Effects of dietary biotin supplement on growth,body composition,intestinal enzyme activities and microbiota of juvenile Jian carp (Cyprinus carpio var. Jian)

A total of 1400 juvenile Jian carp (Cyprinus carpio var. Jian) (7.72 ± 0.02 g) were fed seven purified diets containing 0.010 (basal diet), 0.028, 0.054, 0.151, 0.330, 1.540 and 2.680 mg biotin kg^?1 for 63 days to investigate the effects of biotin on growth, body composition, intestinal enzyme activities and microbiota. Specific growth rate (SGR), feed intake, feed efficiency and protein retention value were the highest when dietary biotin level was 0.151 mg kg^?1 diet. Crude protein, lipid and ash content of fish carcass improved with increasing dietary biotin levels up to 0.054, 0.151 and 0.028 mg kg^?1 diet, respectively (P < 0.05). Intestinal folds height, trypsin, chymotrypsin, lipase, amylase, alkaline phosphatase, Na⁺, K⁺‐ATPase, γ‐glutamyl transpeptidase and creatinekinase activities increased with dietary biotin levels up to 0.151–0.330 mg kg^?1 diet (P < 0.05). Intestinal Aeromonas and Escherichia coli significantly decreased with increasing dietary biotin up to 0.151 mg kg^?1 diet, while Lactobacillus and Bacillus significantly increased with dietary biotin levels up to 0.054 and 0.151 mg kg^?1 diet, respectively. In conclusion, biotin could improve digestive and absorptive ability of fish, and the dietary biotin requirement for SGR of juvenile Jian carp (7.72–32.67 g) was 0.15 mg kg^?1 diet.     

生物素的生理功能及其分子作用机制

生物素是动物机体内维持正常生理机能所必需的一种维生素。它作为4种羧化酶辅酶成分,在哺乳动物体内的葡萄糖、氨基酸和脂肪酸代谢中起着重要作用。越来越多的研究表明,生物素对基因表达的调控起着重要的作用。本文综述了生物素的营养生理作用及其对基因表达调控的影响。     

Detection of Foot and Mouth Disease Virus by RT-PCR and Microplate Hydridization Assay Using Inactivated Viral Antigens

A single step RT-PCR was tested for detection of foot and mouth disease virus (FMDV) and immunoenzymatic determination of amplified products in a microplate hybridization assay. Inactivated reference strains (ELISA antigen) of all seven serotypes were used to optimize the test. Oligonucleotide primers were selected from two different genomic regions coding for RNA polymerase and VP1 protein, respectively. The RT-PCR used to amplify the polymerase gene specific RNA detected FMDV strains A, C, O, Asial and SAT1, and the identity of the fragments obtained was confirmed with a specific internal biotin-labelled capture probe. For the amplification of the VP1 genome region, two sets of oligonucleotide primers were used. One primer pair was successfully applied for the detection of serotypes A, C, O and Asial and a second one for serotypes SAT1, SAT2, SAT3. The specific probe enabled the detection of all the amplified products in a PCR ELISA test. By comparison with antigen ELISA, the PCR ELISA method allowed the detection of smaller amounts of FMDV in the inactivated material examined. The application of molecular diagnostic methods to inactivated antigens offers a good alternative procedure for developing and optimizing a sensitive method for detection of FMDV in laboratories that are not allowed to work with viable FMDV.     

大黄鱼微卫星标记的富集与筛选

根据生物素与链霉亲和素的亲和原理,采用生物素-磁珠富集微卫星,与传统放射性同位素杂交法相结合,构建筛选大黄鱼的微卫星文库。用生物素-微卫星捕捉单链限制性酶切片段（含有接头和大黄鱼微卫星序列）,经PCR扩增单链目的片段形成双链,然后连接至T载体上,转化感受态细胞。将移至硝酸纤维素膜的重组菌用^32P标记的放射性同位素探针50[γ-^32P]ATP（CA）15筛选出阳性克隆菌。测序结果发现,阳性克隆率为71.9％,105个微卫星位点。其中选取设计合成30对并筛选出22对可用引物。说明所建大黄鱼微卫星文库是一个高质量的文库,可为大黄鱼基因组结构分析、大黄鱼精密微卫星连锁图谱构建、分子进化和系统发育研究、分子标记辅助育种以及经济性状的QTL定位提供大量的微卫星标记。     

Wheat Substitutions in Hexaploid Triticale*

Crosses between octoploid and hexaploid triticales have been made m breeding programs for several years, From an analysis of the progeny of such crosses where selections for an octoploid-like phenotype had been made, it was established that 149 out of 150 lines were hexaploid in chromosome number, C-banding and in situ hybridization demonstrated that all but five of the 62 lines analyzed in detail contained visible chromosomes or segments from the D genome. Only four lines had D-genome chromosome replacing rye chromosomes. All of the remaining 53 D-genome substitutions involved the replacing of wheat chromosomes from either the A or B genomes. This establishes the ease with which D-genome genes can be placed into triticale without the loss of rye chromosomes.     

草鱼基因组中微卫星分子标记的制备及筛选

采用新型的生物素-磁珠吸附微卫星富集法与传统的放射性同位素杂交法相结合的方式,研究了草鱼（Ctenopharyngodon idella）基因组中存在的微卫星资源.结果,从1 000个细菌中,挑出90个阳性克隆,把其中45个进行测序分析,在这些序列中共含有68个微卫星核心序列,有55个含有重复次数大于5次的微卫星核心序列.其中,单一型标记49个,占72%,包括CA重复单元共22个,GT重复单元共18个,其他重复单元为9个;在72%的单一型标记中,完美单一型微卫星标记为44个,占65%.另外,混合型标记共19个,13为完美混合型;在所有微卫星标记中,CA重复类型最普遍,依次为GT、GA等.在68个微卫星标记中,有15个依据引物设计原理设计了引物.     

生物素对产蛋高峰期蛋鸭产蛋性能、蛋品质、血液生化指标、卵巢发育及胫骨性状的影响

【目的】本研究旨在探讨生物素在蛋鸭生产中的应用效果及对蛋鸭卵巢发育和胫骨性状的影响。【方法】采用单因素完全随机试验设计,将432羽健康、处于产蛋高峰期的福建龙岩山麻鸭随机分为6个处理,每个处理6个重复,每个重复12羽。采用小麦-豆粕型基础饲粮,生物素添加水平分别为0、0.05、0.10、0.15、0.20、0.25 mg/kg,试验期12周。于第12周,每个重复随机选取4枚蛋,以及2只试验鸭进行采血、屠宰取样,检测蛋品质、血液生化指标及卵巢发育和胫骨性状指标。【结果】(1)饲粮生物素添加水平对产蛋性能影响不显著(P>0.05)。(2)饲粮生物素添加水平为0.10 mg/kg时,蛋黄重量最低,显著低于0.05和0.20 mg/kg添加组(P<0.05);随饲粮生物素添加水平升高,蛋黄中胆固醇(CHO)含量呈现升高趋势(P<0.05)。与对照组相比,生物素添加水平为0.25 mg/kg时,蛋黄中丙二醛(MDA)含量显著下降(P<0.05)。(3)饲粮生物素添加水平对蛋鸭血浆生化指标、卵巢发育指标及胫骨发育指标均无显著影响(P>0.05)。【结论】饲粮中添加不同...     

Biotin in practical fish-meal based diet for Atlantic salmon Salmo salar L. fry

Groups of Atlantic salmon fry (0.19 g initial weight) were fed a fish-meal based starter diet with different supplements of biotin (0, 0.5, 1.0 and 1.5 mg biotin kg^–1) in triplicate tanks for 18 weeks. The basal diet contained 0.3 mg total biotin kg^–1. The experimental design included a negative control diet made by replacing 10% of the fish-meal with spray-dried raw hen's egg white.
Throughout the experimental period the fish grew to about 5 g and there were no significant differences in growth and mortality among the groups of fish fed the fish-meal diets. At the end of the experiment there were no significant differences in biotin level in the liver, while whole-body biotin concentrations correlated significantly with the dietary biotin concentrations. No significant increase in pyruvate carboxylase (PC) activity was found in livers from fish given different dietary levels of biotin. The control diet with egg white resulted in severe growth reduction and increased mortality compared with the other dietary groups. The concentrations of biotin in liver and whole body were decreased in fish fed egg white. Increased levels of glycogen and reduced PC activity in the liver were observed in this group after 18 weeks.
Histology of the gills showed no differences in appearance when fish were fed fish-meal based diets while the addition of egg white resulted in hypertrophy and hyperplasia of the gill tissue and extensive fusions of the secondary gill lamellae.
The results show that there is no need for supplemental biotin in practical fish-meal based diets for Atlantic salmon fry to achieve optimal growth, survival and maximal liver PC activity.     

Dietary biotin requirement determined for Indian catfish, Heteropneustes fossilis (Bloch), fingerlings

Triplicate groups of Indian catfish, Heteropneustes fossilis (Bloch), fingerlings (average wet weight 3.55 ± 0.03 g) were fed semi-purified diets containing six levels of biotin (0, 0.086, 0.26, 0.86, 2.5 and 4.3 mg kg⁻¹ diet) for 15 weeks. After 42 days of feeding, fish fed the control (no biotin) diet had developed severe deficiency signs characterized by convulsions, heavy mortality, listlessness, poor feed conversion and feed intake, dark skin colour, tetanus and weight loss. None of these signs was seen in fish fed biotin-supplemented diets. Among all the biotin-supplemented diets, percentage weight gain was significantly highest for fish fed the diet supplemented with 0.26 mg of biotin kg⁻¹ and significantly lowest for fish fed the diet supplemented with 0.086 mg of biotin kg⁻¹. Feed conversion ratio (FCR) and protein efficiency ratio (PER) patterns were similar to that of percentage weight gain. The carcass protein and lipid contents were influenced by the dietary biotin up to fish fed 0.26 mg of biotin kg⁻¹. Significantly higher body biotin content, liver pyruvate carboxylase and acetyl CoA carboxylase activities were observed in fish fed biotin-supplemented diets than in fish fed the control diet. Broken-line analyses showed that the optimum dietary requirement for biotin for maximal weight gain, body biotin content, liver pyruvate carboxylase and acetyl CoA carboxylase activities was about 0.25 mg kg⁻¹. Associated liver pyruvate carboxylase and acetyl CoA carboxylase activities for normal growth ranged from 105 to 120 units mg⁻¹ protein and from 9 to 11 units mg⁻¹ protein respectively.