New alicyclic musks: the fourth generation of musk odorants

Musk odorants are one of the most important classes of fragrances in perfumery because they impart sensuality to perfume-oil compositions. Among the three well-known classes of musks, a new and very exciting generation of musk odorants, the so-called alicyclic musks, was discovered recently, of which Helvetolide (2) and Romandolide (3) are the most popular representatives so far. To find new, structurally related alicyclic musks, we have synthesized a library of 114 unique alicyclic molecules with modified cyclohexyl moieties. The olfactory properties of all compounds were evaluated to identify the structural requirements to be met for a musk odorant.     

Triparental origin of Damask roses

Damask roses are one group of old rose varieties and a key material in old European rose improvement in the 19th century. To clarify the origin of Damask roses, we selected four varieties as the oldest Damask varieties and examined the relationship between the Damask varieties and their putative ancestors at the molecular level. Randomly amplified polymorphic DNA analysis of the Damask varieties proved that they had an identical profile, indicating they were established from a common ancestor. They have never been allowed to reproduce sexually; their reproduction depends entirely on vegetative propagation. We identified three Rosa species, R. moschata, R. gallica and R. fedschenkoana, as parental species of the original hybridization that contributed to forming the four oldest Damask varieties by sequencing the internal transcribed spacer of ribosomal DNA. We also found that all the four oldest Damask varieties had chloroplasts derived only from R. moschata, as judged from psbA-trnH spacer sequences. This triparental origin of the four oldest Damask varieties can explain some morphological characteristics of the four oldest Damask varieties, like fruit shape, leaf color and the 'Moss' character.     

The year of the tiger and the year of tiger genomes!

Tigers are endangered apex predators. They typify endangered species because they are elusive, rare, and face numerous threats across their range. Tigers also symbolize conservation. However, it is very difficult to study tigers because of their stated nature. Also, tiger conservation is a geopolitically sensitive topic, making it difficult to use the studies to propose evidence-based management that allows their recovery, especially in the context of conservation genetics. Zhang et al. (Mol. Ecol. Resour., 2022) have created very valuable and rare resources to aid the community in conserving tigers. First, they present chromosome level genome assemblies of a South China tiger and an Amur tiger. Second, they present whole genome sequences of 16 captive South China tigers. Additionally, by using the assemblies they model the demographic history of these populations, estimate inbreeding and the potential threats they face in captivity. This approach is particularly important because genetic management is now the only remaining option for South China tigers, because they are extinct in the wild. In other words, captive individuals are our only hope for some day restoring the wild populations of South China tigers.     

Anthocyanins in flowers of genus Rosa, sections Cinnamomeae (=Rosa), Chinenses, Gallicanae and some modern garden roses

Forty-four taxa of three sections (Cinnamomeae (=Rosa) 26, Chinenses 8 and Gallicanae 10) and eight modern garden roses in the genus Rosa were surveyed for their floral anthocyanins. Eleven anthocyanins: 3-glucosides and 3,5-diglucosides of cyanidin (Cy), pelargonidin (Pg) and peonidin (Pn), 3-rutinosides and 3-rho-coumaroylglucoside-5-glucosides of Cy and Pn, and Cy 3-sophoroside, were isolated from flowers of these taxa and identified by chemical and spectroscopic techniques. Four anthocyanins: Cy 3-rutinoside, Pn 3-rutinoside, Pn 3-rho-coumaroylglucoside-5-glucoside and Cy 3-sophoroside were found for the first time in Rosa flowers.Investigated sections of wild roses showed characteristic distribution of anthocyanins. Cy 3,5-diglucoside was the dominant anthocyanin detected in all three sections, but accumulation of Pn 3,5-diglucoside distinguished sections Cinnamomeae from other sections, and the occurrence of Cy 3-glucoside separates section Chinenses from others.Cy 3-sophoroside was detected in large amount in some taxa of section Cinnamomeae: e.g., R. moyesii and its related cultivars, and R. rugosa cv. Salmon Pink. The acylated Cy glycoside was found in all sections and also in some modern garden roses, while the acylated Pn glycoside was detected in the section Cinnamomeae, but not in sections Chinenses and Gallicanae. According to anthocyanin distribution patterns, eight groups were classified chemotaxonomically in genus Rosa.     

Resistance of roses to pathotypes of Diplocarpon rosae

Colonies of Diplocarpon rosae derived from single conidia were isolated on malt extract agar, multiplied (at 23°C) and stored (at ?20°C) on surface‐sterilised leaf discs of a universally susceptible rose, ‘Frensham’. The resistance of 16 species and cultivars of Rosa to different isolates of D. rosae was assessed using surface‐sterilised leaf discs. Four pathotypes of D. rosae were distinguished on the basis of host range. One species and one hybrid were resistant to all pathotypes. Two species and two cultivars were susceptible to all pathotypes. Four species and six cultivars were interpreted as having vertical resistance because they were strongly resistant to some but not all pathotypes. Only species and hybrids of the section Cinnamomeae were resistant to the pathotype identified as CW1 whereas only roses of other origins were resistant to the pathotype DA2.     

The tricarboxylic acid cycle in Dictyostelium discoideum. IV. Resolution of discrepancies between alternative methods of analysis.

Experimental studies of enzyme kinetics in vitro and metabolic fluxes in vivo have been used by Wright and her colleagues to develop a detailed kinetic model of the tricarboxylic acid cycle in Dictyostelium discoideum. This model has recently been been analyzed by two different methods (Albe, K. R., and Wright, B. E. (1992) J. Biol. Chem. 267, 3106-3114; Shiraishi, F., and Savageau, M. A. (1992) J. Biol. Chem. 267, 22926-22933 in an effort to determine the response of individual fluxes and metabolite concentrations to changes in levels of the enzymes that constitute the system. Individual responses were found to differ significantly in magnitude as well as in sign. Perhaps the most glaring difference concerns the influence of the enzyme succinate dehydrogenase on the flux through the cycle; in one study, it has the maximum influence, whereas, in the other, it has absolutely no influence. In this paper, we provide a resolution of these discrepancies. We have reconstructed the methodology of Albe and Wright and have been able to reproduce their results in detail. We show that their methodology does not yield a valid steady state analysis, and, consequently, that the conclusions drawn from their analysis must be called into question. First, they concluded that their model is realistic and predictive. It is now clear that their model is ill-determined and has a steady state only for unrealistically narrow conditions. Second, they concluded that their analysis is valid for variations of less than 2% in the levels of the enzymes because they could satisfy summation relationships considered to be mathematically inevitable. It is now clear that these relationships are neither necessary nor sufficient for establishing the validity of an analysis or the appropriateness of a biochemical model. Third, they concluded on the basis of their empirical methodology that certain enzymes are most important in influencing flux through the cycle. It is now clear that these results are inaccurate because of deficiencies in their methodology. Finally, they concluded that steady state analyses cannot be carried out experimentally because of the small variations required in enzyme levels. It is now clear that the requirement for such small variations reflects the ill-determined character of the underlying model and is not a necessary property of the real system.     

Human-mediated Escalation of a Formerly Eradicable Problem: The Invasion of Caribbean Frogs in the Hawaiian Islands

Two species of neotropical frog, Eleutherodactylus coqui and E. planirostris, have been introduced into the State of Hawaii via the horticulture trade. E. coqui was introduced prior to 1988 and E. planirostris was first reported in 1994. Since these dates frog colonies have rapidly spread accidentally and intentionally and frog abundance within colonies has grown rapidly. Although these frogs were originally restricted to horticulture sites, they are now found in residential areas, resorts and hotels, and public lands. Due to the high potential biomass of introduced frogs there are realistic anthropogenic and ecological concerns associated with the spread of these frogs. Though there currently is a tool that can be used for localized control of frogs in limited circumstances, overall efforts by Federal, State, and County agencies to control the frog in Hawaii have been hampered by limited authorities and funds, disbelief in the threat, and the reluctance to act.     

Vascular occlusion in stems of cut rose flowers exposed to air: Role of xylem anatomy and rates of transpiration

Stems of cut rose flowers were exposed to air at 20°C and 60% relative humidity and then placed in water. The rate of water uptake in Frisco, Sonia, Madelon, and Cara Mia roses was maximally inhibited after 72, 36, 24, and 3 h of exposure to air. respectively. Anatomical observations showed no tyloses, gums, or deposition of hydrophobic material in the xylem conduits (tracheids and vessels) of any of the investigated cultivars. Frisco, Sonia, Madelon, and Cara Mia roses showed no difference in the number, the length, the wall thickness, or the diameter of the lumina of either the tracheids or the vessels. This indicates that differences in recovery are not related to capillary diameter or length.
During exposure to air the decrease in transpiration rate, fresh weight, and water potential was the same in Sonia, Madelon, and Cara Mia roses. Upon exposure to air Frisco roses lost less water than the other cultivars studied In Frisco roses stomatal conductance was similar to that of other cultivars, but the rate of cuticular transpiration was lower.
It is concluded that conservation of water through low cuticular transpiration is one of the reasons for the relatively slow development of the vascular occlusion in Frisco roses, but the differences between Sonia. Madelon and Cara Mia roses were not related to their rates of transpiration.     

Microscopic and biochemical evidence of differentially virulent field isolates of Diplocarpon rosae causing black spot disease of roses

Black spot disease caused by Diplocarpon rosae is one of the most widespread diseases of roses that are very difficult to control due to the generative reproduction and complex genetic constitution of roses and up to now the control of black spot still requires intensive use of systemic fungicides. Here we report for the first time evidence of differentially virulent field isolates of D. rosae. Using a combination of fungal structures, disease symptoms and host cells protein expression pattern analysis we here provide direct biochemical evidence that tropical field isolates of D. rosae are more virulent and caused disease symptoms earlier than their temperate counterparts. The tropical fungal field isolates strongly induced an excessive accumulation of ROS and repressed activity of pathogenesis-related proteins such as peroxidases, chitinase and phenylalanine ammonia lyase compared to their temperate counterparts. These findings bring insights into a hidden pathogenic characteristic of tropical D. rosae field isolates compared to their temperate counterparts and open a novel dimension of parameters to be considered when controlling black spot disease of roses by fungicides in tropical versus temperate regions. Interestingly, we found that treatment of rose leaves with ROS (H₂O₂) prior to fungal inoculation promoted plant defense response regardless of the isolate virulence based on protein expression pattern analysis, suggesting that ROS (H₂O₂) can be efficiently incorporated into black spot disease management.     

Role of animal models in cell biology

Mainly because of their easy use, cell culture has been and remains a useful material for cellular biologist. Nevertheless, these cells loose or gain specific properties when they are cultured in vitro. Moreover, they represent only part of tissue and, a fortiori, of organs, so that results obtained in cell culture cannot strictly reflect that exist in more complex conditions. As a consequence, researcher has to use animal models, the question being now the choice of the animal model. In this paper, the main existing models are described and examples were given to illustrate their contribution to cell biology.     

沈阳城市森林常见树种的物候特征

城市绿化树种的物候配置是城市园林的一个重要组成部分。本文以沈阳城市森林常见树种为对象,利用6年的物候观测数据,绘出了28种主要乔灌木的物候谱。分析各物候现象之间关系,将其划分成4大组:萌动展叶现象组、叶变色现象组、落叶现象组和花果现象组;并根据叶变色和开花早晚对其进行聚类分组,为城市森林树种选择、树种组成和效益评价,提供科学依据。     

月季遗传资源的评价与利用

国产蔷薇属植物82种,约占世界总数的41%.在近200种蔷薇属植物中,只有15种参与了现代月季的形成,新的遗传资源的引入是月季抗性育种的关键.现代月季品种达25000多个,但在欧洲苗圃销售的不到3000个,而以丰花月季为主.月季抗病遗传资源的研究主要针对黑斑病、白粉病和根结线虫.分子标记已广泛应用于月季亲缘关系分析、遗传图谱的构建和品种的鉴定.蔷薇果含有丰富的Vc和药用价值.     

Are islands the end of the colonization road?

Ecologists have, up to now, widely regarded colonization of islands from continents as a one-way journey, mainly because of widely accepted assertions that less diverse island communities are easier to invade. However, continents present large targets and island species should be capable of making the reverse journey, considering they are the direct descendants of successful colonists and provided that they have not lost their dispersal abilities. Recent mapping of geography onto molecular phylogenies has revealed several cases of 'reverse colonization' (from islands to continents). We suggest this phenomenon warrants closer attention in ecology and biogeography. Assessing its significance will contribute to understanding the role of dispersal and establishment in biogeographic distributions and the assembly of natural biotas.     

Structure and functions of linker histones

Linker histones such as variants H1, H5, and other similar proteins play an important role in regulation of chromatin structure and dynamics. However, interactions of linker histones with DNA and proteins, as well as specific functions of their different variants, are poorly studied. This is because they acquire tertiary structure only when interacting with a nucleosome, and because of limitations of currently available methods. However, deeper investigation of linker histones and their interactions with other proteins will address a number of important questions — from structure of compacted chromatin to regulation of early embryogenesis. In this review, structures of histone H1 variants and its interaction with chromatin DNA are considered. A possible functional significance of different H1 variants, a role of these proteins in maintaining interphase chromatin structure, and interactions of linker histones with other cellular proteins are also discussed.     

British and European Legislation Regulating Rhabditid Nematodes

Rhabditid nematodes are invertebrates that introduce pathogenic bacteria to the insects and molluscs they parasitise. Marketed as biopesticides, they provide safe and effective alternatives to chemical pesticides in several important sectors of horticulture. In Great Britain, the introduction of non-indigenous species of nematodes is strictly controlled, as is the contained use and deliberate release of genetically modified nematodes and their bacterial symbionts. Currently, indigenous, unmodified nematodes do not have to be registered for use as biopesticides in the UK, but in some other European countries registration is mandatory. The European Commission is seeking to harmonize procedures for the authorization of plant protection products, including rhabditid nematodes, under the provisions of Council Directive 91/414/EEC.     

农杆菌属介导的植物细胞遗传转化研究现状

自20实际70年代末提出农杆菌属介导产生转基因植物以来,已相继有很多农作物和园艺植物被农杆菌成功转化。在一些发达国家已有大量种植的转基因经济作物如玉米、大豆、棉花、马铃薯、番茄等。但越来越多的经济作物以及园林树木和园艺植物对粒子轰击等转化方法无效或效果不佳,因而农杆菌因其介导的遗传转化率较高就越来越受到重视。但是,农杆菌介导的转基因在表达稳定性和可预见性方面仍然存在诸多问题。本文介绍了有关农杆菌分子生物学的基础研究及提高农杆菌介导的遗传转化效率的研究进展。     

Matriliny as daughter-biased investment

From an evolutionary perspective, matriliny presents a puzzle because men in matrilineal societies transmit wealth to their sisters' sons, to whom they are only half as related as to their own sons. It has been argued that such systems would only maximise fitness under unrealistically high levels of paternity uncertainty. In this paper, we propose that matriliny can arise from daughter-biased investment by parents and/or grandparents. We show that daughter-biased investment is adaptive if the marginal benefit of wealth to sons (compared to daughters) does not outweigh the risk of nonpaternity in sons' offspring. We argue that such conditions will be rare where resource-holding polygyny is prevalent but could otherwise be widespread under even moderate levels of paternity uncertainty. The daughter-biased investment model explains two well-known characteristics of matrilineal descent: (a) matriliny's association with high levels of paternity uncertainty and (b) matriliny's ecological correlates, including its association with horticulture, its rarity in pastoralist and agro-pastoralist societies, and the tendency for matriliny to be replaced by son-biased inheritance during economic development. We present data on wealth, sex, and reproductive success (RS) in two African societies, the matrilineal Chewa in Malawi and patrilineal Gabbra in Kenya, which support the daughter-biased investment theory.     

Organisms in evolution

Organisms constitute one of the most remarkable features of our living world. However, they have not yet received any accepted characterization within the framework of the evolutionary theory. The reasons for this contrast between the saliency of organisms in the biological landscape and their theoretical status are multiple and they are analyzed in the first part of this paper. Starting from this contrast, I argue for a theoretically grounded concept of organism within the framework of evolutionary theory itself. To this effect I argue that the theory of major transitions in evolution (Maynard Smith and Szathmáry 1995; Michod 1999) provides us with the theoretical basis for an understanding of the individuality of organisms and I propose a first characterization of organisms as evolutionary units structured by a division of reproductive labor among their parts. I also discuss one of the most important implications of this definition, namely that some colonial entities are to be counted as superorganisms. Finally, I show that though theoretically satisfying, this definition does not suffice in order fully to individuate the organisms and superorganisms in practice. To this end, physiology is needed, because it offers us some criteria for their individuation in ecological space. These criteria, however, are not immune to errors through misidentification and their shortcomings are discussed in the last section. In conclusion, I emphasize the positive implications of these criteria concerning the ecological significance of organisms.     

The evolution of class 1 integrons and the rise of antibiotic resistance

Class 1 integrons are central players in the worldwide problem of antibiotic resistance, because they can capture and express diverse resistance genes. In addition, they are often embedded in promiscuous plasmids and transposons, facilitating their lateral transfer into a wide range of pathogens. Understanding the origin of these elements is important for the practical control of antibiotic resistance and for exploring how lateral gene transfer can seriously impact on, and be impacted by, human activities. We now show that class 1 integrons can be found on the chromosomes of nonpathogenic soil and freshwater Betaproteobacteria. Here they exhibit structural and sequence diversity, an absence of antibiotic resistance genes, and a phylogenetic signature of lateral transfer. Some examples are almost identical to the core of the class 1 integrons now found in pathogens, leading us to conclude that environmental Betaproteobacteria were the original source of these genetic elements. Because these elements appear to be readily mobilized, their lateral transfer into human commensals and pathogens was inevitable, especially given that Betaproteobacteria carrying class 1 integrons are common in natural environments that intersect with the human food chain. The strong selection pressure imposed by the human use of antimicrobial compounds then ensured their fixation and global spread into new species.