Tandem B1 SINE retro-elements may provide a basis for natural antisense transcription in the Magi1 locus of the mouse (Mus musculus)

Transposable elements, which are DNA sequences that can move between different sites in genomes, comprise approximately 40% of the genome of mammals and are emerging as important contributors to biological diversity. Here we report a transcription unit lying within intron 1 of the murine Magi1 (membrane associated guanylate kinase inverted 1) gene that codes for a cell-cell junction scaffolding protein. The transcription unit, termed Magi1OS (Magi1 Opposite Strand), originates from a region with tandem B1 short interspersed nuclear elements (SINEs) and is an antisense gene to Magi1. Mag1OS transcription initiates in a proximal B1 element that shows only 4% divergence from the consensus sequence, indicating that it has been recently inserted into the mouse genome and could be replication competent. Moreover, a chimaeric transcript may result from intra-chromosomal interaction and trans-splicing of the Magi1 antisense transcript (Magi1OS) and Ghrl, which codes for the multifunctional peptide hormone ghrelin. These two genes are 20 megabases apart on chromosome 6 and are transcribed in opposite directions. We propose that the Magi1OS locus may serve as a useful model system to study exaptation and retrotransposition of B1 SINEs, as well as to examine the mechanisms of intra-chromosomal trans-splicing.

Responses of the Circadian Locomotor Activity Rhythm of Mus Booduga to Shifts in LD Schedules

The responses of the field mouse Mus booduga to shifts in schedules of LD cycles were monitored and the results were interpreted with the help of a PRC constructed for the same species. The results reveal that, M. booduga reentrained faster with a lesser number of transients after delay shifts than advance shifts, thus exhibiting “asymmetry effect.” A positive correlation was observed between the number of transients and the number of hours of shift. In most of the shifts, the sign of the transients (negative for delaying transients and positive for advancing transients) coincided with the direction of the shift. Interestingly, 11 and 12 h of advance shifting resulted in delaying transients. An 11-h advance shift can also be interpreted as a 13-h delay. Reentrainment through delaying transients is faster as compared to reentrainment through advancing transients. Thus, this animal might have taken a “shorter route,” as proved by the fact that an 11-h advance shift has evoked delaying transients. But a 13-h advance shift evoked only advancing transients. This prompts us to speculate that there may be a “phase jump” in M. booduga. Further, irrespective of whether L or D has been doubled in a 12-h shift, both evoked only delaying transients.

白腹鼠属（Niviventer）分子系统发育关系和小家鼠（Mus musculus）分子系统地理学研究

本工作用线粒体细胞色素b基因全序列探讨了白腹鼠属（Niviventer）分子系统发育关系，利用线粒体控制区全序列研究小家鼠（Mus musculus）在中国的分子系统地理学。 在白腹鼠属的分子系统发育研究中，本研究首次对来自青藏高原东南部和台湾的9种（安氏白腹鼠、川西白腹鼠、社鼠、刺毛鼠、梵鼠、灰腹鼠、褐尾鼠、台湾白腹鼠和台湾社鼠）32个个体的细胞色素b全序列进行了测定和分析。用最大简约法、最大似然法和贝叶斯法三种构树方法构出的进化树一致表明，9种分为3个线粒体DNA系：系A包括社鼠、台湾社鼠、台湾白腹鼠、刺毛鼠、梵鼠和灰腹鼠6种；系B包括安氏白腹鼠和川西白腹鼠2种；系C仅包括褐尾鼠一种。应用DNA分类的分析方法表明台湾社鼠不应是社鼠的亚种，而应是一个独立的种。此外，以来自更新世中晚期（1.2-0.13百万年）的社鼠化石为依据推算该属的分歧时间。结果表明该属的起源于1.64百万年前，系A和系B分化发生在1.46百万年以前，该属的其余物种分化时间为1.29-0.67百万年前。这些分化时间和青藏高原的最后一次隆起、昆黄运动以及第四纪大冰期时间相一致，提示地理隔离和冰期作用可能对该属的形成演化起到重要的作用。 在小家鼠的分子系统地理学研究中，通过测定来自中国12个采集地的184只小家鼠的控制区全序列，并结合了Genbank里的单倍型，首次研究小家鼠在中国的分子系统地理格局、种群历史和生物地理过程。184个样品定义了66个单倍型，单倍型多样性为0.95，核苷酸多样性为0.012。用66个单倍型及Genbank里来自周边国家的62个小家鼠单倍型进行分子系统发育分析，邻接法和贝叶斯法构得的分子系统发育树基本一致。结果表明小家鼠在中国分为两个线粒体DNA系（南方系和北方系）。分子变异等级分析结果表明主要的分子变异发生在两个线粒体DNA系之间（84.03%）。根据研究结果推断长江是两个线粒体DNA系之间基因交流受限的主要地理障碍。单倍型进化网络关系表明两个线粒体DNA是异域扩散。两个系的单倍型歧点分布图呈钟型分布，说明经历了快速的种群扩散。经推算小家鼠在中国北方系的种群扩散时间为16 600（22 000－11 000）年前，而南方系的种群扩散时间早于北方系，扩散时间为20 000（40 000－6 700）年前。依据单倍型和核苷酸的多样性、单倍型进化网络关系以及单倍型歧点分布图综合推断小家鼠在中国的两个系在末冰期时经历了快速的种群扩张导致今天的地理分布格局。根据系统发育树的结果推断，北方系种群的大体扩散方向是从北往南，而南方系是从南往北迁移。小家鼠以长江为界分为南方系和北方系的系统地理模式、扩散方向和种群的扩散时间与人以长江为界分为南方人和北方人、扩散方向、扩散时间（60 000－16 000）基本一致，这可能暗示人类活动对小家鼠的迁移产生的重要影响。

间接免疫荧光法鉴别小鼠(Mus musculus)早期胚胎的性别

本工作采用间接免疫荧光法检测昆明品系小鼠早期胚胎雄性特异的H-Y抗原。结果表明：54％的胚胎为H-Y阳性（雄性）；46％为H-Y阴性（雌性）。与昆明品系小鼠的自然性比率（♂：52％；♀：48％）比较无显著性差异。经细胞遗传学方法确定，以免疫荥光法鉴别的胚胎性别，雄性准确率为75.5％；雌性为82.9％。本文还就影响鉴别准确率的若干因素以及本方法在生产中的应用前景等问题进行了分析讨论。

Characterisation of a two-dimensional liquid-filled ion chamber detector array using flattened and unflattened beams for small fields, small MUs and high dose-rates

In this study, the PTW 1000SRS array with Octavius 4D phantom was characterised for FF and FFF beams. MU linearity, field size, dose rate, dose per pulse (DPP) response and dynamic conformal arc treatment accuracy of the 1000SRS array were assessed for 6MV, 6FFF and 10FFF beams using a Varian TrueBeam STx linac. The measurements were compared with a pinpoint IC, microdiamond IC and EBT3 Gafchromic film. Measured dose profiles and FWHMs were compared with film measurements. Verification of FFF volumetric modulated arc therapy (VMAT) clinical plans were assessed using gamma analysis with 3%/3 mm and 2%/2 mm tolerances (10% threshold). To assess the effect of cross calibration dose rate, clinical plans with different dose rates were delivered and analysed. Output factors agreed with film measurements to within 4.5% for fields between 0.5 and 1 cm and within 2.7% for field sizes between 1.5 and 10 cm and were highly correlated with the microdiamond IC detector. Field sizes measured with the 1000SRS array were within 0.5 mm of film measurements. A drop in response of up to 1.8%, 2.4% and 5.2% for 6MV, 6FFF and 10FFF beams respectively was observed with increasing nominal dose rate. With an increase in DPP, a drop of up to 1.7%, 2.4% and 4.2% was observed in 6MV, 6FFF and 10FFF respectively. The differences in dose following dynamic conformal arc deliveries were less than 1% (all energies) from calculated. Delivered VMAT plans showed an average pass percentage of 99.5(±0.8)% and 98.4(±3.4)% with 2%/2 mm criteria for 6FFF and 10FFF respectively. A drop to 97.7(±2.2)% and 88.4(±9.6)% were observed for 6FFF and 10FFF respectively when plans were delivered at the minimum dose rate and calibrated at the maximum dose rate. Calibration using a beam with the average dose rate of the plan may be an efficient method to overcome the dose rate effects observed by the 1000SRS array.

A metodologia artístico-pedagógica MUS-E como veículo para o envolvimento das/dos estudantes em escolas de contextos sócio-culturalmente diversos

Com a presente comunicação pretende-se apresentar / discutir a metodologia artístico-pedagógica MUS-E enquanto vetor estruturante da intervenção do projeto MUSEpe (Associação Menuhin Portugal | Programa Escolhas) na EB1 da Cruz da Picada e junto da comunidade educativa dos bairros da Cruz da Picada e Malagueira (Évora), refletindo em torno do seu impacto na promoção do envolvimento das/dos estudantes na Escola e, consequentemente, do seu sucesso, comportamento, participação e bem-estar. Partindo-se da caracterização e conceptualização do envolvimento das/dos estudantes na Escola utilizada pela “International School Psychologist Association” [ISPA] nos estudos internacionais em torno do conceito (Lam & Jimerson, 2008; Pereira, 2011; Pereira & Melo, 2011) e da descrição e contextualização dos princípios norteadores da intervenção artístico-pedagógica MUS-E, procurar-se-á, com a apresentação e discussão de dados relativos ao sucesso, comportamento, participação e envolvimento escolar das/ dos estudantes da EB1 da Cruz da Picada [2006-2007 a 2010-2011], demonstrar os impactos da adopção desta metodologia neste contexto. Finalmente pretende-se sublinhar os potenciais benefícios da introdução destas práticas em Escolas situadas em contextos marcados pela sua vulnerabilidade e/ou diversidade sociocultural.