Revision of genus Melamphaes (Melamphaidae). II. Multi-Raker species: M. polylepis, M. falsidicus sp. nova, M. pachystomus sp. nova, M. macrocephalus, M. leprus

The second part of the publication is devoted to the Melamphaes species (family Melamphaidae), which are characterized by 20 and more rakers on the first gill arch, by seven soft rays in the ventral fin, by absence of a temporal spine, by 14–15 rays in the pectoral fin, and by 11 abdominal vertebrae. M. polylepis is characterized by circumtropical range (Atlantic Ocean, Indian Ocean, western and central Pacific Ocean). Newly described species M. falsidicus is described from the northern Atlantic Ocean, where it was sampled between 34°N and 58°N. Before, this species was defined as M. microps. Another newly described species, M. pachystomus, is described along the Peruvian Coast. M. macrocephalus is redescribed. This species inhabits the eastern tropical Pacific Ocean (approximately between 30°N and 23°S). One of the studied specimens of M. macrocephalus was characterized by larger body size (SL = 128 mm) than was described before for this species. M. leprus is known currently by single findings from the eastern tropical Atlantic Ocean (between 11°N and 4°S). This species was also found in the samples obtain in the Gulf of Guinea.     

金钟藤分类考证及补充描述

旋花科植物金钟藤在中国华南地区已蔓延暴发成为"森林杀手",已引起各界的高度关注。该文对金钟藤的系统归隶、基名与异名、模式标本、分类文献,以及相关种进行考证和分析,澄清了一些误解和标本鉴定的错误,论证了金钟藤变种黄毛金钟藤在中国仅产于广西,而云南产的黄毛金钟藤实为铜钟藤,并把Merremia biosiana var.sumatrana van Ooststr.作黄毛金钟藤的新异名处理。     

Transformation of Mycoplasma capricolum and Examination of DNA Restriction Modification in M. capricolum and Mycoplasma mycoides subsp. mycoides

Plasmids pIKΔ and pIKΔ-erm have recently been developed as mycoplasmal cloning vectors. In this report, we demonstrate that these plasmids can replicate in Mycoplasma capricolum, a mycoplasmal species for which transformation had not previously been characterized. Both plasmids are stably maintained at a higher copy number than in their parental species, Mycoplasma mycoides subsp. mycoides. We have also examined the possibility of one or more restriction-modification systems affecting transformation frequencies in both species.     

Food plant specialization and feeding efficiency in the tent caterpillars Malacosoma disstria and M. americanum

Larvae of Malacosoma americanum (F.) an oligophagous species that feeds primarily on Prunus and other rosaceous trees, were compared to larvae of the more highly polyphagous congener M. disstria Hb., with respect to the efficiency of utilization of the foliage of a common host plant, Prunus serotina Ehrh. We obtained values similar to those reported for other Lepidoptera for the commonly used measures of the fraction of ingested food that was assimilated, and for the growth in dry weight per unit of food ingested or assimilated. Moreover, the two species did not differ in any measure of efficiency. Our results are compatible with the conclusion that specialized phytophagous insects do not use their host plants with greater physiological efficiency than do generalized insects.

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Zusammenfassung Raupen von Malacosoma americanum, einer oligophagen Art, die sich vor allem auf Prunus und andern baumartigen Rosaceen. entwickelt, wurden mit Raupen der polyphageren Verwandten M. disstria in Hinblick auf die Verwertung der Blätter ihres gemeinsames Wirtes Prunus serotina verglichen. Wirerhielten ähnliche Werte wie sie früher für andere Lepidopteren publiziert worden waren und zwar in Bezug auf die üblichen Messwerte, Anteil verwertete Nahrung, Wachstum in Trockengewicht pro Einheit gefressene oder verwertete Nahrung. Zudem unterschieden sich die beiden Arten in keiner Masszahl für Effizienz. Unsere Resultate sind im Einklang mit der Folgerung, das spezialisierte phytophage Insekten ihre Wirtspflanzen nicht besser ausnützen als as polyphage Arten tun.

     

芒和荻种子对复合盐碱胁迫的生理响应

土壤盐碱化在世界范围内普遍存在,日益严峻的盐碱化形势严重威胁着植物的生长发育。芒(Miscanthus sinensis)和荻(Miscanthus sacchariflora)作为能源植物具有良好的经济效益和生态效益,并且在城市园林中已得到广泛应用。该研究以引种自辽宁省本溪阿家岭的芒和哈尔滨市太阳岛的荻为对象,模拟我国东北大庆盐碱地的低(浓度1、2)、中(浓度3)、高(浓度4、5)浓度土壤环境,分别对芒和荻的种子进行复合盐碱胁迫处理,对芒和荻的种子萌发情况进行研究。结果表明：(1)复合盐碱胁迫处理下,芒种子的发芽率随着复合盐碱浓度的升高而降低,发芽势、活力指数、发芽指数、胚根长度、胚芽长度、胚根鲜重、胚芽鲜重和耐盐碱指数均先升高后降低;荻种子的发芽率、发芽势、活力指数、发芽指数、胚根长度、胚芽长度、胚根鲜重、胚芽鲜重和耐盐碱指数均随着复合盐碱浓度的升高而降低。(2)芒和荻的种子能够抵抗低、中浓度的复合盐碱胁迫处理,当高浓度的复合盐碱胁迫处理时,各项指标均下降明显,且芒种子的各项指标均优于荻种子,说明芒种子比荻种子更耐盐碱。该研究结果基本界定芒荻种子的复合盐碱耐受范围,为今后芒荻类能源植物的耐盐碱性筛选和在园林中的应用提供了理论依据。     

A newly identifiedMinute locus,M(2)32D, encodes the ribosomal protein L9 inDrosophila melanogaster

A gene encoding a ubiquitously expressed mRNA inDrosophila melanogaster was isolated and identified as the gene for ribosomal protein L9 (rpL9) by its extensive sequence homology to the corresponding gene from rat. TherpL9 gene is localized in polytene region 32D where two independent P element insertions flanking the locus are available. Remobilization of either P element generated lines with a typicalMinute phenotype, e.g. thin and short bristles, prolonged development, and female semisterility in heterozygotes as well as homozygous lethality. All these characteristics can be rescued when a 3.9 kb restriction fragment containing therpL9 gene is reintroduced by P element-mediated germline transformation. This result confirms thatM(2)32D codes for ribosomal protein L9.     

Africa goes Europe: The complete phylogeography of the marbled white butterfly species complex Melanargia galathea/M. lachesis (Lepidoptera: Satyridae)

Climatic oscillations influence the distribution of species in time. Thermophilic species survived the ice ages in refugia around the Mediterranean. Northern Africa is one of the possibly important refugia. In this study we test the genetic differentiation between northern African and European populations, using the marbled white butterfly species complex, Melanargia galathea/M. lachesis, as a model. We studied 18 allozyme loci in 876 individuals from 23 populations representing a major part of Europe (northern Spain to Romania) and the western part of northern Africa (Atlas Mountains). The African populations resemble the European ones in allelic richness; their genetic diversity is higher than in Europe. Cluster analysis discriminated five European genetic groups: M. lachesis, a western European lineage, and three eastern European lineages. However, the African samples did not form a separate cluster within this phenogram, but clustered randomly within the Balkan/southeastern European groups. The genetic differentiation among the African populations (F_ST 8.8%) was higher than that within any of the European lineages (F_ST 2.6–5.5%). The high genetic diversity and the relatively strong differentiation of the four African populations sampled in a comparatively limited area of the Atlas Mountains indicate that the most probable origin of M. galathea is northern Africa, with its sibling species, M. lachesis, evolving in parallel in Iberia. Most probably, M. galathea colonised Europe first during the Eem interglacial, some 130 ky ago. Since M. lachesis must have existed on the Iberian peninsula during that period already, M. galathea should have reached Europe via Italy. The genetic differentiation to distinct groups in Europe most probably evolved during the following Würm glacial period.     

利用机器学习提高M. jannaschii酪氨酰tRNA合成酶底物特异性分子建模预测的准确度

设计结合不同化学结构底物的酶结合袋是一个巨大的挑战. 传统的湿实验要筛选成千上万甚至上百万个突变体来寻找对特定配体结合的突变体,此过程需要耗费大量的时间和资源. 为了加快筛选过程,我们提出了一种新的工作流程,将分子建模和数据驱动的机器学习方法相结合,生成具有高富集率的突变文库,用于高效筛选能识别特定底物的蛋白质突变体. M. jannaschii酪氨酰tRNA合成酶（Mj. TyrRS）能识别特定的非天然氨基酸并催化形成氨酰tRNA,其不同的突变体能够识别不同结构的非天然氨基酸,并且已经有了许多报道和数据的积累,因此我们使用TyrRS作为一个例子来进行此筛选流程的概念验证. 基于已知的多个Mj. TyrRS的晶体结构及分子建模的结果,我们发现D158G/P是影响残基158~163位α螺旋蛋白骨架变化的关键突变. 我们的模拟结果表明,在含有687个突变体的测试数据中,与随机突变相比,分子建模和打分函数计算排序可以将目标突变体的富集率提高2倍,而使用已知突变体和对应的非天然氨基酸数据训练的机器学习模型进行校准后,筛选富集率可提高11倍. 这种分子建模和机器学习相结合的计算和筛选流程非常有助于Mj.TyrRS的底物特异性设计,可以大大减少湿实验的时间和成本. 此外,这种新方法在蛋白质计算设计领域具有广泛的应用前景.     

In vitro culture of immature M. truncatula grains under conditions permitting embryo development comparable to that observed in vivo

Working with the model legume species Medicago truncatula, we have developed an in vitro strategy for the culture of immature embryos that permits their development in a way comparable to that observed in planta. Thus, seeds (8 and 12 days after pollination, DAP) and 12 DAP embryos were harvested and cultured on a basal salts medium with 130 g/L added sucrose, and with or without a nitrogen source. With an exogenous nitrogen supply, both 12 DAP seeds and embryos developed, with storage protein synthesis comparable to that observed in vivo as revealed by two-dimensional gel electrophoretic profiles. Conversely, in the absence of added nitrogen, seeds and embryos responded differently; with entire seeds there was a remobilisation of endogenous nitrogen during the initial stages of embryo development from tissues surrounding the embryo, thereby ensuring initial storage protein accumulation, whereas isolated embryos rapidly ceased synthesizing de novo proteins, and their development appeared arrested, presumably reflecting a shortage of nitrogen. This system is therefore useful for investigating the embryo's response to nitrogen.