Linked Life Data

15688442

Source:http://linkedlifedata.com/resource/pubmed/id/15688442

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2005-2-15
pubmed:abstractText
Oogenesis in the glossiphoniid leech Glossiphonia heteroclita (Hirudinea, Rhynchobdellida) is nutrimental, i.e., the growing oocyte is supported by specialized germline cells, the nurse cells. The main function of the nurse cells is to provide oocytes with cell organelles and RNAs (mainly rRNA). However, in studied leech species, irrespective of the nutrimental mode of oogenesis, the germinal vesicle (GV = oocyte nucleus) seems to be very active in rRNA production. As shown in the present study, during early previtellogenesis in the GV the meiotic chromosomes and prominent primary nucleoli occur. In late previtellogenesis the chromosomes condense and occupy a limited space of nucleoplasm in close vicinity to primary nucleolus, forming a karyosome. At the onset of vitellogenesis several prominent extrachromosomal DNA bodies appear in close association with the karyosome. At the same time, the primary nucleolus is no longer visible in the GV. As vitellogenesis proceeds the extrachromosomal DNA bodies undergo fragmentation and numerous spherical, RNA- and AgNOR-positive inclusions occur in the nucleoplasm. They are regarded as multiple nucleoli. Finally, in late oogenesis numerous accessory nuclei are formed in close proximity to the nuclear envelope. They usually contain one dense body, morphologically similar to multiple nucleoli. The amplification of rDNA genes, the occurrence of extrachromosomal DNA bodies, as well as the presence of multiple nucleoli and accessory nuclei are described for the first time in the phylum Annelida.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0362-2525
pubmed:author
pubmed:issnType
Print
pubmed:volume
263
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
330-9
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Structure of the germinal vesicle during oogenesis in leech Glossiphonia heteroclita (Annelida, Hirudinea, Rhynchobdellida).
pubmed:affiliation
Department of Animal Histology and Embryology, Silesian University, 40-007 Katowice, Poland. swiatek@us.edu.pl
pubmed:publicationType
Journal Article