1. Disruption of sperm release from insect testes by cytochalasin and ?-actin mRNA mediated interference
- Author
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Jadwiga M. Giebultowicz, Barbara O. Gvakharia, Piotr Bebas, and B. Cymborowski
- Subjects
Male ,endocrine system ,media_common.quotation_subject ,Circadian clock ,macromolecular substances ,Insect ,Spodoptera ,Biology ,Interference (genetic) ,Cellular and Molecular Neuroscience ,chemistry.chemical_compound ,RNA interference ,Testis ,Animals ,Cytochalasin ,Molecular Biology ,reproductive and urinary physiology ,Actin ,RNA, Double-Stranded ,media_common ,Pharmacology ,Genetics ,Base Sequence ,urogenital system ,Reproduction ,RNA ,DNA ,Cell Biology ,Cytochalasins ,Spermatozoa ,Sperm ,Actins ,Circadian Rhythm ,Cell biology ,chemistry ,Molecular Medicine ,RNA Interference - Abstract
Release of sperm bundles from moth testes is controlled by the local circadian oscillator. The mechanism which restricts migration of sperm bundles to a few hours each day is not understood. We demonstrate that a daily cycle of sperm release is initiated by the migration of folded apyrene sperm bundles through a cellular barrier at the testis base. These bundles have conspicuous concentrations of actin filaments at their proximal end. Inhibition of actin polymerization by cytochalasin at a specific time of day inhibited sperm release from the testis. Likewise, application of double-stranded actin RNA specifically inhibited sperm release. This RNA-mediated interference (RNAi) lowered the pool of actin mRNA in tissues involved in sperm release. The decline in mRNA levels resulted in the selective depletion of F-actin from the tip of apyrene sperm bundles, suggesting that this actin may be involved in the initiation of sperm release. Combined results of RNAi experiments at physiological, cellular and molecular levels identified unique cells that are critically involved in the mechanism of sperm release.
- Published
- 2003
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