RESUMEN
Cytokinin activity was determined in embryo and endosperm tissues from 30-day (stage 1), 55-Jay (stage 2), and 80-day (stage 3) old fruits of Cassia fistual. High cytokinin activity was associated with stage 1 and the least in stage 3. This indicated that the cytokinins disappeared during the course of seed development. Sephadex LH-20 column chromatography with 35% ethanol indicated the presence of cytokinins coeluting with zeatin glucoside, zeatin riboside, and zeatin. Qualitatively the cytokinins in the embryo and endosperm were identical at all the stages. The putative zeatin glucoside predominated at stage 1 but was absent in the later stages while only zeatin riboside was present at stage 3. The high cytokinin activity in the endosperm at early stages indicates that it may act as a supplier of cytokinins to the embryo during these periods. The possible significance of these findings is discussed.
Asunto(s)
Fenómenos Fisiológicos de la Nutrición , Vitamina A , Femenino , Humanos , Lactancia , Masculino , Necesidades Nutricionales , Embarazo , Vitamina A/uso terapéutico , Deficiencia de Vitamina A/diagnóstico , Deficiencia de Vitamina A/tratamiento farmacológico , Deficiencia de Vitamina A/etiologíaAsunto(s)
Distrofias Musculares/congénito , Niño , Preescolar , Consanguinidad , Femenino , Humanos , Masculino , Distrofias Musculares/genética , LinajeRESUMEN
The Shompen, one of the most isolated and poorly understood contemporary hunter-gatherer populations, inhabit Great Nicobar Island, the southernmost island of the Nicobar archipelago. Morphological imprints in the Shompen were interpreted to favour a mixed Indo-Chinese, Malay, Negrito and Dravidian origin. Analyses of the mitochondrial, Y-chromosomal and autosomal gene pool of contemporary Shompen have revealed low diversity, illustrating a founder effect in the island population. Mitochondrial sequence analyses revealed the presence of two haplogroups of R lineage: B5a, and a newly defined clade, R12. Y-chromosomal analyses demonstrated the occurrence of a single lineage found predominantly in Austro-Asiatic speakers across Asia. With the different types of genetic markers analysed, the Shompen exhibit varying levels of genetic relatedness with the Nicobarese, and Austro-Asiatic speakers of mainland India and Southeast Asia. These genetic analyses provide evidence that the Shompen, an offshoot of the Nicobarese, are descendants of Mesolithic hunter-gatherers of Southeast Asian origin, deriving from at least two source populations.
Asunto(s)
Genética de Población , Cromosomas Humanos Y , ADN Mitocondrial/genética , Efecto Fundador , IndiaRESUMEN
A growth inhibitor was isolated in crystalline form from the leaf of Vernonia anthelmintica and was found to be identical with abscisic acid by biological activity and physical measurements namely, melting point, mixed melting point, UV-absorption, mass spectra and paper and thin-layer chromatography.