Responses of liver enzymes to cadmium administration in the goldfish (Carassius auratus) at different times of the year

1. The activity of goldfish liver ornithine decarboxylase increased upon cadmium chloride injection in April and November (water temperature 16 ± 1°C) and did not change significantly in June and July (water temperature 20 ± 1°C and 22 ± 1°C, respectively).2. Adenosylmethionine decarboxylase exhibited similar patterns.3. Tyrosine aminotransferase increased significantly in April, but this was not confirmed the following year.4. Liver metal concentration always increased after the injection and hepatic metallothionein was induced at all times independently of the responses of the three enzymes.     

Polyamine metabolism in the thermotolerant mesophilic fungus Aspergillus fumigatus

Biomass production by Aspergillus fumigatus was greatest at 40–45°C and was associated with an increase in concentration of the diamine putrescine and activity of its biosynthetic enzyme ornithine decarboxylase. Concentrations of the other amines, cadaverine, spermidine and spermine were considerably lower than putrescine concentration and did not change significantly over the temperature range 20–50°C. This is surprising in view of the greatly increased flux of label from ornithine through to spermidine at 45 and 50°C, indicating an increased formation of this triamine. It is suggested that there was increased formation of spermidine derivatives at these temperatures. Interestingly, there was greatly increased formation of the higher homologues of cadaverine, aminopropylcadaverine and N,N′-bis(3-aminopropyl)cadaverine, in A. fumigatus at 45 and 50°C.     

Inhibition of ornithine decarboxylase activity and spermidine accumulation in regenerating rat liver.

Injections of 1,3-diaminopropane, a close structural analogue of putrescine (1,4-diaminobutane), into partially hepatectomized rats powerfully inhibited ornithine decarboxylase (EC 4.1.1.17) activity in the regenerating liver in vivo. The compound did not have any effect on the enzyme activity in vitro (under assay conditions employed) but appeared to exert an inhibitory influence on the synthesis of ornithine decarboxylase itself.Repeated injections of diaminopropane into rats after partial hepatectomy, starting at the time of the operation and continued until 33 h postoperatively, markedly diminished the stimulation of ornithine decarboxylase activity in the regenerating liver remnant, and completely prevented the increases in hepatic spermidine concentration normally occurring in response to partial hepatectomy.Treatment of the rats with diaminopropane did not depress the activity of adenosylmethionine decarboxylase (EC 4.1.1.50) in the regenerating liver. Nor did the compound have any effect, whatsoever, on the activity of spermidine synthase (EC 2.5.1.16) in vitro, thus obiviously proving that the increased accumulation of liver spermidine after partial hepatectomy primarily depends upon a stimulation of ornithine decarboxylase activity and a concomitant accumulation of putrescine. The results also showed that 1,3-diamino-propane could not replace putrescine in the synthesis of higher polyamines in rat liver. The inhibition of ornithine decarboxylase by diaminopropane thus appears to represent “gratuitous” repression of polyamine biosynthesis and might conceivably be used for studies devoted to the elucidation of the physiological functions of natural polyamines.     

The rate of preimaginal development of the blowfly, Calliphora vicina R.-D. (Diptera, Calliphoridae) under field and laboratory conditions

Open field experiments with the blowfly, Calliphora vicina originating from the environs of St. Petersburg showed that the correlation between the rate of its preimaginal development under the natural conditions and the mean daily temperature could be very closely approximated by linear regression. The sum of effective temperatures required for development from the egg to the puparium constituted ca 140 degree-days and from the egg to the adult, ca 320 degree-days with the lower thresholds of 5.8 and 4.8°C, respectively. The minimum duration of development (6–8 days from the egg to the puparium and 16–20 days from the egg to the adult) was recorded during the period of the highest mean temperatures (22–23°C) from July 8 to August 15 of 2010 and 2011. The rate of development under natural thermorhythms was not siggnificantly different from that under the laboratory conditions at constant temperatures from 12 to 23°C.     

Population dynamics of the oriental fruit fly, Bactrocera dorsalis （Diptera： Tephritidae） in the Kunming area,southwestern China

Population dynamics of Bactrocera dorsalis Hendel （Diptera： Tephritidae） were studied through pheromone trapping over 4 years （1997, 1999, 2000, 2003） in the Kunming region, a high plateau area in southwestern China. B. dorsalis immigrates from southern Yunnan to Kunming each year, and occurs during early May through November. Annual trap captures recorded an increase in the B. dorsalis populations from May to July, when they peaked in abundance, and a decline until November. No flies were detected from November to April. The fruit flies had two generations. There was considerable overlapping due to the continuous arrival of immigrating flies during the summer months. Annual capture rates were significantly related to numbers of flies caught in July when peak captures were recorded; whereas the peak captures, in turn, positively depended on numbers of flies recorded in May, the first month of fly appearance in the current year. It suggested that the annual population abundance was mainly dependent on the size of the initial emigrating population. A daily average temperature of 18℃ was probably the threshold temperature required for the flies to undertake long-range dispersal, which partially explained the start of the fly in May each year on this high plateau. Under field conditions, the fruit flies can withstand 13℃ as a daily average temperature. No flies were recorded in any of the study years at a daily temperature colder than 10 ℃.     

The alien false limpet (Siphonaria pectinata) in the Bizerte channel (northern Tunisia): spawning,development and growth under laboratory conditions

Spawning, development and growth of Siphonaria pectinata in the laboratory were studied and described in detail during a one-year study period. Egg ribbons were observed in February, March, April, June, July, August and September, with a peak in number of ribbons per individual in July. On average, individuals laid 9.0 ± 5.1 egg ribbons at a spawning frequency of one egg ribbon day^?1. The number of eggs per ribbon ranged from 752 to 50,400 depending on ribbon length. Embryonic development studied in February (13–15 °C), April (15–17 °C) and July (25–27 °C), reached hatching within 8–16 days with average larval lengths of 76.7 ± 5.9, 83.0 ± 11.3 and 78.3 ± 9.0 μm, respectively. Massive mortality was registered a few days after hatching, with larval longevity depending on the study period. Larval settlement occurred within 36–38 days after hatching, but only in the spawn deposited in February. Larval growth was slow during the first three weeks (18–26 μm week^?1) and then accelerated until the sixth week (40–67 μm week^?1). The present study contributes knowledge on the spawning, development and growth of S. pectinata, an alien species recently spreading throughout the Tunisian coast.     

Phenology and reproductive biology of eelgrass (Zostera marina L.) at Bahia Kino,sea of Cortez,Mexico

At Bahia Kino, Mexico, seeds of Zostera marina L. (eelgrass) germinate in October and early November. By January seedlings are widespread throughout the area. A very rapid vegetative growth ensues. By March all eelgrass at the depth limit (7 m) is flowering; and most is flowering in shallow water (low tide to 4 m depth). In April all plants are in flower; a few plants display mature seeds. Windrows of detached plants occur on the beaches. In May all reproductive plants have mature seeds, and few attached plants remain. In July all eelgrass in the area has disappeared.All reproductive activities and plant detachment are completed before the lethal upper limit for the species is reached (30°C). Thus, eelgrass at Bahia Kino is a true annual and represents an ultimate response to high water temperatures.     

Phenology of annual kelp Eckloniopsis (Phaeophyceae,Laminariales) forest on a Diadema barren in Uchiura Bay,Central Pacific Coast of Honshu,Japan

On the southern coast of Uchiura Bay, central Pacific, Japan, Diadema barrens have expanded since the 1980s but Eckloniopsis radicosa (annual kelp endemic to Japan) has remained in deeper waters (>10 m in depth). Phenology of the kelp was studied on isolated boulders from December 2011 for a year. Young sporophytes appeared in December and rapid growth from April brought the maximum blade length (83.3?±?13.9 cm) and width (56.8?±?12.7 cm) and standing crop (7.4 kg m^?2) in May and June, respectively. Sorus formation began in June and spore release occurred from July to September. Blade length decreased from August and disappeared in November though holdfast remained. The unique holdfast-like spiny ball was found to provide habitats for mobile animals; its forests have an important role to maintain the biodiversity on barrens. During the period, water temperature was between 14.6 and 27.8 °C, salinity was stable around 34–35?‰, and nutrients were never depleted. Tolerance to large and frequent fluctuation of water temperature (7 °C in a day), rapid growth in winter to spring, and occurrence on limited boulders in soft substrata may be the reasons for the success in the maintenance of its forest in Diadema barrens.     

Ornithine decarboxylase activity from an extremely thermophilic bacterium,Clostridium thermohydrosulfuricum effect of GTP analogues on enzyme activity

The activity of ornithine decarboxylase has been detected for the first time in extracts of a thermophilic bacterium, Clostridium thermohydrosulfuricum. The temperature optimum of the thermoresistant ornithine decarboxylase was 55°C and the pH optimum was 7.5. It required pyridoxal phosphate and a thiol (dithiothreitol) for activity. The activity of the enzyme was closely connected to the growth of the thermophilic bacteria, since the activity was highest during the logarithmic growth. The enzyme was not inhibited (in contrast to the enzyme from Escherichia coli) by putrescine, spermidine or other naturally occurring polyamines. When the effect of GTP and a number of GTP analogues was tested on the activity of the enzyme, it was observed that GTP or dGTP was necessary for the full activity. The modification of either the purine base or 5′-phosphate chain of GTP leads to a stimulation smaller than that caused by GTP. Modification of the 3′-carbon of the ribose part of GTP (magic spot I and II of Cashel and Gallant, Nature 221 (1969) 838–841) caused a distinct inhibition of the enzyme activity, indicating that ornithine decarboxylase contains at least two domains for binding of GTP. The enzyme was inhibited irreversibly by high concentrations (50 mM) of difluoromethylornithine. Extracts of the bacterium contained also arginine decarboxylase, but its activity was always very much lower than that of ornithine decarboxylase. The activity of arginine decarboxylase was inhibited irreversibly by difluoromethylarginine, which is an irreversible suicide inhibitor of bacterial arginine decarboxylase (Kallio, A., McCann, P.P. and Bey, P. (1981) Biochemistry 20, 3163–3166).     

Seasonal dynamics of the Acartia tumida Willey, 1920 (Copepoda: Calanoida) population in nearshore waters of Kievka Bay, Sea of Japan

In 2002, the neritic copepod Acartia tumida was present in the plankton of Kievka Bay from February through July at a temperature of ?1.2 to 14°C with an average population density of 6812 ind/m³ and a biomass of 532.75 mg/m³ (0.12–65.33 and 2.2–87.84% of total copepod density and biomass, respectively). The maximum population density of A. tumida (45 600 ind/m³) was recorded in the first ten-day period of April at a temperature of 2.2–3.8°C. Seasonal variations in the age and sex structure of A. tumida population were found. From February to July, A. tumida produced two generations.     

Species composition,abundance, and annual cycles of fleas (Siphonaptera) on bank voles (Clethrionomys glareolus) in the western part of Vologda Province (Babaevo District)

A total of 383 fleas of 11 species were collected off 428 bank voles (Clethrionomys glareolus) captured near Babaevo (59°4′N, 35°8′E). Three of the species recorded (Amphipsylla rossica, Doratopsylla dasycnema, and Palaeopsylla soricis) were not typical of these rodents, infesting the latter occasionally from other animals, such as the common vole Microtus arvalis and shrews inhabiting adjacent or the same biotopes. Peromyscopsylla bidentata, infesting the bank vole in most part of its range, was recorded only as a single female. Megabothris turbidus was also very rare, being sporadically recorded from May to October; the examined territory probably lies at the northern boundary of its range. The most abundant species, Ctenophthalmus uncinatus, had two peaks of abundance: in April, when adults emerged from overwintered cocoons, and in July. Then their abundance decreased and the last occasional individuals were recorded till December. The year-round parasite Amalaraeus penicilliger was most abundant in winter. Other species were few in number. Adults of Megabothris rectangulatus were recorded from April to August with two peaks of abundance: in April, when they emerged from overwintered cocoons and in July, when the second generation emerged. The univoltine species Peromyscopsylla silvatica emerged in July–August and parasitized till September. Rhadinopsylla integella was the most abundant in October–December, but occasional specimens were recorded in January. The polyxenous species Hystrichopsylla talpae emerged in late July and occurred till September.     

Effects of temperature, light, storage conditions, sowing time, and burial depth on the seed germination of Cardiocrinum cordatum var. glehnii (Liliaceae)

In this study, we conducted experiments to accumulate practical information on the propagation and establishment of a population of Cardiocrinum cordatum var. glehnii by seed sowing. C. cordatum var. glehnii seeds require approximately 19 months from seed dispersal to cotyledon emergence in the field. However, the period from seed dispersal to radicle emergence was shortened to approximately 7–8 months by the temperature transition of 25/15°C (60 days) → 15/5°C (30 days) → 0°C (120 days) → 15/5°C (i.e., 15/5°C represents alternating temperature treatment wherein the seeds were placed at 15°C for 12 h during the day and then at 5°C for 12 h during the night). More than 90% of the seeds, which were stored dry at 5°C for 12 months and sown in pots in the field, showed cotyledon emergence, whereas in seeds stored dry at 25°C, dry at room temperature, and non-dry at room temperature, cotyledon emergence was decreased by less than 1%. More than 88% of the seeds that were stored dry at 5°C and sown in the field in October 2002 immediately after collecting, November, and from April to July 2003 showed cotyledon emergence in spring 2004. However, seeds sown in August, September, and October 2003 showed cotyledon emergences of 57.6%, 0%, and 0% in spring 2004, respectively. Seeds collected in October 2002 and sown until July 2003 in the field received adequate high temperature in summer, moderate temperature in autumn, and cold temperature in winter; therefore, the percentage of cotyledon emergence was high in spring 2004. On the other hand, seeds sown in August 2003 or later could not receive enough high temperature; thus, cotyledons emerged from only a few seeds.     

Effect of food and temperature on the reproduction of the blowfly, <Emphasis Type="Italic">Calliphora vicina</Emphasis> R.-D. (Diptera,Calliphoridae), a popular model object in biological research

Egg maturation in Calliphora vicina is known to occur within a wide range of temperatures, from 12°C to nearly 30°C (Vinogradova, 1991). Photoperiodism has no effect on this process. Some females enter diapause already at 20°C; their fraction increases at lower temperatures and reaches 100% at 6°C. Reproducing females with eggs can survive for a long time and even lay eggs at low temperatures (4–5°C). Experiments with C. vicina from Leningrad Province revealed some effects of the diet (liver or fish) and temperature on the fly reproduction. At 20 and 25°C, 7–10-day old females begin to oviposit, but at 20°C egg maturation is observed in 98% of females feeding on liver and in only 5% of females feeding on fish. On the liver diet, the mean daily fecundity is significantly correlated with the day of oviposition but not with the temperature. At 20°C a significant correlation is observed between the mean daily fecundity and both the day of oviposition and food. The total number of eggs laid by flies after feeding on fish is half that produced after feeding on liver. The optimal conditions for Calliphora vicina cultivation are a 16-h light day, temperatures within the range from 20 to 25°C, and liver as food.     

In vivo 13C nuclear magnetic resonance spectroscopy using a solenoid transmit/receiver coil

The administration of cadmium (1.25 mg as Cd2+/kg, ip.) to male rats resulted in a significant increase of hepatic and renal ornithine decarboxylase activity. The maximum increase of ornithine decarboxylase activity to about 10-fold of the controls was seen at 4 hr after the administration of cadmium, and the increased enzyme activity was returned to control levels by 12 hr. Cadmium produced somewhat dose-dependently the increase of ornithine decarboxylase activity. The increase of ornithine decarboxylase seen on the administration of cadmium was cancelled by pretreatment of rats with cycloheximide. The treatment of female rats with cadmium also caused the increase of hepatic ornithine decarboxylase activity, but not renal enzyme activity.     

Evaluation of an improved strain of Porphyra yezoensis Ueda (Bangiales, Rhodophyta) with high-temperature tolerance

The red algae Porphyra yezoensis has high commercial and nutritional value; however, its cultivation and product quality are jeopardized by global warming. Screening of high-temperature-tolerant strains would greatly reduce cultivation risks and benefit the Porphyra industry. Single somatic cells isolated enzymatically from the wild-type (WT) blades irradiated by ⁶⁰Co-?? rays were screened at 25°C; one strain, T-17, displayed significant high-temperature resistance. Further culture studies showed that conchospore germlings of T-17 showed 76.2% survival at 23°C and 65.7% survival at 24°C, while the WT conchospore germlings survived at significantly lower percentages of 16.9% and 11.5%, respectively, over a period of 16 days. Furthermore, T-17 conchospore germlings divided at higher percentages of 100% at both 23 and 24°C compared to the WT conchospores with 99.8% and 81.8%, respectively. When the 50-day-old F₁ gametophytic blades were transferred from the optimal temperature of 18°C to high temperatures of 23 and 24°C, the T-17 blades sustained growth over a 45-day period without rot, and their mean lengths increased by 20 and 4.2 times, respectively. The mean lengths of WT blades only increased by a factor of 0.6 and 0.4 times and were severely decayed after being cultured for 15 days at high temperatures. The mean wet weights of T-17 blades increased by 418.9 and 195.3 times, but only 7.8 and 4.6 times in WT at 23 and 24°C, respectively. These results indicate that T-17 is superior to WT in growth and high-temperature tolerance, which may offer a new cultivar for the nori industry as a high-temperature-resistant strain to counteract the effects of global warming.     

Seasonal change in xylem growth of <Emphasis Type="Italic">Pinus densiflora</Emphasis> in central Japan

This study investigated the seasonal change in xylem growth of Japanese red pine (Pinus densiflora). Wood cores were sampled at 2-week intervals from April to November in 2012 using the microcoring method. Daily increment rates of tracheid number and tree-ring width were compared with seasonal changes in daily mean temperature and photoperiod. Xylem growth started in early to late May and stopped in late October to early November. The maximum daily increment rates of tracheid number and tree-ring width were in early July. The 95 % confidence intervals of the timing of the maximum daily increment rates included the summer solstice (23 June) with the longest photoperiod, but not the warmest day (30 July). The maximum daily increment rate of xylem growth is thought to be controlled by the photoperiod rather than by temperature. The daily mean temperature exceeded 20 °C after the summer solstice, indicating that temperature is not a limiting factor for xylem growth. This study suggests that the timing of maximum daily increment rates of xylem growth of P. densiflora is controlled by the photoperiod.     

Reproduction and development of the limpet Limalepeta lima (Dall, 1918) (Gastropoda: Lepetidae) from Peter the Great Bay, Sea of Japan

Reproduction and larval development of the limpet Limalepeta lima (Dall, 1918) were studied under laboratory conditions for the first time. L. lima breeds in early July; it exhibits external fertilization and the pelagic lecithotrophic type of development. Larvae, juvenile, and adult specimens have different shell sculptures. Development from fertilization to settling and metamorphosis continues for 4–5 days at a water temperature of 16°C.     

Effects of thermoperiods on diapause induction in the cabbage beetle, Colaphellus bowringi (Coleoptera: Chrysomelidae)

Abstract. The effects of thermoperiods on diapause induction in continuous darkness or under a 12 : 12 h LD photoperiod were investigated in the cabbage beetle, Colaphellus bowringi Baly, a typical short‐day species. The diapause response curves both at different constant temperatures and at the thermocycle of format CT x: (24 ? x) h (16 : 28 °C) under continuously dark rearing conditions showed that the incidence of diapause depended mainly on whether or not the mean temperature was ≤20 °C or >20 °C. If the mean temperature was ≤20 °C, all individuals entered diapause; if >20 °C, the incidence of diapause declined gradually with increasing mean temperatures. The thermocycle (CT 12 : 12 h) with a series of different cryophases (8–22 °C) and thermophases (24–32 °C) under continuous darkness demonstrated a cryophase response threshold temperature of approximately 19 °C and a thermophase response threshold temperature of approximately 31 °C. Thermoperiodic amplitude (temperature difference between cryophase and thermophase) was shown to have a significant influence on diapause induction at the mean temperatures of 22, 23 and 24 °C, but not at ≥25 °C. Thermoperiodic responses under LD 12 : 12 h clearly showed that the incidence of diapause was influenced strongly by the photophase temperature. The thermoperiod under LD 12 : 12 h induced a much lower incidence of diapause than the thermoperiod with the same temperature in continuous darkness. The ecological significance of thermoperiodic induction of diapause in this species is discussed.     

Life cycle of the lilac pyralid Palpita nigropunctalis (Bremer) (Lepidoptera: Crambidae) on five oleaceous tree species

The seasonal abundance of Palpita nigropunctalis larvae was studied on five oleaceous tree species in Ibaraki, central Japan, for two years. The larval population peaked on some tree species in both spring and autumn while it peaked on other tree species only in autumn. In bimodal populations, the spring peaks consisted of larvae infesting leaves, while the autumn peaks consisted of larvae infesting various tree parts (flowers, fruits and leaves). Larval development was longer and pupal weights were lower on Ligustrum lucidum fruits than on Ligustrum japonicum fruits. Thus, L. japonicum fruits were suitable for larval development in autumn. First-instar larvae appeared to occur three times per year (in late April to early May, mid to late September and early to mid October). Adults were observed from late March to early April, mid May to early June, and early September to mid November at the census sites, showing that P. nigropunctalis had three generations a year. The percentage of females having premature ovaries were 64.3 and 12.5% at 15 °C under 14-h and 15-h photophases, respectively, and 28.6 and 25% at 20 °C under the respective photophases. These temperatures and photoperiods are typical of those in May and June in the census sites. The ovaries of females collected in the field between late May and mid July were premature, in agreement with the laboratory experiments. The pupal duration was prolonged under the short photoperiod, especially at reduced temperatures. We discuss a possible life cycle of P. nigropunctalis in Ibaraki.     

The Dynamics of Adaptive Changes in the Spleen of the Hibernating Ground Squirrel <Emphasis Type="Italic">Spermophilus undulatus</Emphasis>

In hibernation season during torpor bouts, the spleen weight and the hemoglobin level, as well as the total and extracted protein contents in the spleen of the ground squirrel Spermophilus undulatus are increased when animals enter torpor and reach maximum values when the body temperature drops below 25°C. All these parameters return to the characteristic values of the euthermic animals during arousal, before the body temperature increases to 20°C. There were no significant differences in the numbers of splenocytes between ground squirrels in interbout euthermia and torpor. The minimum number of splenocytes was observed in animals that entered torpor when the core body temperature was approximately 18°C. The activity of ornithine decarboxylase, a key enzyme in polyamine synthesis, which is correlated with the functional and proliferative status of lymphoid tissue, was the same for the euthermic and summer ground squirrels and decreased monotonically during torpor. Upon arousal of the animals when body temperature was below 29°C, no resumption of the spleen ornithine decarboxylase activity was observed.