Related Experiment Video
Updated: Aug 23, 2026
RiboTag Immunoprecipitation in the Germ Cells of the Male Mouse
Published on: March 4, 2020
MSP domain proteins show enhanced expression in male germ line cells
1The W Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA.
Abstract:
Nematode sperm utilize a crawling motility based on polymerization--depolymerization of a nematode-specific cytoskeletal molecule-major sperm protein (MSP). While several proteins that interact with and regulate MSP filament formation have been identified using in vitro approaches, it is likely that additional molecules participate in vivo in the regulation of MSP cytoskeletal dynamics. By comparing EST data generated from an Ascaris suum testis germinal zone cDNA library with EST data from other tissue- and stage-specific A. suum cDNA libraries and with expression profile data from Caenorhabditis elegans, 42 genes were selected with exclusive or enhanced expression in male germ line cells. In addition to 11 protein kinases and seven protein phosphatases, 10 genes encoding proteins with protein-protein interaction domains were identified. These potential cytoskeletal modifiers included five novel MSP-domain proteins (As-MDPs). All five As-mdps were highly expressed in male germ line cells, but only As-mdp-2, 3 and 5 were transcribed exclusively in the testis. The prediction that As-MDP-1, 2 and 3 were cytosolic components and that As-MDP-4 and 5 were associated with the sperm cell membrane proteins was supported by the results of immunoblotting experiments. The 23 members of the MDP family of proteins from C. elegans were predicted to be transcribed in the testis. The findings provide additional candidates to the growing list of molecules that regulate MSP cytoskeletal dynamics.
Insights
Researchers identified novel genes, including five major sperm protein-domain proteins (As-MDPs), that are exclusively expressed in male germ cells. These findings offer new insights into the regulation of nematode sperm motility and cytoskeletal dynamics.
Area of Science:
- Cell Biology
- Molecular Biology
- Genetics
Background:
- Nematode sperm motility relies on the dynamic polymerization and depolymerization of major sperm protein (MSP).
- While some MSP-regulating proteins are known, in vivo regulators of MSP cytoskeletal dynamics remain largely uncharacterized.
Purpose of the Study:
- To identify novel genes involved in regulating major sperm protein (MSP) cytoskeletal dynamics in vivo.
- To discover new molecules that specifically function in male germ line cells and nematode sperm.
Main Methods:
- Comparative analysis of expressed sequence tag (EST) data from Ascaris suum testis germinal zone and other tissues.
- Comparison with expression profile data from Caenorhabditis elegans.
- Bioinformatic selection of genes with male germ line-specific or enhanced expression.
- Immunoblotting experiments to validate protein localization.
Main Results:
- 42 genes showed exclusive or enhanced expression in male germ line cells.
- Identified 11 protein kinases, 7 protein phosphatases, and 10 genes encoding proteins with protein-protein interaction domains.
- Discovered five novel MSP-domain proteins (As-MDPs), with As-MDP-2, 3, and 5 exclusively transcribed in the testis.
- Confirmed cytosolic and sperm cell membrane localization for specific As-MDPs through immunoblotting.
- Predicted transcription of 23 MDP family members in the C. elegans testis.
Conclusions:
- Identified novel candidate genes, including five As-MDPs, that likely regulate MSP cytoskeletal dynamics in vivo.
- These findings expand the known molecular machinery controlling nematode sperm motility.
- The study provides a foundation for further investigation into the function of these novel proteins.
Related Concept Videos
02:19The Y Chromosome Determines Maleness
Evolution
Around 300 million years ago, the two sex chromosomes diverged from two identical autosomal chromosomes. Over time, the Y chromosome has lost most of its genes, shrinking in size. Today,...
02:50Dosage Compensation
In addition to sexual development, the X chromosome has genes involved in autosomal functions such as brain development and the immune system. Therefore, males and females with distinct numbers of X chromosomes will have...