Caracterización del ciclo de desarrollo embrionario y larval de sarda chiliensis chiliensis (Alva, 1987) en un sistema acuícola de recirculación (SAR) / Characterization of the stages in the cycle of embryo development sarda chiliensis chiliensis (Alva, 1987) in an aquatic re-circulation system (SAR)

Los sistemas acuícolas de recirculación (SAR) son utilizados cada vez más en la acuicultura, especialmente en el norte de Chile en donde las condiciones ambientales son propicias para el cultivo de especies nativas como el bonito (Sarda chiliensis chiliensis), del cual se desconoce su desarrollo embrionario y larval, lo que complica evaluar la factibilidad técnica y económica de desarrollar su cultivo en SAR. Por ello se determinó las bases para su cultivo a partir de enero de 2013, durante 45 días. Los periodos embrionarios caracterizados fueron 31 en 71,83 horas, definidos en 5 estadios: Mórula, Blástula, Gástrula, Neurulación y Metamería. Del desarrollo larval se observaron 35 periodos en 519 horas, un estadio prejuvenil observado a las 591 horas y uno juvenil. Los huevos fueron translúcidos de tipo telolecítico de crecimiento lento en relación a Sarda sarda y Sarda ch. lineolata (especies con las que fue comparada), ya que le tomó casi 3 días eclosionar. Las tasas de sobrevivencia y eclosión fueron altas (86,316% ±9,808 y 89,596% ±11,683 respectivamente), por esto las condiciones serían propicias para su desarrollo. Las larvas en tanto, presentaron más semejanzas con Sarda sarda, en los primeros periodos de desarrollo. El periodo crucial fue entre las 81 a 89 horas de vida, cuando se reabsorbió la gota oleosa; ésta además fue un carácter diferenciador con las otras 2 especies, ya que fue la única que presentó 1 gota oleosa en el periodo larval. Se infiere la factibilidad de un hatchery de Sarda ch. chilensis, debido a las semejanzas con Sarda sarda, y dado el éxito obtenido de ésta en cultivo. De los caracteres morfométricos se sugiere monitorear en el futuro, los que representan las mayores variabilidades dentro de los estadios de desarrollo, que fueron longitud y alto de cabeza y longitud y alto de ojo.

Aquatic re-circulation systems (SAR) are being used more and more in agriculture, especially in the north of Chile where the environment conditions are suitable for breeding in SAR (aquatic re-circulation system) of species such as Bonito (Sarda chiliensis chiliensis), whose embryo or larvae origins are unknown, which complicates the evaluation of a technical and economical possibility of developing its breeding in SAR. Due to this, bases for its breeding were determined in January 2013, for 45 days. The characterized embryo periods were 31 in 71, 83 hours, defined in 5 stages: Morula, Blastula, Gastrula, Neurulation and Metamery. From the larvae development 35 periods in 519 hours were observed, a pre-juvenile stage observed at 591 hours and a juvenile one. The eggs were translucent of a telolecitic type of a slow growing in relation to Sarda sarda and Sarda ch. lineolata, since it took them almost three days to hatch. The surviving and hatching rates were high (86,316±9,808% and 89,596±11,683% respectively), so the conditions for their development would be appropriate. Meanwhile, the larvae presented more similarities with Sarda sarda in the first periods of development. The crucial period was between the 81 and 89 hours of life, when the oily drop was re-absorbed; besides, this was a distinguishing feature with the other two species because it was the only one that presented just one oily drop in the larvae period. The possibility of a Sarda ch. chiliensis hatchery is inferred, due to the similarities with Sarda sarda, and because of the success obtained in this breeding. From the morphometric characters, future monitoring is suggested, the ones that represent the most variables in the stages of development such as length and height of the head, and length and height of the eye.

Estudio histológico de los órganos reproductivos del ratón macho CF1 tratado con boro / Histological study on the male reproductive organs of mouse CF1 treated with boron

Boric acid and borate are abundant in the nature and widely used in industrial, agricultural and cosmetology applications. However it is informed as toxic in a high dose. Residents of Arica-Chile with boron-rich geology deposits are regularly exposed to higher levels in drinking water in concentrations of 6. 0 and 12.0 mg/L. The objective of this study was to analyze the damage in the masculine reproductive apparatus of mouse CF1, exposed to boric acid in concentrations of 0.54; 2.0-6.0 and 12.0 mg/L, after 60 days of treatment. Male gonad segments were fixed in Bouin's solution for 6 hours and embedded in paraffin, longitudinal sections (5 mm) were processed for histology using the hematoxyline/eosin method. The results observed in treated animals indicate a significant increase in the weight, volume and size of testicles and seminal vesicles. The histological analysis of testicle shows in treated an epithelium notoriously altered with vacuohzations, scarce gonias and few spermatids. Gonias present picnoticals nuclei, suggesting apoptosis. In conclusion boron in high dose produces important cytotoxics effects, with degeneration of epithelium of seminiferous tubules, possibly inhibiting the spermiation, causing testicular hypertrophy, altering the masculine reproductive patterns and a reduction in fertility of mice CF1.

El ácido bórico y el borato son abundantes en la naturaleza y con amplio uso industrial, agrícola y cosmetológico. Sin embargo, se informa como tóxico en alta dosis. Residentes de la ciudad de Arica-Chile, están expuestos a altos niveles de boro presente en el agua potable, con concentraciones 6.0 y 12.0 mg/1. El objetivo de este estudio fue analizar el daño en el sistema reproductivo masculino del ratón CF1, expuesto a ácido bórico en concentraciones de 0.54; 2.0-6.0 y 12.0 mg/1, por un período de 60 días de tratamiento. Los segmentos masculinos de las gónadas fueron fijados en solución de Bouin por 6 horas e incluidos en parafina, secciones longitudinales (5 /aa) fueron procesadas para histología usando el método hematoxilina/eosina. Los resultados observados en animales tratados indican un aumento significativo en el peso, el volumen y el tamaño de testículos y de vesículas seminales. El análisis histológico de testículo de individuos tratados, muestra un epitelio alterado con vacuolizaciones, escasas gomas y pocas espermátidas. Gonias presentan núcleos picnóticos, sugiriendo apoptosis. En conclusión el boro en alta dosis produce efectos citotóxicos importantes, con degeneración de epitelio de túbulos seminíferos, posiblemente inhibiendo la espermiación, causando hipertrofia testicular, alterando los patrones reproductivos masculinos y una reducción en la fertilidad de los ratones CF1.

Dynamic assembly of tight junction-associated proteins ZO-1, ZO-2, ZO-3 and occludin during mouse tooth development.

Tight junctions might play a role during tissue morphogenesis and cell differentiation. In order to address these questions, we have studied the distribution pattern of the tight junction-associated proteins ZO-1, ZO-2, ZO-3 and occludin in the developing mouse tooth as a model. A specific temporal and spatial distribution of tight junction-associated proteins during tooth development was observed. ZO-1 appeared discontinuously in the cell membrane of enamel organ and dental mesenchyme cells. However, endothelial cells of the dental mesenchyme capillaries displayed a continuous fluorescence at the cell membrane. Inner dental epithelium first showed an evident signal for ZO-1 at the basal pole of the cells at bud/cap stage, but ZO-1 was accumulated at the basal and apical pole of preameloblast/ameloblasts at late bell stage. Surprisingly, in the incisor ZO-1 decreased as the inner dental epithelium differentiated, and was re-expressed in secretory and mature ameloblasts. On the contrary, ZO-2 was confined to continuous cell-cell contacts of the enamel organ in both molars and incisors. The lateral cell membrane of inner dental epithelial cells was specifically ZO-2 labeled. However, ZO-3 was expressed in oral epithelium whereas dental embryo tissues were negative. In addition, occludin was hardly detected in dental tissues at the early stage of tooth development, but was distributed continuously at the cell membrane of endothelial cells of ED19.5 dental mesenchyme. In incisors, occludin was detected at the cell membrane of the secretory pole of ameloblasts. The occurrence and relation during tooth development of tight junction proteins ZO-1, ZO-2 and occludin, but not ZO-3, suggests a combinatory assembly in tooth morphogenesis and cell differentiation.

Analysis of cDNAs from a mouse embryo tooth library: identification of novel genes during tooth development.

Signaling molecules, their receptors, and target genes from pathways and networks regulate the development of the tooth from initiation through cell differentiation. In order to identify genes involved in odontoblast and ameloblast differentiation, we constructed a cDNA library from E19.5 mouse molars. In this work, we report the partial cDNA sequences of 10 noncharacterized genes and we show cell expression of the transcripts on mouse embryo molars by in situ hybridization.

A rat mammary tumor model induced by the organophosphorous pesticides parathion and malathion, possibly through acetylcholinesterase inhibition.

Environmental chemicals may be involved in the etiology of breast cancers. Many studies have addressed the association between cancer in humans and agricultural pesticide exposure. Organophosphorous pesticides have been used extensively to control mosquito plagues. Parathion and malathion are organophosphorous pesticides extensively used to control a wide range of sucking and chewing pests of field crops, fruits, and vegetables. They have many structural similarities with naturally occurring compounds, and their primary target of action in insects is the nervous system; they inhibit the release of the enzyme acetylcholinesterase at the synaptic junction. Eserine, parathion, and malathion are cholinesterase inhibitors responsible for the hydrolysis of body choline esters, including acetylcholine at cholinergic synapses. Atropine, a parasympatholytic alkaloid, is used as an antidote to acetylcholinesterase inhibitors. The aim of this study was to examine whether pesticides were able to induce malignant transformation of the rat mammary gland and to determine whether alterations induced by these substances increase the cholinergic activation influencing such transformation. These results showed that eserine, parathion, and malathion increased cell proliferation of terminal end buds of the 44-day-old mammary gland of rats, followed by formation of 8.6, 14.3, and 24.3% of mammary carcinomas, respectively, after about 28 months. At the same time, acetylcholinesterase activity decreased in the serum of these animals from 9.78 +/- 0.78 U/mL in the control animals to 3.05 +/- 0.06 U/mL; 2.57 +/- 0.15 U/mL; and 3.88 +/- 0.44 U/mL in the eserine-, parathion-, and malathion-treated groups, respectively. However, atropine alone induced a significant (p < 0.05) decrease in the acetylcholinesterase activity from the control value of 9.78 +/- 0.78 to 4.38 +/- 0.10 for atropine alone, to 1.32 +/- 0.06 for atropine in combination with eserine, and 2.39 +/- 0.29 for atropine with malathion, and there was no mammary tumor formation. These results indicate that organophosphorous pesticides induce changes in the epithelium of mammary gland influencing the process of carcinogenesis, and such alterations occur at the level of nervous system by increasing the cholinergic stimulation.