Diversity, systematics and biogeography of French Polynesian Lobophora (Dictyotales, Phaeophyceae)

We re-evaluated the diversity of Lobophora using an integrative taxonomic approach based on a broad sampling across French Polynesian archipelagos. Our results show that French Polynesia supports at least 37 Lobophora species of which ~57% (21) are endemic. This level of endemicity is comparable to that presently known in the Caribbean and the western Indian Ocean, while French Polynesian coastlines cover a much smaller length. With a third of the species in common, French Polynesia shares considerable biogeographic affinities with the Melanesian Islands, situated over 4000 km to the west. Distribution ranges of a few species reach the western Indian Ocean, and two species also occur in the Atlantic. We hypothesize that Lobophora species in French Polynesia have mainly evolved into endemic species from colonizers originating from the Central Indo-Pacific. These rare dispersal events to ocean archipelagos followed by a long period of isolation and speciation represent an important process responsible for the high level of endemism in remote archipelagos. While south-eastern Pacific Islands could be considered an ‘evolutionary graveyard’ for the genus Lobophora as little local radiation occurred, this may simply be due to recent evolutionary history. Based on these new data, the diversity of Lobophora represents ~10% of French Polynesian seaweed diversity. Eighteen new species of Lobophora are here described from French Polynesia

Combining local resources and mobile telephony to increase resort to care and reduce child mortality in Mali

In Mali, 1 child out of 6 does not reach the age of five. Most of these deaths could be avoided: children die mostly from untreated benign pathologies that could be easily cured locally. Though medical treatments are available in the local primary health centers, people resort too little and too late to healthcare, for cultural, financial and geographical reasons. Pesinet deploys an innovative health service that aims to drive prevention, detection and early-treatment of benign diseases. Agents make regular home visits to subscribed families in order to monitor the health of their children. They enter simple health data into a mobile phone and send it to the nearest medical center where the doctor reviews it and summons children at risk. This ongoing health monitoring system is combined with medical insurance at the local healthcare center. For a very affordable monthly fee, subscribing families benefit from the home visits, reductions on check-ups and medications, and education to prevention. This service is currently in operation in the city center of Bamako, and will be adapted for application in rural zones. Pesinet focuses on recourse to care by populations rather than on supply of new medical resources. By helping under-used primary health centers connect with populations, its objective is to generate a cultural change in the behaviors of populations and give health centers the capacity to improve the quality of the health services they offer. This paper intends to explain how this demand-driven approach could contribute to driving a sustainable change in the healthcare situation of Mali, and presents the promising results in terms of increase in resort to healthcare and local acceptability already encountered by the program

First Characterisation of Volatile Organic Compounds Emitted by Banana Plants

Banana (Musa sp.) ranks fourth in term of worldwide fruit production, and has economical and nutritional key values. The Cavendish cultivars correspond to more than 90% of the production of dessert banana while cooking cultivars are widely consumed locally around the banana belt production area. Many plants, if not all, produce Volatile Organic Compounds (VOCs) as a means of communication with their environment. Although flower and fruit VOCs have been studied for banana, the VOCs produced by the plant have never been identified despite their importance in plant health and development. A volatile collection methodology was optimized to improve the sensitivity and reproducibility of VOCs analysis from banana plants. We have identified 11 VOCs for the Cavendish, mainly (E,E)-α-farnesene (87.90 ± 11.28 ng/μl), methyl salicylate (33.82 ± 14.29) and 6-methyl-5-hepten-2-one (29.60 ± 11.66), and 14 VOCs for the Pacific Plantain cultivar, mainly (Z,E)-α-farnesene (799.64 ± 503.15), (E,E)-α-farnesene (571.24 ± 381.70) and (E) β ocimene (241.76 ± 158.49). This exploratory study paves the way for an in-depth characterisation of VOCs emitted by Musa plants

Studying Whole-Genome Duplication Using Experimental Evolution of Chlamydomonas

In this chapter, we present the use of Chlamydomonas reinhardtii in experiments designed to study the evolutionary impacts of whole genome duplication. We shortly introduce the algal species and depict why it is an excellent model for experimental evolution. Subsequently, we discuss the most relevant steps and methods in the design of a ploidy-related Chlamydomonas experiment. These steps include strain selection, ploidy determination, different methods of making diplo- and polyploid Chlamydomonas cells, replication, culturing conditions, preservation, and the ways to quantify phenotypic and genotypic change

Marine flora of French Polynesia: an updated list using DNA barcoding and traditional approaches

Located in the heart of the South Pacific Ocean, the French Polynesian islands represent a remarkable setting for biological colonization and diversification, because of their isolation. Our knowledge of this region’s biodiversity is nevertheless still incomplete for many groups of organisms. In the late 1990s and 2000s, a series of publications provided the first checklists of French Polynesian marine algae, including the Chlorophyta, Rhodophyta, Ochrophyta, and Cyanobacteria, established mostly on traditional morphology-based taxonomy. We initiated a project to systematically DNA barcode the marine flora of French Polynesia. Based on a large collection of ~2452 specimens, made between 2014 and 2023, across the five French Polynesian archipelagos, we re-assessed the marine floral species diversity (Alismatales, Cyanobacteria, Rhodophyta, Ochrophyta, Chlorophyta) using DNA barcoding in concert with morphology-based classification. We provide here a major revision of French Polynesian marine flora, with an updated listing of 702 species including 119 Chlorophyta, 169 Cyanobacteria, 92 Ochrophyta, 320 Rhodophyta, and 2 seagrass species—nearly a two-fold increase from previous estimates. This study significantly improves our knowledge of French Polynesian marine diversity and provides a valuable DNA barcode reference library for identification purposes and future taxonomic and conservation studies. A significant part of the diversity uncovered from French Polynesia corresponds to unidentified lineages, which will require careful future taxonomic investigation

Diversity, systematics and biogeography of French Polynesian Lobophora (Dictyotales, Phaeophyceae)

We re-evaluated the diversity of Lobophora using an integrative taxonomic approach based on a broad sampling across French Polynesian archipelagos. Our results show that French Polynesia supports at least 37 Lobophora species of which similar to 57% (21) are endemic. This level of endemicity is comparable to that presently known in the Caribbean and the western Indian Ocean, while French Polynesian coastlines cover a much smaller length. With a third of the species in common, French Polynesia shares considerable biogeographic affmities with the Melanesian Islands, situated over 4000 km to the west. Distribution ranges of a few species reach the western Indian Ocean, and two species also occur in the Atlantic. We hypothesize that Lobophora species in French Polynesia have mainly evolved into endemic species from colonizers originating from the Central Indo-Pacific. These rare dispersal events to ocean archipelagos followed by a long period of isolation and speciation represent an important process responsible for the high level of endemism in remote archipelagos. While south-eastern Pacific Islands could be considered an 'evolutionary graveyard' for the genus Lobophora as little local radiation occurred, this may simply be due to recent evolutionary history. Based on these new data, the diversity of Lobophora represents similar to 10% of French Polynesian seaweed diversity. Eighteen new species of Lobophora are here described from French Polynesia

Marine macroalgal biodiversity of northern Madagascar: morpho-genetic systematics and implications of anthropic impacts for conservation

A floristic survey of the marine algal biodiversity of Antsiranana Bay, northern Madagascar, was conducted in November 2018. This represents the first inventory encompassing the three major macroalgal classes (Phaeophyceae, Floridophyceae and Ulvophyceae) for the little-known Malagasy marine flora. Combining morphological and DNA-based approaches, we report from our collection a total of 110 species from northern Madagascar, including 30 species of Phaeophyceae, 50 Floridophyceae and 30 Ulvophyceae. Barcoding of rbcL was used for the three algal classes, in addition to tufA for the Ulvophyceae. This study significantly increases our knowledge of the Madagascar marine biodiversity while augmenting the rbcL and tufA algal reference libraries for DNA barcoding. A total of 72 new species records are made for Madagascar. Combining our own data with the literature, we also provide an updated catalogue of 450 taxa of marine benthic macroalgae from Madagascar, comprising 88 Phaeophyceae, 1 Compsopogonophyceae, 244 Floridophyceae and 117 Ulvophyceae. This diversity holds 32 (c. 7%) endemic species to Madagascar. Our results are discussed in the context of increasing threats to biodiversity on Madagascar’s coastal reefs from both anthropic and anthropogenic activities including sewage effluent runoffs and unsustainable agricultural practices such as massive deforestation, leading to ecosystem shifts to algal dominance on reefs, which are recommended to be addressed through integrated land-sea management in a Reef-to-Ridge conservation approach.

Cold/menthol TRPM8 receptors initiate the cold-shock response and protect germ cells from cold-shock-induced oxidation

International audienceTestes of most male mammals present the particularity of being externalized from the body and are consequently slightly cooler than core body temperature (4-8°C below). Although, hypothermia of the testis is known to increase germ cells apoptosis, little is known about the underlying molecular mechanisms, including cold sensors, transduction pathways, and apoptosis triggers. In this study, using a functional knockout mouse model of the cold and menthol receptors, dubbed transient receptor potential melastatine 8 (TRPM8) channels, we found that TRPM8 initiated the cold-shock response by differentially modulating cold- and heat-shock proteins. Besides, apoptosis of germ cells increased in proportion to the cooling level in control mice but was independent of temperature in knockout mice. We also observed that the rate of germ cell death correlated positively with the reactive oxygen species level and negatively with the expression of the detoxifying enzymes. This result suggests that the TRPM8 sensor is a key determinant of germ cell fate under hypothermic stimulation.-Borowiec, A.-S., Sion, B., Chalmel, F., Rolland, A. D., Lemonnier, L., De Clerck, T., Bokhobza, A., Derouiche, S., Dewailly, E., Slomianny, C., Mauduit, C., Benahmed, M., Roudbaraki, M., Jégou, B., Prevarskaya, N., Bidaux, G. Cold/menthol TRPM8 receptors initiate the cold-shock response and protect germ cells from cold-shock-induced oxidation