紫花槭秋季叶色表达转录组初步分析

为了丰富紫花槭转录组数据,进一步开展紫花槭秋季叶片呈色机制研究.本研究以紫花槭秋季转色期三个阶段(前期,中期,后期)叶片为材料,采用高通量测序技术进行转录组初步分析.转录组数据共获得50501条Unigene,有35316条Unigene在数据库中得到注释,其中NR数据库中注释到的Unigene数量最多,共35024条,占69.4％.在注释到的物种中,紫花槭比对的Unigene与甜橙(Citrus sinensis)相似度最高,共有4290条,占12.25％.紫花槭转录组中的Unigene根据GO功能可分为生物学过程、细胞组分和分子功能3大类,共有25375条,其中生物学过程的基因最多,主要聚集于代谢过程和细胞过程等.基于Unigene库的基因结构分析,其中SSR分析共获得12711个SSR标记,占Unigene总数的36％.SSR位点共包含150种重复基元,单碱基重复所占比例最高(7184个,61.86％),四碱基重复、五碱基重复和六碱基重复所占比例较低.Unigene库中共有328239个SNP位点,发生频率为1/190 bp,SNP位点分为转换和颠换两种类型的碱基替换方式,其中碱基转换位点213787个(65.13％),碱基颠换位点114452个(34.87％),碱基转换类型发生频率高于颠换类型.6种单碱基变异中,2种转换类型A/G、C/T的发生频率分别为33.03％和32.10％;4种颠换类型中A/T发生频率最高,为11.52％;C/G发生频率最低,为5.79％.紫花槭转录组秋季叶色表达的转录组分析,可为紫花槭叶色基因调控、定向分子育种和培育彩叶新品种提供研究提供基础的数据信息.     

橡胶园酸性、中性土壤交换性钙、镁测定方法研究

为了获得简单、易操作、准确度高的橡胶园酸性、中性土壤交换性钙、镁测定方法,本试验通过响应面优化试验,建立称样量、提取液体积、提取方式与交换性钙测定结果之间的数学模型。结果表明：在25℃条件下,以1 mol/L的乙酸铵为土壤浸提液,称样量为2 g、提取液体积175 mL、振荡36 min,为橡胶园酸性、中性土壤的最佳提取条件。将上述条件下得到的结果与标准方法条件下得到的结果相对比,两结果的相对误差在1.25~3.04之间,均属合理范围。利用标准样品对优化方法进行试验验证,结果与推荐值相符。改进后的方法分析成本低、操作简便、测定结果准确、稳定性好,可用于橡胶园酸性、中性土壤交换性钙、镁的测定。     

Differential regulation on C5 expression in goose versus mammals by glucose/palmitate provides a potential protection for goose fatty liver

Goose fatty liver is a specific type of nonalcoholic fatty liver that is protected from harmful effects associated with severe steatosis. Our previous findings suggest that suppression of the complement C5 may be relevant, but the mechanism is unclear. Therefore, in this study, we first verified the expression pattern of complement genes (including C5) during goose fatty liver formation and then determined the liver fat content and fatty acid composition by high-performance liquid chromatography (HPLC), followed by selecting the differential metabolites to treat HepG2, goose and mouse primary hepatocytes, aiming to explore the mechanism of C5 and inflammation suppression in goose fatty liver. The data confirmed the suppression of complement genes (including C5) in goose fatty livers. Moreover, fat content was significantly higher in fatty liver versus normal ones, with oleic acid and palmitic acid dominantly accounting for the difference. In line with this, high concentration of palmitate led to down regulation of C5 expression in goose primary hepatocytes whereas upregulation in mouse primary hepatocytes and HepG2 cells. In conclusion, regulation on C5 expression by fatty liver related factors including high level of palmitic acid may contribute to the protection of goose liver from severe hepatic steatosis.     

Effects of Feeding Frequency on Apparent Energy and Nutrient Digestibility/Availability of Channel Catfish,Ictalurus punctatus,Reared at Optimal and Suboptimal Temperatures

This study examined the effects of feeding frequency (daily versus every other day [EOD]) on nutrient digestibility/availability of channel catfish, Ictalurus punctatus, reared at optimal (30 C) and suboptimal (24 C) temperatures. A 28% protein practical diet was used as the test diet, and chromic oxide was used at 0.75% of the diet as a maker. Twenty channel catfish of a mean weight of 141 g/fish were stocked into 12 flow‐through aquaria (110 L). Fish were fed daily or EOD to apparent satiation for 7 d before fecal samples were collected by the dissection method. Fish fed EOD to apparent satiation consumed more diet on days fed than those fed daily, and fish reared at 30 C consumed more diet than those reared at 24 C. Neither feeding frequency nor water temperature significantly affected apparent digestibility coefficients for energy and protein and apparent availability coefficients for total amino acids. Results show no advantage by feeding EOD over feeding daily on nutrient digestibility and diet utilization efficiency.     

典型山地草甸草原主要牧草生长发育情况分析

对天山北坡中山带典型山地草甸草原4种具有代表性的天然牧草——老芒麦（Elymus sibiricus）、黄（Astragalus membranaceus）、老鹳草（Geranium wilfordii）、千叶蓍（Achillea millefolium）的生长发育情况进行了研究。结果表明，4种牧草的高度变化趋势表现为“慢-快-慢”的植物基本生长规律；老芒麦、千叶蓍、老鹳草的生长速率在返青期到分蘖期时较快，而黄芪的生长速率则在返青后就较快，分蘖期后4种牧草的生长速率开始变慢；盖度和产量的最大值出现在6月和7月。     

豚草粗提物对杨树水泡型溃疡病的抑菌作用研究

为解决豚草提取物在林业病虫害防治中的推广与应用问题,以豚草叶片为试验材料,采用温浸-超声波联合提取法提取抑菌活性物质,并开展其对杨树水泡型溃疡病病原菌的室内外抑菌试验。室内抑菌试验表明,粗提物浓度为16 mg/mL时,抑菌率达到73.62%;林间防治试验表明,最小抑菌浓度为 40 mg/mL,抑菌率达到95.14%。通过以上抑菌试验确定豚草粗提物对杨树水泡型溃疡病有较好的抑制效果。     

秀珍菇原基形成相关基因PpFBD1的克隆与表达研究

前期研究中通过对秀珍菇经低温诱导后不同发育阶段样本进行转录组测序及差异表达基因分析发现,ID为Cluster-6377.64510的基因(命名为PpFBD1)在原基形成前期的样本中高表达。为进一步了解分析其表达特性及功能,根据转录组测序结果设计特异性引物,利用RT-PCR技术从秀珍菇中克隆获得了该基因的cDNA全长。该基因由342个核苷酸组成,编码一个由113个氨基酸组成的蛋白,蛋白相对分子质量约11 ku。进化树分析显示,PpFBD1编码蛋白与糙皮侧耳hydrophobin1编码的疏水蛋白亲缘关系最近。Gene Ontology功能分析表明,PpFBD1主要参与真菌类细胞壁的合成。荧光定量RT-PCR检测显示,该基因在菌丝体经低温诱导后恢复至室温阶段(原基形成前期)表达量最高,这表明其可能参与调控秀珍菇原基形成过程。本研究结果为阐明秀珍菇原基形成机制提供参考。     

Effect of chlorogenic acid on intestinal inflammation,antioxidant status,and microbial community of young hens challenged with acute heat stress

Heat stress in poultry is deleterious to productive performance. Chlorogenic acid (CGA) exerts antibacterial, anti-inflammatory, and antioxidant properties. This study was conducted to evaluate the effects of dietary supplemental CGA on the intestinal health and cecal microbiota composition of young hens challenged with acute heat stress. 100-day-old Hy-line brown pullets were randomly divided into four groups. The control group (C) and heat stress group (HS) received a basal diet. HS + CGA₃₀₀ group and HS + CGA₆₀₀ group received a basal diet supplemented with 300- and 600-mg/kg CGA, respectively, for 2 weeks before heat stress exposure. Pullets of HS, HS + CGA₃₀₀, and HS + CGA₆₀₀ group were exposed to 38°C for 4 h while the control group was maintained at 25°C. In this study, dietary CGA supplementation had effect on mitigate the decreased T-AOC and T-SOD activities and the increasing of IL-1β and TNFα induced by acute heat stress. Dietary supplementation with 600 mg/kg CGA had better effect on increasing the relative abundance of beneficial bacterial genera, such as Rikenellaceae RC9_gut_group, Ruminococcaceae UCG-005, and Christensenellaceae R-7_group, and deceasing bacteria genera involved in inflammation, such as Sutterella species. Therefore, CGA can ameliorate acute heat stress damage through suppressing inflammation and improved antioxidant capacity and cecal microbiota composition.     

体细胞克隆荷斯坦奶牛出生后死亡犊牛内脏器官的组织病理学观察

为探究体细胞克隆荷斯坦奶牛出生后死亡的原因,对新生后死亡的克隆荷斯坦公牛和自然繁殖的荷斯坦公犊的主要组织器官进行比较。通过解剖和石蜡切片-HE(hematoxylin-eosin staining)染色技术,对主要的组织器官结构进行观察和分析。结果表明,新生后死亡的克隆荷斯坦公牛肺部结构清晰;肝脏的肝细胞明显肿大,出现脂肪轻度变性;肾小管上皮细胞出现变性;心肌的肌纤维间空隙增大;骨骼肌纤维间隙明显,空泡变性,这可能导致该克隆牛犊肌肉无力并功能不全;淋巴结皮髓质界限不分明,淋巴小结细胞较稀疏,生发中心不明显,淋巴窦细胞较少;脾脏内红细胞较少,这说明该克隆牛的造血功能可能不完善;胸腺的皮质部分和髓质部分界限不明显,嗜酸性胸腺小体不易辨认,可能发育不全。该克隆公牛免疫器官出现不同程度的发育不全现象较严重,这有可能是其出生后死亡率高的主要原因。     

猪繁殖性状的遗传改良策略

猪繁殖性能的提高将为养猪业带来巨大的经济效益 ,目前多数育种者将提高猪的繁殖力作为主要育种目标 ,并用数学遗传学方法和分子育种技术对繁殖性状进行改良。