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Banerjee RP, Srayko M. Sperm-specific glycogen synthase kinase 3 is required for sperm motility and the post-fertilization signal for female meiosis II in Caenorhabditis elegans. Development 2022; 149:275553. [DOI: 10.1242/dev.200229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 04/12/2022] [Indexed: 11/20/2022]
Abstract
ABSTRACT
In most sexually reproducing animals, sperm entry provides the signal to initiate the final stages of female meiosis. In Caenorhabditis elegans, this signal is required for completion of female anaphase I and entry into meiosis II (MII). memi-1/2/3 (meiosis-to-mitosis) encode maternal components that facilitate this process; memi-1/2/3(RNAi) results in a skipped-MII phenotype. Previously, we used a gain-of-function mutation, memi-1(sb41), to identify genetic suppressors that represent candidates for the sperm-delivered signal. Herein, we characterize two suppressors of memi-1(sb41): gskl-1 and gskl-2. Both genes encode functionally redundant sperm glycogen synthase kinase, type 3 (GSK3) protein kinases. Loss of both genes causes defects in male spermatogenesis, sperm pseudopod treadmilling and paternal-effect embryonic lethality. The two kinases locate within the pseudopod of activated sperm, suggesting that they directly or indirectly regulate the sperm cytoskeletal polymer major sperm protein (MSP). The GSK3 genes genetically interact with another memi-1(sb41) suppressor, gsp-4, which encodes a sperm-specific PP1 phosphatase, previously proposed to regulate MSP dynamics. Moreover, gskl-2 gsp-4; gskl-1 triple mutants often skip female MII, similar to memi-1/2/3(RNAi). The GSK3 kinases and PP1 phosphatases perform similar sperm-related functions and work together for post-fertilization functions in the oocyte that involve MEMI.
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Affiliation(s)
| | - Martin Srayko
- University of Alberta Department of Biological Sciences , , Edmonton, AB T6G 2E9 , Canada
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Released ATP Mediates Spermatozoa Chemotaxis Promoted by Uterus-Derived Factor (UDF) in Ascaris suum. Int J Mol Sci 2022; 23:ijms23074069. [PMID: 35409429 PMCID: PMC8999757 DOI: 10.3390/ijms23074069] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/21/2022] [Accepted: 03/21/2022] [Indexed: 11/21/2022] Open
Abstract
Fertilization requires sperm migration toward oocytes and subsequent fusion. Sperm chemotaxis, a process in which motile sperm are attracted by factors released from oocytes or associated structures, plays a key role in sperm migration to oocytes. Here, we studied sperm chemotaxis in the nematode Ascaris suum. Our data show that uterus-derived factor (UDF), the protein fraction of uterine extracts, can attract spermatozoa. UDF is heat resistant, but its activity is attenuated by certain proteinases. UDF binds to the surface of spermatozoa but not spermatids, and this process is mediated by membranous organelles that fuse with the plasma membrane. UDF induces spermatozoa to release ATP from intracellular storage sites to the extracellular milieu, and extracellular ATP modulates sperm chemotaxis. Moreover, UDF increases protein serine phosphorylation (pS) levels in sperm, which facilitates sperm chemotaxis. Taken together, we revealed that both extracellular ATP and intracellular pS signaling are involved in Ascaris sperm chemotaxis. Our data provide insights into the mechanism of sperm chemotaxis in Ascaris suum.
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Havrylenko S, Mezanges X, Batchelder E, Plastino J. Extending the molecular clutch beyond actin-based cell motility. NEW JOURNAL OF PHYSICS 2014; 16:105012. [PMID: 25383039 DOI: 10.1088/1367-2630/16/10/105012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Many cell movements occur via polymerization of the actin cytoskeleton beneath the plasma membrane at the front of the cell, forming a protrusion called a lamellipodium, while myosin contraction squeezes forward the back of the cell. In what is known as the "molecular clutch" description of cell motility, forward movement results from the engagement of the acto-myosin motor with cell-matrix adhesions, thus transmitting force to the substrate and producing movement. However during cell translocation, clutch engagement is not perfect, and as a result, the cytoskeleton slips with respect to the substrate, undergoing backward (retrograde) flow in the direction of the cell body. Retrograde flow is therefore inversely proportional to cell speed and depends on adhesion and acto-myosin dynamics. Here we asked whether the molecular clutch was a general mechanism by measuring motility and retrograde flow for the Caenorhabditis elegans sperm cell in different adhesive conditions. These cells move by adhering to the substrate and emitting a dynamic lamellipodium, but the sperm cell does not contain an acto-myosin cytoskeleton. Instead the lamellipodium is formed by the assembly of Major Sperm Protein (MSP), which has no biochemical or structural similarity to actin. We find that these cells display the same molecular clutch characteristics as acto-myosin containing cells. We further show that retrograde flow is produced both by cytoskeletal assembly and contractility in these cells. Overall this study shows that the molecular clutch hypothesis of how polymerization is transduced into motility via adhesions is a general description of cell movement regardless of the composition of the cytoskeleton.
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Affiliation(s)
- Svitlana Havrylenko
- Institut Curie, Centre de Recherche, Paris, F-75248 France ; Centre National de la Recherche Scientifique, Unité Mixte de Recherche 168, Paris, F-75248 France ; Université Pierre et Marie Curie, Paris F-75248, France
| | - Xavier Mezanges
- Institut Curie, Centre de Recherche, Paris, F-75248 France ; Centre National de la Recherche Scientifique, Unité Mixte de Recherche 168, Paris, F-75248 France ; Université Pierre et Marie Curie, Paris F-75248, France
| | - Ellen Batchelder
- Institut Curie, Centre de Recherche, Paris, F-75248 France ; Centre National de la Recherche Scientifique, Unité Mixte de Recherche 168, Paris, F-75248 France ; Université Pierre et Marie Curie, Paris F-75248, France
| | - Julie Plastino
- Institut Curie, Centre de Recherche, Paris, F-75248 France ; Centre National de la Recherche Scientifique, Unité Mixte de Recherche 168, Paris, F-75248 France ; Université Pierre et Marie Curie, Paris F-75248, France
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Muhlrad PJ, Clark JN, Nasri U, Sullivan NG, LaMunyon CW. SPE-8, a protein-tyrosine kinase, localizes to the spermatid cell membrane through interaction with other members of the SPE-8 group spermatid activation signaling pathway in C. elegans. BMC Genet 2014; 15:83. [PMID: 25022984 PMCID: PMC4105102 DOI: 10.1186/1471-2156-15-83] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 07/03/2014] [Indexed: 01/04/2023] Open
Abstract
Background The SPE-8 group gene products transduce the signal for spermatid activation initiated by extracellular zinc in C. elegans. Mutations in the spe-8 group genes result in hermaphrodite-derived spermatids that cannot activate to crawling spermatozoa, although spermatids from mutant males activate through a pathway induced by extracellular TRY-5 protease present in male seminal fluid. Results Here, we identify SPE-8 as a member of a large family of sperm-expressed non-receptor-like protein-tyrosine kinases. A rescuing SPE-8::GFP translational fusion reporter localizes to the plasma membrane in all spermatogenic cells from the primary spermatocyte stage through spermatids. Once spermatids become activated to spermatozoa, the reporter moves from the plasma membrane to the cytoplasm. Mutations in the spe-8 group genes spe-12, spe-19, and spe-27 disrupt localization of the reporter to the plasma membrane, while localization appears near normal in a spe-29 mutant background. Conclusions These results suggest that the SPE-8 group proteins form a functional complex localized at the plasma membrane, and that SPE-8 is correctly positioned only when all members of the SPE-8 group are present, with the possible exception of SPE-29. Further, SPE-8 is released from the membrane when the activation signal is transduced into the spermatid.
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Affiliation(s)
| | | | | | | | - Craig W LaMunyon
- Department of Biological Science, California State Polytechnic University, 3801 W, Temple Ave, Pomona, CA 91768, USA.
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Role of posttranslational modifications in C. elegans and ascaris spermatogenesis and sperm function. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 759:215-39. [PMID: 25030766 DOI: 10.1007/978-1-4939-0817-2_10] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Generally, spermatogenesis and sperm function involve widespread posttranslational modification of regulatory proteins in many different species. Nematode spermatogenesis has been studied in detail, mostly by genetic/molecular genetic techniques in the free-living Caenorhabditis elegans and by biochemistry/cell biology in the pig parasite Ascaris suum. Like other nematodes, both of these species produce sperm that use a form of amoeboid motility termed crawling, and many aspects of spermatogenesis are likely to be similar in both species. Consequently, work in these two nematode species has been largely complementary. Work in C. elegans has identified a number of spermatogenesis-defective genes and, so far, 12 encode enzymes that are implicated as catalysts of posttranslational protein modification. Crawling motility involves extension of a single pseudopod and this process is powered by a unique cytoskeleton composed of Major Sperm Protein (MSP) and accessory proteins, instead of the more widely observed actin. In Ascaris, pseudopod extension and crawling motility can be reconstituted in vitro, and biochemical studies have begun to reveal how posttranslational protein modifications, including phosphorylation, dephosphorylation and proteolysis, participate in these processes.
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Shang Y, Chen L, Liu Z, Wang X, Ma X, Miao L. Cytosolic Ca(2+) as a multifunctional modulator is required for spermiogenesis in Ascaris suum. Protein Cell 2013; 4:456-66. [PMID: 23686736 DOI: 10.1007/s13238-013-3019-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 04/07/2013] [Indexed: 10/26/2022] Open
Abstract
The dynamic polar polymers actin filaments and microtubules are usually employed to provide the structural basis for establishing cell polarity in most eukaryotic cells. Radially round and immotile spermatids from nematodes contain almost no actin or tubulin, but still have the ability to break symmetry to extend a pseudopod and initiate the acquisition of motility powered by the dynamics of cytoskeleton composed of major sperm protein (MSP) during spermiogenesis (sperm activation). However, the signal transduction mechanism of nematode sperm activation and motility acquisition remains poorly understood. Here we show that Ca(2+) oscillations induced by the Ca(2+) release from intracellular Ca(2+) store through inositol (1,4,5)-trisphosphate receptor are required for Ascaris suum sperm activation. The chelation of cytosolic Ca(2+) suppresses the generation of a functional pseudopod, and this suppression can be relieved by introducing exogenous Ca(2+) into sperm cells. Ca(2+) promotes MSP-based sperm motility by increasing mitochondrial membrane potential and thus the energy supply required for MSP cytoskeleton assembly. On the other hand, Ca(2+) promotes MSP disassembly by activating Ca(2+)/calmodulin-dependent serine/threonine protein phosphatase calcineurin. In addition, Ca(2+)/camodulin activity is required for the fusion of sperm-specifi c membranous organelle with the plasma membrane, a regulated exocytosis required for sperm motility. Thus, Ca(2+) plays multifunctional roles during sperm activation in Ascaris suum.
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Affiliation(s)
- Yunlong Shang
- Laboratory of Noncoding RNA, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
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Singaravelu G, Singson A. Calcium signaling surrounding fertilization in the nematode Caenorhabditis elegans. Cell Calcium 2012; 53:2-9. [PMID: 23218668 DOI: 10.1016/j.ceca.2012.11.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 11/02/2012] [Accepted: 11/03/2012] [Indexed: 01/17/2023]
Abstract
Calcium plays a prominent role during fertilization in many animals. This review focuses on roles of Ca(2+) during the events around fertilization in the model organism, Caenorhabditis elegans. Specifically, the role of Ca(2+) in sperm, oocytes and the surrounding somatic tissues during fertilization will be discussed, with the focus on sperm activation, meiotic maturation of oocytes, ovulation, sperm-egg interaction and fertilization.
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Ma X, Zhao Y, Sun W, Shimabukuro K, Miao L. Transformation: how do nematode sperm become activated and crawl? Protein Cell 2012; 3:755-61. [PMID: 22903434 PMCID: PMC4875351 DOI: 10.1007/s13238-012-2936-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Accepted: 05/09/2012] [Indexed: 01/16/2023] Open
Abstract
Nematode sperm undergo a drastic physiological change during spermiogenesis (sperm activation). Unlike mammalian flagellated sperm, nematode sperm are amoeboid cells and their motility is driven by the dynamics of a cytoskeleton composed of major sperm protein (MSP) rather than actin found in other crawling cells. This review focuses on sperm from Caenorhabditis elegans and Ascaris suum to address the roles of external and internal factors that trigger sperm activation and power sperm motility. Nematode sperm can be activated in vitro by several factors, including Pronase and ionophores, and in vivo through the TRY-5 and SPE-8 pathways. Moreover, protease and protease inhibitors are crucial regulators of sperm maturation. MSP-based sperm motility involves a coupled process of protrusion and retraction, both of which have been reconstituted in vitro. Sperm motility is mediated by phosphorylation signals, as illustrated by identification of several key components (MPOP, MFPs and MPAK) in Ascaris and the characterization of GSP-3/4 in C. elegans.
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Affiliation(s)
- Xuan Ma
- Laboratory of Noncoding RNA, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101 China
| | - Yanmei Zhao
- Laboratory of Noncoding RNA, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101 China
| | - Wei Sun
- Laboratory of Noncoding RNA, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101 China
- Graduate University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Katsuya Shimabukuro
- Department of Chemical and Biological Engineering, Ube National College of Technology, Ube, Yamaguchi, 755-8555 Japan
| | - Long Miao
- Laboratory of Noncoding RNA, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101 China
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Nematode sperm maturation triggered by protease involves sperm-secreted serine protease inhibitor (Serpin). Proc Natl Acad Sci U S A 2012; 109:1542-7. [PMID: 22307610 DOI: 10.1073/pnas.1109912109] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Spermiogenesis is a series of poorly understood morphological, physiological and biochemical processes that occur during the transition of immotile spermatids into motile, fertilization-competent spermatozoa. Here, we identified a Serpin (serine protease inhibitor) family protein (As_SRP-1) that is secreted from spermatids during nematode Ascaris suum spermiogenesis (also called sperm activation) and we showed that As_SRP-1 has two major functions. First, As_SRP-1 functions in cis to support major sperm protein (MSP)-based cytoskeletal assembly in the spermatid that releases it, thereby facilitating sperm motility acquisition. Second, As_SRP-1 released from an activated sperm inhibits, in trans, the activation of surrounding spermatids by inhibiting vas deferens-derived As_TRY-5, a trypsin-like serine protease necessary for sperm activation. Because vesicular exocytosis is necessary to create fertilization-competent sperm in many animal species, components released during this process might be more important modulators of the physiology and behavior of surrounding sperm than was previously appreciated.
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Roberts TM, Stewart M. Role of Major Sperm Protein (MSP) in the Protrusion and Retraction of Ascaris Sperm. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2012; 297:265-93. [DOI: 10.1016/b978-0-12-394308-8.00007-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Sperm development and motility are regulated by PP1 phosphatases in Caenorhabditis elegans. Genetics 2011; 190:143-57. [PMID: 22042574 DOI: 10.1534/genetics.111.135376] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Sperm from different species have evolved distinctive motility structures, including tubulin-based flagella in mammals and major sperm protein (MSP)-based pseudopods in nematodes. Despite such divergence, we show that sperm-specific PP1 phosphatases, which are required for male fertility in mouse, function in multiple processes in the development and motility of Caenorhabditis elegans amoeboid sperm. We used live-imaging analysis to show the PP1 phosphatases GSP-3 and GSP-4 (GSP-3/4) are required to partition chromosomes during sperm meiosis. Postmeiosis, tracking fluorescently labeled sperm revealed that both male and hermaphrodite sperm lacking GSP-3/4 are immotile. Genetic and in vitro activation assays show lack of GSP-3/4 causes defects in pseudopod development and the rate of pseudopodial treadmilling. Further, GSP-3/4 are required for the localization dynamics of MSP. GSP-3/4 shift localization in concert with MSP from fibrous bodies that sequester MSP at the base of the pseudopod, where directed MSP disassembly facilitates pseudopod contraction. Consistent with a role for GSP-3/4 as a spatial regulator of MSP disassembly, MSP is mislocalized in sperm lacking GSP-3/4. Although a requirement for PP1 phosphatases in nematode and mammalian sperm suggests evolutionary conservation, we show PP1s have independently evolved sperm-specific paralogs in separate lineages. Thus PP1 phosphatases are highly adaptable and employed across a broad range of sexually reproducing species to regulate male fertility.
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Comparative transcriptome sequencing of germline and somatic tissues of the Ascaris suum gonad. BMC Genomics 2011; 12:481. [PMID: 21962222 PMCID: PMC3203103 DOI: 10.1186/1471-2164-12-481] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Accepted: 10/01/2011] [Indexed: 11/16/2022] Open
Abstract
Background Ascaris suum (large roundworm of pigs) is a parasitic nematode that causes substantial losses to the meat industry. This nematode is suitable for biochemical studies because, unlike C. elegans, homogeneous tissue samples can be obtained by dissection. It has large sperm, produced in great numbers that permit biochemical studies of sperm motility. Widespread study of A. suum would be facilitated by more comprehensive genome resources and, to this end, we have produced a gonad transcriptome of A. suum. Results Two 454 pyrosequencing runs generated 572,982 and 588,651 reads for germline (TES) and somatic (VAS) tissues of the A. suum gonad, respectively. 86% of the high-quality (HQ) reads were assembled into 9,955 contigs and 69,791 HQ reads remained as singletons. 2.4 million bp of unique sequences were obtained with a coverage that reached 16.1-fold. 4,877 contigs and 14,339 singletons were annotated according to the C. elegans protein and the Kyoto Encyclopedia of Genes and Genomes (KEGG) protein databases. Comparison of TES and VAS transcriptomes demonstrated that genes participating in DNA replication, RNA transcription and ubiquitin-proteasome pathways are expressed at significantly higher levels in TES tissues than in VAS tissues. Comparison of the A. suum TES transcriptome with the C. elegans microarray dataset identified 165 A. suum germline-enriched genes (83% are spermatogenesis-enriched). Many of these genes encode serine/threonine kinases and phosphatases (KPs) as well as tyrosine KPs. Immunoblot analysis further suggested a critical role of phosphorylation in both testis development and spermatogenesis. A total of 2,681 A. suum genes were identified to have associated RNAi phenotypes in C. elegans, the majority of which display embryonic lethality, slow growth, larval arrest or sterility. Conclusions Using deep sequencing technology, this study has produced a gonad transcriptome of A. suum. By comparison with C. elegans datasets, we identified sets of genes associated with spermatogenesis and gonad development in A. suum. The newly identified genes encoding KPs may help determine signaling pathways that operate during spermatogenesis. A large portion of A. suum gonadal genes have related RNAi phenotypes in C. elegans and, thus, might be RNAi targets for parasite control.
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Fraire-Zamora JJ, Broitman-Maduro G, Maduro M, Cardullo RA. Evidence for phosphorylation in the MSP cytoskeletal filaments of amoeboid spermatozoa. INTERNATIONAL JOURNAL OF BIOCHEMISTRY AND MOLECULAR BIOLOGY 2011; 2:263-273. [PMID: 22003439 PMCID: PMC3193295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Accepted: 08/17/2011] [Indexed: 05/31/2023]
Abstract
Nematode spermatozoa are highly specialized cells that lack flagella and, instead, extend a pseudopod to initiate motility. Crawling spermatozoa display classic features of amoeboid motility (e.g. protrusion of a pseudopod that attaches to the substrate and the assembly and disassembly of cytoskeletal filaments involved in cell traction and locomotion), however, cytoskeletal dynamics in these cells are powered exclusively by Major Sperm Protein (MSP) rather than actin and no other molecular motors have been identified. Thus, MSP-based motility is regarded as a simple locomotion machinery suitable for the study of plasma membrane protrusion and cell motility in general. This recent focus on MSP dynamics has increased the necessity of a standardized methodology to obtain C. elegans sperm extract that can be used in biochemical assays and proteomic analysis for comparative studies. In the present work we have modified a method to reproducibly obtain relative high amounts of proteins from C. elegans sperm extract. We show that these extracts share some of the properties observed in sperm extracts from the parasitic nematode Ascaris including Major Sperm Protein (MSP) precipitation and MSP fiber elongation. Using this method coupled to immunoblot detection, Mass Spectrometry identification, in silico prediction of functional domains and biochemical assays, our results indicate the presence of phosphorylation sites in MSP of Caenorhabditis elegans spermatozoa.
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Singaravelu G, Singson A. New insights into the mechanism of fertilization in nematodes. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2011; 289:211-38. [PMID: 21749902 PMCID: PMC3273857 DOI: 10.1016/b978-0-12-386039-2.00006-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Fertilization results from the fusion of male and female gametes in all sexually reproducing organisms. Much of nematode fertility work was focused on Caenorhabditis elegans and Ascaris suum. The C. elegans hermaphrodite produces a limited number of sperm initially and then commits to the exclusive production of oocytes. The postmeiotic differentiation called spermiogenesis converts sessile spermatids into motile spermatozoa. The motility of spermatozoa depends on dynamic assembly and disassembly of a major sperm protein-based cytoskeleton uniquely found in nematodes. Both self-derived and male-derived spermatozoa are stored in spermatheca, the site of fertilization in hermaphrodites. The oocyte is arrested in meiotic prophase I until a sperm-derived signal relieves the inhibition allowing the meiotic maturation to occur. Oocyte undergoes meiotic maturation, enters into spermatheca, gets fertilized, completes meiosis, and exits into uterus as a zygote. This review focuses on our current understanding of the events around fertilization in nematodes.
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Fraire-Zamora JJ, Cardullo RA. The physiological acquisition of amoeboid motility in nematode sperm: is the tail the only thing the sperm lost? Mol Reprod Dev 2010; 77:739-50. [PMID: 20803732 DOI: 10.1002/mrd.21193] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Nematode spermatozoa are highly specialized amoeboid cells that must acquire motility through the extension of a single pseudopod. Despite morphological and molecular differences with flagellated spermatozoa (including a non-actin-based cytoskeleton), nematode sperm must also respond to cues present in the female reproductive tract that render them motile, thereby allowing them to locate and fertilize the egg. The factors that trigger pseudopod extension in vivo are unknown, although current models suggest the activation through proteases acting on the sperm surface resulting in a myriad of biochemical, physiological, and morphological changes. Compelling evidence shows that pseudopod extension is under the regulation of physiological events also observed in other eukaryotic cells (including flagellated sperm) that involve membrane rearrangements in response to extracellular cues that initiate various signal transduction pathways. An integrative approach to the study of nonflagellated spermatozoa will shed light on the identification of unique and conserved processes during fertilization among different taxa.
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Affiliation(s)
- Juan J Fraire-Zamora
- Department of Biology and the Graduate Program in Evolution, Ecology, and Organismal Biology, University of California, Riverside, California 92521, USA
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Nishimura H, L'Hernault SW. Spermatogenesis-defective (spe) mutants of the nematode Caenorhabditis elegans provide clues to solve the puzzle of male germline functions during reproduction. Dev Dyn 2010; 239:1502-14. [PMID: 20419782 DOI: 10.1002/dvdy.22271] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
In most species, each sex produces gametes, usually either sperm or oocytes, from its germline during gametogenesis. The sperm and oocyte subsequently fuse together during fertilization to create the next generation. This review focuses on spermatogenesis and the roles of sperm during fertilization in the nematode Caenorhabditis elegans, where suitable mutants are readily obtained. So far, 186 mutants defective in the C. elegans male germline functions have been isolated, and many of these mutations are alleles for one of the approximately 60 spermatogenesis-defective (spe) genes. Many cloned spe genes are expressed specifically in the male germline, where they play roles during spermatogenesis (spermatid production), spermiogenesis (spermatid activation into spermatozoa), and/or fertilization. Moreover, several spe genes are orthologs of mammalian genes, suggesting that the reproductive processes of the C. elegans and the mammalian male germlines might share common pathways at the molecular level.
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Affiliation(s)
- Hitoshi Nishimura
- Department of Biology, Emory University, Atlanta, Georgia 30322, USA
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Biochemical mechanisms for regulating protrusion by nematode major sperm protein. Biophys J 2009; 97:748-57. [PMID: 19651033 DOI: 10.1016/j.bpj.2009.05.038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2009] [Revised: 05/18/2009] [Accepted: 05/19/2009] [Indexed: 11/22/2022] Open
Abstract
Crawling motion is ubiquitous in eukaryotic cells and contributes to important processes such as immune response and tumor growth. To crawl, a cell must adhere to the substrate, while protruding at the front and retracting at the rear. In most crawling cells protrusion is driven by highly regulated polymerization of the actin cytoskeleton, and much of the biochemical network for this process is known. Nematode sperm utilize a cytoskeleton composed of Major Sperm Protein (MSP), which is considered to form a simpler, yet similar, crawling motility apparatus. Key components involved in the polymerization of MSP have been identified; however, little is known about the chemical kinetics for this system. Here we develop a model for MSP polymerization that takes into account the effects of several of the experimentally identified cytosolic and membrane-bound proteins. To account for some of the data, the model requires force-dependent polymerization, as is predicted by Brownian ratchet mechanisms. Using the tethered polymerization ratchet model with our biochemical kinetic model for MSP polymerization, we find good agreement with experimental data on MSP-driven protrusion. In addition, our model predicts the force-velocity relation that is expected for in vitro protrusion assays.
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Yi K, Wang X, Emmett MR, Marshall AG, Stewart M, Roberts TM. Dephosphorylation of major sperm protein (MSP) fiber protein 3 by protein phosphatase 2A during cell body retraction in the MSP-based amoeboid motility of Ascaris sperm. Mol Biol Cell 2009; 20:3200-8. [PMID: 19458186 DOI: 10.1091/mbc.e09-03-0240] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The crawling movement of nematode sperm requires coordination of leading edge protrusion with cell body retraction, both of which are powered by modulation of a cytoskeleton based on major sperm protein (MSP) filaments. We used a cell-free in vitro motility system in which both protrusion and retraction can be reconstituted, to identify two proteins involved in cell body retraction. Pharmacological and depletion-add back assays showed that retraction was triggered by a putative protein phosphatase 2A (PP2A, a Ser/Thr phosphatase activated by tyrosine dephosphorylation). Immunofluorescence showed that PP2A was present in the cell body and was concentrated at the base of the lamellipod where the force for retraction is generated. PP2A targeted MSP fiber protein 3 (MFP3), a protein unique to nematode sperm that binds to the MSP filaments in the motility apparatus. Dephosphorylation of MFP3 caused its release from the cytoskeleton and generated filament disassembly. Our results suggest that interaction between PP2A and MFP3 leads to local disassembly of the MSP cytoskeleton at the base of the lamellipod in sperm that in turn pulls the trailing cell body forward.
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Affiliation(s)
- Kexi Yi
- Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA
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20
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Demekhin E, Haugen N, Ibanez B, Lederman J, Murphy K, Verzi D, Witczak D. The geometry and motion of nematode sperm cells. CELL MOTILITY AND THE CYTOSKELETON 2009; 66:317-27. [PMID: 19396868 DOI: 10.1002/cm.20362] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The nematode sperm cell crawls by recycling major sperm protein (MSP) from dimers into subfilaments, filaments, and filament complexes, as a result of thermal writhing in the presence of hydrophobic patches. Polymerization near leading edges of the cell intercolates MSP dimers onto the tips of growing filament complexes, forcing them against the cell boundary, and extending the cytoskeleton in the direction of motion. Strong adhesive forces attach the cell to the substrate in the forward part of the lamellipod, while depolymerization in the rearward part of the cell breaks down the cytoskeleton, contracting the lamellipod and pulling the cell body forward. The movement of these cells, then, is caused by coordinated protrusive, adhesive and contractile forces, spatially separated across the lamellipod. This paper considers a phenomenological model that tracks discrete elements of the cytoskeleton in curvilinear coordinates. The pseudo-two dimensional model primarily considers protrusion and rotation of the cell, along with the evolution of the cell boundary. General assumptions are that pH levels within the lamellipod regulate protrusion, contraction and adhesion, and that growth of the cytoskeleton, over time, is perpendicular to the evolving cell boundary. The model follows the growth and contraction of a discrete number of MSP fiber complexes, since they appear to be the principle contributors for force generation in cell boundary protrusion and contraction, and the backbone for the dynamic geometry and motion.
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Affiliation(s)
- Evgeny Demekhin
- Department of Mechanics and Mathematics-Chair of Higher Algebra, Moscow State University, Moscow, Russia
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21
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Cantacessi C, Zou FC, Hall RS, Zhong W, Jex AR, Campbell BE, Ranganathan S, Sternberg PW, Zhu XQ, Gasser RB. Bioinformatic analysis of abundant, gender-enriched transcripts of adult Ascaris suum (Nematoda) using a semi-automated workflow platform. Mol Cell Probes 2009; 23:205-17. [PMID: 19361552 DOI: 10.1016/j.mcp.2009.03.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2009] [Revised: 03/12/2009] [Accepted: 03/16/2009] [Indexed: 12/17/2022]
Abstract
Expressed sequence tag (EST) data representing transcripts with a high level of differential hybridization in suppressive-subtractive hybridization (SSH)-based microarray analysis between adult female and male Ascaris suum were subjected to detailed bioinformatic analysis. A total of 361 ESTs clustered into 209 sequences, of which 52 and 157 represented transcripts that were enriched in female and male A. suum, respectively. Thirty (57.7%) of the 'female' subset of 52 sequences had orthologues/homologues in other parasitic nematodes and/or Caenorhabditis elegans, 13 (25%) exclusively in other parasitic nematodes and nine (17.3%) had no match in any other organism for which sequence data are currently available; the C. elegans orthologues encoded molecules involved in reproduction as well as embryonic and gamete development, such as vitellogenins and chitin-binding proteins. Of the 'male' subset of 157 sequences, 73 (46.5%) had orthologues/homologues in other parasitic nematodes and/or C. elegans, 57 (37.5%) in other parasitic nematodes only, and 22 (14.5%) had no significant similarity match in any other organism; the C. elegans orthologues encoded predominantly major sperm proteins (MSPs), kinases and phosphatases, actins, myosins and an Ancylostoma secreted protein-like molecule. The findings of the present study should support further genomic investigations of A. suum.
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Affiliation(s)
- C Cantacessi
- Department of Veterinary Science, The University of Melbourne, Victoria, Australia
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22
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Wang B. [Recent advances in the study of spermatogenesis and fertilization in Caenorhabditis elegans]. YI CHUAN = HEREDITAS 2008; 30:677-86. [PMID: 18550488 DOI: 10.3724/sp.j.1005.2008.00677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Spermatogenesis in Caenorhabditis elegans, mainly consisting of meiosis and spermiogenesis (or sperm activation), is a complicated cell differentiation process. The germ cells develop into matured motile spermatozoa after the expression of specific genes during meiosis and protein posttranslational modification during spermiogenesis. The spermatozoa compete with each other, communicate with and finally fertilize the oocytes such that new individuals are generated. A group of mutants related to spermatogenesis, sperm motility and fertilization are obtained through the sterile screen. Some specific genes in spermatogenesis and fertilization have been cloned and their functions have been studied. C. elegans is an attractive model to dissect the complexities of spermatogenesis and fertilization. The advances in the study of C. elegans may give insights to important targets for the study of male infertility and contraceptives in humans.
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Affiliation(s)
- Bin Wang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
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