Tahitian Vanilla (Vanilla ×tahitensis): A Vanilla Species with Unique Features

This chapter reviews the main findings on Tahitian vanilla (Vanilla ×tahitensis) over the last 10 years. It brings new insights into the hybrid origin of V. ×tahitensis and its diversification in French Polynesia. It details then the different analytical methods used to characterize the flavour properties and the aroma impact compounds of Tahitian vanilla, with a special emphasis on how they can be used to differentiate Tahitian vanilla from other vanillas. Finally, the effect of the curing process on the chemical composition and the sensory properties is discussed. These results highlight the need to include some of the key volatile compounds into a more adapted quality control, in order to describe the characteristic sensory properties of Tahitian vanilla but also those from other origins

KIT is required for hepatic function during mouse post-natal development

<p>Abstract</p> <p>Background</p> <p>The <it>Kit </it>gene encodes a receptor tyrosine kinase involved in various biological processes including melanogenesis, hematopoiesis and gametogenesis in mice and human. A large number of <it>Kit </it>mutants has been described so far showing the pleiotropic phenotypes associated with partial loss-of-function of the gene. Hypomorphic mutations can induce a light coat color phenotype while complete lack of KIT function interferes with embryogenesis. Interestingly several intermediate hypomorphic mutations induced in addition growth retardation and post-natal mortality.</p> <p>Results</p> <p>In this report we investigated the post-natal role of <it>Kit </it>by using a panel of chemically-induced hypomorphic mutations recently isolated in the mouse. We found that, in addition to the classical phenotypes, mutations of <it>Kit </it>induced juvenile steatosis, associated with the downregulation of the three genes, <it>VldlR</it>, <it>Lpin1 </it>and <it>Lpl</it>, controlling lipid metabolism in the post-natal liver. Hence, <it>Kit </it>loss-of-functions mimicked the inactivation of genes controlling the hepatic metabolism of triglycerides, the major source of energy from maternal milk, leading to growth and viability defects during neonatal development.</p> <p>Conclusion</p> <p>This is a first report involving KIT in the control of lipid metabolism in neonates and opening new perspectives for understanding juvenile steatosis. Moreover, it reinforces the role of Kit during development of the liver and underscores the caution that should be exerted in using KIT inhibitors during anti-cancer treatment.</p

Vanilla: a challenging genus with regards to the development of genomic resources

18International audienceThe development of enabling genomic resources for Vanilla would dramatically advance international efforts to improve the genetic foundation of this important global commodity for vanillagrowing countries worldwide. Currently, global production of Vanilla planifolia rests on a precarious genetic foundation that lacks natural resistance to disease-causing pathogens (such as Fusarium) and environmental fluctuations. This low genetic diversity of cultivated vanilla leaves it highly vulnerable to disease, climatic change, and other environmental stresses, placing the entire vanilla industry potentially at risk. However, Vanilla is a challenging genus with regards to development of genetic resources: not only do Vanilla species have large genomes (approx. Cx = 2.5 Gb), but they are also characterized, like some orchids from various sections, by strict partial endoreplication (SPE) cycles, unknown in any other plant family. We will present how we took these major constraints into account in the definition of genome sequencing strategies for this genu

Vanilla: a challenging genus with regards to the development of genomic resources

18International audienceThe development of enabling genomic resources for Vanilla would dramatically advance international efforts to improve the genetic foundation of this important global commodity for vanillagrowing countries worldwide. Currently, global production of Vanilla planifolia rests on a precarious genetic foundation that lacks natural resistance to disease-causing pathogens (such as Fusarium) and environmental fluctuations. This low genetic diversity of cultivated vanilla leaves it highly vulnerable to disease, climatic change, and other environmental stresses, placing the entire vanilla industry potentially at risk. However, Vanilla is a challenging genus with regards to development of genetic resources: not only do Vanilla species have large genomes (approx. Cx = 2.5 Gb), but they are also characterized, like some orchids from various sections, by strict partial endoreplication (SPE) cycles, unknown in any other plant family. We will present how we took these major constraints into account in the definition of genome sequencing strategies for this genu

Vanilla: a challenging genus with regards to the development of genomic resources

18International audienceThe development of enabling genomic resources for Vanilla would dramatically advance international efforts to improve the genetic foundation of this important global commodity for vanillagrowing countries worldwide. Currently, global production of Vanilla planifolia rests on a precarious genetic foundation that lacks natural resistance to disease-causing pathogens (such as Fusarium) and environmental fluctuations. This low genetic diversity of cultivated vanilla leaves it highly vulnerable to disease, climatic change, and other environmental stresses, placing the entire vanilla industry potentially at risk. However, Vanilla is a challenging genus with regards to development of genetic resources: not only do Vanilla species have large genomes (approx. Cx = 2.5 Gb), but they are also characterized, like some orchids from various sections, by strict partial endoreplication (SPE) cycles, unknown in any other plant family. We will present how we took these major constraints into account in the definition of genome sequencing strategies for this genu

Molecular analysis of introgressive breeding in coffee (Coffea arabica L.)

Nineteen arabica coffee introgression lines (BC1F4) and two accessions derived from a spontaneous interspecific cross (i.e. Timor Hybrid) between #Coffea arabica (2n=4x=44) and #C. canephora (2n=2x=22) were analysed for the introgression of #C. canephora genetic material. The Timor Hybrid-derived genotypes were evaluated by AFLP, using 42 different primer combinations, and compared to 23 accessions of #C. arabica and 8 accessions of #C. canephora. A total of 1062 polymorphic fragments were scored among the 52 accessions analysed. One hundred and seventy-eight markers consisting of 109 additional bands (i.e. introgressed markers) and 69 missing bands distinguished the group composed of the Timor Hybrid-derived genotypes from the accessions of #C. arabica. AFLP therefore seemed to be an extremely efficient technique for DNA marker generation in coffee as well as for the detection of introgression in #C. arabica. The genetic diversity observed in the Timor Hybrid-derived genotypes appeared to be approximately double that in #C. arabica. Although representing only a small proportion of the genetic diversity available in #C. canephora$, the Timor Hybrid obviously constitutes a considerable source of genetic diversity for arabica breeding. Analysis of genetic relationships among the Timor Hybrid-derived genotypes suggested that introgression was not restricted to chromosome substitution but also involved chromosome recombinations. Furthermore, the Timor Hybrid-derived genotypes varied considerably in the number of AFLP markers attributable to introgression. In this way, the introgressed markers identified in the analysed arabica coffee introgressed gentotypes were estimated to represent from 9$ genome. Nevertheless, the amount of alien genetic material in the introgression arabica lines remains substantial and should justify the development of adapted breeding strategies. (Résumé d'auteur