摘要：
The Rac proteins are members of the Rho family of small G proteins and are implicated in the regulation of several pathways, including those leading to cytoskeleton reorganization, gene expression, cell proliferation, cell adhesion and cell migration and survival. In this investigation, a Rac gene (named as LycRac gene) was obtained from the large yellow croaker and it was expressed in Escherichia coli and purified. Subsequently the specific antibody was raised using the purified fusion protein (GST-LycRac). Moreover, the GTP-binding assay showed that the LycRac protein had GTP-binding activity. The LycRac gene was ubiquitously transcribed and expressed in 9 tissues. Quantitative real-time RT-PCR and Western blot analysis revealed the highest expression in gill and the weakest expression in spleen. Time-course analysis revealed that LycRac expression was obviously up-regulated in blood, spleen and liver after immunization with polyinosinic polycytidynic acid (poly I:C), formalin-inactive Gram-negative bacterium Vibrio parahemolyticus and bacterial lipopolysaccharides (LPS). These results suggested that LycRac protein might play an important role in the immune response against microorganisms in large yellow croaker.
摘要：
A 10-week feeding experiment was conducted to evaluate the nutritional value of menhaden oil (MO), soybean oil (SO) and soybean lecithin oil (SL) at different ratios (MO/SO/SL) in practical diets for juvenile Litopenaeus vannamei by determining their effects on survival, growth, blood chemistry and fatty acid composition of hepatopancreas and muscle tissue. Eight isonitrogenous and isolipidic diets were formulated using 3% MO(3/0/0), 3% SO(0/3/0), 3% SL(0/0/3), 1% MO + 1% SO + 1% SL (1/1/1), 1% SO + 2% SL (0/1/2), 1% MO + 2% SL (1/0/2), 2% SO + 1% SL (0/2/1) and 2% MO +1% SL (2/0/1), respectively. There were no significant differences in body weight gain among all treatments. However, shrimp fed diets with SL supplementation showed significantly (P < 0.05) higher survival than those fed diets without SL supplementation (3% MO and 3% SO diets). The fatty acid (FA) composition of hepatopancreas and muscle tissue reflected, to a certain extent, FA composition of the test diets. Shrimp fed the 3% SL diets showed significantly (P < 0.05) higher triglyceride (TG) concentration in serum than those fed the other experimental diets. Shrimp fed diets containing SL have relatively higher total cholesterol (TC) and phospholipid (PL) concentration in serum than those fed the diets without SL (3% MO and 3% SO). The results of the present investigation are encouraging and confirmed soybean lecithin supplement in shrimp practical diets, when sufficiently high levels of phospholipid are present, survival is enhanced.
作者机构：
[Li, L. L.; Yin, F. G.; Zhu, N. S.; Yin, Y. L.; Tang, Z. R.; Liu, G.; Luo, J. J.; Li, F. N.] Chinese Acad Sci, Inst Subtrop Agr, Changsha 410125, Hunan, Peoples R China.;[Li, L. L.; Yin, F. G.; Tang, Z. R.; Liu, G.; Li, F. N.] Key Lab Agroecol Proc Subtrop Reg, Changsha 410125, Hunan, Peoples R China.;[Hou, D. X.; Zhu, N. S.; Zhang, B.; Peng, H. Z.; Luo, J. J.] Hunan Agr Univ, Coll Anim Sci, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Yin, F. G.] C;Chinese Acad Sci, Inst Subtrop Agr, Changsha 410125, Hunan, Peoples R China.
摘要：
The effects of Atractylodes Macrophala Koidz polysaccharides on metabolic status and immune function in early-weaned pigs were determined. 25 [Duroc x (Landrace x Yorkshire)] crossbred pigs, weaned at the age of 21 days (body weight 5.30 +/- 0.25 kg), were randomly allocated to 5 dietary treatments, with 5 pigs in each treatment. The dietary treatments were: the basal diet (BD)fed group, the pure Atractylodes Macrocephala Koidz polysaccharides (PAMKPS)-fed group (BD + 0.3% PAMKPS), the crude polysaccharides mixture (CPSM)-fed group (BD + 0.6% CPSM), the crude Atractylodes Macrocephala Koidz polysaccharides (CAMKPS)-fed group (BD + 0.6% CAMKPS) and the antibiotics (AN)-fed group (BD + 0.015% chlortetracycline + 0.005% flavomycin). Diarrhea scores were recorded daily, and the average daily gain (ADG), average daily feed intake (ADFI) and feed/gain ratio (F/G) were measured weekly. Blood samples were obtained for the measurement of serum metabolites and immune function related parameters, contents from ileum, cecum and colon were collected for enumeration of coliform and lactobacillus counts, and tissue samples were collected for the determination of cAMP contents and mRNA abundances of cytokines. Diets supplemented with the PAMKPS, CPSM and CAMKPS increased ADG (P<0.05) and decreased F/G (P<0.05) compared with the BD. The diarrhea incidence in pigs of the PAMKPS-fed group was lower (P<0.05) than that in both the AN and BD-fed group, and that in the CPSM and AN-fed group was lower (P<0.05) than in the CAMPKS and BD-fed group, respectively. The counts of coliform in ileum contents of the PAMKPS-fed group, that in cecum contents of the PAMKPS, CPSM, CAMKPS and AN-fed group, and that in colon contents of the PAMKPS and AN-fed group were lower (P<0.05) than that in the BD-fed group; the counts of lactobacillus in ileum contents of the PAMKPS-fed group, that in cecum contents of the PAMKPS, CPSM and CAMKPS-fed group, and that in colon contents of the PAMKPS, CPSM, CAMKPS and AN-fed group were higher (P<0.05) than that in the BD-fed group, respectively. Diet supplemented with the PAMKPS ameliorated (P<0.05) the metabolic status of blood urea nitrogen, alanine amiotransterase and aspartate amiotransterase compared with the BD, and diets supplemented with the CAMKPS and CPSM improved (P<0.05) the glucose metabolic process compared with the AN-added diet. Diet supplemented with the PAMKPS increased (P<0.05) the serum concentrations of immunoglobin (Ig) G, IgM, tumor necrosis factor (TNF)-alpha, interferon (IFN)-gamma and cyclic adenosine monophosphate (cAMP), and spleen and liver contents of the cAMP compared with the BD. Diets supplemented with the PAMKPS and CPSM increased (P<0.05) the peripheral blood lymphocyte transformation rates and mRNA abundances of the interleukin-6, TNF-alpha, IFN-gamma, and the nuclear factor of activated T cells transcription factor (NF-AT) in spleen compared with the AN-added and BD diets. We concluded that the PAMKPS, CAMKPS and CPSM could ameliorate the metabolic status and regulate immune function to beneficially improve the growth performance in pigs, and such function was better than that of antibiotics. (C) 2011 Elsevier B.V. All rights reserved.
