Effect of RFRP-3 on reproduction is sex- and developmental status-dependent in the striped hamster (Cricetulus barabensis)

RFamide-related peptides (RFRPs) are orthologous to gonadotropin-inhibitory hormone (GnIH) inhibiting gonadotropin release. There are only two RFRP sequences (RFRP-1 and RFRP-3) encoded in rodents. RFRP-3, which was considered as a hypothetical inhibitor on GnRH, shows a stimulatory effect on the male Syrian and male Siberian hamster in short days. As a dominant rodent pest in northern China farmland, the striped hamster (Cricetulus barabensis) has higher reproductive activities and could act as a model to study the mechanism of reproduction. However, the effect of RFRP-3 on the reproductive activity for the striped hamster is less understood. In the study, we cloned 643 bp RFRP cDNA from the striped hamster hypothalamus, which contained an ORF of 570 bp encoding two RFamide-related peptide (RFRP) sequences: SPAPANKVPHSAANLPLRF-NH₂ (C. barabensis RFRP-1) and TLSRVPSLPQRF-NH₂ (C. barabensis RFRP-3). We also investigated the expression variation of RFRP mRNA and GnRH mRNA in the hypothalamus from hamsters with different developmental statuses (7-week-, 13-week- and 1.5-year-olds) using FQ-PCR, in which the 13-week-old female individuals were in estrous. The striped hamsters that are 7 weeks and 1.5 years old are non-breeding individuals, and those that are 13-week hamsters have breeding phenomena. The highest hypothalamus RFRP mRNA level was found in breeding males as compared to non-breeding males. Conversely, the lowest RFRP mRNA level in the hypothalamus was observed in breeding females, with no significant level when the breeding females were compared to the 7-week-old individuals. Additionally, the investigation of GnRH expression level showed a declining expression trend across the developmental stages (7-week-, 13-week- and 1.5-year-olds) in both sexes. Significant negative and positive relationships were detected in the 13-week estrous female (r = − 0.997, P = 0.035) and the 13-week male (r = 0.998, P = 0.029) striped hamsters respectively, which suggest that RFRP-3 has inhibitory and stimulatory effects on female and male adults respectively. Our results suggest that the effects of RFRP-3 on reproduction are sex- and developmental status-dependent in the striped hamster.     

凋缨菊属在广西的首次记录及其生物地理学意义

报道了广西菊科斑鸠菊族的1个新记录属——凋缨菊属,描述了凋缨菊的分类学特征,给出了详细的图解,绘制了整个凋缨菊属的分布图。这一发现表明了我国桂西南热带地区与滇南以及中南半岛在植物区系上的紧密联系。     

水盾草—南四湖外来水生植物新记录及其生境特点

外来生物入侵与生境改变被认为是导致全球生物多样性下降的两大主因[1]。其中入侵植物通过营养竞争、植被结构改变、化感作用等,影响土著植物种群和群落,进而影响生态系统结构和功能。水生植物的入侵已成为影响我国淡水水体景观和生物多样性的重要因素[2—4]。水盾草     

非冬眠期刺猬血液生理生化指标季节变化

目的了解刺猬的血液生理生化参数正常值及其季节性差异。方法采用BC-3000 Plus全自动血液细胞分析仪和BAYER-ADVIA-1650全自动生化分析仪,分别对刺猬的13项生理指标和15项生化指标进行了测定,并比较分析了春季、夏季和秋季的血液生理生化指标。结果刺猬雌体和雄体的平均红细胞体积（MCV）在夏季均显著小于秋季,雄体夏季的平均红细胞血红蛋白（MCH）小于秋季,说明刺猬秋季的血液载氧能力高于夏季。白细胞数目（WBC）没有季节和性别的显著差异,说明刺猬在三个季节的免疫能力差别不大。在血液生化指标中,刺猬（雌雄）春季和秋季的葡萄糖（GLU）含量均显著高于夏季;雌性刺猬春季的谷草转氨酶（AST）显著大于夏季和秋季;雄性刺猬的总胆固醇（CHOL）和低密度脂蛋白（LDLC）均表现为秋季的显著高于春季和夏季的。结论生理生化指标的不同反映了刺猬在活动能力、代谢水平、营养状况、健康状况等方面存在性别和季节性差异。     

莱芜猪心脏cDNA文库的构建与鉴定

以莱芜猪心脏为供试材料,采用改进的异硫氰酸胍法提取心脏总RNA。通过SMART技术反转录合成全长cD-NA,经LD-PCR扩增后与pMD18-T载体连接并转化细菌DH5α,测定滴度和重组率,构建成莱芜猪心脏全长cDNA文库。经初步检测,原始文库的滴度为1.8×105CFU/mL,重组率约为94.4%。从原始文库随机挑取13个单菌落过夜培养,提取质粒,经HindⅢ和EcoRⅠ双酶切,凝胶电泳显示插入片段大小在0.3-2.0kb之间。     

莱芜猪肝脏组织全长cDNA文库的构建和鉴定

目的:构建莱芜猪肝脏组织全长cDNA文库,以便研究与莱芜猪优良性状相关的基因。方法:采用改良的异硫氰酸酸胍一步法制备总RNA;利用SMART技术,以PrimeScript反转录酶逆转录合成第一链cDNA,通过LD-PCR扩增获得cDNA双链;经蛋白酶K消化和CHROMA SPIN-400柱分级分离后,收集500 bp以上的cDNA片段,并与pMD18-T载体连接,转化大肠杆菌DH5α感受态细胞,建成原始文库;随机挑取单菌落,用HindⅢ和EcoRⅠ进行双酶切鉴定重组子插入片段大小。结果:经鉴定,原始文库的滴度为2.8×105 cfu/mL,重组率约为98%,插入片段大小为0.5～2 kb,平均插入片段长度大于1 kb。结论:建立的cDNA文库质量良好,可以用于目的基因的筛选。     

叶绿素的快速提取与精密测定

Arnon法是叶绿素提取和测定最经典、最常用的方法, 此法虽经多次改进, 但仍存在着检测波长误差大、计算公式有误、提取速度慢、测定结果不够准确以及操作步骤繁琐等缺陷。该文提出了二甲基亚砜(DMSO)高温提取、80%丙酮稀释的两步快速浸提法, 使叶绿素提取和测定过程缩短至3小时以内。通过对提取温度、提取时间、稀释比例及吸收光谱等进行系统分析, 筛选出了叶绿素的最佳提取条件和叶绿素含量的准确计算公式, 并用多种类型的植物材料验证了改进后的提取方法, 证明该方法具优越性和可靠性。具体测定方法是将植物材料切成1 mm宽的细丝或细段, 取50-100 mg材料于10 mL具塞试管中; 加入2 mL DMSO, 使植物材料浸没其中, 65°C高温避光提取至植物材料变白或透明; 冷却后加入8 mL 80%丙酮, 混匀, 测定663.6和646.6 nm处的吸光度。用公式计算叶绿素浓度: C_a (mg∙L^-1)=12.27A_663.6-2.52A_646.6; C_b (mg∙L^-1)=20.10A_646.6-4.92A_663.6; C_T (mg∙L^-1)=C_a+C_b=7.35A_663.6+17.58A_646.6。     

Divergent homoeolog evolution of the anthocyanin regulatory gene R in Oryza allopolyploids

Polyploidization is an important evolutionary force in plant speciation and diversification. Retention and elimination of homoeologs derived by polyploidization are prevalent, whereas the evolutionary details of some duplicated genes in closely related natural polyploids are largely unknown. In the present study, we used an important regulatory gene (R) that encodes a bHLH protein in the anthocyanin metabolism pathway to demonstrate divergent evolutionary fates of homoeologs among four related Oryza allotetraploids. The BBCC genome species O. punctata Kotschy ex Steud. maintained both of its homoeologs, whereas three CCDD genome species (O. alta Swallen, O. grandiglumis (Döll) Prod., and O. latifolia Desv.) lost their C subgenome homoeologous copies. In addition, the evolutionary rates of the homoeologs in the polyploids were equivalent to their corresponding homologs in diploids. We also found a slightly higher level of nucleotide diversity inR for the C subgenome homoeolog than for the B subgenome counterpart in O. punctata. After comparing the two types of polyploids, we conclude that inconsistent evolutionary patterns of R in these polyploids are probably associated with different evolutionary time, asymmetrical subgenome evolutionary dynamics, and unique demographical characteristics of these species.     

利用叶绿体基因探讨稻属BBCC基因组物种的系统起源

基于9个叶绿体基因片段(atpA、atpB、matK、petA、psaA、psbA、psbB、psbC和rbcL), 深入探讨了稻属(Oryza)3个BBCC基因组异源四倍体和5个与之相关的BB或CC基因组二倍体物种间的谱系关系。进一步的系统发育分析表明: 3个具有相同BBCC基因组的四倍体物种并非同一次物种形成事件的产物, 而是在不同的分布区经历了至少3次分别的物种起源。其中, 四倍体Oryza punctata的母本可能来自同样分布在非洲并具有CC基因组的二倍体物种O. eichingeri; 而四倍体O. malampuzhaensis和O. minuta的母本则可能来自亚洲已经灭绝的具有BB基因组的不同二倍体。研究结果不但为追溯稻属异源四倍体的复杂网状进化提供了重要的分子证据, 而且拓展了我们对有花植物复杂物种形成的深入理解。     

刺猬嗅球冬眠期与非冬眠期c-Fos 表达的差异

利用免疫组化法检测c-Fos 蛋白在不同季节刺猬嗅球各层次的表达差异,探讨c-Fos、嗅觉、冬眠三者的关系。分别选取春、夏、秋、冬四个季节各6 只野生健康刺猬,固定剥离嗅球,石蜡切片,免疫组化显色,拍片,载入Motic Images Advanced 3.2 软件,测量四个季节刺猬嗅球各层次c-Fos 的表达率,将结果载入GraphPadPrism4 软件分析,Microsoft Excel 作图。结果表明:c-Fos 蛋白在成年刺猬嗅球各层均有不同程度的表达,阴性对照不着色,且表现出明显的季节性差异。1)与秋季相比,冬眠期c-Fos 蛋白在刺猬嗅球各层次的表达均有极显著的降低(P <0.01);2)与夏季相比,冬眠期c-Fos 蛋白在外网丛层、僧帽细胞层、颗粒细胞层的表达有极显著降低(P < 0. 01),在嗅神经层、嗅小球层、室管膜层的表达也有显著降低(P < 0. 05);3)与冬眠期相比,春季c-Fos 蛋白在嗅小球层、僧帽细胞层、颗粒细胞层的表达有极显著的升高(P <0. 01),在嗅神经层、外网丛层、室管膜层的表达却没有显著变化(P ﹥ 0.05);4)嗅神经层c-Fos 的表达在春季显著低于秋季,夏季与秋季没有显著差异。颗粒细胞层夏季显著低于秋季(P < 0.05)。秋季c-Fos 在其余各层次的表达与春季、夏季相比都有极显著的提高(P <0.01)。结论:秋季刺猬嗅球神经元最活跃,嗅觉最灵敏,冬眠期刺猬嗅球活跃性大大降低,嗅觉系统最迟钝。c-Fos 在刺猬嗅球中的强表达表明其在嗅觉信息的传递中可能发挥一定作用,c-Fos 表达率的显著季节性差异揭示了刺猬嗅球的活跃性与其冬眠具有一定的相关性。