Interactions between different media and follicle‐stimulating hormone supplementation on in vitro culture of preantral follicles enclosed in ovarian tissue derived from collared peccaries (Pecari tajacu Linneaus, 1758)

The aim was to verify the effect of follicle‐stimulating hormone (FSH) supplementation to α‐MEM+ or TCM199+ media on the in vitro development of ovarian preantral follicles (PFs) derived from collared peccaries. Ovaries (n = 5 pairs) were collected and divided into fragments destined to control group (non‐cultured) or treatments that were cultured for 7 days. The PFs morphology, growth and activation were evaluated by classical histology. The immunohistochemistry markers Ag‐NOR and PCNA were used for nuclear proliferation analysis, and the picrosirius red labelling was used for ovarian extracellular matrix (ECM) evaluation. After 7‐day culture, only the TCM199+ treatment maintained the proportion of intact PFs similar to day 1 (63.2%), but no differences were found among treatments (p > .05). In addition, a significant increase in the growing follicles proportion was verified for all the treatments, indicating follicular activation (p > .05). By the Ag‐NOR analysis, only the TCM199+/FSH maintained the nuclear proliferation similar to the first day (p > .05). The picrosirius red staining revealed that the ECM remained intact in all the treatments (p > .05). We suggest the use of TCM199+ medium supplemented of FSH for the in vitro development of peccaries PFs under 7‐day culturing conditions.     

Effects of extracerebral dopamine on salsolinol‐ or thyrotropin‐releasing hormone‐induced prolactin (PRL) secretion in goats

The aim of the present study was to clarify the effect of extracerebral dopamine (DA) on salsolinol (SAL)‐induced prolactin (PRL) secretion in goats. An intravenous injection of SAL or thyrotropin‐releasing hormone (TRH) was given to female goats before and after treatment with an extracerebral DA receptor antagonist, domperidone (DOM), and the PRL‐releasing response to SAL was compared with that to TRH. DOM alone increased plasma PRL concentrations and the PRL‐releasing response to DOM alone was greater than that to either SAL alone or TRH alone. The PRL‐releasing response to DOM plus SAL was similar to that to DOM alone, and no additive effect of DOM and SAL on the secretion of PRL was observed. In contrast, the PRL‐releasing response to DOM plus TRH was greater than that to either TRH alone or DOM alone and DOM synergistically increased TRH‐induced PRL secretion. The present results demonstrate that the mechanism involved in PRL secretion by SAL differs from that by TRH, and suggest that the extracerebral DA might be associated in part with the modulation of SAL‐induced PRL secretion in goats.     

Genetic variant BDNF (Val66Met) polymorphism alters anxiety-related behavior

A common single-nucleotide polymorphism in the brain-derived neurotrophic factor (BDNF) gene, a methionine (Met) substitution for valine (Val) at codon 66 (Val66Met), is associated with alterations in brain anatomy and memory, but its relevance to clinical disorders is unclear. We generated a variant BDNF mouse (BDNF(Met/Met)) that reproduces the phenotypic hallmarks in humans with the variant allele. BDNF(Met) was expressed in brain at normal levels, but its secretion from neurons was defective. When placed in stressful settings, BDNF(Met/Met) mice exhibited increased anxiety-related behaviors that were not normalized by the antidepressant, fluoxetine. A variant BDNF may thus play a key role in genetic predispositions to anxiety and depressive disorders.     

Effects of photoperiod on salsolinol‐induced prolactin secretion in goats

The aim of the present study was to clarify the relation between salsolinol (SAL)‐induced prolactin (PRL) release and photoperiod in goats. A single intravenous (i.v.) injection of SAL was given to adult female goats under short (8 h light, 16 h dark) or long (16 h light, 8 h dark) photoperiod conditions at two different ambient temperatures (20°C or 5°C), and the PRL‐releasing response to SAL was compared to that of thyrotropin‐releasing hormone (TRH) or a dopamine (DA) receptor antagonist, sulpiride. SAL, as well as TRH or sulpiride, stimulated the release of PRL promptly after each injection in both 8‐ and 16‐h daily photoperiods at 20°C (P < 0.05). The area under the response curve (AUC) of PRL for the 60‐min period after injections of saline (controls), SAL, TRH and sulpiride in the 16‐h daily photoperiod group was greater than each corresponding value in the 8‐h daily photoperiod group (P < 0.05). There were no significant differences in the AUC of PRL among the values produced after the injection of SAL, TRH and sulpiride in 16‐h daily photoperiod group; however, the values produced after the injection of TRH were smallest among the three in the 8‐h daily photoperiod group (P < 0.05). The PRL‐releasing responses to SAL, TRH and sulpiride under a short and long photoperiod condition at 5°C resembled those at 20°C. These results show that a long photoperiod highly enhances the PRL‐releasing response to SAL as well as TRH or sulpiride in either medium or low ambient temperature in goats.     

Deep‐water cirripedes colonizing dead shells of the cephalopod Nautilus macromphalus from New Caledonian waters

Fossil cephalopods are frequently encrusted by epibionts; however, determining whether encrustation occurred prior to or post‐mortem to the host, and whether the final environment of deposition corresponds to the habitat of encrustation is complex. The present paper describes cirripede epibionts, their calcareous bases and their attachment scars on 6 post‐mortem shells of Nautilus macromphalus, collected from deep water off New Caledonia. The cirripedes have left both cemented calcareous bases of Hexelasma and scars associated with bioerosion and discoloration produced by verrucomorph barnacles. Live cirripedes included a Metaverruca recta, with articulated opercular plates and organic tissue (on a shell that had been exposed on the sea floor for at least 150 years), and specimens of Hexelasma velutinum, one of which was partly attached to an internal surface of a shell. The disposition of verrucomorphs indicates that most Nautilus shells were colonized post‐mortem rather than during a floating stage. However, as cirripedes are known to have colonized living Nautilus, some Hexelasma, preserved only as calcareous eroded bases, may represent specimens that settled on a living Nautilus. The degree of bioerosion and discoloration induced by verrucomorph barnacles varies according to the surface preservation of Nautilus shells, with deeper and discolored traces preserved on old and degraded shells. Traces made by verrucomorphs described here are ellipsoidal and a new ichnotaxon, Anellusichnus ellipticus, is proposed to accommodate them. Importantly, verrucomorphs and other cirripede taxa with membranous bases that were attached to pristine shells may not leave any substantial scars, and, thus, will be difficult to detect in the fossil record.     

Effects of elevated CO2 concentration on the respiratory behavior of the branches of field-grown hinoki cypress (Chamaecyparis obtusa)

The effects of elevated atmospheric CO₂ concentrations on the nighttime respiration were examined for two sample branches of a hinoki cypress tree (Chamaecyparis obtusa) growing in the field with an open gas exchange system for a one-year period from July 1994 to June 1995. The branches were of a similar size and located at a similar position within the crown. One branch was subjected to an elevated CO₂ concentration of 800 μmol mol⁻¹ and the other was subjected to ambient air which had a CO₂ concentration of about 370 μmol mol⁻¹. Nighttime respiration rate was higher in elevated CO₂ level than in ambient CO₂ level. The relationship between nighttime respiration and the corresponding nighttime air temperature was fitted by the exponential function in every month of the year. The segregation of regression lines between the two CO₂ treatments increased gradually as the seasons progressed during the treatment period. TheQ ₁₀ values for nighttime respiration were lower in elevated CO₂ (1.9 ≤Q ₁₀ ≤ 3.7) than in ambient CO₂ (2.4 ≤Q ₁₀ ≤ 4.5) in every month of the year. TheQ ₁₀ was inversely related to the monthly mean nighttime air temperature in both elevated and ambient CO₂. The estimated daily nighttime respiration rate under both CO₂ treatments had a similar seasonal pattern, which almost synchronized with the temperature change. The respiration ratio of elevated CO₂ to ambient CO₂ increased gradually from 1.1 to 1.6 until the end of the experiment. Our results indicate that the CO₂ level and the temperature have a strong interactive effect on respiration and suggest that a potential increase in respiration of branches will occur when ambient CO₂ increases.     

Biochemical changes during the development of cork spot of apples

Biochemical changes occurring during the development of cork spot of York Imperial were investigated. At the first visible sign of the disorder, the rate of ethylene production increases in the affected tissue. Respiration also increases, acetate being the major respiratory substrate rather than glucose. Protein synthesis, pectin synthesis, and the movement of inorganic ions into the tissue follow. During the time the chemical changes are taking place in the tissue, abnormal cell division is initiated, packing the newly-formed cells into the intercellular spaces. At the final stage of development, the tissue becomes brown and appears as a firm brown spot in the flesh of the apple. Cork spot is somewhat different from bitter pit in that the spots appear early in the season, the affected tissue is deeper in the flesh, and firmer. The chemical changes discovered so far in both disorders, however, appear to be similar. We consider the abnormal chemical changes that occur in both disorders to be common to diseases and injuries and not specific for either cork spot or bitter pit.

---

Zusammenfassung Die Untersuchungen erstreckten sich auf biochemische Veränderungen, die während der Entwicklung von cork spot bei Äpfeln der Sorte York Imperial auftreten. Beim ersten sichtbaren Anzeichen der Störung steigt die Rate der Äthylenbildung im befallenen Gewebe an. Auch die Atmung nimmt zu, wobei Acetat das grössere Atmungsprodukt darstellt als Glucose. Protein- und Pektin-Synthese sowie Bewegung anorganischer Ionen in das Gewebe folgen. Während der Zeit chemischer Veränderungen im Gewebe beginnt eine abnorme Zellteilung, indem die neugebildeten Zellen in die interzellularen Zwischenräume eingebaut werden. Im Endstadium der Entwicklung wird das Gewebe braun und erscheint als fester Fleck im Fleisch des Apfels. Cork spot unterscheidet sich etwas von der Stippigkeit dadurch, dass die Flecken früher in der Saison erscheinen, sich die befallenen Gewebe tiefer im Fleisch befinden und fester sind. Die chemischen Veränderungen beider Störungen scheinen sich — soweit sie bekannt sind — zu ähneln. Wir glauben, dass die chemischen Veränderungen, die bei beiden Störungen auftreten, allgemein für Krankheiten und Verletzungen zutreffen und nicht entweder für Stippigkeit oder cork spot spezifisch sind.

---

Resume Quelques changements biochimiques se produisant pendant le développement du cork spot chez la York Imperial ont été étudiés.Au premier signe visible de désordre, la vitesse de production d'éthylène augmente dans le tissu atteint. La respiration augmente également; l'acétate devient le substrat principal de la respiration, plutôt que le glucose. Une synthèse de protéines, de pectine, ainsi que des déplacements d'ions inorganiques dans le tissu se produisent ensuite.Pendant que les changements biochimiques ont lieu, une division cellulaire anormale est initiée, et les cellules nouvellement formées s'accumulent dans les espaces intercellulaires.Au stade final de développement, le tissu devient brun et apparaît comme une tache brune et ferme, dans la chair de la pomme. Le cork spot diffère quelque peu du bitter pit par le fait que les taches apparaissent tôt dans la saison, le tissu malade étant localisé plus profondément dans la chair, et plus ferme. Les modifications chimiques trouvées dans les deux maladies paraissent cependant être similaires. Nous considérons ces changements chimiques comme propres aux maladies et blessures en général et comme non spécifiques, ni du cork spot, ni du bitter pit en particulier.

     

Effect of FE level and solution culture PH on severity of chlorosis and elemental content of apple seedlings

The development of chlorosis and subsequent growth of apple seedlings grown in solution cultures containing various levels of Fe under a range of solution pH regimes were examined. Initial solution pHs were 5.5, 6.5 and 7.8 respectively, with Fe levels of 0.0, 0.13 and 1.3 ppm in a 3x3 factorial arrangement. Leaf chlorosis increased with a decrease in Fe levels and with higher solution pH. Nutrient solutions were changed weekly and during each weekly cycle solution pH levels were monitored. Independent of Fe level, the lower the initial solution pH the greater the change in solution pH during each weekly cycle. Decreasing solution Fe levels decreased both leaf and root Fe concentrations but both parameters were relatively unaffected by solution pH suggesting a solution pH by Fe supply interaction at the root surface.