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Made available in DSpace on 2021-06-25T10:23:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 The release of pollutants is increasing along the coast of Chile, and the use of biomarkers in biomonitoring programs is essential to assess the early biological effects of marine contamination. The Micronucleus (MN) test was carried out using hemocytes of the mussel Perumytilus purpuratus from two sites in northern-central Chile (La Pampilla and Totoralillo). Nuclear abnormalities were assessed, and high frequencies of micronucleus (10.7–14.4‰) and other abnormalities were found (51.9–76.6‰). These values tended to be higher in La Pampilla, possibly due to the large presence of pollution sources in that site. However, considerably high values were observed in both sites. P. purpuratus is a suitable bioindicator and further monitoring along the Chilean coast using this species should be developed using the MN test and/or other biomarkers to comprehend the effects of human activities on the coastal environment of Chile. Departamento de Biología Marina Facultad de Ciencias del Mar Universidad Católica del Norte Departamento de Biología Facultad de Ciencias Universidad de La Serena São Paulo State University – UNESP, Praça Infante Dom Henrique, s/n São Paulo State University – UNESP, Praça Infante Dom Henrique, s/n

Seriolella violacea Guichenot, 1848 is an important component of the fish fauna of the Chilean coast and is of great economic interest. Cytogenetic information for the family Centrolophidae is lacking and the genomic size of five of the twenty-eight species described for this family are is barely known. This study aimed to describe for the first time the karyotype structure via classical and molecular cytogenetics analysis with the goal of identifying the constitutive heterochromatin distribution, chromosome organization of rDNA sequences and quantification of nuclear DNA content. The karyotype of S. violacea is composed of 48 chromosomes, with the presence of conspicuous blocks of heterochromatin on chromosomal pairs one and two. FISH assay with a 5S rDNA probe, revealed the presence of fluorescent markings on the heterochromatic block of pair one. The 18S rDNA sites are located exclusively on pair two, characterizing this pair as the carrier of the NOR. Finally, the genomic size of S. violacea was estimated at 0.59 pg of DNA as C-value. This work represents the first effort to document the karyotype structure and physical organization of the rDNA sequences in the Seriolella genome, contributing with new information to improve our understanding of chromosomal evolution and genomic organization in marine perciforms.

Studies on cytogenetic diversity within the Alstroemeriaceae family along its intercontinental distribution are scarce when comparing species of their four genera. This study aimed at exploring the cytogenetic diversity of the family along their geographical distribution, including species that inhabit Oceania and South America. Using quantitative and qualitative methods, we analysed 50 species of the four genera (24% of the species of the family), comparing cytogenetic characters such as chromosome number, karyotype morphology and asymmetry, location of chromosome satellites, total haploid length, meiotic behaviour, C and FISH banding, and DNA C-values. We concur with other authors in that generic delimitation based on chromosome number is clear among Alstroemeria (2n = 16) and Bomarea (2n = 18), both belonging to Alstroemerioideae. Moreover, these two genera have different chromosome numbers compared to those of Luzuriaga and Drymophila (both 2n = 20) belonging to Luzuriagoideae. The above observations were also supported by the phylogeny reconstructed here. In addition, analyses on karyotype morphology and asymmetry have determined gradual differences in nuclear architecture among genera and species. We concluded that the cytogenetic diversity described within Alstroemeriaceae is concentrated mainly in South America, which is to be expected given the higher species diversity that has been described for that continent. Although the presence of three chromosome numbers within Alstroemeriaceae has no relation with their wide geographical distribution in two continents, an appreciable variation was observed in karyotype morphology and asymmetry, total haploid length and cytomolecular features when the species were compared along their geographical range.

Chia ( Salvia hispanica L.) is a native plant to southern Mexico and northern Guatemala although in these days also is cultivated in others South American countries such as Bolivia and Argentina. This study describes a genetic, cytological and molecular characterization of nine provenances of Salvia hispanica . The genome size was estimated to be C = 0.84 pg of DNA. Also a quantitative description of the karyotype is presented. The karyo-idiogram analysis shows that pairs 5 and 6 of the chromosomes are in the limit between submetacentric and subtelocentric types. When the nine provenances were studied using ISSR markers we were able to observe a very low genetic variability for the ISSR loci analysed (h = 0.08–0.15; I = 0.10–0.23; P = 9.3–23.5%). Selfing and reduced genetic background produced by genetic drift and human selection, might explain in part the scarce genetic differentiation found among provenances. These genetic characterizations are part of the basic genetic information, which should be considered for improvement and germplasm conservation programs.

The family Sphaeriidae is a group of cosmopolitan freshwater clams that inhabit temporary and permanent fluvial and lacustrine environments around the world. In Chile, Sphaeriidae is represented by 11 species belonging to the genera Musculium, Pisidium and Sphaerium. In this study, the nuclear DNA content (or 2C-value) of Musculium argentinum (d’Orbigny, 1835) and Pisidium llanquihuense Ituarte, 1999 was estimated for the first time. Musculium argentinum showed a 2C-value of 3.7 ± 0.38 pg, whereas P. llanquihuense showed a 2C-value of 3.57 ± 0.36 pg. These 2C-values are within the range previously reported for Sphaeriidae (2.35–5.7 pg), which includes diploids and polyploids, amounting to 13 of the species examined around the world. Of the cytological data available for the family, the nuclear DNA content can have a unifying role in understanding the magnitude of the chromosome polymorphisms within this polyploid complex.

RESUMEN Krameria cistoidea Hook. & Arn. tiene un valor 2C de 18,64 + 1,09 pg con un coeficiente de variacion de 5,8%. El numero cromosomico 2n = 12 descrito para otras seis especies de Krameria esta tambien presente en K. cistoidea. Estos datos citologicos de K. cistoidea son discutidos en relacion a antecedentes disponibles para otras Angiospermas, asi como para tres generos de la familia taxonomicamente relacionada Zygophyllaceae.

El selenio es esencial y requerido por distintos sistemas biologicos para su crecimiento y metabolismo. Su transformacion en el ambiente ocurre principalmente por microorganismos que reducen el selenito a selenio elemental. Pantoea agglomerans UC-32 reduce el selenito a nanoparticulas de selenio elemental. El objetivo de este trabajo fue determinar la cinetica de reduccion de selenito a selenio elemental y la ubicacion celular de la actividad reductora en Pantoea agglomerans UC-32. Se ensayo la actividad reductora de P. agglomerans frente a diferentes concentraciones de selenito, evaluandose la disminucion de selenito y aparicion de selenio elemental. La ubicacion de la actividad reductora fue estudiada por fraccionamiento celular y zimograma. Al ensayar la actividad reductora de selenito se encontro que la enzima se satura a concentraciones bajas de este compuesto y el zimograma localizo esta actividad en la fraccion citoplasmatica y que requiere NADPH como coenzima. En conclusion, P. agglomerans es capaz de reducir selenito a selenio elemental insoluble inmovilizado en la biomasa en condiciones aerobicas y que la enzima que cataliza esta reduccion se localiza en la fraccion de citoplasmatica. Estas caracteristicas permitirian la "sintesis verde" de nanoparticulas de selenio las cuales tienen aplicacion en la biorremediacion de diferentes matrices, como suelo o agua contaminadas.

Plasticity and local adaptation have been suggested as two main mechanisms that alien species use to successfully tolerate and invade broad geographic areas. In the present study, we try answer the question if the mechanism for the broad distributional range of T. officinale is for phenotypic plasticity, ecotypic adaptation or both. For this, we used individuals of T. officinale originated from seeds collected in five localities along its latitudinal distribution range in the southern-hemisphere. Seedlings were acclimated at 5 and 25°C for one month. After the acclimation period we evaluated ecophysiological and cytogenetic traits. Additionally, we assessed the fitness at each temperature by recording the seed output of individuals from different localities. Finally, we performed a manipulative experiment in order to assess the tolerance to herbivory and competitive ability between T. officinale from all origins and Hypochaeris scorzonerae a co-occurring native species. Overall, individuals of T. officinale showed high plasticity and ecotypic adaptation for all traits assessed in this study. Changes both in physiology and morphology observed in T. officinale from different origins were mostly correlated, enhancing their ecophysiological performance in temperatures similar to those of their origin. Additionally, all localities showed the same chromosome number and ploidy level. On the other hand, all individuals showed an increase the seed output at 25°C, but those from northern localities increased more. T. officinale from all origins was not significantly affected by herbivory while native showed a negative effect. On the other hand, T. officinale exerted a strong negative effect on the native species, but this former not effected significantly to the invasive T. officinale. High plasticity and local adaptation in all ecophysiological traits, seed-set and the low cytogenetic variability in T. officinale suggests that both strategies are present in this invasive plant species and are not mutually exclusive. Finally, higher tolerance to herbivory and competitive ability suggests that T. officinale could perform successfully in environments with different climatic conditions, and thus colonize and invade South-America.

Se documenta un número cromosómico 2n = 26 (x = 13) para Nothofagus dombeyi (Mirb.) Oerst. y N. glauca (Phil.) Krasser, el cual es similar al descrito previamente para otras especies del género. Se incrementan a 13 las especies de Nothofagus con número cromosómico conocido, existiendo dos números básicos (x = 13, 14).

The karyotype of Luzuriaga radicans R. & P. was quantitatively studied, assessing characters such as chromosome morphology and size, satellite location, asymmetry level and bimodality. L. radicans has an asymmetric and bimodal karyotype 2n = 20 with three metacentric pairs, followed by six submetacentric and one subtelocentric chromosome pair. One satellite was observed in the short arm of chromosome pair 6. The total haploid set length was 48.7 μm and the mean chromosome size was 4.87 ± 2.35 μm. Comparing L. radicans with other two species of the genus a high resemblance among their karyotypes was found.

The pill clams Pisidium chilense (d'Orbigny, 1846) and Pisidium huillichum (Ituarte, 1999) showed a 2C DNA content of 4.04 ± 0.4 pg and 2.35 ± 0.24 pg, respectively. The somatic DNA content of these 2 Chilean Pisidium Pfeiffer 1821 species is within the range described previously for diploid Heterodonta, despite the fact that both showed a high chromosome number (> 100–120 chromosomes) equivalent to the polyploid level described for other species of the genus. The nuclear DNA content is shown here for the first time for species of the family Sphaeriidae. The Pisidium, like other species, are not economically important as edible species, but they play a significant role in the dynamics of nutrient and energy cycles in freshwater bodies similar to that described for other Sphaeriidae species.

Species from two genera belonging to the Alstroemeriaceae, Bomarea and Leontochir, were cytogenetically studied and compared to determine their detailed karyotypic composition. Bomarea is a polytypic genus represented by 100 species, with a distribution range from Mexico and Antilles (24°N) to Argentina (29°S) and Chile (17–40°S). In contrast Leontochir is a monotypic genus, endemic to the coastal area of the Atacama Desert in Chile (28°S). Bomarea salsilla, B. involucrosa, and Leontochir ovallei have a karyotype 2n = 18 with similar chromosome morphology. These data confirm the close relationship between both genera, suggested by earlier studies.

Luma apiculata (DC.) Burret, had a symmetric karyotype, with 2n = 22 small sized chromosomes, ranging between 2.2 μηι and 0.8 μηι. The haploid karyotype formula was 9m + 2sm = 11. These karyotype characteristics of L. apiculata are a common character within Myrtaceae.

Estudios cariotípicos en Rhodophiala bagnoldii (Herb.) Traub (2n = 18) han descrito constricciones secundarias subteloméricas localizadas en el brazo largo del par cromosómico 7. En este trabajo, una señal Ag-NOR positiva fue observada en la constricción secundaria de ambos cromosomas homólogos. Nucléolos fusionados y no fusionados fueron también observados en núcleos interfásicos de células meristemáticas.

Scallop aquaculture has a 20-y-old history in Coquimbo, Chile. At the beginning develop and introduce on industrial level the culture techniques was the main goal, but in recent years research to improve the broodstock quality has been introduced. Development of non destructive procedures to determine gonadal ripeness were necessary. The use of magnetic resonance imaging proved to be an interesting tool to view the internal anatomy of the Chilean scallop Argopecten purpuratus (Lamarck 1819) without any harmful side effect. A central groove located in the middle of the adductor muscle, became visible using MRI, and could possibly be related to the haemolymphatic circulation system.

RESUMEN Las determinaciones de ADN nuclear realizadas muestran que el valor 2C para Rhodolirium montanum Phil. (2n=2x=16) es de 17,39 pg y de 15,16 pg para Phycella ignea (Lindl.) Lindl. (2n=2x=16). Sin embargo, el tetraploide Phycella scarlatina Ravenna (2n = 4x = 32) tiene un valor de ADN 2C de 30,63 pg , el cual es concordante con su nivel de ploidia.

The nuclear DNA content (2C value) was determined in the commercial fish Galaxias maculatus (Galaxiidae) was determined by microdensitometry of erythrocyte nuclei after Feulgen staining; rainbow trout erythrocytes with a known 2C value were used as a standard. The 2C value of G. maculatus was 2.21 +/- 0.12 pg and its C value was equivalent to 1.105 pg (1,082.9 Mbp). This C value is within the range recorded for other osmeriform species (0.62-3.2 pg). The average sperm head diameter of G. maculatus is lower than the average sperm head diameter of rainbow trout (used as a standard), which coincides with the differences observed in the nuclear DNA content of both species. This information increases the genome data available for G. maculatus and might be useful in future programs dealing with its genetic manipulation.

Galaxias platei, es un pez endémico de Chile y cubre una extensa área geográfica desde la zona centro-sur hasta gran parte de la Patagonia (38°S-54°S), incluyendo también parte de Argentina. En este trabajo se determinó el contenido somático de ADN nuclear (valor 2C) de Galaxias platei (Galaxiidae) mediante microdensitometría nuclear de eritrocitos sometidos a tinción de Feulgen. El valor 2C de G platei es 1,88+0,16 pg y su valor C es equivalente a 0,94 pg (921,2 pMb). El valor C de G platei está dentro del rango descrito para otras especies de Osmeriformes (valores entre 0,62 y 3,2 pg) y es menor al valor documentado previamente para G maculatus (C = 1,105 pg). Estos datos contribuyen a incrementar los antecedentes genómicos disponibles para el género Galaxias los que, en conjunto con los resultados de análisis cromosómicos previos, podrían ser útiles para evaluar aquellas relaciones genéricas y específicas que han sido propuestas para la familia Galaxiidae.

Mitotic chromosome counts in Chilean pteridophytes confirm the diploidy described for Equisetum L. (2n = 216) and Blechnum L. (2n = 66), as well as the tetraploidy of Asplenium L. (2n = 144). Megalastrum spectabile (Kaulf.) A.R.Sm. et R.C.Moran is diploid (2n = 82), while in metaphases of Polystichum subintegerrimum (Hook. et Arn.) R.A.Rodr. chromosome numbers from ca. 311 to 328 were counted. Tetraploidy was also described in Adiantum chilense Kaulf. (2n = 116)

Se analizaron placas metafasicas mitoticas de Eucalyptus globulus Labill. y Eucalyptus cladocalyx F. Muell. Los cromosomas se observaron mediante aplastado de meristemas radiculares, previamente tratados con 8-Hidroxiquinolina y tenidos con la reaccion de Feulgen. Las dos especies mostraron un cariotipo 2n = 22, con un nivel de simetria 1A y con tamanos cromosomicos que variaron entre 0,68 y 2,03 m m. El tamano cromosomico promedio difirio significativamente al comparar entre E. globulus (1,42 m m) y E. cladocalyx (1,02 m m) (P < 0,01). El mayor tamano cromosomico de E. globulus sugiere una mayor cantidad de ADN, originado probablemente por alteraciones cromosomicas estucturales. Este patron de evolucion del cariotipo estaria asociado, ademas, con un alto nivel de conservacion en la morfologia cromosomica.

The karyotype of a freshwater population of Diplodon chilensis located in La Poza area of the Villarrica Lake (39º18'S; 72º05'W), Southern Chile, was studied. The chromosomes were obtained by squash of cleaving embryos, previously treated with colchicine and fixed in ethanol-acetic acid 3:1 at 4ºC and stained using the Feulgen reaction. Diplodon chilensis showed a diploid karyotype of 2n = 34, with metacentric and submetacentric chromosomes. This work is the first approach to cytogenetic characterization of Chilean populations of this species.