Foundation characteristics of edible Musa triploids revealed from allelic distribution of SSR markers

Background and Aims The production of triploid banana and plantain (Musa spp.) cultivars with improved characteristics (e.g. greater disease resistance or higher yield), while still preserving the main features of current popular cultivars (e.g. taste and cooking quality), remains a major challenge for Musa breeders. In this regard, breeders require a sound knowledge of the lineage of the current sterile triploid cultivars, to select diploid parents that are able to transmit desirable traits, together with a breeding strategy ensuring final triploidization and sterility. Highly polymorphic single sequence repeats (SSRs) are valuable markers for investigating phylogenetic relationships. Methods Here, the allelic distribution of each of 22 SSR loci across 561 Musa accessions is analysed. Key Results and ConclusionsWe determine the closest diploid progenitors of the triploid 'Cavendish' and 'Gros Michel' subgroups, valuable information for breeding programmes. Nevertheless, in establishing the likely monoclonal origin of the main edible triploid banana subgroups (i.e. 'Cavendish', 'Plantain' and 'Mutika- Lujugira'), we postulated that the huge phenotypic diversity observed within these subgroups did not result from gamete recombination, but rather from epigenetic regulations. This emphasizes the need to investigate the regulatory mechanisms of genome expression on a unique model in the plant kingdom. We also propose experimental standards to compare additional and independent genotyping data for reference. (Résumé d'auteur

Analyse multiéchelle de la diversité génétique des sorghos : compréhension des processus évolutifs pour la conservation in situ = Multi-scale analysis of sorghum genetic diversity : understanding the evolutionary processes for in situ conservation

Using microsatellite genetic markers, we analyzed 1,518 sorghum samples collected at different spatial scales in Burkina Faso, Mali, Niger, and in the village of Wante, from the landrace to the country scale. Genetic diversity and differentiation parameters were estimated to assess the effects of the main evolutionary processes on sorghum genetic diversity. The genetic variability found within a variety is mainly the result of the sorghum reproduction biology and the genetic drift process caused by the limited number of reproductive individuals at the time of variety introduction into a household or each year when farmers select their seeds. At the village scale, a low correlation is observed between the diversity of vernacular names and the genetic diversity assessed by microsatellites. No spatial genetic structuration is observed among villages more than 30 kilometers apart. This point highlightss that traditional seed systems operate at a very local scale. in Mali, a similar proportion of allelic richness is observed along a longitudinal transect and a latitudinal gradient that crosses a larger range of agroclimatic conditions. At the country scale, sorghum exhibits more genetic diversity in Niger than in Mali despite a lower agroclimatic range in Niger. These results demonstrate that the diversity of human groups acts together with the agro-ecological factors to shape the structure of sorghum genetic diversity. An important proportion of the overall genetic diversity present in the Cirad (Centre de cooperation internationale en recherche agronomique pour le developpement) "core collection" is found in Mali and Niger. The tremendous diversity cultivated by farmers in traditional agroecosystems of Western Africa supports the relevance of in situ approaches for sorghum conservation programs in this region. Both conservation and crop improvement requirements can be achieved through a better use of local germplasm in decentralized breeding programs

Fingerprinting data musa accessions with SSR

561 accessions fingerprinted at CIRAD with 22 SSRs

The ALP-Enigma Protein ALP-1 Functions in Actin Filament Organization to Promote Muscle Structural Integrity in Caenorhabditis elegans

Mutations that affect the Z-disk–associated ALP-Enigma proteins have been linked to human muscular and cardiac diseases. Despite their clear physiological significance for human health, the mechanism of action of ALP-Enigma proteins is largely unknown. In Caenorhabditis elegans, the ALP-Enigma protein family is encoded by a single gene, alp-1; thus C. elegans provides an excellent model to study ALP-Enigma function. Here we present a molecular and genetic analysis of ALP-Enigma function in C. elegans. We show that ALP-1 and α-actinin colocalize at dense bodies where actin filaments are anchored and that the proper localization of ALP-1 at dense bodies is dependent on α-actinin. Our analysis of alp-1 mutants demonstrates that ALP-1 functions to maintain actin filament organization and participates in muscle stabilization during contraction. Reducing α-actinin activity enhances the actin filament phenotype of the alp-1 mutants, suggesting that ALP-1 and α-actinin function in the same cellular process. Like α-actinin, alp-1 also interacts genetically with a connectin/titin family member, ketn-1, to provide mechanical stability for supporting body wall muscle contraction. Taken together, our data demonstrate that ALP-1 and α-actinin function together to stabilize actin filaments and promote muscle structural integrity

Removal of Trace Organic Chemicals and Performance of a Novel Hybrid Ultrafiltration-Osmotic Membrane Bioreactor

A hybrid ultrafiltration-osmotic membrane bioreactor (UFO-MBR) was investigated for over 35 days for nutrient and trace organic chemical (TOrC) removal from municipal wastewater. The UFO-MBR system uses both ultrafiltration (UF) and forward osmosis (FO) membranes in parallel to simultaneously extract clean water from an activated sludge reactor for nonpotable (or environmental discharge) and potable reuse, respectively. In the FO stream, water is drawn by osmosis from activated sludge through an FO membrane into a draw solution (DS), which becomes diluted during the process. A reverse osmosis (RO) system is then used to reconcentrate the diluted DS and produce clean water suitable for direct potable reuse. The UF membrane extracts water, dissolved salts, and some nutrients from the system to prevent their accumulation in the activated sludge of the osmotic MBR. The UF permeate can be used for nonpotable reuse purposes (e.g., irrigation and toilet flushing). Results from UFO-MBR investigation illustrated that the chemical oxygen demand, total nitrogen, and total phosphorus removals were greater than 99%, 82%, and 99%, respectively. Twenty TOrCs were detected in the municipal wastewater that was used as feed to the UFO-MBR system. Among these 20 TOrCs, 15 were removed by the hybrid UFO-MBR system to below the detection limit. High FO membrane rejection was observed for all ionic and nonionic hydrophilic TOrCs and lower rejection was observed for nonionic hydrophobic TOrCs. With the exceptions of bisphenol A and DEET, all TOrCs that were detected in the DS were well rejected by the RO membrane. Overall, the UFO-MBR can operate sustainably and has the potential to be utilized for direct potable reuse applications

Archaeometry and materiality: materials based analysis in theory and practice

Due to the diversity of contemporary archaeology, the aims and approaches of archaeological scientists and archaeological theorists are often at odds. I suggest that this position is problematic, both intellectually and methodologically, as both groups are fundamentally engaged in the same task: an understanding of past societies through the medium of material culture. This paper offers a review of the intellectual positions of both groups, with a brief discussion of the history of archaeological theory and an appraisal of its current trajectory. I will discuss how and why contemporary theoretical perspectives have fundamentally diverged from the perspectives of archaeological scientists and how the recent theoretical emphasis upon materiality offers a rapprochement between theoreticians and archaeological scientists