Publicaciones

The role of spatial processes and environmental determinants in microgeographic shell variation of the freshwater snail Chilina dombeyana (Bruguière, 1789).

Bertin, A., Ruíz, V., Figueroa, R., & Gouin, N.

Wildlife data often show spatial organization, demonstrating positive correlations either as a result of processes occurring over the landscape or due to the influence of spatially structured environmental variables. It is, thus, essential to consider non-random spatial structure when evaluating the underlying causes of biological variation. In this study, we analyzed the population structure of Chilina dombeyana shell morphology of 14 populations that are close geographically and belong to the same hydrographic basin. We utilized a variation partitioning approach to evaluate the importance of spatial processes, such as migration, acting over the landscape, and environmental characteristics, including habitat and hydrologic characteristics, and the occurrence of aquatic predators in promoting between population variation. Our results demonstrate spatially structured variation in C. dombeyana shell morphology, with populations living near each other having more similar shell sizes than populations living farther apart. The shell size variation partition indicated that both spatially structured environmental factors and genetic relationships resulting from migration or shared common ancestry may explain this pattern. Shell shape variation, in contrast, was found to be essentially under the influence of non-spatially structured environmental factors, with habitat and water characteristics accounting for about half of the total variation among populations. The large proportion of the variation in shell size that is spatially structured demonstrates that spatial structure on morphological traits might be strong and highlights the need to consider such phenomenon in intraspecific studies of phenotypic evolution.

Año: 2012

Palabras claves: Shape, Size, Environmental factors, Spatial structure, Gastropod, Variation partition, Lotic environment

Isolation of microsatellite markers for two Chilean freshwater anomuran species (Aegla araucaniensis and Aegla pewenchae) using PCR-based methods.

Gouin, N., Bórquez, J., Samollow, P., Douglas, K., Jasti, M., & Bertin, A.

We developed ten polymorphic microsatellite markers for two species of freshwater anomura endemic to Chile, Aegla araucaniensis and Aegla pewenchae, using two PCR-based methods, PIMA and ISSR-PCR. Nine markers per species gave useful PCR products, revealing moderate to high levels of genetic variation. The number of alleles per locus ranged from 2 to 13 and the observed heterozygosity from 0.103 to 0.929. All the markers appeared to segregate independently. No departure from Hardy–Weinberg equilibrium was found in A. araucaniensis while three markers showed evidence for deficits of heterozygotes and presence of null alleles in A. pewenchae. These markers will be useful for population genetics analyses.

Año: 2012

Palabras claves: Aeglidae, Crustacean, Microsatellite, PIMA, ISSR-PCR, Population genetics.

Effects of high hydrostatic pressure on microstructure, texture, colour and biochemical changes of red abalone (Haliotis rufecens) during cold storage time.

Briones-Labarca, V., Perez-Won, M., Zamarca, M., Aguilera-Radic, J., & Tabilo-Munizaga, G.

This study was carried out to evaluate the effect of high hydrostatic pressure on quality changes (microstructure, colour, texture and biochemical) of red abalone (Haliotis rufecens) during storage time at 4 °C. High hydrostatic pressure (HHP) treatments were applied at 500 MPa for 8 min and 550 MPa for 3 and 5 min. Biochemical indices covering pH, total volatile basic nitrogen (TVB-N) and trimethylamine (TMA), as well as instrumental texture, microstructure and colour of abalone samples were determined immediately after treatment and throughout subsequent storage at 4 °C. Results have shown that HHP-treated abalones have significantly (p ≤ 0.05) higher pH, moisture and ash content than untreated abalones. Protein and fat contents of treated abalones were significantly (p ≤ 0.05) lower compared to untreated sample (control). TVB-N and TMA levels for HHP-treated abalones rose over the storage period but did not exceed 28 mg TVB-N/100 g and 3 mg TMA/100 g, respectively at the end of 60 days. Instead, the untreated sample exceeded the allowed limit in a 30 day period for the TVB-N and TMA. However, all HHP treatments had less negative effects on tissue colour of abalone than untreated samples in the cold storage time; moreover, whiteness index was reduced to 8% at the end of day 60. A more compact structure was identified as high hydrostatic pressure was higher. Thus, it was concluded that holes in muscle fibres were often due to protein gelation, whenever pressure and protein concentration are high enough, confirming that the structure of abalone muscle treated with high hydrostatic pressure differed significantly from that of raw abalone meat.

Año: 2012

Palabras claves: High hydrostatic pressure; Abalone; Colour; pH; TVB-N; TMA; Microstructure

Effect of high pressure on the interactions of myofibrillar proteins from abalone (Haliotis rufencens) containing several food additives.

Barrios-Peralta, P., Pérez-Won, M., Tabilo-Munizaga, G., & Briones-Labarca, V.

Changes induced by high hydrostatic pressure (HHP) processing on the chemical and functional properties of seafood proteins and their interactions with selected food additives, such as potato starch (PS), dried egg whites (EW) and agar, were studied at pressures ranging from 200 to 550 MPa for 3, 5 and 10 min. Phosphate buffers were used to extract abalone muscle myofibrillar proteins. Protein changes was studied by UV–visible spectroscopy and functionality by their emulsifying capacity. The results show changes in peak heights and the appearance of new peaks at 327 nm in pressurised samples with additives; however, interactions between myofibrillar proteins and food additives did not take place, the same was observed by SDS-PAGE, regardless of the pressure treatment applied. In contrast, the emulsifying capacity increased in samples with agar and PS treated at 350–550 MPa. The highest emulsifying capacity was obtained in samples with 4 g PS/100 mL of protein dilution at 450 MPa for 5 min, while the emulsifying capacity decreased at 200 MPa using 10 g EW/100 mL of protein. No changes in protein bands were observed for all samples, suggesting that high pressure did not influence changes in the molecular weights of the proteins.

Año: 2012

Palabras claves: Myofibrillar protein; High hydrostatic pressure; Starch; Agar; Abalone.

Permanent Genetic Resources added to Molecular Ecology Resources Database 1 August 2011-30 September 2011.

A’hara, S. W., Amouroux, P., Argo, E. E., Avand-Faghih, A., Barat, A., Barbieri, L., Bert, T. M., Blatrix, R., Blin, A., Bouktila, D., Broome, A., Burban, C., Capdevielle-Dulac, C., Casse, N., Chandra, S., Cho, K. J., Cottrell, J. E., Crawford, C. R., Davis, M. C., Delatte, H., Desneux, N., Djieto-lordon, C., Dubois, M. P., El-Mergawy, R. A. A. M., Gallardo-Escárate, C., Garcia, M., Gardiner, M.M., Guillemaud, T., Haye, P. A., Hellemans, B., Hinrichsen, P., Jeon, J. H., Kerdelhué, C., Kharrat, I., Kim, K. H., Kim, Y. Y., Kwan, Y.-S., Labbe, E. M., Lahood, E., Lee, K. M., Lee, W.-O., Lee, Y.-H., Legoff, I., Li, H., Lin, C.-P., Liu, S. S., Liu, Y. G., Long, D., Maes, G. E., Magnoux, E., Mahanta, P. C., Makni, H., Makni, M., Malausa, T., Matura, R., Mckey, D., Mcmillen Jackson, A. L., Méndez, M. A., Mezghani-Khemakhem, M., Michel, A. P., Paul, M., Murielcunha, J., Nibouche, S., Normand, F., Palkovacs, E. P., Pande, V., Parmentier, K., Peccoud, J., Piatscheck, F., Puchulutegui, C., Ramos, R., Ravest, G., Richner, H., Robbens, J., Rochat, D., Rousselet, J., Saladin, V., Sauve, M., Schlei, O., Schultz, T. F., Scobie, A. R., Segovia, N. I., Seyoum, S., Silvain, J.-f., Tabone, E., Van Houdt, J. K. J., Vandamme, S. G., Volckaert, F. A. M., Wenburg, J., Willis, T. V., Won, Y.-J., Ye, N. H., Zhang, W. and Zhang, Y. X.

This article documents the addition of 299 microsatellite marker loci and nine pairs of single-nucleotide polymorphism (SNP) EPIC primers to the Molecular Ecology Resources (MER) Database. Loci were developed for the following species: Alosa pseudoharengus, Alosa aestivalis, Aphis spiraecola, Argopecten purpuratus, Coreoleuciscus splendidus, Garra gotyla, Hippodamia convergens, Linnaea borealis, Menippe mercenaria, Menippe adina, Parus major, Pinus densiflora, Portunus trituberculatus, Procontarinia mangiferae, Rhynchophorus ferrugineus, Schizothorax richardsonii, Scophthalmus rhombus, Tetraponera aethiops, Thaumetopoea pityocampa, Tuta absoluta and Ugni molinae. These loci were cross-tested on the following species: Barilius bendelisis, Chiromantes haematocheir, Eriocheir sinensis, Eucalyptus camaldulensis, Eucalyptus cladocalix, Eucalyptus globulus, Garra litaninsis vishwanath, Garra para lissorhynchus, Guindilla trinervis, Hemigrapsus sanguineus, Luma chequen. Guayaba, Myrceugenia colchagüensis, Myrceugenia correifolia, Myrceugenia exsucca, Parasesarma plicatum, Parus major, Portunus pelagicus, Psidium guayaba, Schizothorax richardsonii, Scophthalmus maximus, Tetraponera latifrons, Thaumetopoea bonjeani, Thaumetopoea ispartensis, Thaumetopoea libanotica, Thaumetopoea pinivora, Thaumetopoea pityocampa ena clade, Thaumetopoea solitaria, Thaumetopoea wilkinsoni and Tor putitora. This article also documents the addition of nine EPIC primer pairs for Euphaea decorata, Euphaea formosa, Euphaea ornata and Euphaea yayeyamana.

Año: 2012

Palabras claves:

The role of ex situ seed banks in the conservation of plant diversity and in ecological restoration in Latin America.

León-Lobos, P., Way, M., Aranda, P., & Lima-Junior, M.

The collection, conservation and use of seeds from arid and semi-arid biomes is highly effective; however the higher frequency of recalcitrant seeds in humid tropical forests requires a greater investment in research to underpin large-scale seed banking. In order to safeguard native species and provide adequate diversity of seeds for habitat restoration programmes, we anticipate the need to strengthen the capacity of the region's seed banks for preservation, research and propagation of native species.

Año: 2012

Palabras claves: desiccation-tolerance, gene bank, genetic diversity, germination, germplasm, plant conservation, threatened species.

Heritability and genetic correlations of escape behaviours in juvenile scallop Argopecten purpuratus.

Brokordt, K., Farías, W., Lhorente, J., & Winkler, F.

Escape behaviours are generally considered adaptive because of their obvious effects on fitness. However, little is known about the genetic basis of escape responses. The estimation of the magnitude of hereditary factors affecting variation in escape responses indicates their potential to evolve by natural selection. Scallops are exceptional among bivalve molluscs because they possess an excellent swimming capacity, which helps them to escape predators. In this study we estimated the narrow-sense heritability (h2), phenotypic variance components and phenotypic and genetic correlations of several escape response traits (i.e. reaction time, number of claps (rapid valve closures and openings), and the duration and intensity of the clapping response) in juvenile Argopecten purpuratus scallops. We stimulated scallop escape responses using their natural predator, the sea star Meyenaster gelatinosus. Genetic estimates for escape response traits were determined by the animal model. Most studied traits showed substantial amounts of additive genetic variance controlling their phenotypic variation (CVA = 18.43–100.2), were repeatable (at least over a short period, R = 0.36–0.42), and had significant heritabilities (h2 = 0.36–0.57). Indeed, it can be inferred that most of the analysed escape response traits of A. purpuratus could evolve through natural selection. Moreover, significant genetic correlations between some escape response traits were observed, suggesting that selection acting on one escape trait will affect that of another, facilitating their coevolution.

Año: 2012

Palabras claves: Argopecten purpuratus; escape behaviour; genetic correlation; heritability; scallop

Asociacion del color de la concha de reproductores de Argopecten purpuratus (Lamarck, 1819) con la supervivencia, crecimiento y desarrollo larval de sus progenies.

Garcia, R. & Winkler, F.

Las conchas de moluscos bivalvos marinos son extremadamente diversas en sus patrones de pigmentación y riqueza de colores. Tal diversidad se debe a factores ambientales y genéticos. En bivalvos marinos adultos, individuos con coloraciones de concha poco comunes en las poblaciones silvestres suelen presentar tasas de crecimiento y supervivencia menores que aquellos con colores de concha más frecuentes. Conociendo que la variación del color de la concha en Argopecten purpuratus está bajo control genético, en este trabajo se pone a prueba la hipótesis de que los loci responsables de dicha variación pueden afectar el crecimiento, la supervivencia y la tasa de desarrollo de las larvas de esta especie. Se estimó la supervivencia y el crecimiento en progenies de cruzamientos dirigidos entre individuos de A. purpuratus con colores de concha blanco, naranja y marrón, y se verificó la existencia de diferencias en las tasas de desarrollo. El crecimiento de las larvas producidas en cruzamientos que incluyeron individuos marrones o blancos con naranja no mostraron diferencias entre sí. En cambio, las progenies producto de autofecundaciones de individuos naranja y blancos presentaron tasas de crecimiento significativamente menores que las anteriores y distintas entre sí. Las tasas de desarrollo y de supervivencia, en cambio, no mostraron diferencias entre las progenies de los distintos tipos de cruzamientos. Los resultados sugieren que los genes que controlan la variación del color en las conchas de juveniles y adultos de A. purpuratus afectarían la tasa de crecimiento de sus larvas, pero no la tasa de desarrollo ni su supervivencia.

Año: 2012

Palabras claves: Argopecten purpuratus, ostión del norte, pectinidos, cultivo, desarrollo larval, color, Chile.

Application of high hydrostatic pressure to aloe vera (Aloe barbadensis Miller) gel: Microbial inactivation and evaluation of quality parameters

Vega-Gálvez, A., Giovagnoli, C., Pérez-Won, M., Reyes, J., Vergara, J., & Miranda, M. et al.

High hydrostatic pressure (HHP) is an innovative technology which minimizes loss of physicochemical and nutritional quality matching consumer demands for fresh-like foods. The aim of this study was to investigate the effect of high hydrostatic pressure (300, 400 and 500 MPa/1, 3 and 5 min) on microbial inactivation and quality parameters of A. vera gel after 60 days of storage. Shelf life was determined successfully by fitting experimental microbial data to the modified Gompertz equation for samples treated at 300 MPa/1 min. The samples treated at 400 and 500 MPa during 1, 3 and 5 min presented undetectable levels of microorganisms' counts. Based on microbiological results, the analysis of quality attributes was focused on the effects of HHP (300, 400 and 500 MPa) during 5 min of processing. Antioxidant activity, which was analyzed by means of total polyphenols content and DPPH-radical scavenging activity, showed a maximum value at 500 MPa. At 400 MPa, vitamin C showed the maximum retention (93%) and vitamin E increased the initial value of the gel. An increase of polysaccharides at 500 MPa also affected the gel firmness. Differences in surface color were also observed. Based on results, application of 500 MPa during 5 min may be successfully used to preserve main quality attributes of A. vera gel.

Año: 2012

Palabras claves: High hydrostatic pressure; Quality indices; Microbial growth; Shelf life; A. vera gel