中国鸭源H5N6 AIV血凝素和神经氨酸酶基因特征及遗传进化分析

为明确中国鸭源H5N6 AIV的HA和NA基因特征及其遗传变异情况,研究选取了NCBI流感病毒资源库里的32株具有完整ORF编码区的中国鸭源H5N6 AIV的HA和NA基因序列,利用分子生物学软件分析其HA和NA基因特征及其遗传进化情况。结果显示,中国鸭源H5N6 AIV的HA裂解位点有REKRRKR↓G、RERRRKR↓G和KEKRRKR↓G三种类型,HA有6个潜在的N-糖基化位点,其中第182、222、224位氨基酸依次为N、Q、G,具有与禽源唾液酸α-2,3受体结合的特性,然而HA发生了S123P/T、T156A、S223R氨基酸位点突变,部分毒株发生了I151T氨基酸位点突变;HA基因核苷酸遗传进化分析显示,中国鸭源H5N6 AIV遗传进化上均处于clade2.3.4.4分支,并进一步进化出Ⅰ和Ⅱ两个亚分支。部分中国鸭源H5N6 AIV NA第59~69位缺失11个氨基酸,中国鸭源H5N6 AIV NA基因遗传进化上分为两个大的分支,分别对应NA基因颈部缺失型和完整型两种类型;NA颈部完整型的NA有6个潜在的N-糖基化位点,NA颈部缺失型的NA由于第59~69位氨基酸的缺失,导致其第67位丢失了一个N-糖基化位点。研究为中国鸭源H5N6 AIV的生物学特性和遗传进化特征研究奠定基础。     

不同禽类传染性法氏囊病毒VP2基因的克隆与序列比较分析

应用RT-PCR法对分离于不同禽类的IBDV HN 01株(鸡源)、W J株(乌鸡源)和YL 997株(鸭源)的VP2基因分别进行了克隆,对其与核苷酸序列及其编码的VP2蛋白氨基酸序列进行了分析,并对此3株IBDV与标准血清Ⅰ型STC株的VP2基因和VP2蛋白进行了同源性分析。结果表明,W J株、LY 997株、HN 01株与标准血清Ⅰ型STC株的核苷酸同源性分别为91.30%,92.50%和93.47%,氨基酸同源性分别为92.74%,91.90%和95.10%;HN 01株与W J株的核苷核和氨基酸的同源性分别为97.9%和98.4%,HN 01株与LY 997株的核苷酸和氨基酸的同源性分别为98.7%和99.05%,W J株与LY 997株的核苷酸和氨基酸同源性分别为99.1%和97.68%,3个毒株的VP2基因序列均完全具备超强毒株的主要特征,均为超强毒株,且与标准血清Ⅰ型STC株的核苷酸和氨基酸同源性均较低;3个野毒株之间虽具有较高的同源性,但相互之间也有一定的差异。     

Dietary supplementation of 25-hydroxycholecalciferol increases tibial mass by suppression bone resorption in meat ducks

Leg problems often result from the rapid weight gain and poor bone quality in modern ducks, leading to a high risk of fractures and continuous pain. We hypothesized that improving bone quality in combination with delaying weight gain via a low nutrient density (LND) diet probably reverses these skeletal abnormalities. Studies indicated that 25-hydroxycholecalciferol (25-OH-D₃), a vitamin D₃ metabolite, is effective in treating bone-related disorders. Therefore, Exp. 1 evaluated the effects of 25-OH-D₃ on tibial mass of meat ducks. Male meat ducklings were fed a standard nutrient density diet (containing a regular vitamin regimen) without or with 25-OH-D₃ at 0.069 mg/kg for 35 d. The results showed that 25-OH-D₃ supplementation improved the mineral content, microarchitecture and mechanical properties of tibias, and this companied by a decreased serum bone resorption marker and a concomitant decrement in osteoclast-specific marker genes expression. Subsequently, Exp. 2 was conducted to examine the impacts of 25-OH-D₃ incorporating an LND diet on tibial quality of ducks under 2 different vitamin regimens (regular and high). Ducklings were allocated to a 2 × 2 factorial arrangement with 2 kinds of vitamin premixes and without or with 25-OH-D₃ at 0.069 mg/kg in LND diets. The high premix had higher levels of all vitamins except biotin than the regular premix. The results demonstrated that high vitamin diets exhibited more significant effects than regular vitamin diets on inhibiting bone turnover and increasing minerals deposition. Tibial mineral content, microarchitecture, and strength of birds under the regular vitamin regimen were increased by 25-OH-D₃ supplementation; However, these positive effects were not observed in ducks under the high vitamin regimen. To conclude, 25-OH-D₃ supplementation improves tibial mass by suppressing osteoclast-mediated bone resorption in meat ducks, and this positive impact only was observed in regular but not high vitamin regimen when birds fed an LND diet.     

5个鸭群体遗传关系的微卫星标记分析*

 选用12个微卫星标记对5个鸭群体（金陵黑鸭、樱桃谷鸭、乌嘴鸭、莆田黑鸭和三穗鸭）的进行了了群体内杂合度、多态信息含量和群体间遗传距离进行检测和分析。结果表明，12个微卫星标记只有7个在5个群体中检测到多态性，5个群体的平均杂合度在0.530 8~0.634 7之间，其中金陵黑鸭的平均杂合度最高，乌嘴鸭的最低。基于Nei氏标准遗传距离构建的系统发生树结果表明，樱桃谷鸭独聚为一大类，金陵黑鸭与乌嘴鸭聚集为一类，莆田黑鸭和三穗鸭聚集为一类。上述5个群体7个微卫星座位的检测和分析结果为这些鸭群体的资源利用提供了参考依据。     

丽佳雏鸭传染性浆膜炎的诊疗报告

１９９２年１０月底，泉州市郊两个养鸭户的两批丽佳雏鸭相继于１５日龄左右发生一种以萎顿、软脚、眼界有分泌物、下痢和摇头、角弓反张等神经症状为特征的疫病．根据临诊和病理学检查和病原学检验，分离出一株血清Ⅰ型鸭疫巴氏杆菌，确诊为鸭传染性浆膜炎．为国内另一鸭品种发生本病的首次报道．     

桂花果类黄酮分离纯化工艺及其抗氧化研究

从桂花果中提取类黄酮并用分光光度法测出其含量,通过静态吸附、解吸试验,筛选出对桂花果类黄酮化合物有吸附优势的吸附剂,并检测静态吸附性能,从而达到纯化提取液之目的;最后对桂花果中类黄酮化合物体外清除羟基自由基、超氧自由基的作用进行了研究.结果表明:AB-8树脂具有较好的吸附和解吸效果,其在吸附时间6 h、解吸剂浓度80%、解吸剂体积10 mL的条件下,对桂花果类黄酮化合物的分离纯化效果最佳;桂花果中类黄酮化合物对羟基自由基、超氧自由基有一定的清除作用,并具有较强的还原能力,且类黄酮化合物的浓度在试验范围内与清除率呈正相关.     

饲粮非植酸磷水平对高峰期蛋鸭产蛋性能、蛋品质和胫骨指标的影响

本试验旨在研究饲粮非植酸磷水平对高峰期蛋鸭产蛋性能、蛋品质和胫骨指标的影响。选取即将达到产蛋高峰期的山麻鸭900只,随机分为6组,每组6个重复,每个重复25只。各组非植酸磷水平分别为0.20%、0.25%、0.30%、0.35%、0.40%、0.45%,试验期11个月。结果表明:1)饲粮非植酸磷水平对蛋鸭产蛋性能和蛋品质均无显著影响(P0.05)。2)饲粮非植酸磷水平对蛋鸭的胫骨重、胫骨长度和折断力无显著影响(P0.05)。骨密度和骨矿盐含量随饲粮非植酸磷水平升高呈现先上升后降低的变化趋势,0.35%组和0.40%组的胫骨密度显著高于0.20%组和0.25%组(P0.05),当饲粮非植酸磷水平升至0.35%以上时,骨矿盐含量显著高于0.20%组(P0.05)。3)饲粮非植酸磷水平对胫骨灰分中钙和磷含量、血清中钙和磷含量均无显著影响(P0.05)。由此可见,在本试验条件下,由于饲粮非植酸磷水平对产蛋性能和蛋品质无显著影响,以骨密度和骨矿盐含量作为参考指标,通过回归方程得出蛋鸭适宜的饲粮非植酸磷水平为0.33%~0.38%。在实际生产中,若只考虑生产性能,建议采用0.20%饲粮非植酸磷水平,可节约饲料成本。     

Determination of the Complete Genome of DHAV GX Strain and Bioinformatics Analysis of VP1 Protein

In order to investigate the genotypic characteristics and biological characteristics of major capsid protein (VP1) of duck hepatitis A virus (DHAV) GX strain, the whole genome of GX strain was sequenced and compared with 3 serotypes reference strains of DHAV by the molecular biology software.The results showed that the full-length genome of DHAV GX strain was 7 800 bp, including 5'UTR (652 bp), 3'UTR (369 bp) and ORF (6 756 bp) encoding 2 251 aa and its coding products were 12 (VP0/VP3/VP1/2A1/2A2/2A3/2B/2C/3A/3B/3C/3D) at least.Sequence analysis showed that DHAV GX strain could be ranked DHAV 3 style.This strain shared the highest homology with DHAV-3 reference strains; Furthermore, GX strain and DHAV-3 FS strain were in the same cluster, might come from the same ancestor.Amino acid segments locating in 195 to 201 and 211 to 221 aa could be larvaceous dominant B-cell linear epitopes.It suggested that VP1 gene could be used as a candidate gene for the development of genetic engineering vaccine of DHAV.     

Secretory Expression of DTMUV E Gene in Insect Cells and Study on its Immunogenicity and Protective Efficacy

Duck Tembusu virus (DTMUV) was newly emerged which caused severe egg-drop syndrome in duck.Here,we constructed the recombinant baculovirus by honeybee melittin signal peptide (Mels) which expressed E protein of DTMUV JSXZ strain,and its immunogenicity and protective efficacy were investigated in duck infection model.Western blotting and indirect immunofluorescence assay (IFA) showed E protein was effectively secretory expressed in supernatant of Sf9 insect cells.Indirect ELISA result showed E protein could induce high levels of anti-E IgG in the sera.MTT result showed that E protein could stimulate the proliferation of T lymphocytes.Moreover,the protection rates were 80% in 0.3 mL group and 100% in both 0.6 mL and 0.8 mL groups,respectively,whereas,all ducks in PBS control group showed the typical clinical signs with 3 died post challenge.These results laid a foundation for the study of DTMUV subunit vaccine.     

Polymorphisms of MEF2A Gene and its Relationship with Slaughter Traits in Sansui Duck

To understand the relationship between single nucleotide polymorphism sites (SNPs) of myocyte enhancer factor 2A (MEF2A) gene and slaughter traits in Sansui duck, a total of 60 individuals of Sansui ducks were selected to investigate in this study, direct sequencing of PCR and PCR-SSCP methods were used on single nucleotide polymorphisms of MEF2A gene, and genetic effects of its on slaughter traits were analyzed.The results showed that two SNPs which include g.47915G>A and g.47918G>A of exon 11 were found in MEF2A gene, and the G/A mutation in the g.47915G>A SNP resulted in the change of codon from GAA to AAA, and the coding amino acid from Glu to Lys, and the G/A mutation in the g.47918G>A SNP resulted in the change of codon from GAT to AAT, and the coding amino acid from Asp to Asn.The result of association of SNPs with slaughter traits showed various results were as follows:g.47915G>A and g.47918G>A had affected the eviscerated percentage.This result revealed that the polymorphism of MEF2A gene had basilic influence on slaughter traits.