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Formation of polar‐body‐like structures induced in polyspermic starfish oocytes that had been inseminated at the germinal vesicle stage
Author(s) -
Tei Jinsei,
Kani Satomi,
Hanai Kuninari,
Miyaguchi Tohru,
Yamamoto Kenya
Publication year - 2004
Publication title -
development, growth and differentiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.864
H-Index - 66
eISSN - 1440-169X
pISSN - 0012-1592
DOI - 10.1111/j.1440-169x.2004.00760.x
Subject(s) - polar body , starfish , germinal vesicle , prophase , meiosis , centrosome , sperm , biology , microbiology and biotechnology , staining , anatomy , oocyte , genetics , embryo , cell cycle , ecology , gene , cell
Immature starfish oocytes, which are arrested at the first meiotic prophase and contain a large nucleus called the germinal vesicle (GV), are known to accept multiple sperm on insemination. We found that if these polyspermic starfish oocytes are induced to mature, they often form small protrusion(s) adjacent to the first polar body emitted shortly earlier. We refer to these protrusion(s) as ‘polar‐body‐like structures (PLS).’ Fluorescent staining of PLS indicated that they were not merely cytoplasmic protrusions, but contained some chromatin. Maturing process of these polyspermic oocytes was examined by immnofluorescent staining, which showed that: (i) numerous sperm asters were observed after the onset of GV breakdown; (ii) before the first polar body (PB1) emission, a complex microtubular structure resembling a multipolar spindle was formed; and (iii) several isolated asters were observed after PB1 emission. These results indicate that PLS formation may be induced by interaction of meiosis‐I spindle with paternal centrosomes incorporated at GV stage.