title: Transient expression of the cholecystokinin gene in male germ cells and accumulation of the peptide in the acrosomal granule: possible role of cholecystokinin in fertilization.
abstract: Expression of the gene encoding the neurotransmitter/neuromodulator cholecystokinin (CCK) was demonstrated in testis of several different species. Two testicular CCK mRNA transcripts of different sizes were detected, and studies on the ontogeny of CCK gene expression indicated that the gene was expressed in male germ cells. In situ hybridization revealed CCK mRNA-expressing cells in the peripheral parts of the seminiferous tubules. Biochemical identification showed that the majority of prepro-CCK products in the testis represented pro-CCK. Immunofluorescence studies revealed CCK-like peptides primarily in spermatocytes and spermatids of mouse, rat, and monkey. Immuno electron microscopy of monkey testis demonstrated CCK immunoreactivity in the acrosomal granule of spermatids. Hence, an interesting possibility is that CCK peptides can be released during the acrosome reaction and thus may be of importance in the fertilization process.
authors.affiliation: Department of Medical Chemistry, Karolinska Institute, Stockholm, Sweden.
authors.forename: H
authors.initials: H
authors.lastname: Persson
authors.forename: J F
authors.initials: JF
authors.lastname: Rehfeld
authors.forename: A
authors.initials: A
authors.lastname: Ericsson
authors.forename: M
authors.initials: M
authors.lastname: Schalling
authors.forename: M
authors.initials: M
authors.lastname: Pelto-Huikko
authors.forename: T
authors.initials: T
authors.lastname: Hökfelt
mesh_terms: D000177:Acrosome / Q000502:physiology*; D000818:Animals; D002766:Cholecystokinin / Q000235:genetics / Q000502:physiology*; D004822:Epididymis / Q000502:physiology; D005306:Fertilization; D005455:Fluorescent Antibody Technique; D005796:Genes; D008297:Male; D051379:Mice; D009928:Organ Specificity; D012333:RNA, Messenger / Q000235:genetics*; D051381:Rats; D013087:Spermatids / Q000378:metabolism / Q000648:ultrastructure; D013094:Spermatozoa / Q000502:physiology*; D013737:Testis / Q000502:physiology; D014158:Transcription, Genetic
chemical_list: D012333:RNA, Messenger; D002766:Cholecystokinin