Characterization,tissue distribution and regulation of neuropeptideY in Schizothorax prenanti

In this study, the full‐length neuropeptide Y (npy) complementary (c)DNA was cloned in ya fish Schizothorax prenanti. npy cDNA was composed of 789 nucleotides with a 288 nucleotide open reading frame encoding a protein of 96 amino acids. The deduced amino acid sequences contained a 28 amino acids signal peptide followed by a 36 amino acids mature neuropeptide Y (NPY). The npy mRNA was expressed mainly in the brain and eye as detected by real‐time quantitative polymerase chain reaction RT‐PCR (rt‐qPCR). The S. prenanti NPY was detectable from blastulation to hatch, suggesting that npy might be involved in the late embryonic development of S. prenanti. An experiment was conducted to determine the expression profile of npy during feeding of a single meal and during long‐term fasting. The expression level of npy in fed fish was significantly decreased at 0·5, 1·5, 3 and 9 h post‐feeding (hpf) than in fasting fish. Fasting for 14 days induced an increase in npy messenger (m)RNA expression in the brain. Overall, the results suggest that NPY is a conserved peptide that might be involved in the regulation of feeding and other physiological function in S. prenanti.     

齐口裂腹鱼血细胞的发生

为了探讨齐口裂腹鱼(Schizothorax prenanti)血细胞发生发育的模式,采用Wright’s、碘酸雪夫氏(PAS)和苏丹黑B(SBB)染色方法对齐口裂腹鱼的头肾、中肾、脾和肝组织印片进行染色,了解其发生的具体组织和发育的一般过程。结果表明:齐口裂腹鱼血细胞可分为红细胞系、淋巴细胞系、单核细胞系、粒细胞系和其他细胞,且这些细胞系的发育均经过3个阶段,即原始阶段、幼稚阶段、成熟阶段。通过观察和统计不同阶段各种血细胞的形态、大小、比例及染色特征,发现原始阶段的血细胞体积较大,其中原始单核细胞最大,大小为(18.90±1.59)μm×(16.32±0.70)μm,在4种组织中原始阶段的红细胞和单核细胞在头肾中所占比例最大,分别为0.64%和0.59%,原粒细胞和原淋巴细胞分别在中肾和脾中比例最大,在肝中少量存在,此外在各组织印片中均发现血栓细胞的存在,在肝中发现巨噬细胞。因此头肾、中肾和脾是齐口裂腹鱼的主要造血组织,少量细胞在肝中产生。粒细胞发育过程中,除原始粒细胞PAS染色阴性外,其他阶段均呈阳性,且阳性随不断成熟逐渐增强;单核细胞从原单核细胞到成熟的单核细胞,PAS阳性逐渐增强;而SBB染色发现,粒细胞、淋巴细胞及单核细胞均呈阳性,未成熟的细胞染色程度不一致,成熟的细胞阳性染色最为强烈。在红细胞系发育过程中经历了细胞由大变小再变大的过程,而粒细胞和淋巴细胞发育过程仅出现由大变小的过程,在红细胞的发育过程中还出现了染色质固缩和血红蛋白增加。     

Coordinate upregulation of proteolytic-related genes in rat muscle during late fasting

The present study examines whether and to what extent the profiles of proteolytic-related genes are altered in atrophying muscle during prolonged food deprivation. Long-term fasted animals exhibited three metabolic phases characterized by changes in lipid and protein utilization. Starvation induced an increase in some proteolytic gene expressions during P2 of fasting, especially for Cat L (by 3-fold). In P3, the fasting-induced enhancement of mRNA expression involved all proteolytic pathways and was much more pronounced than in P2 for pUb, E2(14k), CAPN3, and Cat B, D, and H (by 2- to 4-fold), for C2, C5, and S5a (by 5- to 6-fold), and mainly for Cat L, C3, and C8 (by 10- to 15-fold). At the molecular level, it is concluded that the three proteolytic systems found in skeletal muscle are selectively induced in P2 of fasting and coordinately upregulated in late fasting.     

Chronic Food Deprivation Decreases Extracellular Dopamine in the Nucleus Accumbens: Implications for a Possible Neurochemical Link Between Weight Loss and Drug Abuse

In rats reduced to 80% of normal body weight (n=9), the basal levels of extracellular dopamine (DA) in the nucleus accumbens (NAC), as determined by microdialysis, decreased significantly to 33 % (mean ± SEM) of their normal baseline (p<.01). Basal extracellullar DA did not change significantly over a matching 3-week period in controls (n=7). No changes were observed in NAC serotonin after weight reduction. These results indicate that parts of the mesolimbic DA system are depressed in underweight rats. The observed decrease in basal DA may be responsible for a variety of behavioral changes observed in undernourished humans and animals including the tendency to eat and gain weight when food becomes available. Given that DA can be released in the NAC when rats self-inject drugs of abuse, the present findings may help explain why animals increase drug intake when they are underweight.     

生长抑素在齐口裂腹鱼消化道和脑中的定位

采用链霉亲合素一生物素过氧化物酶复合物免疫组化法研究生长抑素（Somatostatin,Som）在齐口裂腹鱼（Schizothorax prenanti）脑和消化道中的定位。在消化道中,口咽腔和食道为阴性反应;肠道有Som强阳性细胞,其中前肠密度最高,后肠最低。这些Som阳性细胞多分布于粘膜上皮,形态多样。肠道巨噬细胞呈Som强阳性反应。Som广泛分布于各脑区的神经元或神经纤维中,呈弱或强阳性反应,其中下丘脑下叶乳头体内Som阳性细胞密度最高,背嗅核、侧嗅核、原始纹体、视前核、内嗅沟旁、缰核下区、前丘脑核、前圆核、下丘脑中叶、下丘脑下叶、中脑室侧次之;小脑分子层和延脑VI、V核较少。端极和脑上腺有阳性神经纤维。这说明Som在肠道中的分布与该鱼食性、消化道结构和功能密切相关;Som在下丘脑中的分布特点为鱼类GH调控提供了形态学证据;Som在脑中广泛分布,提示可能作为一种神经递质或调质,发挥更为广泛的生理功能。     

Recombinant leptin in the hypothalamic response to late fasting

The aim of the current study was to gain further insight into the implication of leptin in the regulation of hypothalamic gene expression during long-term food deprivation with emphasis on phase 3 of fasting (P3, late protein breakdown). Among plasma parameters, glucose, non-esterified fatty acids, and insulin levels tended to be decreased by leptin infusion, whilst corticosterone levels remained unchanged. From Northern blot analysis, NPY, AGRP, and MCH mRNA gene expressions were differentially regulated during prolonged fasting in leptin-perfused rats. In comparison with fed animals, NPY, AGRP, and MCH mRNA levels in P3 rats treated with leptin either remained stable or increased slightly. Regarding anorexigenic peptides (CART and POMC) and prepro-OX, fasting with leptin induced only slight changes in gene expression. Similar data have been obtained in leptin-treated fasted rats at various doses within the physiological range. We conclude that leptin and particularly low levels of plasma leptin can reasonably be considered as a constituent of a signal triggering the fasting-induced enhanced drive for refeeding in P3.     

The influence of hunger on food‐stocking behaviour of climbing perch Anabas testudineus

The present study demonstrated that the climbing perch Anabas testudineus collected and stocked food pellets in its mouth, a behaviour that has not yet been reported in any other species of fish. In this species, food deprivation for 24 h increased food stocking, but not food intake.     

Microwave-specific heating affects gene expression

The effects of low-level microwave radiation on gene expression in Escherichia coli have been examined in a sensitive model. We confirm the previously reported existence of an increase in β-galactosidase expression by microwave radiation—an increase not duplicated by bulk heating. However, the effect was not frequency dependent and appeared to be due to heating effects peculiar to microwaves. These results indicate that small thermal gradients may be a source of biological effects of non-ionizing radiation.     

齐口裂腹鱼和鲤鱼H-FABP基因的克隆及其表达谱

心型脂肪酸结合蛋白（heart fatty acid binding protein, H-FABP）的水平与影响肉质性状的肌内脂肪含量有关,鱼类H-FABP的表达水平对其肌内脂肪含量是否相关仍未见报道.本研究获得齐口裂腹鱼和鲤鱼心脏型脂肪酸结合蛋白基因序列,利用半定量RT-PCR分析其表达特性并测定肌内脂肪含量,比较H-FABP基因在不同生活环境的2种鲤科鱼肌内脂肪沉积中的作用.结果显示,齐口裂腹鱼和鲤鱼H-FABP基因的ORF为402 bp,编码133个氨基酸,它们的氨基酸序列相同,与人、猪、小鼠、斑马鱼、大西洋鲑、虹鳟等的同源性为71.3%~ 90%;H-FABP基因在2种鲤科鱼的心、肌肉、脂肪、肝、脑、脾、肾和鳃等组织中均有表达,肝中的表达量显著高于其它组织（P<0.05）,H-FABP基因的肌肉表达谱在齐口裂腹鱼和鲤鱼中存在明显差异：齐口裂腹鱼中的表达随生长发育呈上升趋势,在大体重鱼（500 g）中的表达显著高于小体重鱼（P<0.05),其表达与肌内脂肪含量呈显著正相关（R=0.370,P<0.05）;H-FABP基因在鲤鱼生长发育中呈下降趋势,而小体重鱼（50~60 g）中的表达显著高于其它大体重鱼(P<0.05),其表达与肌内脂肪含量呈显著负相关（R=-7.083,P<0.01）.据此推测,齐口裂腹鱼和鲤鱼肌肉组织H-FABP基因表达与肌内脂肪关联性的差异可能与2种鱼的生活环境不同有关.     

Shortening of the photoperiod affects sleep distribution, EEG and cortical temperature in the Djungarian hamster

To asses the influence of photoperiod on sleep regulation EEG, EMG, and cortical temperature were continuously recorded for two baseline days and after 4 h sleep deprivation in Djungarian hamsters (Phodopus sungorus) adapted to a short photoperiod (light dark 816). Comparison to previous data collected in a long photoperiod (lightdark 168) showed several major effects of photoperiod: 1. A prominent change in the 24-h distribution, duration and number of vigilance state episodes, whereas the total amount of sleep and waking was unchanged; 2. Cortical temperature was 0.7°C lower in the short photoperiod; 3. There was a significant negative correlation between cortical temperature and the frequency of REM sleep episodes; and 4. Absolute EEG power density showed a marked reduction in the short photoperiod. After sleep deprivation EEG slow-wave activity (mean power density 0.75–4.0 Hz) in NREM sleep showed a remarkably similar increase in both photoperiods demonstrating the robustness of the homeostatic regulation of sleep. Cortical temperature remained above baseline values after sleep deprivation in the short photoperiod whereas a negative rebound was present in the long photoperiod. Our results support the hypothesis that cortical temperature has a strong influence on REM sleep propensity and indicate the possibility of an optimum cortical temperature for recovery sleep after sleep deprivation. The lower EEG power density in the short photoperiod may contribute to energy conservation.Abbreviations LP long photoperiod - NREM non-rapid-eye-movement - REM rapid-eye-movement - SCN suprachiasmatic nucleus - SD sleep deprivation - SP short photoperiod - SWA slow-wave activity - T _CRT cortical temperature     

Larval feeding status regulates the transcript levels of genes encoding PTTH and allatoregulatory peptides in silkworm Bombyx mori

In Bombyx mori, two dorsolateral neurosecretory cells (NSCs) in each of the two brain lobes have been identified as prothoracicotropic hormone (PTTH) producing cells. This neuropeptide in insects stimulates the prothoracic gland for the synthesis and release of ecdysone, responsible for the molting events. Allatotropin (AT) and allatostatin (AST) are allatoregulatory neuropeptides that regulate juvenile hormone biosynthesis. Here, by using RT-qPCR, we showed that in B. mori, nutritional stress modulates the mRNA expression of AT and AST-C (allatostain type C) in the central nervous system consisting of the brain lobes and all the associated ganglia. Using whole-mount in situ hybridization, we showed that the feeding status of Bombyx larvae also influences the expression of PTTH in the NSCs of the brain. Food deprivation significantly decreased the mRNA expression levels of PTTH in larvae at active or terminal growth period. Further, we showed that insulin modulates the expression level of PTTH. However, its action was dependent on the feeding status of the larvae. At feeding, the insulin decreased the PTTH expression level, while at food deprivation, the insulin increased the PTTH expression level. The data thus indicates that larval feeding status plays an important role in altering the mRNA expression levels of allatoregulatory peptide genes and PTTH.     

Food shortage affects reproduction of Feral Pigeons Columba livia at rearing of nestlings

Feral Pigeons Columba livia are highly adapted to urban environments and are thus often abundant in cities. This can lead to various problems, including fouling of building facades and pavements, transmission of allergens and pathogenic micro‐organisms, and infestations of ectoparasites derived from breeding sites. To develop effective, long‐lasting and humane control strategies, it is necessary to understand the demography of Feral Pigeons. Although food shortage is a major source of reproductive failure in Feral Pigeons, it is still unclear at which phase of the reproductive cycle this reduces overall reproductive success. Here, we assess the effect of a sudden reduction in the food base on the reproduction of a well‐studied Feral Pigeon breeding colony. The findings of this study suggest that the number of broods per pair decreases significantly during food scarcity, and that although hatching success remains constant, a significantly greater number of nestlings die during the rearing phase. This suggests that the high energy demand of Feral Pigeon nestlings could not be met under conditions of food scarcity, which reduced the total number of fledged young by more than half and led to a reduction in the colony size. These results have important implications for selecting suitable, durable and humane control strategies for the management of large Feral Pigeon populations in urban environments.     

饲料蛋白质和能量水平对齐口裂腹鱼生长、体组成和蛋白质利用的影响

齐口裂腹鱼（Schizothorax prenanti Tchang）隶属鲤科、裂腹鱼亚科,俗称“雅鱼”,为长江上游重要经济鱼类,也是川西高原特有的冷水性鱼类。其肉质细嫩,味道鲜美,是名贵野生经济鱼类。近年来由于过度捕捞、环境污染等因素的影响,齐口裂腹鱼种群数量不断下降,分布区域日趋缩小,而随着人们生活水平的不断提高,对齐口裂腹鱼等名优水产品的需求却在不断增加。为保护和持续利用这一野生动物资源,     

Characterization of a cis-acting element involved in cell-specific expression of the zebrafish brain aromatase gene

The cytochrome P450 Aromatase is the key enzyme catalyzing the conversion of androgens into estrogens. In zebrafish, the brain aromatase is encoded by cyp19b. Expression of cyp19b is restricted to radial glial cells bordering forebrain ventricles and is strongly stimulated by estrogens during development. At the promoter level, we have previously shown that an estrogen responsive element (ERE) is required for induction by estrogens. Here, we investigated the role of ERE flanking regions in the control of cell-specific expression. First, we show that a 20 bp length motif, named G x RE (glial x responsive element), acts in synergy with the ERE to mediate the estrogenic induction specifically in glial cells. Second, we demonstrate that, in vitro, this sequence binds factors exclusively present in glial or neuro-glial cells and is able to confer a glial specificity to an artificial estrogen-dependent gene. Taken together, these results contribute to the understanding of the molecular mechanisms allowing cyp19b regulation by estrogens and allowed to identify a promoter sequence involved in the strong estrogen inducibility of cyp19b which is specific for glial cells. The exceptional aromatase activity measured in the brain of teleost fish could rely on such mechanisms.