Beauty will save the world,but will the world save beauty? The case of the highly endangered Vavilovia formosa (Stev.) Fed.

Main conclusion

Vavilovia formosa (Stev.) Fed. is a scientifically valuable common ancestor of the plant tribe Fabeae and also important in breeding and agronomy studies of the cultivated Fabeae, but it is close to extinction. A concerted academic and geovernmental effort is needed to save it.

Abstract

Since 2007, an informal international group of researchers on legumes has been working to increase awareness of Vavilovia formosa (Stev.) Fed., a relict and endangered wild-land relative to crop plant species. A majority of the modern botanical classifications place it within the tribe Fabeae, together with the genera vetchling (Lathyrus L.), lentil (Lens Mill.), pea (Pisum L.) and vetch (Vicia L.). V. formosa is encountered at altitudes from 1,500 m up to 3,500 m in Armenia, Azerbaijan, Georgia, Iran, Iraq, Lebanon, Russia, Syria and Turkey. This species may be of extraordinary importance for broadening current scientific knowledge on legume evolution and taxonomy because of its proximity to the hypothetical common ancestor of the tribe Fabeae, as well as for breeding and agronomy of the cultivated Fabeae species due to its perenniality and stress resistance. All this may be feasible only if a concerted and long-term conservation strategy is established and carried out by both academic and geovernmental authorities. The existing populations of V. formosa are in serious danger of extinction. The main threats are domestic and wild animal grazing, foraging, and early frosts in late summer. A long-term strategy to save V. formosa from extinction and to sustain its use in both basic and applied research comprises much improved in situ preservation, greater efforts for an ex situ conservation, and novel approaches of in vitro propagation.     

Is the endangered Apium repens (Jacq.) Lag. rare because of a narrow regeneration niche?

The conservation of rare plant species is an important aspect of global biodiversity protection, but in many cases these species and the reasons why they are rare are poorly understood. The perennial umbellifer Apium repens is generally regarded to be a rare species all over its European range. We hypothesized that its rarity might be caused by a restricted regeneration niche, that is, highly specific requirements for sexual regeneration, low seed dispersal potential and low endurance capacity of seeds in the ground. We conducted several experimental investigations on its germination ecology, hydrochorous dispersal potential and soil seed bank properties. Apium repens showed high germination success under a variety of abiotic conditions. Either light or cold-wet stratification was necessary to stimulate germination. Seeds were able to float for more than 50 days when protected from precipitation, and soil seed bank sampling revealed that at least some seeds of A. repens were contained in soil depths of up to 10 cm. Overall, our findings do not support the hypothesis that the rarity of A. repens is caused by highly specific requirements for its sexual regeneration. Nonetheless, its germination ecology should be considered when designing conservation measures for this endangered species.     

Should ecomorphs be conserved? The case of Nostoc flagelliforme,an endangered extremophile cyanobacteria

Nostoc flagelliforme has been reported from deserts of all continents and more recently from semiarid environments in south-east Spain and Australia. Its cylindrical thalli are very conspicuous on soils after rains and can be easily differentiated from other taxa and it is considered endangered in some countries, e. g. China. It was firstly described as variety flagelliforme of Nostoc commune but later was considered a separate species. The morphology, fine structure and ecology of populations of both taxa from Australia and different regions of Spain were studied and 16S rRNA and trnL^Leu (UAA) genes were sequenced to identify their intraspecific genetic variation. The morphological study revealed the presence of several intermediate morphs, from spheres and sheets to ribbons followed by the cylindrical thalli and the overlapping of cell dimensions, permitting the differentiation of cylindrical morphs from the others. The molecular data did not allow for a distinction between N. commune and N. flagelliforme which is clearly polyphyletic and both show a high genetic diversity. The presence of cylindrical thalli seems to be related to extreme conditions of aridity, usually on soils but occasionally on rock walls. The ecotype that N. flagelliforme represents deserves to be protected for itself and for the evolutionary process it represents opening up the possibility of implementation of recovery measures and even opportunities to explore its biotechnological production from a different point of view.     

Mate limitation in populations of the endangered Convolvulus lineatus L.: A case for genetic rescue?

In self-incompatible clonal plants, the spread of individual plants can exacerbate mate limitation to the point that it becomes a serious constraint on long-term population persistence, especially in small, isolated populations. In such species, it may be necessary to introduce new genetic material from other populations to restore seed production, a strategy termed “genetic rescue”. In this study we assess the potential pertinence of such genetic rescue in the clonal perennial plant Convolvulus lineatus L., whose populations are often highly reduced in spatial extent and are currently being fragmented by land development projects in Mediterranean France. To do so, we quantify fruit production in a range of populations of different size over four years and perform a series of hand-pollination experiments in natural populations to assess whether fruit set is limited by mate availability. We found that C. lineatus is a self-incompatible species that shows extremely low values of fruit set in natural populations and that a principal cause of this low fruit set is a lack of compatible pollen. This may be primarily due to clonal spread that causes individual populations to be comprised of patches containing one or very few incompatibility types. In small populations fragmented by human activities and which show an absence of fruit production, we thus argue that genetic rescue represents a promising conservation management strategy to avoid inevitable long-term future population decline. We discuss how best to introduce new genetic material into the study populations.     

Cutaneous photobiology. The melanocyte vs. the sun: who will win the final round?

Solar ultraviolet radiation (UV) is a major environmental factor that dramatically alters the homeostasis of the skin as an organ by affecting the survival, proliferation and differentiation of various cutaneous cell types. The effects of UV on the skin include direct damage to DNA, apoptosis, growth arrest, and stimulation of melanogenesis. Long-term effects of UV include photoaging and photocarcinogenesis. Epidermal melanocytes synthesize two main types of melanin: eumelanin and pheomelanin. Melanin, particularly eumelanin, represents the major photoprotective mechanism in the skin. Melanin limits the extent of UV penetration through the epidermal layers, and scavenges reactive oxygen radicals that may lead to oxidative DNA damage. The extent of UV-induced DNA damage and the incidence of skin cancer are inversely correlated with total melanin content of the skin. Given the importance of the melanocyte in guarding against the adverse effects of UV and the fact that the melanocyte has a low self-renewal capacity, it is critical to maintain its survival and genomic integrity in order to prevent malignant transformation to melanoma, the most fatal form of skin cancer. Melanocyte transformation to melanoma involves the activation of certain oncogenes and the inactivation of specific tumor suppressor genes. This review summarizes the current state of knowledge about the role of melanin and the melanocyte in photoprotection, the responses of melanocytes to UV, the signaling pathways that mediate the biological effects of UV on melanocytes, and the most common genetic alterations that lead to melanoma.     

The ethics of functional genomics: same, same, but different?

Respect for human life--a notion of worth uniting all members of the human race--constitutes a sense of anthropocentrism that has long been the justification for the enrollment of animals in experimentation executed to develop therapies to alleviate human suffering. Currently, however, advances in functional genomics are causing a qualitative transformation of the rationale for medical research performed on animals. The notion of human distinctness is being fundamentally challenged when gene sequences similar to those found in humans are identified in different species. In this Opinion article, we would like to highlight an inherent tension brought about by the current developments in functional genomics: a tension between the scientific and the ethical status of gene sequences. Is it reasonable to argue that they are the same for all practical purposes but different in ethical status?     

The Harvard case of Xu Xiping: exploitation of the people, scientific advance, or genetic theft?

A unique history and make-up of a population may make it an attractive research target for population geneticists and pharmaco-genomic investors. The promise of pharmaceutical profits and advances in medical knowledge attracted Harvard researchers and the company Millennium Pharmaceuticals to remote areas in Anhui Province, Central China, leading to international diplomatic disagreements about issues such as the ownership of genetic material and informed consent (IC). This article discusses the role of genomics and genetic sampling in China, the way it is related to population policies (the new eugenics), the national importance of genetic materials and the conflicts it led to between the Chinese government and Harvard University. Here many consider the Xu Xiping case as textbook example of ruthless Western exploitation of development countries, illustrating the cold rationality of science in the process of globalisation. Ten perspectives on this case show that this view is simplistic and contributes little to an understanding of bioethical issues important to the population actually donating the samples. Viewing the Xu Xiping case as the nexus of the intertwinement of international, transnational, national, and local interest groups shows how different interest groups make use of different units of analysis. It also clarifies why the same practice of genetic sampling continues under a different regime, and why the discussion about genetic sampling has shifted from a concern with health care of the poor to an issue of international exploitation, terrorism and development.     

Invasive species are less parasitized than native competitors, but for how long? The case of the round goby in the Great Lakes-St. Lawrence Basin

There is increasing evidence that parasitism represents an unpredictable dimension of the ecological impacts of biological invasions. In addition to the risk of exotic pathogen transmission, other mechanisms such as parasite-release, could contribute to shaping the relationship between introduced species and native communities. In this study, we used the Eurasian round goby (Neogobius menalostomus) in the Great Lakes-St. Lawrence River ecosystem to further explore these ideas. As predicted by the parasite-release hypothesis, recently established populations of round goby were parasitized by a depauperate community of generalist helminths (8 taxa), all commonly found in the St. Lawrence River. In comparison, two native species, the logperch (Percina caprodes) and spottail shiner (Notropis hudsonius), were the hosts of 25 and 24 taxa respectively. Round gobies from each of 3 sampled localities were also less heavily infected than both indigenous species. This is in contrast to what is observed in round goby’s native range where the species is often the most parasitized among gobid competitors. This relative difference in parasite pressure could enhance its competitiveness in the introduced range. However, our study of an older population of round goby in Lake St. Clair suggests that this advantage over native species could be of short duration. Within 15 years, the parasite abundance and richness in the round goby has more than doubled whereas the number of parasite species per fish has increased to levels of those typical of fish indigenous to the St. Lawrence-Great Lakes watershed.     

The right time,the right place: will targeting human cancer-associated mutations to the mouse provide the perfect preclinical model?

Over the past 10 years the realisation that genetic mouse models of cancer may play a key role in preclinical drug development has gained strong momentum. Moreover sequencing studies of human tumours have provided key insights into the mutational complexity of epithelial cancer, unleashing important clues for researchers to generate accurate genetically engineered mouse (GEM) models of cancer. Thus by targeting multiple cancer associated human mutations to the appropriate murine epithelia, mice develop tumours that more closely recapitulate the human disease. As a number of excellent models now exist, the next 5-10 years will ascertain whether these models will predict response of human cancer to intervention. If so they might become the 'gold standard' where all drugs are required to be tested in mouse models of disease before proceeding into the patient. However, although this principle is very attractive, it is relatively untested and here, using examples of prevalent human cancers, we will review the latest data on preclinical GEM studies and comment on what challenges are left to overcome.     

Chagas disease: from bush to huts and houses. Is it the case of the Brazilian Amazon?

Two of the major problems facing the Amazon - human migration from the other areas and uncontrolled deforestation - constitute the greatest risk for the establishment of endemic Chagas disease in this part of Brazil. At least 18 species of triatomines had been found in the Brazilian Amazon, 10 of them infected with Trypanosoma cruzi, associated with numerous wild reservoirs. With wide-range deforestation, wild animals will perforce be driven into other areas, with tendency for triatomines to become adapted to alternative food sources in peri and intradomicilies. Serological surveys and cross-sectional studies for Chagas disease, carried out in rural areas of the Rio Negro, in the Brazilian Amazon, showed a high level of seropositivity for T. cruzi antibodies. A strong correlation of seroreactivity with the contact of gatherers of pia?ava fibers with wild triatomines could be evidenced.     

Are the patterns of regeneration in the endangered Eucalyptus gunnii ssp. divaricata shifting in response to climate?

Increasing drought frequency is a major driver of changes in forest structure and has been implicated in the decline of the endangered tree species, Eucalyptus gunnii ssp. divaricata (McAulay & Brett) in the Central Plateau region of Tasmania, Australia. In this study, we examined patterns of regeneration, aspects of the water relations of E. gunnii ssp. divaricata and its replacement Eucalyptus pauciflora and, whether shifts in stand dominance have occurred where the subspecies co‐occurs with E. pauciflora could be related to recent changes in climate. Successful E. gunnii ssp. divaricata seedling regeneration was restricted to micro‐sites with relatively deep soils within slight depressions. In contrast, poor E. gunnii ssp. divaricata regeneration and declining adult cohorts of this species all occurred on steeper, concave micro‐sites with shallow soils. This apparent shift in suitable regeneration micro‐site, from sites with shallow to deeper soils, may be linked to an observed 25% reduction in summer rainfall over the last 50 years. On slopes surrounding waterlogged depressions where E. gunnii ssp. divaricata co‐occurs with E. pauciflora, E. pauciflora was in higher abundance than E. gunnii ssp. divaricata in small adult and sapling size‐classes, compared with the adult cohorts (>30 cm d.b.h.), a trend consistent with a shift in stand dominance. Despite existing paradigms related to differential drought tolerance between these two species as a driver of this shift in stand dominance, there were no differences in predawn (Ψ_pd) water potentials between species. Furthermore, pressure–volume analysis showed that E. gunnii ssp. divaricata had lower values for osmotic potential at turgor loss point (?2.33 ± 0.06 MPa) than E. pauciflora (?2.13 ± 0.03 MPa), suggesting that E. gunnii ssp. divaricata may be more drought tolerant than E. pauciflora, in contrast to the prevailing paradigm that it is more susceptible to drought than E. pauciflora.     

The influence of native populations’ genetic history on the reconstruction of invasion routes: the case of a highly invasive aquatic species

Biological Invasions - Insufficient data on the origins of the first introduced propagule and the initial stages of invasion complicate the reconstruction of a species’ invasion history....     

Plant–pathogen interactions: will the understanding of common mechanisms lead to the unification of concepts?

Plant-pathogen interactions are still classically described using concepts that make a distinction between qualitative and quantitative aspects linked to these concepts. This article first describes these aspects, using the terminology associated with them. It then presents some recent experimental observations that demonstrate that such concepts share either common or closely related mechanisms at the cellular and molecular levels. The emergence of a more global vision and understanding of the interactions between plants and their parasites is discussed.