31 research outputs found
Phytolith Analysis for Differentiating between Foxtail Millet (Setaria italica) and Green Foxtail (Setaria viridis)
Foxtail millet (Setaria italica) is one of the oldest domesticated cereal crops in Eurasia, but identifying foxtail millets, especially in charred grains, and differentiating it from its wild ancestor, green foxtail (Setaria viridis), in the archaeobotanical remains, is still problematic. Phytolithic analysis provides a meaningful method for identifying this important crop. In this paper, the silicon structure patterns in the glumes, lemmas, and paleas from inflorescence bracts in 16 modern plants of foxtail millet and green foxtail from China and Europe are examined using light microscopy with phase-contrast and a microscopic interferometer. Our research shows that the silicon structure of ΩIII from upper lemmas and paleas in foxtail millet and green foxtail can be correspondingly divided into two groups. The size of ΩIII type phytolith of foxtail millet is bigger than that from green foxtail. Discriminant function analysis reveals that 78.4% of data on foxtail millet and 76.9% of data on green foxtail are correctly classified. This means certain morphotypes of phytoliths are relatively reliable tools for distinguishing foxtail millet from green foxtail. Our results also revealed that the husk phytolith morphologies of foxtail millets from China and Eastern Europe are markedly different from those from Western Europe. Our research gives a meaningful method of separating foxtail millet and green foxtail. The implications of these findings for understanding the history of foxtail millet domestication and cultivation in ancient civilizations are significant
Distribution and chromosomal organization of 18S-5.8S-25S and 5S rDNA in Petunia species
We have analyzed the interspecific variation of the 5S rDNA spacer by the polymerase chain reaction in seven Petunia species. The species studied could be separated into two groups with regard to the size of the amplified 5S rDNA variants: one group, with a 460-bp repeat unit, including P linearis (2n = 18) and P integrifolia (2n = 14) and the second group, with a 350-bp repeat unit, including all the other wild species (2n = 14) studied and the P hybrida lines. The amplified fragments have been cloned, and used in FISH experiments to determine the number and the location of the 5S rDNA units. The chromosomal organization of the 5S rDNA enabled us to distinguish a group of coloured flowered species with one locus adjacent to the major 18S-5.8S-25S rDNA locus on chromosome II, and a group of white flowered species with an additional locus in the centromeric region of a metacentric chromosome (IV/VII). FISH analysis also revealed four hybridization sites of 18S-5.8S-25S rDNA in the majority of the Petunia species studied. Only P linearis and P parviflora (2n = 18) showed two hybridization sites. The four sites of 18S-5.85-25S rDNA are transcriptionally active as shown by their expression pattern in interphase nuclei. Our FISH results combined with PCR amplification and RFLP studies of the rDNA clusters give a new insight into the phylogenetic relationships between wild species and the P hybrida lines.Distribution et organisation chromosomique des gĂšnes ribosomiques 18S-5.8S-25S et 5S chez Petunia. Nous avons analysĂ© la variation interspĂ©cifique de l'espaceur 5S ADNr par la tehnique d'amplification gĂ©nique (PCR) dans sept espĂšces de Petunia. Les espĂšce Ă©tudiĂ©es peuvent ĂȘtre sĂ©parĂ©es en deux groupes suivant la taille des variants 5S ADNr amplifiĂ©s : un groupe avec une unitĂ© de rĂ©pĂ©tition de 460 pb comprenant P linearis (2 n = 18) et P integrifolia (2 n = 14), et un deuxiĂšme groupe avec une unitĂ© de rĂ©pĂ©tition de 350 pb comprenant toutes les autres espĂšces sauvages (2 n = 14) Ă©tudiĂ©es et les lignĂ©es de P hybrida. Les fragments amplifiĂ©s ont Ă©tĂ© clonĂ©s et ont servi de sondes pour l'hybridation in situ fluorescente afin de dĂ©terminer le nombre et la localisation des unitĂ©s 5S. L'organisation chromosomique du 5S ADNr nous a permis de distinguer un groupe d'espĂšces Ă fleurs colorĂ©es avec un locus adjacent au locus majeur 18S-5.8S-25S ADNr du chromosome II et un groupe d'espĂšces Ă fleurs blanches avec un locus supplĂ©mentaire situĂ© dans la rĂ©gion centromĂ©rique d'un chromosome mĂ©tacentrique (IV/VII). L'hybridation in situ fluorescente a Ă©galement rĂ©vĂ©lĂ© quatre sites d'hybridation pour le 18S-5.8S-25S ADNr dans la majoritĂ© des espĂšces de Petunia Ă©tudiĂ©es. Seuls P linearis et P parviflora (2 n = 18) ont montrĂ© deux sites d'hybridation. L'observation des pattern d'expression dans les noyaux interphasiques nous a permis de montrer que les quatre sites d'ADNr18S-5.8S-25S sont en activitĂ© de transcription. Les rĂ©sultats obtenus en hybridation in situ fluorescente ainsi que les amplifications par PCR et les Ă©tudes RFLP des ADNr nous ont conduits Ă une nouvelle approche des relations phylogĂ©niques entre les espĂšces sauvages et les lignĂ©es de P hybrida
Copia-like retrotransposons in the genus Setaria : sequence heterogeneity, species distribution and chromosomal organization
International audienc
Copia -like retrotransposons in the genus Setaria : Sequence heterogeneity, species distribution and chromosomal organization
Distribution and chromosomal organization of 18S-5.8S-25S and 5S rDNA in Petunia species
We have analyzed the interspecific variation of the 5S rDNA spacer by the polymerase chain reaction in seven Petunia species. The species studied could be separated into two groups with regard to the size of the amplified 5S rDNA variants: one group, with a 460-bp repeat unit, including P linearis (2n = 18) and P integrifolia (2n = 14) and the second group, with a 350-bp repeat unit, including all the other wild species (2n = 14) studied and the P hybrida lines. The amplified fragments have been cloned, and used in FISH experiments to determine the number and the location of the 5S rDNA units. The chromosomal organization of the 5S rDNA enabled us to distinguish a group of coloured flowered species with one locus adjacent to the major 18S-5.8S-25S rDNA locus on chromosome II, and a group of white flowered species with an additional locus in the centromeric region of a metacentric chromosome (IV/VII). FISH analysis also revealed four hybridization sites of 18S-5.8S-25S rDNA in the majority of the Petunia species studied. Only P linearis and P parviflora (2n = 18) showed two hybridization sites. The four sites of 18S-5.85-25S rDNA are transcriptionally active as shown by their expression pattern in interphase nuclei. Our FISH results combined with PCR amplification and RFLP studies of the rDNA clusters give a new insight into the phylogenetic relationships between wild species and the P hybrida lines.Distribution et organisation chromosomique des gĂšnes ribosomiques 18S-5.8S-25S et 5S chez Petunia. Nous avons analysĂ© la variation interspĂ©cifique de l'espaceur 5S ADNr par la tehnique d'amplification gĂ©nique (PCR) dans sept espĂšces de Petunia. Les espĂšce Ă©tudiĂ©es peuvent ĂȘtre sĂ©parĂ©es en deux groupes suivant la taille des variants 5S ADNr amplifiĂ©s : un groupe avec une unitĂ© de rĂ©pĂ©tition de 460 pb comprenant P linearis (2 n = 18) et P integrifolia (2 n = 14), et un deuxiĂšme groupe avec une unitĂ© de rĂ©pĂ©tition de 350 pb comprenant toutes les autres espĂšces sauvages (2 n = 14) Ă©tudiĂ©es et les lignĂ©es de P hybrida. Les fragments amplifiĂ©s ont Ă©tĂ© clonĂ©s et ont servi de sondes pour l'hybridation in situ fluorescente afin de dĂ©terminer le nombre et la localisation des unitĂ©s 5S. L'organisation chromosomique du 5S ADNr nous a permis de distinguer un groupe d'espĂšces Ă fleurs colorĂ©es avec un locus adjacent au locus majeur 18S-5.8S-25S ADNr du chromosome II et un groupe d'espĂšces Ă fleurs blanches avec un locus supplĂ©mentaire situĂ© dans la rĂ©gion centromĂ©rique d'un chromosome mĂ©tacentrique (IV/VII). L'hybridation in situ fluorescente a Ă©galement rĂ©vĂ©lĂ© quatre sites d'hybridation pour le 18S-5.8S-25S ADNr dans la majoritĂ© des espĂšces de Petunia Ă©tudiĂ©es. Seuls P linearis et P parviflora (2 n = 18) ont montrĂ© deux sites d'hybridation. L'observation des pattern d'expression dans les noyaux interphasiques nous a permis de montrer que les quatre sites d'ADNr18S-5.8S-25S sont en activitĂ© de transcription. Les rĂ©sultats obtenus en hybridation in situ fluorescente ainsi que les amplifications par PCR et les Ă©tudes RFLP des ADNr nous ont conduits Ă une nouvelle approche des relations phylogĂ©niques entre les espĂšces sauvages et les lignĂ©es de P hybrida
Phylogenetic and genomic relationships in Setaria italica and its close relatives based on the molecular diversity and chromosomal organization of 5S and 18S-5,8S-25S rDNA genes
International audienc
Genomic in situ hybridization (GISH) discriminates between the A and the B genomes in diploid and tetraploid Setaria species
International audienc
Genome discrimination in progeny of interspecific hybrids between Brassica napus and Raphanus raphanistrum
International audienc
Chromosomal organization of simple sequence repeats in the Pacific oyster (Crassostrea gigas): (GGAT)4, (GT)7 and (TA)10 chromosome patterns
Effects of an environmentally relevant concentration of diuron on oyster genitors during gametogenesis: responses of early molecular and cellular markers and physiological impacts
International audienceGenitors of the Pacific oyster Crassostrea gigas were submitted during gametogenesis to a short pulse exposure to the herbicide diuron at a realistic environmental concentration. Histological analysis showed no effect of diuron on gametogenesis course, sex ratio and reproductive effort. A non-significant increase in testosterone and progesterone levels was observed in genitors exposed to the herbicide. At cell level, diuron exposure was shown to modulate the phagocytic activity of circulating hemocytes. The results of a transcriptional analysis showed that diuron affected the expression of genes belonging to functions known to play a major role during oyster gametogenesis such as gene transcription regulation, DNA replication and repair, DNA methylation and cytokinesis. Taking into account the results we previously obtained on the same genitors, this study showed a negative effect of diuron on oyster reproduction by inducing both structural and functional modifications of the DN