Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2006-4-26
pubmed:abstractText
Seasonal variations in the morphology of the parenchymal mass and function of the albumen gland/capsule gland complex have been studied in Pomacea canaliculata, together with the cellular types involved in the synthesis and secretion of perivitellin fluid components. The two major parenchymal cell types, albumen secretory cells (AS) and labyrinthic cells (LC), undergo seasonal variations throughout the annual reproductive cycle, which is divided into three periods. Both cellular types show maximal development and structural complexity during the reproductive period (spring and summer). AS cells have a well-developed Golgi complex and rough endoplasmic reticulum and their secretory granules show electron-dense particles of about 20 nm (probably galactogen). These cells are uniquely involved in ovorubin and PV2 perivitellin synthesis and their secretory granules are the single storage site for these two major perivitellins, as revealed by immunoelectron microscopy. AS also possess calcium deposits that infiltrate the cytoplasmic matrix. The luminal surfaces of LC exhibit long cilia intermingled with sparce short microvilli. Basally, the plasma membrane shows deep irregular folds that extend through the cytoplasm up to the subapical region. Calcium deposits infiltrate the cytoplasm and accumulate in the extracellular space of the basal labyrinth. Nerve terminals seem to be involved in the regulation of parenchymal cell secretion. At the post-reproductive period, AS markedly change their aspect following the release of most of the secretory granules into the acinar lumen. LC decrease in volume, the number of their cilia decreases, their cytoplasmic folds are much thinner and their extracellular spaces lack calcium particles. At the pre-reproductive period (winter), AS and LC recover and prepare for the subsequent period.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0302-766X
pubmed:author
pubmed:issnType
Print
pubmed:volume
324
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
523-33
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Pallial oviduct of Pomacea canaliculata (Gastropoda): ultrastructural studies of the parenchymal cellular types involved in the metabolism of perivitellins.
pubmed:affiliation
Departamento Servicios de Microscopía Electrónica, INSIBIO, UNT-CONICET, Tucumán, Argentina.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't