Cytological, Immunocytochemical and Ultrastructural Study of the Adenohypophyseal Pars Distalis of the Kid (Capra hircus): The TSH cell

The structure and ultrastructure of the adenohypophyseal pars distalis in kids of the Murciano-granadiana breed (18 males and 12 females), aged 2-3 months and with an average carcass weight of 8 kg has been studied. Techniques of staining (Tetrachrome Herlant's, and Cleveland-Wolfe) and histochemistry (PAS, PAS-OG and BA-PAS-OG) contrasted with immunolabelling (PAP) have been used. In addition an ultrastructural study has been made and nucleus and cytoplasm, secretory granules, mitochondria and lysosomes have been measured with a semiautomatic image analyzer (IBAS-1). TSH cells are found in sagittal section in the anterior area and in an antero-caudodorsal band, and transversally in the ventral and medial region; they are 6% and their average size is 14.15 microns. Ultrastructurally they are a single cellular type with spherical granules whose size is 195 nm in males and 149 in females; these granules are characterized by a clear halo and a variable electronic density. The rough endoplasmic reticulum is found as slightly enlarged vesicles with a homogeneous and moderately electro-dense content or in concentric stratifications.     

Modulation of Uptake and Translocation of Iron and Copper from Root to Shoot in Common Bean by Siderophore-Producing Microorganisms

Microbes have developed high-affinity uptake mechanisms to assimilate iron (Fe) and other metals such as aluminum (Al), gallium (Ga), chromium (Cr), and copper (Cu). Siderophores, which are metal chelating compounds, and membrane receptor proteins are involved in these specialized mechanisms. A few siderophore-producing microorganisms associated with plant roots also influence the uptake of some metals. In this study, the potential microbial-assisted Cu and Fe uptake by Phaseolus vulgaris (common bean) plants was evaluated. Seedlings of cultivated common bean varieties Bayo-INIFAP (B) and Negro-150 (N) and wild types yellowish (WY) and black (WB) were developed in the presence of a Cu and Fe solution and associated with the siderophore-producing microorganisms R. leguminosarumbv. Phaseoli (strains 19, 44, and 46); Pseudomonas fluorescens(strain Avm), and Azospirillum brasilense (strain 154). Seedlings of cultivated variety N and black wild type WB inoculated with the strain CPMex.44 accumulated 71% and 30% more Fe than the un-inoculated plants, respectively; however, the wild black bean accumulated the highest absolute amount of Fe (221.56 mg/kg of dry matter) as compared with the cultivated black variety N (126.16 mg/kg of dry matter) (P < 0.05). In the wild type WY seedlings, the highest Fe accumulation was observed when the seeds were inoculated with the Pseudomonas strain Avm (206 mg/kg of dry matter) (P < 0.05). The interaction of Pseudomonas strain Avm with seedlings of the cultivated B variety and the wild type WB promoted the highest accumulation of Cu (51 and 54 mg/kg of dry matter, respectively), 7 and 14 mg more than in the respective non-inoculated seedlings. No promotion of Fe accumulation was observed in the seedlings of the cultivated B variety and in roots; instead, less Fe was accumulated. The wild type WY did not show any improvement in Cu accumulation. In this study, Rhizobiumstrains promoted Fe but not Cu uptake in P. vulgaris seedlings while Pseudomonas strains promoted the uptake of both Cu and Fe.     

Changes in fruit sugar concentrations in response to assimilate supply,metabolism and dilution: a modeling approach applied to peach fruit (Prunus persica)

The influence of assimilate supply, metabolism and dilution on sugar concentrations in the mesocarp of peach (Prunus persica (L.) Batsch) fruit during the main stage of fruit enlargement was analyzed with the SUGAR model of Génard and Souty (1996). The model predicts the partitioning of carbon into sucrose, sorbitol, glucose and fructose in the mesocarp of peach fruit. Based on measured data and the model, we determined values for the relative rates of sugar transformation. These rates were constant, varied with time or varied with relative fruit growth rate, depending on the type of sugar. Equations were derived to describe these rates and incorporated into the SUGAR model. The model simulated the effects of changing assimilate supply and fruit volume on sugar concentrations. The set of equations for the SUGAR model was rewritten to include the three components influencing sugar concentrations: assimilate supply, metabolism and dilution. The sugar types differed in sensitivity to these components. Sucrose was highly sensitive to changes in assimilate supply and to the dilution effect; it was not subject to intense metabolic transformation. Sorbitol was the most important carbohydrate in fruit metabolism, which explains why the sorbitol concentration was always low despite the strong positive effect of assimilate supply. The reducing sugars constituted a transitory storage pool and their concentrations were closely related to metabolism.     

Morphogenesis in leaf and single-cell cultures of mature Juniperus oxycedrus

Single cells were mechanically isolated from leaf-derived callus of mature Juniperus oxycedrus L. These cells divided and gave rise to callus when plated on medium containing growth regulators. Best plating efficiency was obtained on a modified Schenk and Hildebrandt medium supplemented with 0.6 micro M 2,4-dichlorophenoxyacetic acid and 100 mg l(-1) casein hydrolyzate. Although single-cell-derived callus showed poor morphogenic potential, both adventitious shoots and embryogenic tissues differentiated from the callus. We also achieved induction of somatic embryogenesis in leaf explants of mature J. oxycedrus trees cultured in the presence of 6.0 or 10.0 micro M 2,4-dichlorophenoxyacetic acid or picloram. Frequency of embryogenic callus ranged from 6 to 18%; however, under the culture conditions tested, isolated embryos failed to develop into plants.     

Comparison of three types of adhesives in attaching coral transplants to clam shell substrates

• 1. Nubbins from 12 coral species were transplanted onto dead giant clam shells at three sites in a lagoon near Bolinao, north‐western Philippines. Transplants were attached using three types of adhesives: cyanoacrylate glue (SG), epoxy putty (EP) and marine epoxy (ME) and were monitored over five months for detachment, in situ mortality and natural self‐attachment by tissue growth.
• 2. Corals attached with SG showed a significantly higher rate of detachment (logrank test) than those attached with either EP or ME (P<0.001 in each case). Also, those attached with EP showed a higher rate of detachment than corals attached with ME (logrank=6.46, P<0.05).
• 3. ANOVA (P>0.05) and survival analysis (logrank=2.85, P>0.05) showed no among‐adhesives differences in in situ mortality. Among the species used, Porites cylindrica, Pavona frondifera, Heliopora coerulea and Porites rus had the highest survivorship with 82%, 80%, 76% and 73%, respectively, of nubbins alive at the end of the experiment and also displayed the highest cumulative rates of self‐attachment. Species with the lowest survival rates included Acropora muricata and four pocilloporids.
• 4. Although there was no significant difference in the number of self‐attaching transplants among the adhesives, corals transplanted using ME and EP self‐attached earlier than those transplanted using SG (logrank=11.19, P<0.01).
• 5. Results from this study highlight the importance of selecting the appropriate means of attaching corals to substrates and carefully considering species‐specific traits of candidate corals for transplantation.

Copyright © 2008 John Wiley & Sons, Ltd.     

Impact of weather variables and season on sporulation of Phytophthora pluvialis and Phytophthora kernoviae

Phytophthora pluvialis and Phytophthora kernoviae are the causal agents of important needle diseases on Pinus radiata in New Zealand. Little is known about the epidemiology of the diseases, making the development of control strategies challenging. To investigate the seasonality and climatic drivers of sporulation, inoculum traps, consisting of pine fascicles floating on water in plastic containers, were exchanged fortnightly at five sites in P. radiata plantations between February 2012 and December 2014. Sections of needle baits were plated onto selective media and growth of Phytophthora pluvialis and P. kernoviae recorded. To explore the generalizability of these data, they were compared to detection data for both pathogens from the New Zealand Forest Health Database (NZFHDB). Further, equivalent analyses on infection of Rhododendron ponticum by P. kernoviae in Cornwall, UK allowed the comparison of the epidemiology of P. kernoviae across different host systems and environments. In New Zealand, inoculum of P. pluvialis and P. kernoviae was detected between January–December and March–November, respectively. Inoculum of both species peaked in abundance in late winter. The probability of detecting P. pluvialis and P. kernoviae was greater at lower temperatures, while the probability of detecting P. pluvialis also increased during periods of wet weather. Similar patterns were observed in NZFHDB data. However, the seasonal pattern of infection by P. kernoviae in the UK was the opposite of that seen for sporulation in New Zealand. Phytophthora kernoviae was likely limited by warmer and drier summers in New Zealand, but by colder winter weather in the UK. These results emphasize the importance of considering both environmental drivers and thresholds in improving our understanding of pathogen epidemiology.     

Extracellular Polymeric Substances Produced by the Thermophilic Cyanobacterium Gloeocapsa gelatinosa: Characterization and Assessment of Their Antioxidant and Metal-Chelating Activities

Cyanobacteria, particularly thermophilic strains, represent an important potential source of EPSs, harboring structural complexity that predicts diverse and specific bioactive potential. The thermophilic cyanobacteria Gloeocapsa gelatinosa, isolated from a natural hot source in Ain Echfa (Tunisia), was cultivated in a cylindrical reactor, and the production of biomass and EPSs was investigated. Results revealed that the strain is amongst the most efficient EPSs producers (0.89 g L⁻¹) and that EPSs production was not correlated with the growth phase. EPSs were sulfated heteropolysaccharides containing carbohydrates (70%) based on nine different monosaccharides, mainly mannose (22%), and with the presence of two uronic acids. EPSs were formed by two polymers moieties with a molecular weight of 598.3 ± 7.2 and 67.2 ± 4.4 kDa. They are thermostable in temperatures exceeding 100 °C and have an anionic nature (zeta potential of −40 ± 2 mV). Atomic force microscopy showed that EPSs formed multimodal lumps with 88 nm maximum height. EPSs presented high water holding capacity (70.29 ± 2.36%) and solubility index (97.43 ± 1.24%), and a strong bivalent metal sorption capacity especially for Cu²⁺ (91.20 ± 1.25%) and Fe²⁺ (75.51 ± 0.71%). The antioxidant activity of G. gelatinosa EPSs was investigated using four methods: the β-carotene-bleaching activity, DPPH assays, iron-reducing activity, and metal-chelating activity. EPS has shown high potential as free radicals’ scavenger, with an IC₅₀ on DPPH (0.2 g L⁻¹) three-fold lower than ascorbic acid (0.6 g L ⁻¹) and as a metal chelating activity (IC₅₀ = 0.4 g L⁻¹) significantly lower than EDTA. The obtained results allow further exploration of the thermophilic G. gelatinosa for several biotechnological and industrial applications.     

Attainment of Puberty in the European Mouflon (Ovis gmelini musimon) and the Domestic Manchega Ewe (Ovis aries)

The onset of puberty was assessed from plasma progesterone profiles for Mouflon (n = 8) and Manchega (n = 7) female lambs born in April. Four Mouflons exhibited their first ovulation at a mean date of 27 November ± 1.4 days, the mean age being 248.5 ± 3.9 days and the mean body weight 23.8 ± 0.6 kg. The remaining four Mouflons, which had a slower growth rate, attained puberty during the autumn of the following year. Five of seven Manchega lambs attained puberty in their first year at a mean date of 5 Oct ± 3.3, the mean age being 185.6 ± 2.6 days and the mean body weight 41.8 ± 2.0 kg. The mean live‐weight at the onset of puberty was 65.1 and 82% (p < 0.05) of adult body weights for Manchega and Mouflons, respectively. Overall, the results indicate that there is a threshold of body‐weight necessary for the attainment of puberty in the first breeding season for spring‐born lambs, which is very different between both Mouflon and Manchega. When body weight was below 23.8 ±0.6 and 41.8 ± 2.0 kg for Mouflon and Manchega lambs, respectively, first ovulation did not occur until the beginning of the next breeding season. The onset of puberty during the second year of life occurred within the specific reproductive seasons for Mouflon (October–April) and Manchega (July–March) ewes, despite minimal further growth.