samples within each specific distribution range. It was established that the pattern of the conscutum central area is subjected to individual and geographical variability on an extreme degree and gives very few intraspecific differential characters, but it shows interspecific differences in some cases. However the dark patches of marginal flank (npkappadelta and 3deltakappa respectively, see Fig. 3) show statistically significant differences in length in all geographical samples of the first four species. Characteristic features of ixodid ticks morpogenesis rule out to a considerable extent the possibility to trace geographical variability of the same characters by all stages of ontogenesis. In these cases, when it is possible, the tendencies to variability on different stages do not always coincide. There is no coordination within the species in the degree of differences of examined geographical samples by pattern and morphological characters, i. e. very complex polymorphis is observed. In the context of the evolution that kind of polymorphism of the geographical samples has provided the species with high adaptive potential for conquest of the extensive range and maintaining large numbers. The question of allopatric speciation of the closely related D. marginatus-D. silvarum with small secondary area of transgression their ranges, and sympatric speciation of the D. ushakovae-D. niveus is postulated.  相似文献   

20.
Aim This paper aims to examine the relationship between versatility as measured by geographic range, bathymetric range and morphological variability (species and subspecies richness and the occurrence of morphologically highly variable populations), and the geologic longevities of trachyleberidid ostracode species and genera, while accounting for sampling biases and other confounding factors. Location Global. Methods A large database of occurrence records of species of the family Trachyleberididae s.l. was analysed. The relationships between genus and species longevity and the above mentioned variables were examined singly and in concert. Re‐analyses of subsets of data and rarefaction techniques were employed to account for sampling biases, while randomization was used to account for autocorrelation of variables. Results The mean number of occurrence records, and latitudinal and longitudinal ranges, were strongly and positively correlated with genus and species longevities. The number of bathymetric zones occupied by genera had no consistent bearing on their longevities, but species data subsets tended to indicate significant positive relationships between bathymetric range and longevities. Species richness was significantly and positively correlated with genus longevities. Species and genera with subspecies and species with high morphological variability all had significantly greater longevities. Genus‐level characteristics can be explained largely by species‐level characteristics, including longevity, latitudinal ranges and bathymetric ranges to a lesser degree. However, genus longevity was best explained by species richness and genus age, even for extinct genera, while species longevity was best explained by species latitudinal range. Main conclusions In spite of the incompleteness of the fossil record, we can control for biasing factors and still confidently draw the conclusion that both ecological and evolutionary versatility contribute to lineage longevity, beyond the shorter temporal observation windows available to most ecological studies.  相似文献   

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