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1.
BMC Evol Biol ; 17(1): 27, 2017 01 19.
Article in English | MEDLINE | ID: mdl-28103805

ABSTRACT

BACKGROUND: Podarcis tiliguerta is a wall lizard endemic to the Mediterranean islands of Corsica and Sardinia. Previous findings of high mtDNA and morphological diversity have led to the suggestion that it may represent a species complex. Here, we analysed mitochondrial and nuclear markers (mtDNA, 3110 bp; 6 nDNA loci, 3961 bp) in P. tiliguerta sampled from thirty-two localities across Corsica and Sardinia. RESULTS: We find much greater intraspecific genetic divergence than between sister species of other Mediterranean island Podarcis, i.e., between P. lilfordi and P. pityusensis. We detected three mtDNA clusters in Corsica (North, South-East and South-West) and either two or three in Sardinia (North vs. South) depending on the clustering method. Only one or two nDNA groups were identified within each main island (again, depending on the method). A Bayesian time-calibrated multispecies coalescent tree was obtained from mtDNA and provided statistical support for a Miocene origin of the species (13.87 Ma, 95% HPD: 18.30-10.77 Ma). The posterior mean divergence time for the Corsican and Sardinian lineages was 12.75 Ma ago (95% HPD: 16.94-9.04 Ma). CONCLUSION: The results support the evolutionary distinctiveness of Corsican and Sardinian populations and also indicate a lack of post-divergence migration despite periods of contact being possible. Further to this, species delimitation analyses of Corsican and Sardinian lineages provided statistical support for their recognition as distinct (sister) taxa. Our results provide new insights into the biogeography of the Mediterranean biodiversity hotspot, and contribute important findings relevant to the systematics and evolution of this speciose lizard genus.


Subject(s)
Evolution, Molecular , Lizards/genetics , Animals , Bayes Theorem , DNA, Mitochondrial/genetics , France , Genetic Variation , Italy , Mediterranean Islands , Phylogeny , Phylogeography
2.
Mol Ecol ; 23(19): 4799-812, 2014 10.
Article in English | MEDLINE | ID: mdl-25156032

ABSTRACT

Population divergence and speciation are often explained by geographical isolation, but may also be possible under high gene flow due to strong ecology-related differences in selection pressures. This study combines coalescent analyses of genetic data (11 microsatellite loci and 1 Kbp of mtDNA) and ecological modelling to examine the relative contributions of isolation and ecology to incipient speciation in the scincid lizard Chalcides sexlineatus within the volcanic island of Gran Canaria. Bayesian multispecies coalescent dating of within-island genetic divergence of northern and southern populations showed correspondence with the timing of volcanic activity in the north of the island 1.5-3.0 Ma ago. Coalescent estimates of demographic changes reveal historical size increases in northern populations, consistent with expansions from a volcanic refuge. Nevertheless, ecological divergence is also supported. First, the two morphs showed non-equivalence of ecological niches and species distribution modelling associated the northern morph with mesic habitat types and the southern morph with xeric habitat types. It seems likely that the colour morphs are associated with different antipredator strategies in the different habitats. Second, coalescent estimation of gene copy migration (based on microsatellites and mtDNA) suggest high rates from northern to southern morphs demonstrating the strength of ecology-mediated selection pressures that maintain the divergent southern morph. Together, these findings underline the complexity of the speciation process by providing evidence for the combined effects of ecological divergence and ancient divergence in allopatry.


Subject(s)
Genetic Speciation , Genetics, Population , Islands , Lizards/genetics , Animals , DNA, Mitochondrial/genetics , Gene Flow , Microsatellite Repeats , Models, Biological , Molecular Sequence Data , Phylogeography , Spain
3.
Mol Ecol ; 22(19): 4829-41, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23962158

ABSTRACT

Two monophyletic sister species of wall lizards inhabit the two main groups of Balearic Islands: Podarcis lilfordi from islets and small islands around Mallorca and Menorca and Podarcis pityusensis from Ibiza, Formentera and associated islets. Genetic diversity within the endangered P. lilfordi has been well characterized, but P. pityusensis has not been studied in depth. Here, 2430 bp of mtDNA and 15 microsatellite loci were analysed from P. pityusensis populations from across its natural range. Two main genetic groupings were identified, although geographical structuring differed slightly between the mtDNA and the nuclear loci. In general, individuals from islets/islands adjacent to the main island of Ibiza were genetically distinct from those from Formentera and the associated Freus islands for both mtDNA and the nuclear loci. However, most individuals from the island of Ibiza were grouped with neighbouring islets/islands for nuclear loci, but with Formentera and Freus islands for the mitochondrial locus. A time-calibrated Bayesian tree was constructed for the principal mitochondrial lineages within the Balearics, using the multispecies coalescent model, and provided statistical support for divergence of the two main P. pityusensis lineages 0.111-0.295 Ma. This suggests a mid-late Pleistocene intraspecific divergence, compared with an early Pleistocene divergence in P. lilfordi, and postdates some major increases in sea level between 0.4 and 0.6 Ma, which may have flooded Formentera. The program IMa2 provided a posterior divergence time of 0.089-0.221 Ma, which was similar to the multispecies coalescent tree estimate. More significantly, it indicated low but asymmetric effective gene copy migration rates, with higher migration from Formentera to Ibiza populations. Our findings suggest that much of the present-day diversity may have originated from a late Pleistocene colonization of one island group from the other, followed by allopatric divergence of these populations. Subsequent gene flow between these insular groups seems likely to be explained by recent human introductions. Two evolutionary significant units can be defined for P. pityusensis but these units would need to exclude the populations that have been the subjects of recent admixture.


Subject(s)
Biological Evolution , Gene Flow , Genetic Variation , Lizards/genetics , Animals , Bayes Theorem , Cell Nucleus/genetics , DNA, Mitochondrial/genetics , Genetics, Population , Microsatellite Repeats , Molecular Sequence Data , Phylogeny , Sequence Analysis, DNA , Spain
4.
Mol Phylogenet Evol ; 68(2): 259-68, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23567019

ABSTRACT

The Qinghai-Tibetan Plateau (QTP) is an important biogeographical area and has recently become a focus for biodiversity studies. Phyrnocephalus lizards form a widespread Eurasian group with oviparous and viviparous reproductive modes, but two previous mtDNA studies of species from around the QTP have provided different phylogenetic hypotheses. We analysed three loci (mtDNA, RAG-1, AME) from all recognised Chinese Phrynocephalus species to reconstruct the speciation history of the group and to estimate species divergence times. The effects of mtDNA partitioning strategy on phylogenetic inference were examined. Bayes factor comparisons of marginal likelihoods (mLs) estimated using stepping-stone sampling revealed that partitioning strategy had a major impact on mL. Nevertheless, it had a negligible effect on the inferred tree topology. The impact of hard-bound uniform or equivalent soft-bound gamma speciation time calibration priors as well as the use of a fixed topology (as opposed to integration over all possible species histories) on divergence time estimation were also assessed, and found to have little impact on posterior estimates. All three gene trees and the species tree supported the hypothesis that the Chinese species form oviparous and viviparous sister clades. This was in agreement with an early mtDNA study but differed from a subsequent reanalysis of the mtDNA data. Inclusion of mtDNA from more widely distributed Phrynocephalus (from previous studies) indicates that the oviparous P. interscapularis from Central Asia lies outside the clade of Chinese viviparous and oviparous species, but that other Asian oviparous species lie within the Chinese oviparous clade. The median of the posterior on the divergence time of Chinese oviparous and viviparous species was 9.7 Ma ago (95% interval: 7.2-13.0 Ma ago), which coincides with major uplifting of the QTP and indicates that viviparity evolved when this clade became restricted to regions of high elevation. We also found that cladogenesis within the viviparous clade began around 5 Ma ago whereas those in the oviparous clade began around 8.6 Ma ago. We establish more robust estimates of divergence times and relationships within this important group and so provide improved insights into the origins of Phrynocephalus diversity across the QTP.


Subject(s)
Lizards/genetics , Oviparity/genetics , Phylogeny , Viviparity, Nonmammalian/genetics , Animals , Bayes Theorem , DNA, Mitochondrial/genetics , Evolution, Molecular , Female , Genetic Speciation , Models, Genetic , Multilocus Sequence Typing , NADH Dehydrogenase/genetics , RNA, Transfer, Amino Acid-Specific/genetics , Reptilian Proteins/genetics , Tibet
5.
Med Hypotheses ; 78(5): 571-9, 2012 May.
Article in English | MEDLINE | ID: mdl-22365651

ABSTRACT

A theory is proposed to explain the benefits of yoga practices in diverse, frequently comorbid medical conditions based on the concept that yoga practices reduce allostatic load in stress response systems such that optimal homeostasis is restored. It is hypothesized that stress induces (1) imbalance of the autonomic nervous system (ANS) with decreased parasympathetic nervous system (PNS) and increased sympathetic nervous system (SNS) activity, (2) underactivity of the gamma amino-butyric acid (GABA) system, the primary inhibitory neurotransmitter system, and (3) increased allostatic load. It is further hypothesized that yoga-based practices (4) correct underactivity of the PNS and GABA systems in part through stimulation of the vagus nerves, the main peripheral pathway of the PNS, and (5) reduce allostatic load. Depression, epilepsy, post traumatic stress disorder (PTSD), and chronic pain exemplify medical conditions that are exacerbated by stress, have low heart rate variability (HRV) and low GABAergic activity, respond to pharmacologic agents that increase activity of the GABA system, and show symptom improvement in response to yoga-based interventions. The observation that treatment resistant cases of epilepsy and depression respond to vagal nerve stimulation corroborates the need to correct PNS underactivity as part of a successful treatment plan in some cases. According to the proposed theory, the decreased PNS and GABAergic activity that underlies stress-related disorders can be corrected by yoga practices resulting in amelioration of disease symptoms. This has far-reaching implications for the integration of yoga-based practices in the treatment of a broad array of disorders exacerbated by stress.


Subject(s)
Depression/physiopathology , Depression/therapy , Epilepsy/therapy , Stress Disorders, Post-Traumatic/therapy , Yoga/psychology , Allostasis/physiology , Anxiety Disorders/physiopathology , Anxiety Disorders/therapy , Autonomic Nervous System/physiopathology , Chronic Pain/physiopathology , Chronic Pain/therapy , Electric Stimulation Therapy , Epilepsy/physiopathology , Heart Rate/physiology , Humans , Hydrocortisone/physiology , Hypothalamo-Hypophyseal System/physiopathology , Models, Neurological , Models, Psychological , Stress Disorders, Post-Traumatic/physiopathology , Stress, Physiological , Temporal Lobe/physiopathology , Vagus Nerve/physiopathology , Walking/physiology , gamma-Aminobutyric Acid/physiology
6.
Ecol Evol ; 2(12): 2962-73, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23301164

ABSTRACT

Delimitation of species is an important and controversial area within evolutionary biology. Many species boundaries have been defined using morphological data. New genetic approaches now offer more objective evaluation and assessment of the reliability of morphological variation as an indicator that speciation has occurred. We examined geographic variation in morphology of the continuously distributed skink Chalcides mionecton from Morocco and used Bayesian analyses of nuclear and mitochondrial DNA (mtDNA) loci to examine: (i) their concordance with morphological patterns, (ii) support for species delimitation, (iii) timing of speciation, and (iv) levels of gene flow between species. Four digit individuals were found at sites between Cap Rhir (in the south) and the northern extreme of the range, whereas five-digit individuals were found in two disjunct areas: (i) south of Cap Rhir and (ii) the north of the range where they were often syntopic with four-digit individuals. The pattern of variation in generalized body dimensions was largely concordant with that in digit number, suggesting two general morphotypes. Bayesian analyses of population structure showed that individuals from sites south of Cap Rhir formed one genetic cluster, but that northern four- and five-digit individuals clustered together. Statistical support for delimitation of these genetic clusters into two species was provided by a recent Bayesian method. Phylogenetic-coalescent dating with external time calibrations indicates that speciation was relatively recent, with a 95% posterior interval of 0.46-2.66 mya. This postdates equivalent phylogenetic dating estimates of sequence divergence by approximately 1 Ma. Statistical analyses of a small number of independent loci provide important insights into the history of the speciation process in C. mionecton and support delimitation of populations into two species with distributions that are spatially discordant with patterns of morphological variation.

7.
Mol Ecol Resour ; 10(6): 1098-105, 2010 Nov.
Article in English | MEDLINE | ID: mdl-21565124

ABSTRACT

This article documents the addition of 396 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Anthocidaris crassispina, Aphis glycines, Argyrosomus regius, Astrocaryum sciophilum, Dasypus novemcinctus, Delomys sublineatus, Dermatemys mawii, Fundulus heteroclitus, Homalaspis plana, Jumellea rossii, Khaya senegalensis, Mugil cephalus, Neoceratitis cyanescens, Phalacrocorax aristotelis, Phytophthora infestans, Piper cordulatum, Pterocarpus indicus, Rana dalmatina, Rosa pulverulenta, Saxifraga oppositifolia, Scomber colias, Semecarpus kathalekanensis, Stichopus monotuberculatus, Striga hermonthica, Tarentola boettgeri and Thermophis baileyi. These loci were cross-tested on the following species: Aphis gossypii, Sooretamys angouya, Euryoryzomys russatus, Fundulus notatus, Fundulus olivaceus, Fundulus catenatus, Fundulus majalis, Jumellea fragrans, Jumellea triquetra Jumellea recta, Jumellea stenophylla, Liza richardsonii, Piper marginatum, Piper aequale, Piper darienensis, Piper dilatatum, Rana temporaria, Rana iberica, Rana pyrenaica, Semecarpus anacardium, Semecarpus auriculata, Semecarpus travancorica, Spondias acuminata, Holigarna grahamii, Holigarna beddomii, Mangifera indica, Anacardium occidentale, Tarentola delalandii, Tarentola caboverdianus and Thermophis zhaoermii.

8.
J Appl Toxicol ; 30(2): 172-82, 2010 Mar.
Article in English | MEDLINE | ID: mdl-19839026

ABSTRACT

Limited experimental models exist to assess drug toxicity in pediatric populations. We recently reported how a multi-age rat model could be used for pre-clinical studies of comparative drug toxicity in pediatric populations. The objective of this study was to expand the utility of this animal model, which previously demonstrated an age-dependent sensitivity to the classic nephrotoxic compound, gentamicin, to another nephrotoxicant, namely cisplatin (Cis). Sprague-Dawley rats (10, 25, 40 and 80 days old) were injected with a single dose of Cis (0, 1, 3 or 6 mg kg(-1) i.p.). Urine samples were collected prior and up to 72 h after treatment in animals that were >or= 25 days old. Several serum, urinary and 'omic' injury biomarkers as well as renal histopathology lesions were evaluated. Statistically significant changes were noted with different injury biomarkers in different age groups. The order of age-related Cis-induced nephrotoxicity was different than our previous study with gentamicin: 80 > 40 > 10 > 25 day-old vs 10 >or= 80 > 40 > 25-day-old rats, respectively. The increased levels of kidney injury molecule-1 (Kim-1: urinary protein/tissue mRNA) provided evidence of early Cis-induced nephrotoxicity in the most sensitive age group (80 days old). Levels of Kim-1 tissue mRNA and urinary protein were significantly correlated to each other and to the severity of renal histopathology lesions. These data indicate that the multi-age rat model can be used to demonstrate different age-related sensitivities to renal injury using mechanistically distinct nephrotoxicants, which is reflected in measurements of a variety of metabolite, gene transcript and protein biomarkers.


Subject(s)
Aging/physiology , Cisplatin/toxicity , Kidney Diseases/chemically induced , Kidney/metabolism , Age Factors , Animals , Biomarkers/metabolism , Biomarkers/urine , Child , Disease Susceptibility/metabolism , Disease Susceptibility/pathology , Gentamicins/toxicity , Humans , Kidney/pathology , Kidney Diseases/pathology , Kidney Diseases/urine , Models, Animal , Pediatrics , Rats , Rats, Sprague-Dawley , Sensitivity and Specificity
9.
Acta Psychiatr Scand ; 121(4): 289-300, 2010 Apr.
Article in English | MEDLINE | ID: mdl-19694633

ABSTRACT

OBJECTIVE: This study evaluated the effect of a yoga breath program alone and followed by a trauma reduction exposure technique on post-traumatic stress disorder and depression in survivors of the 2004 Asian tsunami. METHOD: In this non-randomized study, 183 tsunami survivors who scored 50 or above on the Post-traumatic Checklist-17 (PCL-17) were assigned by camps to one of three groups: yoga breath intervention, yoga breath intervention followed by 3-8 h of trauma reduction exposure technique or 6-week wait list. Measures for post-traumatic stress disorder (PCL-17) and depression (BDI-21) were performed at baseline and at 6, 12 and 24 weeks. Data were analyzed using anova and mixed effects regression. RESULTS: The effect of treatment vs. control was significant at 6 weeks (F(2,178) = 279.616, P < 0.001): mean PCL-17 declined by 42.5 +/- 10.0 SD with yoga breath, 39.2 +/- 17.2 with Yoga breath + exposure and 4.6 +/- 13.2 in the control. CONCLUSION: Yoga breath-based interventions may help relieve psychological distress following mass disasters.


Subject(s)
Depression/therapy , Implosive Therapy , Stress Disorders, Post-Traumatic/therapy , Survivors/psychology , Yoga/psychology , Adolescent , Adult , Asia, Southeastern , Combined Modality Therapy , Depression/epidemiology , Disasters , Female , Humans , Male , Middle Aged , Stress Disorders, Post-Traumatic/epidemiology , Tsunamis , Young Adult
10.
Mol Phylogenet Evol ; 48(1): 350-8, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18501640

ABSTRACT

Phylogenetic relationships and timings of major cladogenesis events are investigated in the Balearic Island lizards Podarcislilfordi and P.pityusensis using 2675bp of mitochondrial and nuclear DNA sequences. Partitioned Bayesian and Maximum Parsimony analyses provided a well-resolved phylogeny with high node-support values. Bayesian MCMC estimation of node dates was investigated by comparing means of posterior distributions from different subsets of the sequence against the most robust analysis which used multiple partitions and allowed for rate heterogeneity among branches under a rate-drift model. Evolutionary rates were systematically underestimated and thus divergence times overestimated when sequences containing lower numbers of variable sites were used (based on ingroup node constraints). The following analyses allowed the best recovery of node times under the constant-rate (i.e., perfect clock) model: (i) all cytochrome b sequence (partitioned by codon position), (ii) cytochrome b (codon position 3 alone), (iii) NADH dehydrogenase (subunits 1 and 2; partitioned by codon position), (iv) cytochrome b and NADH dehydrogenase sequence together (six gene-codon partitions), (v) all unpartitioned sequence, (vi) a full multipartition analysis (nine partitions). Of these, only (iv) and (vi) performed well under the rate-drift model. These findings have significant implications for dating of recent divergence times in other taxa. The earliest P.lilfordi cladogenesis event (divergence of Menorcan populations), occurred before the end of the Pliocene, some 2.6Ma. Subsequent events led to a West Mallorcan lineage (2.0Ma ago), followed 1.2Ma ago by divergence of populations from the southern part of the Cabrera archipelago from a widely-distributed group from north Cabrera, northern and southern Mallorcan islets. Divergence within P.pityusensis is more recent with the main Ibiza and Formentera clades sharing a common ancestor at about 1.0Ma ago. Climatic and sea level changes are likely to have initiated cladogenesis, with lineages making secondary contact during periodic landbridge formation. This oscillating cross-archipelago pattern in which ancient divergence is followed by repeated contact resembles that seen between East-West refugia populations from mainland Europe.


Subject(s)
Lizards/genetics , Animals , Bayes Theorem , DNA, Mitochondrial/genetics , Mediterranean Region , Phylogeny
11.
Mol Ecol ; 17(3): 854-66, 2008 Feb.
Article in English | MEDLINE | ID: mdl-18179441

ABSTRACT

The phylogeography of the lacertid lizard Gallotia atlantica from the small volcanic island of Lanzarote (Canary Islands) was analysed based on 1075 bp of mitochondrial DNA (mtDNA) sequence (partial cytochrome b and ND2) for 157 individuals from 27 sites (including three sites from neighbouring islets). Levels of sequence divergence were generally low, with the most distant haplotypes separated by only 14 mutational steps. MtDNA divergence appears to coincide with formation of the middle Pleistocene lowland that united formerly separate ancient islands to form the current island of Lanzarote, allowing rejection of a two-island model of phylogeographical structure. There was evidence of large-scale population expansion after island unification, consistent with the colonization of new areas. A nested clade phylogeographical analysis (NCPA) revealed significant phylogeographical structuring. Two-step and higher-level clades each had disjunct distributions, being found to the east and west of a common area with a north-south orientation that extends between coasts in the centre-east of the island (El Jable). Other clades were almost entirely restricted to the El Jable region alone. Bayesian Markov chain Monte Carlo analyses were used to separate ongoing gene flow from historical associations. These supported the NCPA by indicating recent (75,000-150,000 years ago) east-west vicariance across the El Jable region. Lava flows covered El Jable and other parts of the central lowland at this time and likely led to population extinctions and temporary dispersal barriers, although present-day evidence suggests some populations would have survived in small refugia. Expansion of the latter appears to explain the presence of a clade located between the eastern and western components of the disjunct clades. Direct relationships between mtDNA lineages and morphology were not found, although one of two morphological forms on the island has a disjunct distribution that is broadly concordant with east-west components of the phylogeographical pattern. This work demonstrates how recent volcanic activity can cause population fragmentation and thus shape genetic diversity on microgeographical scales.


Subject(s)
DNA, Mitochondrial/genetics , Ecosystem , Lizards/genetics , Volcanic Eruptions , Animals , Atlantic Islands , Bayes Theorem , Cytochromes b/chemistry , Cytochromes b/genetics , DNA, Mitochondrial/chemistry , Genetic Variation , Haplotypes/genetics , Markov Chains , Monte Carlo Method , NADH Dehydrogenase/chemistry , NADH Dehydrogenase/genetics , Phylogeny , Polymerase Chain Reaction , Sequence Analysis, DNA
12.
Mol Ecol Resour ; 8(3): 666-8, 2008 May.
Article in English | MEDLINE | ID: mdl-21585865

ABSTRACT

The scincid lizard Chalcides sexlineatus is endemic to the island of Gran Canaria, within which it shows a pronounced phylogeographical pattern. Understanding the maintenance of this pattern requires knowledge of nuclear DNA structuring. Eleven polymorphic tetranucleotide microsatellite loci were isolated from a library constructed from genomic DNA enriched for AAAG repeat sequence. The number of alleles per locus ranged from 12 to 19, and expected heterozygosities spanned from 0.738 to 0.933 (n = 30). The majority of these could be cross-amplified in other endemic Canarian Chalcides. The loci will be used to investigate gene flow between the principal mitochondrial clades within C. sexlineatus.

13.
Ecotoxicol Environ Saf ; 65(1): 36-47, 2006 Sep.
Article in English | MEDLINE | ID: mdl-16029893

ABSTRACT

Reproductive and developmental effects of diisononyl phthalate (DINP) and diisodecyl phthalate (DIDP) were evaluated in a Japanese medaka (Oryzias latipes) multigeneration protocol. Each phthalate was administered via fish flake diets at a concentration of 20 microg/g (1 microg/g fish/day). Two controls were included, untreated and acetone carrier. The F(0) and F(1) generation adults were reared to sexual maturation and the test was ended prior to sexual maturation of the F(2) generation. Biochemical, individual, and population parameters were evaluated: testosterone metabolism, 7-ethoxyresorufin-o-deethylase (EROD) activity, survival, development, growth, gonadal-somatic index, histopathology, sex ratio, and fecundity. Male fish showed a two-fold induction of several testosterone metabolites in the DINP-treated group compared to the untreated control but not the acetone control. In a similar manner, in female fish only the DIDP-treated group expressed greater testosterone hydroxylase activity. There were neither sex- nor treatment-related differences in the results from the EROD assay. A statistically significant transient delay in red blood cell pigmentation was observed. The male-to-female ratio was consistent across treatments and the phenotypic and histological gender classifications were in agreement. Egg production was not significantly different among treatment groups. Neither phthalate elicited an effect on reproduction or development at various levels of biological organization.


Subject(s)
Hazardous Substances/toxicity , Oryzias/metabolism , Phthalic Acids/toxicity , Animals , Body Weight/drug effects , Cytochrome P-450 CYP1A1/metabolism , Diet , Embryo, Nonmammalian/drug effects , Embryo, Nonmammalian/embryology , Evaluation Studies as Topic , Female , Gonads/drug effects , Male , Organ Size/drug effects , Ovum/drug effects , Survival Analysis , Testosterone/metabolism
15.
Heredity (Edinb) ; 90(4): 302-7, 2003 Apr.
Article in English | MEDLINE | ID: mdl-12692583

ABSTRACT

Island differentiation and relationships with congenerics were investigated in the endemic Canary Island bat Plecotus teneriffae, based on approximately 1 kb of mtDNA from the 16S rRNA and cytochrome b genes. P. teneriffae had closer affinities with P. austriacus than with P. auritus. Levels of differentiation between Canary Islands were quite high relative to Pipistrelle-like bats, consistent with philopatric behaviour in the Plecotus genus. Cladogenesis within P. teneriffae appears to have occurred after the emergence of the islands of El Hierro and La Palma during the Pleistocene. An intraspecific network shows that haplotypes from the younger islands of La Palma and El Hierro are connected to the Tenerife haplotype by a similarly large number of mutational steps. This suggests that they were both colonised at a similar time from the much older island of Tenerife. The other Plecotine bat species, Barbastellus barbastellus shows close affinities with B. barbastellus from mainland Spain, with levels of mtDNA divergence being comparable with intraspecific variation within other mammal species.


Subject(s)
Chiroptera/genetics , DNA, Mitochondrial/genetics , Phylogeny , Animals , Atlantic Islands , Base Sequence , DNA Primers , Geography , Haplotypes/genetics , Likelihood Functions , Models, Genetic , Molecular Sequence Data
16.
Mol Phylogenet Evol ; 26(1): 56-63, 2003 Jan.
Article in English | MEDLINE | ID: mdl-12470938

ABSTRACT

Evolution of three Canary Island Vespertilionid bat species, Pipistrellus kuhlii, Pipistrellus maderensis, and Hypsugo savii was studied by comparison of approximately 1 kbp of mtDNA (from cytochrome b and 16S rRNA genes) between islands. mtDNA reveals that both P. kuhlii and P. maderensis exist in sympatry on Tenerife (and possibly other islands). Their morphological similarity explains why their co-occurrence had not been detected previously. Levels of sequence divergence are quite low within P. maderensis. Haplotypes were either identical or separated by /=12 mutational steps) indicating colonization of the latter from the former sometime during the last approximately 1.2 Ma, with low subsequent gene flow. Unlike P. maderensis the El Hierro population alone appears to represent an ESU. The H. savii haplotypes detected in Gran Canaria and Tenerife are identical or separated by 1 mutational step.


Subject(s)
Chiroptera/genetics , DNA, Mitochondrial , Geography , Phylogeny , Animals , Cytochrome b Group/genetics
17.
Mol Phylogenet Evol ; 24(2): 324-32, 2002 Aug.
Article in English | MEDLINE | ID: mdl-12144765

ABSTRACT

Since the early Miocene there have been several physical events within NW Africa that are likely to have had a major impact on its faunal diversity. Phylogeographical studies will shed new light on the biogeography of the region. We analysed mitochondrial DNA diversity in the agamid lizard Agama impalearis (also called A. bibronii) based on sequences from mitochondrial genes with very different evolutionary rates (16S rRNA and ND2). Well-supported topologies of rooted maximum parsimony trees (with a Laudakia outgroup) and unrooted haplotype networks indicated two major clades with similar branch lengths. These clades have non-overlapping distributions representing respective areas to the North and West and South and East of the Atlas mountain chain and each could be given full species recognition. Nested clade analyses indicate that historical and possible present-day allopatry account for the primary phylogeographic pattern. Further evidence is provided by the estimated timing of cladogenesis, based on calibration of evolutionary rates in the ND2 gene of another continental Agamid. Sequence divergence between clades corresponds to 8.5-9.4mya, coinciding with the main period of orogenic uplift of the Atlas. Additional evidence of cladogenesis by allopatric fragmentation is also detected within the North/West Atlas clade, although contiguous range expansion is the most predominant explanation of more recent phylogeographic effects in this species. Miocene vicariance mediated by the Atlas may provide a general explanation of intra- and interspecific biogeographical patterns in NW African species.


Subject(s)
DNA, Mitochondrial/genetics , Lizards/physiology , Phylogeny , Africa, Northern , Africa, Western , Animals , Evolution, Molecular , Models, Biological , Molecular Sequence Data , RNA, Ribosomal, 16S
18.
Ecotoxicol Environ Saf ; 49(1): 17-25, 2001 May.
Article in English | MEDLINE | ID: mdl-11386712

ABSTRACT

A rigorous approach to evaluating the reliability and relevance of experimental methods and results is critical for making appropriate, scientifically sound decisions. A literature evaluation framework was modified and adapted based on criteria described by Klimisch et al. (H. J. Klimisch, M. Andrae, and U. Tillman, 1997, Reg. Tox. Pharm. 25, 1-5) and requirements of the USEPA High Product Volume Challenge Program. This simple framework was used to evaluate an appropriate selection of peer-reviewed references to assign a Study Reliability "score" to the study design, endpoints, and conclusions compared to established data quality guidelines. Subsequently, the interpretation of the data was evaluated and assigned a Relevance Index based on the overall strength of evidence of endocrine modulation potential, which was evaluated based on the Weybridge (European Commission (1996). European workshop on the impact of endocrine disrupters on human health and wildlife. Report of proceedings from a workshop held in Weybridge, UK, 2-4 December 1996. Report reference EUR 17549, European Commission, DGXII, Brussels, Belgium.) definition. This report describes the evaluation of 50 peer-reviewed primary publications. The vast majority of studies reviewed were published in the period from 1996 to the present and most examined in vivo responses of fish to natural hormones, organochlorines, or alkylphenolic compounds. Of the studies reviewed, approximately 40% received a score of "2-Reliable with Restrictions," while approximately 60% received a score of "3-Not Reliable," where reliability was interpreted to include scientific integrity, technical credibility, endpoint relevance, and regulatory compliance. The most common deficiencies were inadequate methods, lack of suitable controls, exceeding aqueous solubility, inappropriate statistics, and unsupported conclusions. Based on the Relevance Index, few of the studies examined attained the level of quality necessary to identify the study results as providing an acceptable basis for evaluation of endocrine modulation potential directly resulting from identified deficiencies in meeting the established study reliability criteria.


Subject(s)
Animals, Wild , Endocrine System/drug effects , Xenobiotics/adverse effects , Animals , Fishes/physiology , Peer Review , Quality Control , Reproducibility of Results , Research Design , Water Pollutants, Chemical/adverse effects
19.
Mol Ecol ; 10(6): 1593-7, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11412378

ABSTRACT

The Cape Verde Islands are of volcanic origin with most having appeared between the early Miocene and mid-Pleistocene. They contain six known species of Mabuya skinks. Phylogeographical relationships within and among the relatively widespread taxa M. stangeri, M. spinalis and M. delalandii were inferred, based on approximately 1 kbp of the cytochrome b gene (mitochondrial DNA). Reciprocal monophyly of M. spinalis and M. stangeri was established, which may have arisen from an early Pliocene/late Miocene cladogenetic event. Considerable between-island sequence divergence was detected among M. spinalis, which appears to have colonized the older islands (Sal and Boavista) first. Much lower sequence divergence was found in M. delalandii, indicating a more recent range expansion. Here, evidence points to colonization of the younger islands of Brava and Fogo soon after appearance. There are similarities between some of the described patterns and those seen in lizards from the Canary Islands.


Subject(s)
DNA, Mitochondrial , Genetic Variation , Lizards/genetics , Phylogeny , Africa, Western , Animals , Biological Evolution , Cytochrome b Group/genetics , Genetics, Population , Molecular Sequence Data
20.
J Psychiatr Pract ; 7(2): 75-91, 2001 Mar.
Article in English | MEDLINE | ID: mdl-15990509

ABSTRACT

Although a multitude of pharmaceutical agents are available for the treatment of mood disorders, anxiety and insomnia, many patients have difficulty tolerating the side effects, do not respond adequately, or eventually lose their response. Many therapeutic herbs and nutrients have far fewer side effects and may provide an alternative treatment or can be used to enhance the effect of prescription medications. In the article, the authors review the quality of the evidence supporting the clinical effects of a number of commonly used types of complementary/alternative medicine (CAM) for mood disorders, anxiety, and insomnia. They review data on the use of St. John's Wort, S-adenosyl-methionine (SAM-e), B vitamins, inositol, omega-3 fatty acids, and choline for mood disorders; data on the use of kava and other herbal agents and fish extract for anxiety and insomnia; and data on valerian and melatonin for insomnia. The authors also discuss the use of CAM to treat migraines, which may be comorbid with mood and anxiety disorders, and obesity, which can occur as a side effect of psychotropic medications. They consider the data on feverfew and butterbur for migraines and on chromium picolinate and the combination of ephedrine and caffeine for obesity. The authors also review issues related to comorbid medical illness, side effects, drug interactions, dosage, and brand selection.

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