Regulation of acrosome formation in mice expressing green fluorescent protein as a marker.
Transgenic mice expressing enhanced green fluorescent protein under acrosin promoter were used to study the role of the Golgi complex and of the cytoskeleton during early development of the acrosomic system in exactly defined stages of the seminiferous epithelial cycle during in vitro differentiation. First acrosin expression was found uniformly in the cytoplasm of stage IV pachytene spermatocytes. The steady-state level increased up to stage X pachytene spermatocytes, and in diakinetic primary spermatocytes, acrosin started to accumulate into the Golgi complex. During step 2 of spermiogenesis, several small fluorescent proacrosomic granules were seen in various parts of the Golgi complex, and they fused to a solid acrosomic system at step 3. In cultured stage I-III seminiferous tubule segments, nocodazole slowed down acrosin incorporation and increased the distance of the acrosomic system from the nucleus. Follicle stimulating hormone had an opposite effect by increasing density of the acrosomic system together with activation of the surrounding microtubule network. The observations suggest that microtubules have an important function during the early differentiation of the acrosomic system.
Ventelä
S
S
Department of Anatomy, University of Turku, Kiinamyllynkatu 10, FIN-20520 Turku, Finland. satuve@utu.fi
Mulari
M
M
Okabe
M
M
Tanaka
H
H
Nishimune
Y
Y
Toppari
J
J
Parvinen
M
M
D000176:Acrosin / Q000235:genetics / Q000378:metabolism; D020101:Acrosome Reaction / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D015638:Cytochalasin D / Q000494:pharmacology; D004792:Enzyme Precursors / Q000235:genetics; D015870:Gene Expression / Q000502:physiology; D017930:Genes, Reporter; D015292:Glycoprotein Hormones, alpha Subunit; D006056:Golgi Apparatus / Q000378:metabolism; D049452:Green Fluorescent Proteins; D007202:Indicators and Reagents / Q000378:metabolism; D008164:Luminescent Proteins / Q000235:genetics*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D018613:Microscopy, Confocal / Q000379:methods; D008856:Microscopy, Fluorescence / Q000379:methods; D015739:Nocodazole / Q000494:pharmacology; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D013091:Spermatogenesis / Q000187:drug effects / Q000502:physiology
D000970:Antineoplastic Agents; D004792:Enzyme Precursors; D015292:Glycoprotein Hormones, alpha Subunit; D007202:Indicators and Reagents; D008164:Luminescent Proteins; D019384:Nucleic Acid Synthesis Inhibitors; D049452:Green Fluorescent Proteins; D015638:Cytochalasin D; C022438:proacrosin; D000176:Acrosin; D015739:Nocodazole