The annual number of breeding adults and the effective population size of syntopic newts (Triturus cristatus, T-marmoratus)

Pond-breeding amphibians are deme-structured organisms with a population genetic structure particularly susceptible to demographic threats. We estimated the effective number of breeding adults (N-b) and the effective population size (N-e) of the European urodele amphibians Triturus cristatus (the crested newt) and T. marmoratus (the marbled newt), using temporal shifts in microsatellite allele frequencies. Eight microsatellite loci isolated from a T. cristatus library were used, five of which proved polymorphic in T. marmoratus, albeit with high frequencies of null alleles at two loci. Three ponds in western France were sampled, situated 4-10 kilometres apart and inhabited by both species. Parent-offspring cohort comparisons were used to measure N-b; samples collected at time intervals of nine or 12 years, respectively, were used to measure N-e. The adult population census size (N) was determined by mark-recapture techniques. With one exception, genetic distances (F-ST) between temporal samples were lower than among populations. N-b ranged between 10.6 and 101.8 individuals, N-e ranged between 9.6 and 13.4 individuals. For the pond where both parameters were available, N-b/N (overall range: 0.10-0.19) was marginally larger than N-e/N (overall range: 0.09-0.16), which is reflected in the temporal stability of N. In line with the observed differences in reproductive life-histories between the species, N-b/N ratios for newts were about one order of magnitude higher than for the anuran amphibian Bufo bufo. Despite of the colonization of the study area by T. cristatus only some decades ago, no significant genetic bottleneck could be detected. Our findings give rise to concerns about the long-term demographic viability of amphibian populations in situations typical for European landscapes

Epigenetic Patterns Maintained in Early Caenorhabditis elegans Embryos Can Be Established by Gene Activity in the Parental Germ Cells

Epigenetic information, such as parental imprints, can be transmitted with genetic information from parent to offspring through the germ line. Recent reports show that histone modifications can be transmitted through sperm as a component of this information transfer. How the information that is transferred is established in the parent and maintained in the offspring is poorly understood. We previously described a form of imprinted X inactivation in Caenorhabditis elegans where dimethylation on histone 3 at lysine 4 (H3K4me2), a mark of active chromatin, is excluded from the paternal X chromosome (Xp) during spermatogenesis and persists through early cell divisions in the embryo. Based on the observation that the Xp (unlike the maternal X or any autosome) is largely transcriptionally inactive in the paternal germ line, we hypothesized that transcriptional activity in the parent germ line may influence epigenetic information inherited by and maintained in the embryo. We report that chromatin modifications and histone variant patterns assembled in the germ line can be retained in mature gametes. Furthermore, despite extensive chromatin remodeling events at fertilization, the modification patterns arriving with the gametes are largely retained in the early embryo. Using transgenes, we observe that expression in the parental germline correlates with differential chromatin assembly that is replicated and maintained in the early embryo. Expression in the adult germ cells also correlates with more robust expression in the somatic lineages of the offspring. These results suggest that differential expression in the parental germ lines may provide a potential mechanism for the establishment of parent-of-origin epigenomic content. This content can be maintained and may heritably affect gene expression in the offspring

Pits versus patterns: effects of transponders on recapture rate and body condition of Danube crested newts (Triturus Dobrogicus) and common spadefoot toads (Pelobates Fuscus)

During a long-terrn study (1987-1996) near Vienna (Austria), individual Danube crested newts (Trititrus dobrogicus) and cornmon spadefoot toads (Pelobates fuscus) were registered by photographs of highly variable Skin patterns, and the implantation of Passive lntegrated Transponders (PIT tags). To test for potential detrirnental efficts of the electronic tags, we cornpared within-year (for P. fiiscus) and between-year (for T. dobrogiczts) recapture rates and body condition index (CI) of individuals rnarked with the two altcrnative techniques. No significant negative effects of PIT tags on CI and recapture rate could be dernonstrated for either spccies. There was a decrease in body condition and recapture rates in the study years 1995 and 1996, but can be attributed to population trends rather than to the different rnarking rnethods. For recaptured T ~iobrogicusa 10.5% loss of PIT tags was observed

Structure and dynamics of central European amphibian populations: A comparison between Triturus dobrogicus (Amphibia, Urodela) and Pelobates fuscus (Amphibia, Anura)

During a long-term study of the amphibian fauna on an artificial island near Vienna (Austria), one isolated site was completely encircled with a permanent drift fence and pitfall traps. Eleven amphibian species occurred at the study site. For the Common Spadefoot Toad (Pelobates fuscus) and for the Danube Crested Newt (Triturus dobrogicus). individuals could be recognized by photographing the highly variable dorsal/ventral patterns. Daily patrols of the drift fence, for 6 years since 1986, enabled us to monitor the demography and dynamics of these two species. For T. dobrogicus, the adult part of the censused population decreased from 207 to 87 individuals during the first 2 years of investigation and then remained stable. Pelobates fuscus showed a constant decrease over 6 years, from 626 to 62 individuals. Juveniles were produced annually; a massive increase in this age class was observed for both species during the period of investigation. Triturus dobrogicus showed higher adult survival than P. fuscus. The constancy of several population parameters of both species may reflect the stability of the cultured parkland habitat in which the study site is located

Verrucous lupus erythematosus

Chronic cutaneous lupus erythematosus is a cutaneous expression of lupus erythematosus including a broad spectrum of clinically and histopathologically distinct types of lesions. Among them the verrucous or hypertrophic type represents an uncommon cutaneous manifestation resembling clinically as well as histopathologically keratoacanthoma or verrucous lichen planus. The course of the disease is - in most but not in all instances - marked by chronicity, absence of regression and resistance to treatment. The diagnosis is based on clinicopathologic findings. We herein present a patient with a longstanding history of DLE with keratoacanthomalike verrucous lesions on both forearms and hands

The annual number of breeding adults and the effective population size of syntopic newts ( Triturus cristatus , T. marmoratus )

Pond-breeding amphibians are deme-structured organisms with a population genetic structure particularly susceptible to demographic threats. We estimated the effective number of breeding adults ( N b ) and the effective population size ( N e ) of the European urodele amphibians Triturus cristatus (the crested newt) and T. marmoratus (the marbled newt), using temporal shifts in microsatellite allele frequencies. Eight microsatellite loci isolated from a T. cristatus library were used, five of which proved polymorphic in T. marmoratus , albeit with high frequencies of null alleles at two loci. Three ponds in western France were sampled, situated 4–10 kilometres apart and inhabited by both species. Parent–offspring cohort comparisons were used to measure N b ; samples collected at time intervals of nine or 12 years, respectively, were used to measure N e . The adult population census size ( N ) was determined by mark–recapture techniques. With one exception, genetic distances ( F ST ) between temporal samples were lower than among populations. N b ranged between 10.6 and 101.8 individuals, N e ranged between 9.6 and 13.4 individuals. For the pond where both parameters were available, N b / N (overall range: 0.10–0.19) was marginally larger than N e / N (overall range: 0.09–0.16), which is reflected in the temporal stability of N . In line with the observed differences in reproductive life-histories between the species, N b / N ratios for newts were about one order of magnitude higher than for the anuran amphibian Bufo bufo . Despite of the colonization of the study area by T. cristatus only some decades ago, no significant genetic bottleneck could be detected. Our findings give rise to concerns about the long-term demographic viability of amphibian populations in situations typical for European landscapes

Genetic dissimilarity predicts paternity in the smooth newt (Lissotriton vulgaris)

Under sperm competition, paternity is apportioned by polyandrous females according to the order of matings and the genetic quality of the inseminating males. In order to distinguish between these two effects, we sequentially paired 12 female smooth newts (Lissotriton vulgaris) with each of two males and, where possible, repeated the same procedure in reverse order of the identical males after assumed sperm depletion. For a total of 578 offspring, amplified fragment length polymorphisms genetic markers revealed multiple paternities in all matings, without significant first- or second-male sperm precedence. The paternity share of individual males was transitive across the two trials with male order switch, and successful males had a significantly higher genetic dissimilarity to the female than expected by chance. We argue that patterns of paternity in natural newt populations are determined through a combination of good genes and relatedness

Bimodal signal requisite for agonistic behavior in a dart-poison frog, Epipedobates femoralis

Animal acoustic signals play seminal roles in mate attraction and regulation of male spacing, maintenance of pairbonds, localization of hosts by parasites, and feeding behavior. Among vertebrate signals, it is becoming clear that no single stereotyped signal feature reliably elicits species-specific behavior, but rather, that a suite of characters is involved. Within the largely nocturnal clade of anuran amphibians, the dart-poison frog, Epipedobates femoralis, is a diurnal species that physically and vigorously defends its calling territory against conspecific intruders. Here we report that physical attacks by a territorial male are provoked only in response to dynamic bimodal stimuli in which the acoustic playback of vocalizations is coupled with vocal sac pulsations, but not by either unimodal cues presented in isolation or static bimodal stimuli. These results suggest that integration of dynamic bimodal cues is necessary to elicit aggression in this species

The World Congress of Herpetology and Animal Conservation: excerpts from the 6th World Congress

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