Sequence analysis of a chloroplast intergenic spacer for phylogenetic estimates in Allium section Cepa and a PCR-based polymorphism detecting mixtures of male-fertile and male-sterile cytoplasmic onion

Restriction-enzyme analysis of the chloroplast (cp) DNA yielded maternal phylogenies supporting a close phylogenetic relationship among normal (N) male-fertile and male-sterile (S) cytoplasmic bulb onion (Allium cepa), Allium altaicum, Allium fistulosum, Allium galanthum, Allium roylei, and Allium vavilovii. The S cytoplasm of onion is most likely an alien cytoplasm introduced in antiquity into onion populations. We previously showed that size differences in an intergenic spacer in the cp DNA distinguish N and S cytoplasms of onion. We cloned and sequenced this intergenic spacer from the N and S cytoplasms of onion, A. altaicum, A. fistulosum, A. galanthum, Allium pskemense, Allium oschaninii, A. roylei, and Allium ampeloprasm (outgroup) to identify the nature of previously described RFLPs and to develop a PCR-based marker revealing N-cytoplasmic contamination of S-cytoplasmic hybrid seed lots. Phylogenies based on restriction-enzyme analysis of the entire cp DNA were similar, but not identical, to those based on sequence divergence in this intergenic region. Received: 29 November 1999 / Accepted: 28 April 2000     

Reversibility of germinative and endocrine testicular function after long-term contraception with a GnRH-agonist implant in the tom—a follow-up study

A significantly reduced gonadotropin and testosterone secretion is a well-described result of long-term administration of GnRH agonists in the male dog and cat. To date, no data are available about the duration of efficacy and the reversibility of treatment-induced effects after long-term treatment with a 4.7 mg deslorelin implant. Seven healthy male European Shorthair cats (3.2 ± 0.5 kg, 1–6 years) were treated with a 4.7 mg deslorelin implant. Blood samples (testosterone, T), testicular volume, penile spines, and mating behavior were recorded once weekly. Considering T > 0.5 ng/mL as the biological endpoint, mean duration of efficacy was 78.8 ± 12.9 weeks (range: 61.7–100.7 weeks) with T concentrations increasing rapidly after the last T less than 0.1 ng/mL (basal) (P < 0.0001), and pretreatment T concentrations being reached after 3 weeks. Testicular volume rapidly increased after the first increase of T (P < 0.001) with pretreatment testicular volume being reached after 6.9 ± 3.4 weeks (5–11 weeks). “Normal” libido reoccurred 88.7 ± 12.4 weeks after treatment, and “normal” mating behavior was observed even later. Fertile matings occurred 7 to 42 weeks after the last T less than 0.1 ng/mL with a mean of 4.0 ± 0.0 kittens, and 13.6 to 47.6 weeks afterwards testicular histology revealed normal spermatogenesis. The present data confirm that the use of slow-release GnRH-agonist implants containing deslorelin in tomcats represents an effective and safe reversible alternative for long-term contraception; however, as number of animals is low, further fertility trials are recommended.     

DNA methylation changes in photoperiod-thermo-sensitive male sterile rice PA64S under two different conditions

Epigenetic modification can occur at a high frequency in crop plants and might generate phenotypic variation without changes in DNA sequences. DNA methylation is an important epigenetic modification that may contribute to environmentally-induced phenotypic variations by regulating gene expression. Rice Photoperiod-Thermo-Sensitive Genic Male Sterile (PTGMS) lines can transform from sterility to fertility under lower temperatures and short-day (SD) conditions during anther development. So far, little is known about the DNA methylation variation of PTGMS throughout the genome in rice. In this study, we investigated DNA cytosine methylation alterations in the young panicles of PTGMS line PA64S under two different conditions using methylation sensitive amplified polymorphism (MSAP) method. Compared with the DNA methylation level of PA64S under lower temperatures and SD conditions (fertility), higher methylation was observed in PA64S (sterility). The sequences of 25 differentially amplified fragments were successfully obtained and annotated. Three methylated fragments, which are homologous to D2, NAD7 and psaA, were confirmed by bisulfite sequencing and their expression levels were also evaluated by qPCR. Real time quantitative PCR analysis revealed that five of the six selected methylated genes were downregulated in PA64S (sterility). These results suggested that DNA methylation may be involved in the sterility–fertility transition of PA64S under two different environmental conditions.     

A model for the coordinated stepping of cytoplasmic dynein

Cytoplasmic dynein play an important role in transporting various intracellular cargos by coupling their ATP hydrolysis cycle with their conformational changes. Recent experimental results showed that the cytoplasmic dynein had a highly variable stepping pattern including “hand-over-hand”, “inchworm” and “nonalternating-inchworm”. Here, we developed a model to describe the coordinated stepping patterns of cytoplasmic dynein, based on its working cycle, construction and the interaction between its leading head and tailing head. The kinetic model showed how change in the distance between the two heads influences the rate of cytoplasmic dynein under different stepping patterns. Numerical simulations of the distribution of step size and striding rate are in good quantitative agreement with experimental observations. Hence, our coordinated stepping model for cytoplasmic dynein successfully explained its diverse stepping patterns as a molecular motor. The cooperative mechanism carried out by the two heads of cytoplasmic dynein shed light on the strategies adopted by the cytoplasmic dynein in executing various functions.     

How is a giant sperm ejaculator formed? Development of the Zenker organ after the last moult in Pseudocandona marchica (Crustacea,Ostracoda, Candonidae)

‘Giant sperm’, in terms of exceptionally long spermatozoa, occur in various taxa in the animal kingdom, particularly in arthropods. In freshwater ostracods (Cypridoidea) reproducing with giant sperm, males are equipped with a pair of specialized ejaculators, or Zenker organs, located in the distal part of vas deferens.     

加替沙星注射液无菌检查方法的验证

目的:建立加替沙星注射液无菌检查方法。方法:根据《中国药典》2010年版二部附录XIH无菌检查法验证试验指导原则,采用薄膜过滤法和添加硫酸锰中和剂去除加替沙星抑菌活性的实验方法和条件进行了验证,建立了加替沙星注射液无菌检查的方法。结果:采用薄膜过滤法用pH7.0无菌氯化钠-蛋白胨缓冲液进行冲洗,每桶5×100mL的冲洗量,每桶(100mL)培养基中加入硫酸锰溶液可去除加替沙星对各菌株的抑菌作用。结论:加替沙星注射液的无菌检查可采用上述方法。     

外来入侵害虫棉花粉蚧雄虫生殖能力研究

采用单头雄虫与不同数量雌虫配比的方法研究了棉花粉蚧雄虫的生殖能力。结果表明,与1～7头雌虫配比,雄虫的交配成功率分别为94.4%、91.2%、85.4%、80.7%、77.7%、69.5%、66.2%;产仔雌虫数量与雌雄性比关系符合逻辑斯蒂曲线方程Ff=5.2159EXP(-2.5304EXP (-0.421739N)),1头雄虫平均可以满足4～5 头雌虫生殖需要,最多为5.22头;与单头雄虫交配后雌虫总产仔量由358.8头增大至1274.2头,其数量与雌雄性比关系符合S型增长曲线F?t=1524.589e-1.3922/N,总产仔量最大可达1525头;单雌产仔量先由358.8头上升至427.6头,其后逐渐下降至266.5头;子代性比(♀:♂)变化无规律,为1.13～1.86;子代中雌虫数量由206.1头增大到727.4头,其数量与雌雄性比关系可由F?of=840.1124e-1.2599/N描述,最大值是840头。     

Boldness is related to the development of the cephalic crest in the male of the river blenny Salariafluviatilis （Asso, 1801）

Boldness is defined as the tendency of an individual to take risks when exposed to novel objects or situations. The main aim of this work was to dilucidate if boldness was related to the development of the secondary sexual traits （SSTs） in the male of the fiver blenny Salariafluviatilis, a freshwater fish which takes care of eggs. As a second objective SSTs effect on pa rental status adoption was also be explored. Wild young fish were caught in the Segre River （Ebro basin） in November 2010. Fish were kept in five aquaria in groups of eight males and eight females with artificial nests. Boldness （boldness score and hesitancy） of males （initially with little SSTs development） was tested as the time required to exit a refuge when exposed to a new environ ment. Fish were mantained in the same aquaria for several months, and males＇ SSTs development and reproductive behaviour were monitored. Boldness score was negatively associated to cephalic crest development. Hesitancy was negatively related to male length and was also influenced by the interaction between male length and cephalic crest. Parental status acquisition was positively related to the male＇s length, marginally related to anal gland development, and nonrelated to cephalic crest. These re sults suggest an intrasexual role of the crest as an informative trait of boldness （honest signal） which might not necessarily be chosen by the females. It is also discussed that correlational selection could be responsible for linking boldness and growth rate in this species. Sexual selection, in addition to having directed the evolution of secondary sexual traits, might have favored certain personality traits （e.g. boldness） associated with the achievement of a larger body length .     

Agrotis segetum雄蛾触角叶性信息素反应神经元对电刺激触角神经的反应

为探讨电刺激Agrotis segetum雄蛾触角神经是否可以作为MGC中神经元的识别手段,采用细胞内电生理记录方法,共记录34个对性信息素有反应的MGC神经元,并测试了其中12个神经元对性信息素刺激的反应,22个神经元对性信息素刺激和电刺激的反应。结果表明,MGC神经元对性信息素及电刺激的反应模式基本一致,为一种双相反应模式。两种刺激方式均能诱导出兴奋反应,电刺激得到的兴奋反应比由信息素刺激引起的要短;MGC神经元对两种刺激的超极化反应（抑制反应）幅度影响没有显著性差别,在电刺激实验的22个神经元上,超极化反应幅度和抑制时间都与神经元本身放电频率有一定的相关性。超极化反应是在LN参与下一定的神经回路对刺激所产生的反应而形成的。这提示两种刺激所作用的神经回路应是一致的,但从整个实验过程记录到的神经元情况来看,还须进一步结合形态学实验来验证电刺激触角神经作为MGC神经元的识别手段。