Comparative genomics of Mycoplasma feriruminatoris, a fast-growing pathogen of wild Caprinae.

Mycoplasma feriruminatoris is a fast-growing Mycoplasma species isolated from wild Caprinae and first described in 2013. M. feriruminatoris isolates have been associated with arthritis, kerato conjunctivitis, pneumonia and septicemia, but were also recovered from apparently healthy animals. To better understand what defines this species, we performed a genomic survey on 14 strains collected from free-ranging or zoo-housed animals between 1987 and 2017, mostly in Europe. The average chromosome size of the M. feriruminatoris strains was 1,040±0,024 kbp, with 24 % G+C and 852±31 CDS. The core genome and pan-genome of the M. feriruminatoris species contained 628 and 1312 protein families, respectively. The M. feriruminatoris strains displayed a relatively closed pan-genome, with many features and putative virulence factors shared with species from the M. mycoides cluster, including the MIB-MIP Ig cleavage system, a repertoire of DUF285 surface proteins and a complete biosynthetic pathway for galactan. M. feriruminatoris genomes were found to be mostly syntenic, although repertoires of mobile genetic elements, including Mycoplasma Integrative and Conjugative Elements, insertion sequences, and a single plasmid varied. Phylogenetic- and gene content analyses confirmed that M. feriruminatoris was closer to the M. mycoides cluster than to the ruminant species M. yeatsii and M. putrefaciens. Ancestral genome reconstruction showed that the emergence of the M. feriruminatoris species was associated with the gain of 17 gene families, some of which encode defence enzymes and surface proteins, and the loss of 25 others, some of which are involved in sugar transport and metabolism. This comparative study suggests that the M. mycoides cluster could be extended to include M. feriruminatoris. We also find evidence that the specific organization and structure of the DnaA boxes around the oriC of M. feriruminatoris may contribute to drive the remarkable fast growth of this minimal bacterium

Appl Environ Microbiol

Understanding the mechanisms behind the typicity of regional wines inevitably brings attention to microorganisms associated with their production. Oenococcus oeni is the main bacterial species involved in wine and cider making. It develops after the yeast-driven alcoholic fermentation and performs the malolactic fermentation, which improves the taste and aromatic complexity of most wines. Here, we have evaluated the diversity and specificity of O. oeni strains in six regions. A total of 235 wines and ciders were collected during spontaneous malolactic fermentations and used to isolate 3,212 bacterial colonies. They were typed by multilocus variable analysis, which disclosed a total of 514 O. oeni strains. Their phylogenetic relationships were evaluated by a second typing method based on single nucleotide polymorphism (SNP) analysis. Taken together, the results indicate that each region holds a high diversity of strains that constitute a unique population. However, strains present in each region belong to diverse phylogenetic groups, and the same groups can be detected in different regions, indicating that strains are not genetically adapted to regions. In contrast, greater strain identity was seen for cider, white wine, or red wine of Burgundy, suggesting that genetic adaptation to these products occurred. This study reports the isolation, genotyping, and geographic distribution analysis of the largest collection of O. oeni strains performed to date. It reveals that there is very high diversity of strains in each region, the majority of them being detected in a single region. The study also reports the development of an SNP genotyping method that is useful for analyzing the distribution of O. oeni phylogroups. The results show that strains are not genetically adapted to regions but to specific types of wines. They reveal new phylogroups of strains, particularly two phylogroups associated with white wines and red wines of Burgundy. Taken together, the results shed light on the diversity and specificity of wild strains of O. oeni, which is crucial for understanding their real contribution to the unique properties of wines.Multi-strain indigenous Yeast and Bacterial starters for ‘Wild-ferment’ Wine productio

High-quality SNPs from genic regions highlight introgression patterns among European white oaks (Quercus petraea and Q. robur)

International audienceIn the post-genomics era, non-model species like most Fagaceae still lack operational diversity resources for population genomics studies. Sequence data were produced from over 800 gene fragments covering ~530 kb across the genic partition of European oaks, in a discovery panel of 25 individuals from western and central Europe (11 Quercus petraea, 13 Q. robur, one Q. ilex as an outgroup). Regions targeted represented broad functional categories potentially involved in species ecological preferences, and a random set of genes. Using a high-quality dedicated pipeline, we provide a detailed characterization of these genic regions, which included over 14500 polymorphisms, with ~12500 SNPs −218 being triallelic-, over 1500 insertion-deletions, and ~200 novel di- and tri-nucleotide SSR loci. This catalog also provides various summary statistics within and among species, gene ontology information, and standard formats to assist loci choice for genotyping projects. The distribution of nucleotide diversity (θπ) and differentiation (FST) across genic regions are also described for the first time in those species, with a mean n θπ close to ~0.0049 in Q. petraea and to ~0.0045 in Q. robur across random regions, and a mean FST ~0.13 across SNPs. The magnitude of diversity across genes is within the range estimated for long-term perennial outcrossers, and can be considered relatively high in the plant kingdom, with an estimate across the genome of 41 to 51 million SNPs expected in both species. Individuals with typical species morphology were more easily assigned to their corresponding genetic cluster for Q. robur than for Q. petraea, revealing higher or more recent introgression in Q. petraea and a stronger species integration in Q. robur in this particular discovery panel. We also observed robust patterns of a slightly but significantly higher diversity in Q. petraea, across a random gene set and in the abiotic stress functional category, and a heterogeneous landscape of both diversity and differentiation. To explain these patterns, we discuss an alternative and non-exclusive hypothesis of stronger selective constraints in Q. robur, the most pioneering species in oak forest stand dynamics, additionally to the recognized and documented introgression history in both species despite their strong reproductive barriers. The quality of the data provided here and their representativity in terms of species genomic diversity make them useful for possible applications in medium-scale landscape and molecular ecology projects. Moreover, they can serve as reference resources for validation purposes in larger-scale resequencing projects. This type of project is preferentially recommended in oaks in contrast to SNP array development, given the large nucleotide variation and the low levels of linkage disequilibrium revealed

Prédiction de la qualité des bois de chêne pour l’élevage des vins et des alcools : comparaison des approches physicochimiques, sensorielles et moléculaires

Au cours du vieillissement, les caractéristiques organoleptiques du vin se modifient au contact du bois de chêne. Le composé aromatique le plus important, la whisky-lactone, aux notes noix de coco et boisé, est facilement détectable et apprécié par les consommateurs.Quercus petraea et Q. robur, les deux principales espèces européennes de chêne utilisées pour le vieillissement des vins, ont des profils aromatiques très contrastés, particulièrement pour la whisky-lactone. Parvenir à identifier l’espèce de chêne permettrait de fournir aux tonnelleries des lots de bois plus homogènes. L’objectif de cette étude est d’identifier l’espèce de chêne à partir de bois sec, à l’aide de marqueurs moléculaires utilisables dans un contexte industriel. Le bois sec est un tissu mort dans lequel l’ADN est très dégradé et donc difficilement accessible. Pour optimiser l’extraction d’ADN à partir de ce tissu, nous avons développé une méthode de PCR en temps-réel ciblant l’ADN chloroplastique, permettant ainsi d’évaluer l’efficacité des différents protocoles d’extraction. Nous avons également développé des marqueurs moléculaires (SSRs et SNPs) fortement différenciés entre espèces et particulièrement bien adaptés au bois. Grâce à des protocoles d’extraction d’ADN optimisés et ces marqueurs performants, nous avons pu identifier l’espèce sur des lots de bois séchés pendant deux ans. De plus, par l’étude de 262 SNPs dont la moitié est fortement différenciée entre espèces, nous avons démontré que les gènes sélectionnés (loci « outlier ») sont très performants pour délimiter ces deux espèces proches. Ils permettent également de détecter des processus démographiques fins (flux de gènes intra- et interspécifiques), alors que les gènes a priori non-sélectionnés (loci neutres) se révèlent peu informatifs.Most of aromatic compounds in wine are directly induced during maturation by the contactwith oak wood. For example, whisky-lactone, the most important aromatic compound,which gives a coconut and woody taste, is easily detected and appreciated by consumers.Quercus petraea and Q. robur, the two major European oak species used for wine maturation,have very contrasted aromatic patterns, especially for whisky-lactone. Identifying the speciesused for cooperage will facilitate the maturation process, for instance by providing winerieswith more homogenous batches of barrels. The objective of our study is to characterize theoak species directly from dry wood, using molecular markers that will be applicable in anindustrial context. Unfortunately, dry wood is a dead tissue in which DNA is highlydegraded and difficult to access. To optimize DNA recovery from dry wood, we developed aquantitative PCR protocol based on chloroplast DNA to evaluate the efficiency of DNAisolation protocols. We identified and developed molecular markers (SSRs and SNPs)adapted to dry wood that are particularly diagnostic. Using an optimized DNA isolationprotocol and these powerful markers, the species identity from wood samples dried duringtwo years could be successfully characterized. Using 262 SNPs highly differentiated betweenthe two species, we also demonstrate that genes under selection (outlier loci) haveoutstanding power to delimitate the two oak species and provide unique insights on intraandinterspecific gene flow, whereas genes lacking such a signature (putatively neutral loci)provide little or no resolution

Prédiction de la qualité des bois de chêne pour l’élevage des vins et des alcools : comparaison des approches physicochimiques, sensorielles et moléculaires

Most of aromatic compounds in wine are directly induced during maturation by the contactwith oak wood. For example, whisky-lactone, the most important aromatic compound,which gives a coconut and woody taste, is easily detected and appreciated by consumers.Quercus petraea and Q. robur, the two major European oak species used for wine maturation,have very contrasted aromatic patterns, especially for whisky-lactone. Identifying the speciesused for cooperage will facilitate the maturation process, for instance by providing winerieswith more homogenous batches of barrels. The objective of our study is to characterize theoak species directly from dry wood, using molecular markers that will be applicable in anindustrial context. Unfortunately, dry wood is a dead tissue in which DNA is highlydegraded and difficult to access. To optimize DNA recovery from dry wood, we developed aquantitative PCR protocol based on chloroplast DNA to evaluate the efficiency of DNAisolation protocols. We identified and developed molecular markers (SSRs and SNPs)adapted to dry wood that are particularly diagnostic. Using an optimized DNA isolationprotocol and these powerful markers, the species identity from wood samples dried duringtwo years could be successfully characterized. Using 262 SNPs highly differentiated betweenthe two species, we also demonstrate that genes under selection (outlier loci) haveoutstanding power to delimitate the two oak species and provide unique insights on intraandinterspecific gene flow, whereas genes lacking such a signature (putatively neutral loci)provide little or no resolution.Au cours du vieillissement, les caractéristiques organoleptiques du vin se modifient au contact du bois de chêne. Le composé aromatique le plus important, la whisky-lactone, aux notes noix de coco et boisé, est facilement détectable et apprécié par les consommateurs.Quercus petraea et Q. robur, les deux principales espèces européennes de chêne utilisées pour le vieillissement des vins, ont des profils aromatiques très contrastés, particulièrement pour la whisky-lactone. Parvenir à identifier l’espèce de chêne permettrait de fournir aux tonnelleries des lots de bois plus homogènes. L’objectif de cette étude est d’identifier l’espèce de chêne à partir de bois sec, à l’aide de marqueurs moléculaires utilisables dans un contexte industriel. Le bois sec est un tissu mort dans lequel l’ADN est très dégradé et donc difficilement accessible. Pour optimiser l’extraction d’ADN à partir de ce tissu, nous avons développé une méthode de PCR en temps-réel ciblant l’ADN chloroplastique, permettant ainsi d’évaluer l’efficacité des différents protocoles d’extraction. Nous avons également développé des marqueurs moléculaires (SSRs et SNPs) fortement différenciés entre espèces et particulièrement bien adaptés au bois. Grâce à des protocoles d’extraction d’ADN optimisés et ces marqueurs performants, nous avons pu identifier l’espèce sur des lots de bois séchés pendant deux ans. De plus, par l’étude de 262 SNPs dont la moitié est fortement différenciée entre espèces, nous avons démontré que les gènes sélectionnés (loci « outlier ») sont très performants pour délimiter ces deux espèces proches. Ils permettent également de détecter des processus démographiques fins (flux de gènes intra- et interspécifiques), alors que les gènes a priori non-sélectionnés (loci neutres) se révèlent peu informatifs

Development of nuclear SNP markers for the timber tracking of the African tree species Sapelli, Entandrophragma cylindricum

We describe the development of new nuclear SNP markers for the genetic timber tracking of the geographical origin of Sapelli, Entandrophragma cylindricum (Meliaceae). Restriction associated DNA sequencing (RADseq) of two reference individuals yielded 1131 putative SNPs. Among those, 131 were selected to design four MassARRAY multiplexes and screened at 178 individuals. Seventy-two loci were selected for further use in genetic tracking

ASEF 3-4-2010.indb

Abstract. Two ecotypes of Aedes aegypti, Ae. ae. aegypti and Ae. ae. formosus, were experimentally infected with a dengue 2 virus to test (1) the inheritance of susceptibility, and (2) the impact of infection on survival and reproduction. Ae. ae. aegypti, the main vector involved in dengue epidemics, displayed higher mortalities than Ae. ae. formosus, the ancestral form, which is a forest-dwelling, less anthropophilic species confi ned to Africa. Differential mortalities were observed between females with disseminated infection and females without disseminated infection. Ae. ae. formosus females with disseminated infection showed an increase in survival rate and reproduction success. These results are discussed in the light of changes in resource allocation that may occur in infected females. Résumé. Mortalités liées à l'infection par le virus de la dengue du moustique Aedes aegypti: résultats préliminaires. Les deux formes d'Aedes aegypti, Ae. ae. aegypti and Ae. ae. formosus, ont été infectées expérimentalement avec le virus de la dengue pour défi nir (1) l'héritabilité de la réceptivité à l'infection et (2) les conséquences de l'infection virale sur la survie et la reproduction du vecteur. Ae. ae. aegypti, la forme domestique, vecteur majeur des virus de la dengue durant les épidémies urbaines, subit une plus forte mortalité qu'Ae. ae. formosus, la forme selvatique, peu anthropophile qui est originaire des forêts d'Afrique. Des différences de mortalités sont observées entre femelles ayant une infection disséminée (ayant ingéré un repas infecté et présentant du virus ayant disséminé au delà du tube digestif) et femelles sans infection disséminée (ayant ingéré un repas infecté et ne présentant pas de virus ayant disséminé au delà du tube digestif). Les femelles d'Ae. ae. formosus avec infection disséminée survivent mieux et ont un meilleur succès reproductif. Ces résultats seront discutés à la lumière des données de la littérature sur la réallocation des ressources énergétiques d'un vecteur lorsqu'il est infecté par un agent pathogène