Unonopsis guatterioides: morphological and chemical characteristics of its fruits and seeds, and germination processes under experimental conditions.

The Unonopsis guatterioides (Annonaceae) species provides wood which is used in rural construction projects, has leaves which are used in traditional medicine and its fruit is important in bird diets. This study aimed to evaluate the morphometry of seeds and fruits, their chemical composition, and the germination at different temperatures using seeds subjected to tegumentary dormancy break from fruits collected in a semi-deciduous seasonal forests in Mato Grosso do Sul, Brazil. The fruits under ripening showed a higher number of secondary metabolites and higher phenolic compounds. Morphometry results indicated that most seeds have length between 3.5 and 5.6 (81.3%), width between 8.1 and 9.0 mm (85.0%) and average weight of 0.28 g. The results indicate that there is a greater number of fruits with length ranging between 9.0 and 16.5 mm (74.8%), width between 9.0 and 12.0 mm (60.0%) and average weight of 1.33 g. Germination was strongly affected by temperature, reaching 58.0% and 62.0% of germinability at 30 °C and 25-35 °C, respectively, with seeds showing integumentary dormancy, requiring scarification.

Characterization of transgenic tilapia lines with different ectopic expression of tilapia growth hormone.

The transfer of growth hormone (GH) genes has opened new possibilities for the manipulation of growth in economically important fish species. However, the ectopic GH levels to optimize growth acceleration in fish, and specially in tilapia, are not known and must be determined experimentally. The tilapia GH (tiGH) cDNA was used to construct chimeric genes expressing different levels of tiGH in vitro and in vivo. These constructs were used to generate four lines of transgenic tilapia by microinjection into one-cell embryos. Different patterns and levels of ectopic expression of tiGH and IGF were detected in organs of transgenic tilapia by RNA or protein analysis. The two lines with lower ectopic tiGH mRNA levels were the only ones showing growth acceleration, suggesting that the expression of ectopic tiGH promoted growth only at low expression levels. The effect of higher ectopic tiGH levels resembled the physiologic situation of low condition factor and permitted us to postulate a model for growth acceleration in transgenic tilapia expressing ectopic tiGH.

Growth enhancement in transgenic tilapia by ectopic expression of tilapia growth hormone.

The generation of transgenic fish with the transfer of growth hormone (GH) genes has opened new possibilities for the manipulation of growth in economically important fish species. The tilapia growth hormone (tiGH) cDNA was linked to the human cytomegalovirus (CMV) enhancer-promoter and used to generate transgenic tilapia by microinjection into one-cell embryos. Five transgenic tilapia were obtained from 40 injected embryos. A transgenic animal containing one copy of the transgene per cell was selected to establish a transgenic line. The transgene was stably transmitted to F1 and F2 generations in a Mendelian fashion. Ectopic, low-level expression of tiGH was detected in gonad and muscle cells of F1 transgenic tilapia by immunohystochemical analysis of tissue sections. Nine-month-old transgenic F1 progeny were 82% larger than nontransgenic fish at p = .001. These results showed that low-level ectopic expression of tiGH resulted in a growth acceleration in transgenic tilapia. Tilapia GH gene transfer is an alternative for growth acceleration in tilapia.

Kynurenate and 2-amino-5-phosphonovalerate alter the spinal seizures evoked by sudden cooling of toad isolated cords.

Sudden cooling of the isolated spinal cord of toads results in characteristic seizure-like activity in the hindlegs. In the present investigation, kynurenate (KYN), a noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist and 2-amino-5-phosphonovalerate (APV), a competitive NMDA receptor antagonist, were tested in the pattern, latency and duration of the spinal seizures. APV, 1.3-2.5 mmol/kg and KYN, 2.6 mmol/kg, inhibited the tonic phase of the spinal seizures and prolonged the duration of the clonic phase after intralymphatic (i.l.) administration. The same effect was observed after intrathecal injection of either 10 or 20 mumol/20 microliter of each drug. The clonic phase was markedly attenuated by KYN at high doses of 5.3 or 10.6 mmol/kg, i.l., suggesting that non-NMDA receptors may have some mediation in the generation of that phase. Both antagonists retarded the onset of seizures indicating that activation of NMDA receptors is likely involved in the beginning of this convulsive-like activity. This model may be a useful technique to assay other excitatory amino acid antagonists.

Kynurenate and 2-amino-5-phosphonovalerate alter the spinal seizures evoked by sudden cooling of toad isolated cords.

Sudden cooling of the isolated spinal cord of toads results in characteristic seizure-like activity in the hindlegs. In the present investigation, kynurenate (KYN), a noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist and 2-amino-5-phosphonovalerate (APV), a competitive NMDA receptor antagonist, were tested in the pattern, latency and duration of the spinal seizures. APV, 1.3-2.5 mmol/kg and KYN, 2.6 mmol/kg, inhibited the tonic phase of the spinal seizures and prolonged the duration of the clonic phase after intralymphatic (i.l.) administration. The same effect was observed after intrathecal injection of either 10 or 20 mumol/20 microliter of each drug. The clonic phase was markedly attenuated by KYN at high doses of 5.3 or 10.6 mmol/kg, i.l., suggesting that non-NMDA receptors may have some mediation in the generation of that phase. Both antagonists retarded the onset of seizures indicating that activation of NMDA receptors is likely involved in the beginning of this convulsive-like activity. This model may be a useful technique to assay other excitatory amino acid antagonists.