Feeding larvae of Chrysomela lapponica (Coleoptera: Chrysomelidae) acquire characteristic O-glucosides from the leaves of their food plants. The glucosides are selectively channeled from the gut to the defensive gland. Subsequent enzymatic transformations generate a blend of different defensive compounds, e.g., salicylaldehyde and two series of 2-methylbutyl and isobutyryl esters. By using systematically modified and hydrolysis-resistant thioglucosides as structural mimics of the plant-derived glucosides, e.g., salicin and its o-, m-, and p-isomers 1, 2, and 3; o-, m-, and p-cresols 5, 6, 7; along with thioglucosides of 2-phenylethanol 9 and (3Z)-hexenol 10, we demonstrated that the larvae of C. lapponica are able to sequester a broad range of structurally different thioglucosides with comparable efficiency. This sharply contrasts with the sequestration habitus previously observed in Chrysomela populi and Phratora vitellinae, which secrete almost pure salicylaldehyde and posses a highly specific transport mechanism for salicin (Kuhn et al., Proc. Natl. Acad. Sci. USA 101:13808-13813, 2004). Also, neither C. lapponica nor C. populi sequester in their gland the thioglucoside of 8-hydroxygeraniol, the mimic of the glucoside specifically transported by larvae secreting iridoid monoterpenes (Phaedon cochleariae, Gastrophysa viridula). Accordingly, leaf beetle larvae possess selective membrane carriers in their gut and their defensive systems that match the orientation of the functional groups of glucosides from their food plants probably by embedding the substrate in a network of hydrogen bonds inside the membrane carriers. The synthesis and the spectroscopic properties of the test compounds along with a comparative evaluation of the transport capabilities of larvae of C. populi and C. lapponica are described.

RESUMEN. La deforestación de las selvas provoca la fragmentación de los hábitats, lo cual interviene en la composición, abundancia y demografía de las especies, y por lo tanto, en el aislamiento poblacional en muchas especies. Los impactos de la fragmentación dependerán de la capacidad de respuesta de las especies a los disturbios en su há-bitat, y de la configuración y estructura del paisaje. En algunas poblaciones, la fragmentación del hábitat puede provocar el aislamiento poblacional a largo plazo, por la reducción del tamaño poblacional y el debilitamiento de relaciones entre individuos, aún en especies de alta movilidad como los murciélagos. En México, A. jamaicensis es de los murciélagos más estudiados; sin embargo, son pocos los trabajos enfocados en conocer los impactos de la modificación de su hábitat, en su diversidad y estructura genética. Por lo tanto, el objetivo de este trabajo fue evaluar la diversidad, la estructura y la diferenciación genética, así como analizar la historia demográfica de A. jamaicensis en dos hábitats diferentes, utilizando un fragmento de 396 pb de la región mitocondrial D-loop. La red de haplotipos reveló 34 haplotipos únicos de 34 individuos analizados. La diversidad haplotípica fue alta (h = 1) para ambas poblaciones, y la diversidad nucleotídica fue relativamente baja (< 0.03). El análisis de la distribución de diferencias nucleotídi-cas pareadas (distribución mismatch), y los valores negativos de los estadísticos basados en pruebas de neutralidad, sugieren un proceso de expansión demográfica reciente y repentina de A. jamaicensis. Una moderada diferenciación genética apunta a que existe estructura gené-tica de A. jamaicensis. Palabras clave: D-loop, diversidad genética, estructura, haplotipos, historia demográfica. ABSTRACT. Deforestation causes fragmentation of habitats, which in turn affects the composition, abundance and demography of species, and therefore the population isolation of many species. The impacts of fragmentation will depend on the responsiveness of the species to disturbances in their habitat, and the configuration and structure of landscape. In some populations, habitat fragmentation can cause long-term population isolation by the reduction in population size and the weakening of relations between individuals, even in highly mobile species like bats. In Mexico, A. jamaicensis is the most studied bat; however, few studies focused on the knowledge of the impacts of habitat modification in its diversity and genetic structure. Therefore, the objective of this study was to evaluate the diversity, structure and genetic differentiation, and analyze demographic history of A. jamaicensis in two different habitats, using a 396 bp fragment of the mitochondrial Dloop region. Haplotype network revealed 34 unique haplotypes of 34 individuals analyzed. Haplotype diversity was high (h = 1) for both populations, and nucleotide diversity was relatively low (< 0.03). The analysis of the distribution of pairwise differences between sequences and negative values of statisti...

The Meso-American slider turtle (Trachemys venusta) is a freshwater turtle endemic to Mexico and Central America. Due to the overexploitation of its natural populations, it is in the at risk category formulated by the Official Mexican Standard NOM-059-ECOL-2010. In the state of Tabasco, Management Units for the Conservation of Wildlife (UMA) were created to reduce the impact of overexploitation of freshwater turtles. However, no genetic management plan was considered. This study presents the level of genetic diversity of the founder individuals in order to develop a management plan which will optimize reproduction in the UMA. Genetic diversity was compared between captive (n = 45) and wild (n = 86) individuals using 14 microsatellite molecular markers. Level of genetic diversity could be considered as low (He < 0.6) for a species of turtle and suggests that a higher level of protection is required for this particular species. Furthermore, values were slightly higher for the captive group reflecting the mix of genetic sources (founding individuals from different localities) and demonstrating that the captive population is genetically representative of natural populations. The genetic structure analysis revealed a relationship between captive and wild populations, indicating the influence of the two principal river basins in this region on the population of freshwater turtles. Finally, according to the results obtained from the analysis conducted using Storm and ML-Relate programs, we recommend the use of 19 females and 13 males, generating a potential of 247 dyads with no relationship. These first results of genetic management in a Mexican UMA, demonstrate the importance of molecular approaches at the time of managing and conserving species in captivity.