用RACE技术扩增并克隆牛BMP4基因3′端序列

RACE技术是一项扩增基因末端序列的新技术。该研究从牛BMP4基因出发,以牛软骨的RNA为模板,按照不同物种BMP4基因的相似性设计特异引物,运用PCR和RACE技术扩增并获得了特异片段,该片段经PCR、酶切和测序验证,证实所克隆序列为牛BMP4的3′端序列,包含有1170bp组成的开放读码框(ORF),编码389个氨基酸,3′非编码区121bp个核苷酸和poly(A)15。同源性分析结果表明,牛BMP4 cDNA最大开放读码框所推测的氨基酸序列与已知人、小鼠、大鼠、狗、羊和鸡等真核生物BMP4氨基酸序列进行比较,分别有94.5%、93.1%、91.9%、87.4%、94.2%、79%的同源性。这为克隆其他物种的BMP4基因提供了依据,同时牛骨形态发生蛋白的测序为我们更好的理解牛的生骨机理提供帮助。     

VOCAL REPERTOIRE OF WILD BREEDING ORANGE-WINGED PARROTS AMAZONA AMAZONICA IN AMAZONIA

ABSTRACT

The vocal repertoire of Amazona amazonica during its breeding season has been recorded from wild individuals in Santa Bárbara do Pará, Pará State, Brazil. At individual nests, we continuously recorded vocalizations and behaviour for four hours in the early morning and three hours in the late afternoon, three times a week throughout the breeding season. We identified nine vocalizations that we classified in three behavioural categories: (1) Flight call—emitted when parrots arrive in the nest area; (2) Perched contact calls—two different vocalizations, one of them related to feeding, were emitted when the pair was perched in the nest area and interacted socially between themselves or with other individuals; (3) Aggressive calls—emitted when birds were in a dangerous situation, i.e. alarm (three types of calls), agonistic contact and distress calls (two types of call). The Orange-winged Parrot is a highly social species and the complexity of its social interactions is reflected in the diversity of its vocal repertoire.     

Evolutionary conservation of the chromosomal configuration and regulation of amylase genes among eight species of the Drosophila melanogaster species subgroup

Nuclear DNA was extracted from each of the eight species comprising the Drosophila melanogaster species subgroup. Southern hybridization of this DNA by using a molecular probe specific for the alpha-amylase coding region showed that the duplicated structure of the amylase locus, first found in D. melanogaster, is conserved among all species of the melanogaster subgroup. Evidence is also presented for the concerted evolution of the duplicated genes within each species. In addition, it is shown that the glucose repression of amylase gene expression, which has been extensively studied in D. melanogaster, is not confined to this species but occurs in all eight members of the species subgroup. Thus, both the duplicated gene structure and the glucose repression of Drosophila amylase gene activity are stable over extended periods of evolutionary time.      

High rate of DNA loss in the Drosophila melanogaster and Drosophila virilis species groups

We recently proposed that patterns of evolution of non-LTR retrotransposable elements can be used to study patterns of spontaneous mutation. Transposition of non-LTR retrotransposable elements commonly results in creation of 5' truncated, "dead-on-arrival" copies. These inactive copies are effectively pseudogenes and, according to the neutral theory, their molecular evolution ought to reflect rates and patterns of spontaneous mutation. Maximum parsimony can be used to separate the evolution of active lineages of a non-LTR element from the fate of the "dead-on-arrival" insertions and to directly assess the relative frequencies of different types of spontaneous mutations. We applied this approach using a non-LTR element, Helena, in the Drosophila virilis group and have demonstrated a surprisingly high incidence of large deletions and the virtual absence of insertions. Based on these results, we suggested that Drosophila in general may exhibit a high rate of spontaneous large deletions and have hypothesized that such a high rate of DNA loss may help to explain the puzzling dearth of bona fide pseudogenes in Drosophila. We also speculated that variation in the rate of spontaneous deletion may contribute to the divergence of genome size in different taxa by affecting the amount of superfluous "junk" DNA such as, for example, pseudogenes or long introns. In this paper, we extend our analysis to the D. melanogaster subgroup, which last shared a common ancestor with the D. virilis group approximately 40 MYA. In a different region of the same transposable element, Helena, we demonstrate that inactive copies accumulate deletions in species of the D. melanogaster subgroup at a rate very similar to that of the D. virilis group. These results strongly suggest that the high rate of DNA loss is a general feature of Drosophila and not a peculiar property of a particular stretch of DNA in a particular species group.      

博尔纳病病毒pEGFP-p24基因重组质粒的构建及鉴定

构建博尔纳病病毒pEGFP-p24基因重组表达质粒。通过PCR方法扩增获得博尔纳病痛毒p24基因的完整序列,将此片段定向克隆到pEGFP-N1载体多克隆位点区,筛选重组阳性菌株,提取重组质粒,利用PCR方法和核酸序列测定验证重组质粒构建的正确性。PCR及核酸序列测定证明博尔纳病病毒pEGFP-p24基因重组表达质粒构建成功。构建的重组质粒将为研究博尔纳病病毒p24基因在真核细胞中的功能和作用提供实验依据。     

RCPAQAP First Combined Measurement and Reference Interval Survey

Reference intervals are commonly considered to allow for between-laboratory bias. The RCPAQAP Liquid Serum Chemistry Program has collected data on laboratory measurements as well as reference intervals. This allows assessment of the between-laboratory variation in results, reference intervals and the information transmitted by the combination of these factors. For the majority of common chemistry analytes, the between-laboratory variation in reference intervals is greater than the variation in results. Additionally the reference interval variation is generally not related to bias between the results. Use of common reference intervals, either as an average of the current intervals in use, or the intervals proposed by the AACB Harmonisation Group, improved the variation seen in the information produced by different laboratories.     

Variability in host plant resistance of Sorghum to Striga Hermonthica infestation in West Africa

Fourteen elite sorghum lines were evaluated for their resistance to Striga hermonthica at three locations in Nigeria and Mali. Results showed that many of the lines especially MALISOR 84-1, SAMSORG 41, 97-SB-F5DT-64 (Keninkédié) and the check SRN 39 remained resistant to Striga in all locations with low emerged Striga counts, while SAMSORG 14 had the highest Striga infestation in all locations. Considerable variation in reaction to Striga infestation was observed on Séguètana, 97-SB-F5DT-63 (Wasa), 97-SB-F5DT-65, CMDT 38, CMDT 39 and CMDT 45 which were susceptible to Striga at Samaru, Nigeria but were resistant to Striga at both locations in Mali. Based on low Striga resistance and high grain yield, lines MALISOR 84-1, SAMSORG 41, 97-SB-F5DT-64, 97-SB-F5DT-65, CMDT 39 and SAMSORT 14 have been nominated for wider evaluation across more West African countries.