Widespread anti-sense transcription in apple is correlated with siRNA production and indicates a large potential for transcriptional and/or post-transcriptional control

Characterizing the transcriptome of eukaryotic organisms is essential for studying gene regulation and its impact on phenotype. The realization that anti-sense (AS) and noncoding RNA transcription is pervasive in many genomes has emphasized our limited understanding of gene transcription and post-transcriptional regulation. Numerous mechanisms including convergent transcription, anti-correlated expression of sense and AS transcripts, and RNAi remain ill-defined.Here, we have combined microarray analysis and high-throughput sequencing of small RNAs (sRNAs) to unravel the complexity of transcriptional and potential post-transcriptional regulation in eight organs of apple (Malus × domestica). The percentage of AS transcript expression is higher than that identified in annual plants such as rice and Arabidopsis thaliana. Furthermore, we show that a majority of AS transcripts are transcribed beyond 3′UTR regions, and may cover a significant portion of the predicted sense transcripts. Finally we demonstrate at a genome-wide scale that anti-sense transcript expression is correlated with the presence of both short (21–23 nt) and long (> 30 nt) siRNAs, and that the sRNA coverage depth varies with the level of AS transcript expression. Our study provides a new insight on the functional role of anti-sense transcripts at the genome-wide level, and a new basis for the understanding of sRNA biogenesis in plants

Essai d'optimisation des performances de ponte chez la dinde reproductrice (Meleagris gallopavo) : approche nutritionnelle

Co-encadrée par : Mr LEVEQUE G. Thèse confidentielle Diplôme : Dr. d'Universit

Chiral Quaternary Ammonium Salts in Organocatalysis

International audienc

Ingérés nutritionnels des reproducteurs, bien être et reproduction mâle et femelle : des liens complexes

National audienc

Alimentation, fertilité et bien-être des oiseaux reproducteurs domestiques : des liens complexes

Dossier : Bien-être du poulet de chairIn birds, as in other species, nutrition and energy influence the function of reproduction. The hyperphagic models have shown the negative effect of over-feeding in both sexes, and the potential rescue by food restriction treatment which can increase the length of the fertile period. However, the mechanisms underlying the relationship between nutrition, energy metabolism and reproductive functions are poorly understood. These changes in metabolic and nutritional status can be transmitted to the gonadotrope axis (hypothalamus, pituitary and gonads) by changes in hormone levels (insulin, adipokines...), or directly by the energy substrates (glucose, fatty acids and amino acids). Briefly, we discuss the effects of different components of the diet on fertility. Finally, we discuss alternative methods involving qualitative restriction rather than quantitative methods on feeding in order to improve animal welfare and in particular by reducing the behaviour of frustration and hunger.Chez les oiseaux, comme toutes autres espèces, la nutrition et plus particulièrement le métabolisme énergétique influence la fonction de reproduction. Les modèles d’oiseaux hyperphagiques ont permis de montrer l’effet négatif dans les deux sexes d’une suralimentation, alors qu’une restriction alimentaire pendant leur croissance augmente les taux de ponte et la durée de la période fertile. Cependant les mécanismes qui sous-tendent les relations entre la nutrition, le métabolisme énergétique et la fonction de reproduction sont mal connus. Ces changements du statut nutritionnel et métabolique peuvent être transmis à l’axe de la reproduction (hypothalamus, hypophyse et gonades) aussi bien par les modifications des concentrations hormonales en insuline, adipocytokines, etc., que par celles des substrats énergétiques eux mêmes : glucose, acides gras et acides aminés. Nous rappellerons brièvement ici les effets des différents composants présents dans l’alimentation et les conséquences sur la reproduction. Les propositions d’utiliser un rationnement qualitatif seront également abordées : existe-t-il des méthodes alternatives impliquant une restriction qualitative plutôt que quantitative

Recent Advances in Catalytic and Technology-Driven Radical Addition to N,N-Disubstituted Iminium Species

International audienceRecently, radical chemistry has grown exponentially in the toolbox of organic synthetic chemists. Upon the (re)introduction of modern catalytic and technology-driven strategies, the implementation of highly reactive radical species is currently facilitated while expanding the scope of numerous synthetic methodologies. In this context, this review intends to cover the recent advances in radical-based transformations of N,N-disubstituted iminium substrates that encompass unique reactivities with respect to imines or protonated iminium salts. In particular, we have focused on the literature concerning the dipole type substrates, such as nitrones or azomethine imines, together with the chemistry of N+-X− (X = O, NR) azaarenium dipoles, which proved to be very versatile platforms in that field of research. The N-alkylazaarenium salts were been considered, which demonstrated specific reactivity profiles in radical chemistry

Meldrum's acid derivatives and chiral ammonium phenoxides : a useful combination for asymmetric synthesis

International audienc

Progressive acquisition of sperm storage potential in the chicken oviduct

National audienc