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91.
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93.
Murray D. Wiegand Cheryl L. Kitchen Joy M. Hataley 《Fish physiology and biochemistry》1991,9(3):199-213
In five separate experiments, eggs from a single female goldfish were fertilized at 20°C. They were incubated at 22°C for 6 hours, after which some of the eggs were transferred to 13°C. When a defined post-hatch developmental stage was reached, lipid extracts were prepared from larvae, both with yolk sacs intact and after removal of the yolk sac by dissection. Other larvae were sampled at yolk exhaustion. Gas chromatographic analysis of fatty acid profiles revealed that larvae incorporated 16:0, 18:0, 20:4 (n–6) and 22:6 (n–3) into their tissues in proportions higher than those present in the eggs from which they were derived. At 22°C, these trends were particularly apparent at yolk exhaustion. At 13°C, proportions of polyunsaturated fatty acids in the bodies of newly hatched larvae were higher than those in the 22°C larval bodies. Monounsaturated fatty acids were preferentially depleted during development, especially in larvae from high quality eggs. No dependence of egg quality, as assessed by larval viability at 22°C, on total egg lipid mass or fatty acid composition was found. Larvae from the lowest quality eggs showed a reduced preference for incorporation of (n–3) polyunsaturated fatty acids into their tissues. 相似文献
94.
Sarawut Srithongouthai Akira Endo Akihiro Inoue Kyoko Kinoshita Miho Yoshioka Ayako Sato Takaaki Iwasaki Ichiro Teshiba Hisatsune Nashiki Daigo Hama Hiroaki Tsutsumi 《Fisheries Science》2006,72(3):485-493
ABSTRACT: A microscopic bubble generating system (MBGS) has been developed to control dissolved oxygen (DO) levels suitable for fish farming. The MBGS has been tested to confirm its capability in net pens. Water conditions in a fish farm were monitored every two hours from June to October 2004 by setting an online vertical profiling system (OVPS) close to the net pen. DO in the net pen water decreased to physiologically stressful levels for the fish during the night (4.84–5.51 mg/L), while the DO was kept in saturated conditions during the day, due to oxygen supply from phytoplankton. The MBGS was operated from the evening to the morning of the next day for 16 h, to successfully create DO-saturated conditions in the net pen water at night. By using microscopic bubbles during the warm seasons, DO levels in the net pen water could be improved to a level suitable for fish farming. However, the low DO levels (<5.0 mg/L) of the bottom water occasionally extended to the net pen layers, despite the supply of microscopic bubbles to the water. To maintain the DO of the net pen water at levels suitable for fish farming, DO supply to the net pen water and the bottom water needs to be increased, and the organically enriched sediment just below the net pens needs to be treated. 相似文献
95.
The effects of different photoperiod regimes, and total darkness on day-night variations in hypothalamic serotonin (5-HT)
content and turnover index (TI), and monoamine oxidase (MAO) activity that occur exclusively during the gonadal preparatory
phase (February–March) were investigated in female Heteropneustes fossilis. Exposure of the fish to long photoperiods (16L:8D; light between 06.00–22.00h, for 40 days elevated both the midphotophase
and midscotophase values of 5-HT content and MAO, and abolished their day-night differences. The daily variations of 5-HT-TI
was further intensified by the treatment. Under short photoperiods (4L:20D; light between 18.00–22.00h for 40 days), there
was a significant decrease in both 5-HT content and TI, a reversal of the day-night variations of 5-HT content and MAO activity,
and loss of the 5-HT-TI pattern. In fish maintained in total darkness the day-night variations were not found and there was
a significant inhibition of 5-HT. Exposure of the fish to continuous light abolished the day-night variations of these correlates
and elevated their values at both intervals. When the LD cycle was reversed, there was a corresponding shift in the day-night
patterns. The gonadosomatic index (GSI) was significantly elevated in the long photoperiod and continuous illumination groups,
significantly decreased in the short photoperiod and total darkness groups, and unchanged in the reversed LD cycle regime.
The results indicate that the day-night variations of 5-HT and MAO are photoperiod-dependent and are controlled by the prevailing
LD cycle during the gonadal preparatory phase of the annual reproductive cycle. The photoperiod effects on the gonadal activity
may be mediated through the hypothalamic serotonergic system. 相似文献
96.
Miho Tatsuki Hiroko HayamaHirohito Yoshioka Yuri Nakamura 《Postharvest Biology and Technology》2011,62(3):282-287
1-Methylcyclopropene (1-MCP) treatment maintains apple fruit quality during storage, but its efficacy is dependent on a number of conditions. ‘Tsugaru’ apples are a major early season cultivar in Japan, but because ‘Tsugaru’ fruit produce abundant ethylene, they have a short shelf-life, and efficacy of 1-MCP is not as high with ‘Tsugaru’ as with other cultivars. To improve 1-MCP efficacy, ‘Tsugaru’ fruit were pre-cooled at −1 °C or −3 °C for 24 h before 1-MCP treatment. Ethylene production decreased with the cold treatment, resulting in better storage after 1-MCP treatment. Although ethylene production was low at the end of 24 h of the cold pre-treatment, expression of ACS1, the ethylene receptor genes ERS1, ETR1(a), ETR1b, ETR2 and ETR5, and the cell wall degradation-related gene PG1 all increased with a 24 h cold treatment. It is assumed that these elevated gene expression levels were not caused by ethylene, but more directly by cold stimulus. Thus, a short period of cold stimulus suppresses ethylene production, but induces expression of some genes. 1-MCP treatment was more effective with some initial fruit chilling. 相似文献
97.
98.
Shuta Asai Miki Yoshioka Hironari Nomura Chiyori Tone Kazumi Nakajima Eiichi Nakane Noriyuki Doke Hirofumi Yoshioka 《Journal of General Plant Pathology》2011,77(3):152-162
Glucose-6-phosphate dehydrogenase (G6PDH) has been implicated in the supply of reduced nicotine amide cofactors for resistance
to biotic and abiotic stresses. Here, we show participation of the plastidic P2 isoform of G6PDH in plant immunity. A cytosolic
isoform (NbG6PDH-Cyto) and two plastidic isoforms (NbG6PDH-P1 and NbG6PDH-P2) cloned from Nicotiana benthamiana were localized in cytosol and chloroplasts, respectively. Hypersensitive response (HR) cell death and NADPH oxidase (RBOH;
respiratory burst oxidase homolog)-dependent reactive oxygen species (ROS) production after recognition of INF1 elicitin,
secreted by oomycete Phytophthora infestans, decreased in NbG6PDH-P2-silenced plants, but not in NbG6PDH-Cyto- and NbG6PDH-P1-silenced plants. Silencing of the cytosolic NAD kinase NbNADK1, which phosphorylates NADH to form NADPH, compromised HR cell death and ROS production, and concomitant silencing with NbG6PDH-P2 reduced HR cell death and ROS to levels near those in NbG6PDH-P2-silenced plants. Similarly, silencing NbG6PDH-P2 and NbNADK1 resulted in high susceptibility to P. infestans. These results suggest that NADPH produced by the P2 isoform of G6PDH in chloroplasts is responsible for HR cell death and
ROS production mediated by RBOH and that NbNADK1 is involved in this pathway. 相似文献
99.
Konishi K Yonai M Kaneyama K Ito S Matsuda H Yoshioka H Nagai T Imai K 《The Journal of reproduction and development》2011,57(5):572-578
The reproductive ability, milk-producing capacity, survival time and relationships of these parameters with telomere length were investigated in 4 groups of cows produced by somatic cell nuclear transfer (SCNT). Each group was produced using the same donor cells (6 Holstein (1H), 3 Holstein (2H), 4 Jersey (1J) and 5 Japanese Black (1B) cows). As controls, 47 Holstein cows produced by artificial insemination were used. The SCNT cows were artificially inseminated, and multiple deliveries were performed after successive rounds of breeding and conception. No correlation was observed between the telomere length and survival time in the SCNT cows. Causes of death of SCNT cows included accidents, accident-associated infections, inappropriate management, acute mastitis and hypocalcemia. The lifetime productivity of SCNT cows was superior to those of the controls and cell donor cows. All SCNT beef cows with a relatively light burden of lactation remained alive and showed significantly prolonged survival time compared with the cows in the SCNT dairy breeds. These results suggest that the lifetime productivity of SCNT cows was favorable, and their survival time was more strongly influenced by environmental burdens, such as pregnancy, delivery, lactation and feeding management, than by the telomere length. 相似文献
100.
Pujols J Lorca-Oró C Díaz I Russell LE Campbell JM Crenshaw JD Polo J Mateu E Segalés J 《Veterinary journal (London, England : 1997)》2011,190(2):e16-e20
The objective of this study was to evaluate if spray dried porcine plasma (SDPP) containing porcine circovirus type 2 (PCV2) genome supplemented in feed could transmit PCV2 to pigs challenged with porcine reproductive and respiratory syndrome virus (PRRSV). Twenty-three PRRSV-free pigs, non-viraemic for PCV2, were housed in bio-safety level 3 facilities and assigned to four groups in a 2×2 factorial design consisting of PRRSV challenge and a negative control. The diet contained 0 or 8kg SDPP per 100kg of feed. PRRSV challenge groups were inoculated intranasally with 2mL of a suspension containing 10(6) TCID(50)/mL PRRSV. The SDPP used in the study contained 7.56×10(5) PCV2 genome copies per gram. Dietary treatments were fed from 4days prior to PRRSV inoculation until 28days post-inoculation (PI). All challenged pigs developed PRRSV viraemia by day 3PI and PRRSV antibodies were detected in sera by day 14PI, with no difference between diet treatments. Neither PRRSV viraemia nor seroconversion was observed in non-challenged pigs. PCV2 was not detected in the serum of any pigs throughout the experimental period. SDPP containing the PCV2 genome supplemented in feed did not result in PCV2 transmission to either healthy or PRRSV-infected pigs under these experimental conditions. 相似文献