Ultrastructure and development during meiosis and the tetrad period of sporogenesis in the leptosporangiate fern Alsophila setosa (Cyatheaceae) compared with corresponding stages i...

Authors
Gabarayeva, Nina I.; Grigorjeva, Valentina V.; Marquez, Gonzalo Javier
Publication Year
2011
Language
English
Format
article
Status
Published version
Description
The pre-meiotic, meiotic and tetrad stages of development in microsporangia of Alsophila setosa were studied with particular emphasis on the early establishment of patterning in the microspore wall and the subsequent development of the sporoderm. The data obtained were compared with corresponding ontogenetic stages of Psilotum nudum. Tapetal behaviour was also examined. During the tetrad period, only one layer, a thin undulating sheet, appeared alongside the plasma membrane of the tetraspores, and this was evidently formed on a pre-patterned structure - a fibrillar layer, corresponding to a kind of primexine matrix. The early free microspores had a wavy plasma membrane with a parallel, sinusoidal, thin initial sporoderm layer. The proximal apertural fold was observed to be an extended outgrowth of this initial spore envelope. Sporoderm ontogeny during the tetrad period in Alsophila and Psilotum show some common points, but also fundamental differences, mainly in the relative timing of events: in Alsophila the end of the tetrad period is the starting point for exospore development, whereas in Psilotum the exospore is already complete at this stage. Considerable differences were also observed in the tapetum of the two species.
Fil: Gabarayeva, Nina I.. Russian Academy of Sciences; Rusia
Fil: Grigorjeva, Valentina V.. Russian Academy of Sciences; Rusia
Fil: Marquez, Gonzalo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata; Argentina
Subject
ALSOPHILA SETOSA
MEIOSIS
MICELLES
PRE-MEIOSIS
PSILOTUM NUDUM
SELF-ASSEMBLY
SPORE WALL AND TAPETUM DEVELOPMENT
SPORODERM PATTERN FORMATION
ULTRASTRUCTURE
Biología Celular, Microbiología
Ciencias Biológicas
CIENCIAS NATURALES Y EXACTAS
Access level
Restricted access
License
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repository
CONICET Digital (CONICET)
Institution
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identifier
oai:ri.conicet.gov.ar:11336/79661