Developmental Genetics of Secretory Vesicle Acidification During Caenorhabditis elegans Spermatogenesis
| Autor: | Elizabeth J. Gleason, Paul D. Hartley, Robby M. Weimer, Tim L. Kroft, Steven W. L'Hernault, Suzanne Cordovado, Guang-dan Zhu, Melissa Henderson, Paul W. Price, Katherine L. Hill-Harfe |
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| Rok vydání: | 2012 |
| Předmět: |
Male
Vacuolar Proton-Translocating ATPases Protein subunit Molecular Sequence Data Mutant Gene Expression Investigations Biology medicine.disease_cause Testis Genetics medicine Animals Amino Acid Sequence Caenorhabditis elegans Caenorhabditis elegans Proteins Spermatogenesis X chromosome Mutation Spermatid Secretory Vesicles biology.organism_classification Spermatozoa Molecular biology Secretory Vesicle Protein Transport medicine.anatomical_structure Sequence Alignment |
| Zdroj: | Genetics. 191:477-491 |
| ISSN: | 1943-2631 |
| DOI: | 10.1534/genetics.112.139618 |
| Popis: | Secretory vesicles are used during spermatogenesis to deliver proteins to the cell surface. In Caenorhabditis elegans, secretory membranous organelles (MO) fuse with the plasma membrane to transform spermatids into fertilization-competent spermatozoa. We show that, like the acrosomal vesicle of mammalian sperm, MOs undergo acidification during development. Treatment of spermatids with the V-ATPase inhibitor bafilomycin blocks both MO acidification and formation of functional spermatozoa. There are several spermatogenesis-defective mutants that cause defects in MO morphogenesis, including spe-5. We determined that spe-5, which is on chromosome I, encodes one of two V-ATPase B paralogous subunits. The spe-5 null mutant is viable but sterile because it forms arrested, multi-nucleate spermatocytes. Immunofluorescence with a SPE-5-specific monoclonal antibody shows that SPE-5 expression begins in spermatocytes and is found in all subsequent stages of spermatogenesis. Most SPE-5 is discarded into the residual body during spermatid budding, but a small amount remains in budded spermatids where it localizes to MOs as a discrete dot. The other V-ATPase B subunit is encoded by vha-12, which is located on the X chromosome. Usually, spe-5 mutants are self-sterile in a wild-type vha-12 background. However, an extrachromosomal transgene containing wild-type vha-12 driven by its own promoter allows spe-5 mutant hermaphrodites to produce progeny, indicating that VHA-12 can at least partially substitute for SPE-5. Others have shown that the X chromosome is transcriptionally silent in the male germline, so expression of the autosomally located spe-5 gene ensures that a V-ATPase B subunit is present during spermatogenesis. |
| Databáze: | OpenAIRE |
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