Search results for "Sperm"

Use of translational genomics to identify genes important for legume seed development

2015

BAP Pôle GEAPSI; International audience; We have exploited the extensive synteny between the model legume Medicago truncatula and the cultivated garden pea, Pisumsativum, to identify loci controlling seed filling and seedcomposition in the crop species. QTLs for these traits are mapped by analyzing variation with in collections of recombinant inbred lines. Candidate genes with in the QTL intervals are identified by reference to the M.truncatula genomic sequence. This approach was used to uncover an endosperm subtilase that is associated with syntenic seed weight QTLs in Medicago and pea, and we discuss the possible role played by this enzyme in contributing to final seed weight.

Regulation of legume seed size by an endosperm-expressed transcription factor

2015

BAP Pôle GEAPSI; International audience; There are numerous reports of transcription factors (TFs) which are implicated in the control of seed size and seed composition. We have identified, using a platform of TF sequences derived from the Medicago truncatula genome sequence, a class of TFs specifically expressed during the seed filling stage. One such TF, DASH, was shown to be confined to the developing endosperm. We investigated the role played by DASH through analysis of mutant alleles. These give rise to seed-lethal or near-lethal phenotypes, with degeneration of the endosperm and arrested embryo development. The relation of this phenotype to seed auxin action was investigated.

Uptake of triticonazole, during imbibition, by wheat caryopses after seed treatment

1997

The uptake of 14C-labelled triticonazole by wheat caryopses during imbibition was investigated. The uptake from an aqueous solution appeared to be driven by mass flow rather than by accumulation in seed lipids. During treatment with a liquid seed-dressing preparation of triticonazole, c. 1 μg triticonazole per caryopsis (2·4% of applied triticonazole) entered the seed. During germination in soil, another c. 1 μg triticonazole per caryopsis entered the seed in 24 h. In killed seeds, no penetration was observed between 24 h and 72 h after the beginning of imbibition. After seed treatment and imbibition in soil, triticonazole appeared to be located in the seed coats and embryo, but not in endo…

Corispermum intermedium, C. hyssopifolium un C. leptopterum augu sabiedrības, to ietekmējošie faktori un taksonu radniecība

2015

Latvijas endēmam Corispermum intermedium un svešzemju sugām C. hyssopifolium ar C. leptopterum ir ļoti līdzīga gan morfoloģija, gan ekoloģiskie apstākļi. Literatūrā trūkst datu par Corispermum augu sabiedrībām un to sastopamības noteicošajiem ekoloģiskajiem faktoriem. Maģistra darba mērķis – noteikt jūras piekrastes smiltājos sastopamo kamieļzāļu augu sabiedrību piederību un to ietekmējošos faktorus, kā arī C. intermedium, C. hyssopifolium un C. leptopterum radniecību. Corispermum augu sabiedrībām Latvijas smiltājos konstatēta līdzība ar Centrāleiropā sastopamo Bromo tectorum-Corispermetum leptopteri un Corispermum-Ammophila sabiedrību. Augu sabiedrību noteicošais faktors ir nabadzīgs subst…

Impact of Leptospermone, a Natural β-Triketone Herbicide, on the Fungal Composition and Diversity of Two Arable Soils

2019

International audience; Impact of leptospermone, a β-triketone bioherbicide, was investigated on the fungal community which supports important soil ecological functions such as decomposition of organic matter and nutrients recycling. This study was done in a microcosm experiment using two French soils, Perpignan (P) and Saint-Jean-de-Fos (SJF), differing in their physicochemical properties and history treatment with synthetic β-triketones. Soil microcosms were treated with leptospermone at recommended dose and incubated under controlled conditions for 45 days. Untreated microcosms were used as control. Illumina MiSeq sequencing of the internal transcribed spacer region of the fungal rRNA re…

Impact of Leptospermone, a Natural β-Triketone Herbicide, on the Fungal Composition and Diversity of Two Arable Soils

2019

Impact of leptospermone, a β-triketone bioherbicide, was investigated on the fungal community which supports important soil ecological functions such as decomposition of organic matter and nutrients recycling. This study was done in a microcosm experiment using two French soils, Perpignan (P) and Saint-Jean-de-Fos (SJF), differing in their physicochemical properties and history treatment with synthetic β-triketones. Soil microcosms were treated with leptospermone at recommended dose and incubated under controlled conditions for 45 days. Untreated microcosms were used as control. Illumina MiSeq sequencing of the internal transcribed spacer region of the fungal rRNA revealed significant chang…

Terpenoid composition and chemotaxonomic aspects of Miocene amber from the Koroglu Mountains, Turkey

2014

Abstract A recently discovered fossil resin from Koroglu Mountain in Turkey has been analyzed by gas chromatography–mass spectrometry and pyrolysis gas chromatography–mass spectrometry to determine its structural class and botanical origin. The sesqui- and diterpenoids contained in the amber extract were used as chemosystematic markers when compared with terpenoids in extant conifers. The pyrolysis products were dominated by labdanoid derived bicyclic products together with succinic acid indicating Class Ia type amber. The biomarker compositions of the resin comprise mainly sesqui- and diterpenoids, and lack triterpenoids. This distribution suggests a gymnosperm, and more specifically a con…

Body size and mating strategies in the simultaneous hermaphrodite Oxynoe olivacea (Mollusca, Opisthobranchia, Sacoglossa).

2004

Summary 1To better understand the role and importance of body size in hermaphroditic mating system theory, the mating behaviour of the shelled sacoglossan Oxynoe olivacea was studied. This simultaneous hermaphrodite exhibits bilateral and unilateral sperm transfer and thus it is particularly suitable for studies on hermaphrodite sexual conflict. 2In this study three hypotheses on body size were tested: that O. olivacea partner size has an effect on (i) mating mode choice, (ii) duration of mating modes, and (iii) choice of sexual role. Furthermore, we tested Charnov's hypothesis that in O. olivacea, like many simultaneous hermaphrodites, a sexual conflict exists and the male role is preferre…

Microarray-Based Determination of Response of Tumor Cells to Cycloshikonin

2011

An Analysis of the Process of Fertilization and Activation of the Egg

1957

Publisher Summary Fertilization consists fundamentally in the release of a chain of metabolic reactions by virtue of which morphogenesis is started. The result of fertilization is the activation of the egg. This can be achieved also by several agents other than the spermatozoon and it is then spoken of as “artificial activation.” This chapter discusses the structural, physiological, and chemical changes that occur in the egg at fertilization that are significant in the understanding of the mechanisms of the activation. The chapter presents the hypothesis that in the cortex of the unfertilized sea urchin egg an inhibitor–enzyme complex is present. By reacting with some substance introduced b…