Transpositional feeding rhythm of loach <Emphasis Type="Italic">Misgurnus anguillicaudatus</Emphasis> from larvae to juveniles and its ontogenesis under artificial rearing conditions     

Youji Wang  Menghong Hu  Weimin Wang  Ling Cao  Yi Yang  Biping Lü  Rongrong Yao 《Aquaculture International》2008,16(6):539-549

The diel feeding rhythm and ontogenesis during early life stage of loach Misgurnus anguillicaudatus were investigated under experimental conditions (light: L 06:00–18:00, D 18:00–06:00 h). Morphological and behavioral developments of loach from newly hatched to 40 days after hatching were observed. Larvae were able to prey on daphnia 3–4 days after hatching at 23 ± 0.5°C. As the larvae grew, they showed an increasing feeding capacity and a distinct feeding rhythm. Feeding intensity and incidence for day-4 larvae were highest at 10:00 and 16:00 h. The highest levels of feeding intensity for day-12 larvae occurred at 08:00, 12:00, and 18:00 h as did feeding incidence. By day 20, when the larvae metamorphosed, the highest levels of feeding intensity occurred at 06:00, 18:00, and 24:00 h and were concurrent with the highest feeding incidence. After metamorphosis, feeding capacity had again increased considerably and, in contrast to the earlier stages before day 20, feeding intensity for day-30 juveniles peaked at 05:00 and 20:00 h, about 1–2 h after the maximum feeding incidence. The feeding rhythm of loach juveniles at day 40 was almost the same as the day-30 juveniles. The estimated maximum daily feeding rates were 43.1%, 33.4%, 19.0%, 12.8%, and 5.8% of body weight on days 4, 12, 20, 30, and 40, respectively. Thus, loach was found to have different feeding rhythms in the pre- and post-metamorphosis stages, with the highest feeding activity in daytime during the larval planktonic stage before metamorphosis, and intensely nocturnal feeding behavior during the juvenile benthic stage after metamorphosis.  相似文献   

藏绵羊PRDX5基因的克隆及其在睾丸中的表达     

陈娜娜  安雪姣  满永恒  李讨讨  王霞  马友记 《草业科学》2022,39(5):1015-1023

过氧化物氧化还原酶5 (PRDX5)是一种硫氧还蛋白,参与机体多种生物学过程。为了研究PRDX5基因在藏绵羊(Ovis aries)睾丸发育和精子发生过程中的作用,本研究以不同发育阶段(3月龄、1周岁和3周岁)的藏绵羊为研究对象,克隆了PRDX5基因的CDS区,并对其进行生物信息学分析;通过实时荧光定量PCR(qRT-PCR)、Western blot和免疫组织化学染色法,对PRDX5基因在藏绵羊睾丸不同发育阶段的表达和分布进行了检测。结果显示,PRDX5基因CDS区全长659 bp,可编码219个氨基酸;蛋白质结构预测显示PRDX5以α-螺旋为主,无信号肽;系统进化树显示,藏绵羊PRDX5基因与山羊(Capra hircus)亲缘关系最近;1周岁(性成熟期)和3周岁(成年)藏绵羊睾丸中PRDX5 mRNA相对表达量极显著(P <0.01)高于3月龄(性成熟前),但PRDX5蛋白表达量极显著(P <0.01)低于3月龄,且两者在性成熟后趋于稳定;PRDX5蛋白在藏绵羊睾丸不同发育阶段的支持细胞和间质细胞中均有表达。推测PRDX5基因可能通过调节细胞内ROS的水平影响精子发生...  相似文献   

新型水产饲料添加剂--左旋肉碱 (L-Carnitine)   总被引：4，自引：0，他引：4  

胡梦红  王有基 《现代渔业信息》2006,21(6):18-20,23

L-肉碱又称肉毒碱，是一种维生素的类似物。参与β-氧化等生理学作用，与脂肪代谢有关。能够维持水产动物体内的能量代谢的正常进行，是一种新型的功能性营养添加剂。在水产动物饲料中添加适量的L-肉碱，有着提高水产动物生长速度，降低饲料系数；提高水产动物蛋白含量，降低体脂率．改善肉质提高鱼类的繁殖率等功能。本文在大量相关研究文献的基础上，概述了L-肉碱的来源、水产动物对其吸收和代谢的机制、生物学功能以及在水产动物体内的营养生理学效应，并针对目前L-肉碱的使用存在的问题。提出了一些建议，展望了其广阔的应用前景。  相似文献   

Isolation and culture of rabbit primordial germ cells   总被引：2，自引：0，他引：2  

Kakegawa R  Teramura T  Takehara T  Anzai M  Mitani T  Matsumoto K  Saeki K  Sagawa N  Fukuda K  Hosoi Y 《The Journal of reproduction and development》2008,54(5):352-357

Primordial germ cells (PGCs) are embryonic precursors of the gametes of adult animals and are considered stem cells of the germline. Since their proliferation in vitro correlates well with the schedule of developmental changes in vivo, they might be interesting research tools for genomic imprinting, germ-cell tumors and fertility. Furthermore, once primordial germ cells are separated and placed on a feeder layer with cytokines, they become cultured pluripotent cell lines called embryonic germ (EG) cells. EG cells share several important characteristics with embryonic stem (ES) cells as they can also contribute to the germ line of chimeras. To investigate the characteristics of PGCs and establish rabbit EG (rEG) cells, we cultured rabbit PGCs (rPGCs) in vitro with various combinations of leukemia inhibitory factor (LIF), basic fibroblast growth factor (bFGF) and forskolin on inactivated mouse embryonic fibroblast (MEF) feeder layers. The present study found PGC proliferation in early cultures and induction of rEG-like colonies. These cells expressed pluripotent markers, such as alkaline phosphatase activity, OCT-4, Sox-2 and SSEA-1, in the undifferentiated state; however, the cells did not develop into a teratoma when injected into the kidney capsules of SCID mice, although the restricted differentiation potentials to neural cells were determined via embryoid body formation. From these characteristics and further characterization of the germ stem cell markers Vasa, SCP-1 and SCP-3, we suggested that these were hybrid cells with characteristics somewhere between PGC and EG cells.  相似文献   

Effects on growth and survival of loach (Misgurnus anguillicaudatus) larvae when co-fed on live and microparticle diets     

Youji Wang  Menghong Hu  Weimin Wang  & Ling Cao 《Aquaculture Research》2009,40(4):385-394

The effectiveness of co-feeding loach ( Misgurnus anguillicaudatus ) larvae with live and microparticle diets on weaning performance was described here. Dry weight, total length, length and weight-specific growth rate (SGR) and survivals were monitored at 23–25 °C from the 4th day post hatching (dph) in different diet regimes, which included: microparticle diets (A), live cladocerans (B), enriched cladocerans (C), half microparticle diets plus half live cladocerans (D) and half microparticle diets plus half enriched cladocerans (E). The SGR (L and W) were significantly lower in treatment A than in other treatments after completing metamorphosis (day 4–20, P <0.05). On 30 dph, dry weight (mg) and total length (mm) were significantly lower in treatment A than in other treatments ( P <0.05). There were no significant differences in growth in treatments B, C, D and E before 30 dph. However, when live feed was withdrawn from 31–60 dph, in metamorphosed fish, there were significant differences ( P <0.05) among the treatments in survival and growth. Metamorphosed fish in treatment E had higher survival than the fish in other treatments at the end of the experiment. The SGR (L and W) of weaned fish in treatments B and C were similar but lower than in treatments A, D and E respectively. However, dry weight and total length in treatment A were significantly lower than in treatments D and E. It is suggested that weaning of M. anguillicaudatus from early development would appear to be feasible and that larval co-feeding improves the growth and the survival.  相似文献   

Induced ovulation of yellow catfish (Pelteobagrus fulvidraco) using a combination of a gonadotrop‐releasing hormone analogue and domperidone     

Youji Wang  Menghong Hu  Siu Gin Cheung  Paul K. S. Shin  Limin Song  Weimin Wang 《Aquaculture Research》2010,41(8):1243-1249

The effects of an intraperitoneal hormone injection of gonadotropin‐releasing hormone agonist (D‐Ala⁶, Pro⁹‐NEt GnRHa) alone or in combination with a dopamine antagonist, domperidone (DOM), on ovulation induction in yellow catfish Pelteobagrus fulvidraco were tested. The hormone treatments were as follows: 6 mg kg⁻¹ body weight (BW) of carp pituitary extract as a positive control, GnRHa 10, 20, 40 and 80 μg kg⁻¹ BW and a combination of GnRHa and DOM as follows: 10 μg+5 mg, 20 μg+10 mg, 40 μg+20 mg and 80 μg+40 mg kg⁻¹ BW. Physiological saline (0.7% NaCl) was used as a negative control. Significant differences in the ovulation ratio, latency period and ovulation index (OI) were observed among treatments (P<0.05). The combination of GnRHa and DOM at doses of 40 μg+20 mg kg⁻¹ BW had higher values of the ovulation ratio and OI, and a shorter latency period compared with other treatments. The highest OI in GnRHa treatments was only 56.67%, suggesting a dopaminergic tone on gonadotropin secretion in this fish at the pre‐ovulatory stage. Therefore, ovulation can be successfully induced in yellow catfish with 40 μg kg⁻¹ GnRHa+20 mg kg⁻¹ DOM without affecting the egg quality.  相似文献   

黄河三角洲盐碱地低效防护林现状分析与类型划分   总被引：1，自引：0，他引：1  

王月海  韩友吉  夏江宝  杜振宇  吴俊杰  李永涛 《水土保持通报》2018,38(2):303-306

[目的]依据黄河三角洲盐碱地低效防护林的现状,探讨其成因机理并进行类型划分,为黄河三角洲盐碱地低效防护林恢复及重建提供理论依据和技术支撑,完善现有盐碱地防护林体系建设。[方法]通过全面、深入的调查,结合已有的研究成果,分析黄河三角洲盐碱地低效防护林的成因机理;依据低效林的立地条件、生长特点和形成原因等因素,划分其主要类型并探讨每种类型的改造技术。[结果]黄河三角洲地区现有盐碱地防护林由于受自然诱发因素和非自然因素及其共同作用的影响,有相当一部分林分形成了低效林;低效林可划分为6种主要类型,针对每种类型的低效林改造,应采取不同的技术方式和方法。[结论]低效林改造技术涉及低效林成因分析、类型划分和改造方式选择等一系列环节,在实施低效林改造的实践中应把握好每一环节,因地(林)制宜进行实施;针对黄河三角洲地区盐碱地防护林是生态公益林的实际,亦应处理好技术与政策的关系。  相似文献   

观赏海棠新品种‘昌辉’     

胡丁猛  韩友吉  许景伟  王立辉  朱升祥  囤兴建 《园艺学报》2018,45(Z2):2811-2812

‘昌辉’是采用自然杂交方法培育的观赏海棠新品种,大花重瓣,花量较少,浅杯形,红紫色,花期4月上旬至5月上旬。适应性和观赏性强,可在园林中推广应用。  相似文献   

外源因子介导调控ROS对中国鲎血淋巴细胞参数的影响     

徐镇  江宁锦  何锦锋  台宗光  朱全刚  王有基  胡梦红 《水产学报》2021,45(12):1973-1982

以鲎血为主要原料制备鲎试剂是我国鲎资源开发的关键产业链。我国鲎种群数量逐年下降,为实现鲎资源的保护和可持续利用,开展对中国鲎造血作用机理的相关研究刻不容缓。本研究向中国鲎体内注射N-乙酰半胱氨酸(NAC)和灭活鳗弧菌(V),比较注射后0, 6, 12, 24, 48小时(h)中国鲎的血淋巴细胞总数、活性氧含量及非特异性免疫酶活性变化。结果表明,与对照组相比,注射NAC后血淋巴细胞总数(THC)、活性氧(ROS)、丙二醛(MDA)活性均有下降趋势,超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、总抗氧化酶(T-AOC)、溶菌酶(LZM)、碱性磷酸酶(AKP)活性均有升高趋势。NAC与不同浓度V共同刺激下,THC、ROS、MDA含量相对仅注射NAC的下降有所减缓,其它酶活性有所升高。而血蓝蛋白(HC)在整个实验中无明显变化。6-48h,NAC组的THC、ROS与V组、NAC和V共刺激组相比呈降低趋势,共同刺激下SOD活性显著高于其它组。48h,NAC、V及共刺激下CAT、T-AOC组间无显著差异,但均高于对照组。NAC+10⁶V的MDA含量在48h最低,AKP活性在12-48h呈升高趋势,而NAC组的LZM活性在48h最高。注射NAC可降低THC、ROS,共刺激可缓和下降,V组THC、ROS升高,但其余血淋巴参数均提高,由此推测NAC和V均能刺激中国鲎血淋巴细胞的免疫机能;机体内的ROS含量对中国鲎血淋巴细胞增殖及再生起着重要作用。  相似文献   

天祝白牦牛HSP60基因的克隆及其在下丘脑-垂体-睾丸中的表达定位研究     

阮崇美  王相生  张勇  马友记  胡俊杰  赵兴绪 《核农学报》2017,31(7)

热休克蛋白60(HSP60)不仅在细胞保护方面发挥作用,也参与雄性动物生殖生理的调控。为研究HSP60基因序列特性及其在天祝白牦牛下丘脑-垂体-睾丸轴(HPT-axis)上的表达情况,探寻其在白牦牛睾丸发育、精子发生过程中的作用机制,本研究采用RT-PCR和RACE技术获得白牦牛HSP60基因全长cDNA序列,采用生物信息学方法分析HSP60蛋白的理化性质、结构及不同物种之间的同源性等,并利用qPCR、Western blotting、免疫组化法分析HSP60在白牦牛下丘脑-垂体-睾丸轴中的表达及定位。结果表明,白牦牛HSP60基因cDNA全长为2 300 bp,开放阅读框为1 722 bp,编码572个氨基酸;其理论分子量为60.977k Da、等电点为5.69,编码的蛋白为非跨膜可溶性蛋白。氨基酸序列比对结果显示,白牦牛HSP60氨基酸序列与牛、瘤牛、绵羊、藏羚羊、骆驼、白犀牛、兔和黑猩猩的氨基酸序列同源性高、进化水平相近。HSP60基因及蛋白在白牦牛的下丘脑、垂体及睾丸组织中均有表达,其中下丘脑及垂体组织表达量显著高于睾丸,下丘脑和垂体之间差异不显著。免疫组化结果显示,HSP60蛋白定位表达于白牦牛下丘脑组织的室旁核大细胞、室旁核小细胞和神经角演网、垂体组织的腺细胞、睾丸组织的精原细胞、精母细胞、支持细胞和间质细胞,而精子细胞中表达较弱。通过对健康成年白牦牛HSP60在下丘脑-垂体-睾丸轴的表达与定位检测,推断HSP60参与雄性白牦牛生殖轴调控,并参与睾丸发育与精子发生。本研究结果为进一步研究HSP60对雄性生殖调控奠定了基础。  相似文献