1
|
Skinner MW, Simington CJ, López-Jiménez P, Baran KA, Xu J, Dayani Y, Pryzhkova MV, Page J, Gómez R, Holland AJ, Jordan PW. Spermatocytes have the capacity to segregate chromosomes despite centriole duplication failure. EMBO Rep 2024; 25:3373-3405. [PMID: 38943004 PMCID: PMC11316026 DOI: 10.1038/s44319-024-00187-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 06/13/2024] [Accepted: 06/14/2024] [Indexed: 06/30/2024] Open
Abstract
Centrosomes are the canonical microtubule organizing centers (MTOCs) of most mammalian cells, including spermatocytes. Centrosomes comprise a centriole pair within a structurally ordered and dynamic pericentriolar matrix (PCM). Unlike in mitosis, where centrioles duplicate once per cycle, centrioles undergo two rounds of duplication during spermatogenesis. The first duplication is during early meiotic prophase I, and the second is during interkinesis. Using mouse mutants and chemical inhibition, we have blocked centriole duplication during spermatogenesis and determined that non-centrosomal MTOCs (ncMTOCs) can mediate chromosome segregation. This mechanism is different from the acentriolar MTOCs that form bipolar spindles in oocytes, which require PCM components, including gamma-tubulin and CEP192. From an in-depth analysis, we identified six microtubule-associated proteins, TPX2, KIF11, NuMA, and CAMSAP1-3, that localized to the non-centrosomal MTOC. These factors contribute to a mechanism that ensures bipolar MTOC formation and chromosome segregation during spermatogenesis when centriole duplication fails. However, despite the successful completion of meiosis and round spermatid formation, centriole inheritance and PLK4 function are required for normal spermiogenesis and flagella assembly, which are critical to ensure fertility.
Collapse
Affiliation(s)
- Marnie W Skinner
- Department of Biochemistry and Molecular Biology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, USA
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Carter J Simington
- Department of Biochemistry and Molecular Biology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, USA
| | - Pablo López-Jiménez
- Department of Biology, Autonomous University of Madrid, Madrid, Spain
- MRC Laboratory of Medical Sciences, London, W12 0NN, UK
| | - Kerstin A Baran
- Department of Biochemistry and Molecular Biology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, USA
| | - Jingwen Xu
- Department of Biochemistry and Molecular Biology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, USA
| | - Yaron Dayani
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
| | - Marina V Pryzhkova
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
| | - Jesús Page
- Department of Biology, Autonomous University of Madrid, Madrid, Spain
| | - Rocío Gómez
- Department of Biology, Autonomous University of Madrid, Madrid, Spain
| | - Andrew J Holland
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Philip W Jordan
- Department of Biochemistry and Molecular Biology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, USA.
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, Bethesda, MD, USA.
| |
Collapse
|
2
|
Zhang Y, Liu G, Huang L, He X, Su Y, Nie X, Mao Z, Xing X. SUN5 interacts with nuclear membrane LaminB1 and cytoskeletal GTPase Septin12 mediating the sperm head-and-tail junction. Mol Hum Reprod 2024; 30:gaae022. [PMID: 38870534 DOI: 10.1093/molehr/gaae022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 05/21/2024] [Indexed: 06/15/2024] Open
Abstract
Acephalic spermatozoa syndrome (ASS) is a severe teratospermia with decaudated, decapitated, and malformed sperm, resulting in male infertility. Nuclear envelope protein SUN5 localizes to the junction between the sperm head and tail. Mutations in the SUN5 gene have been identified most frequently (33-47%) in ASS cases, and its molecular mechanism of action is yet to be explored. In the present study, we generated Sun5 knockout mice, which presented the phenotype of ASS. Nuclear membrane protein LaminB1 and cytoskeletal GTPases Septin12 and Septin2 were identified as potential partners for interacting with SUN5 by immunoprecipitation-mass spectrometry in mouse testis. Further studies demonstrated that SUN5 connected the nucleus by interacting with LaminB1 and connected the proximal centriole by interacting with Septin12. The binding between SUN5 and Septin12 promoted their aggregation together in the sperm neck. The disruption of the LaminB1/SUN5/Septin12 complex by Sun5 deficiency caused separation of the Septin12-proximal centriole from the nucleus, leading to the breakage of the head-to-tail junction. Collectively, these data provide new insights into the pathogenesis of ASS caused by SUN5 deficiency.
Collapse
Affiliation(s)
- Yunfei Zhang
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Gang Liu
- Institute of Reproduction and Stem Cell Engineering, Central South University, Changsha, China
| | - Lihua Huang
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Xiyi He
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Yuyan Su
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Xinmin Nie
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Zenghui Mao
- Hunan Provincial Key Laboratory of Regional Hereditary Birth Defects Prevention and Control, Changsha Hospital for Maternal & Child Health Care Affiliated to Hunan Normal University, Changsha, China
| | - Xiaowei Xing
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| |
Collapse
|
3
|
Liu R, Qu R, Li Q, Chen B, Mu J, Zeng Y, Luo Y, Xu F, Wang L, Zhang Z, Sang Q. ARRDC5 deficiency impairs spermatogenesis by affecting SUN5 and NDC1. Development 2023; 150:dev201959. [PMID: 37997706 DOI: 10.1242/dev.201959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 11/17/2023] [Indexed: 11/25/2023]
Abstract
Sperm with normal morphology and motility are essential for successful fertilization, and the strong attachment of the sperm head-tail coupling apparatus to the nuclear envelope during spermatogenesis is required to ensure the integrity of sperm for capacitation and fertilization. Here, we report that Arrdc5 is associated with spermatogenesis. The Arrdc5 knockout mouse model showed male infertility characterized by a high bent-head rate and reduced motility in sperm, which led to capacitation defects and subsequent fertilization failure. Through mass spectrometry, we found that ARRDC5 affects spermatogenesis by affecting NDC1 and SUN5. We further found that ARRDC5 might affect the vesicle-trafficking protein SEC22A-mediated transport and localization of NDC1, SUN5 and other head-tail coupling apparatus-related proteins that are responsible for initiating the attachment of the sperm head and tail. We finally performed intracytoplasmic sperm injection as a way to explore therapeutic strategies. Our findings demonstrate the essential role and the underlying molecular mechanism of ARRDC5 in anchoring the sperm head to the tail during spermatogenesis.
Collapse
Affiliation(s)
- Ruyi Liu
- Institute of Pediatrics, Children's Hospital of Fudan University, the Institutes of Biomedical Sciences, and the State Key Laboratory of Genetic Engineering, Fudan University, Shanghai 200032, China
| | - Ronggui Qu
- Institute of Pediatrics, Children's Hospital of Fudan University, the Institutes of Biomedical Sciences, and the State Key Laboratory of Genetic Engineering, Fudan University, Shanghai 200032, China
| | - Qun Li
- Institute of Pediatrics, Children's Hospital of Fudan University, the Institutes of Biomedical Sciences, and the State Key Laboratory of Genetic Engineering, Fudan University, Shanghai 200032, China
| | - Biaobang Chen
- NHC Key Lab of Reproduction Regulation (Shanghai Institute for Biomedical and Pharmaceutical Technologies), Fudan University, Shanghai 200032, China
| | - Jian Mu
- Institute of Pediatrics, Children's Hospital of Fudan University, the Institutes of Biomedical Sciences, and the State Key Laboratory of Genetic Engineering, Fudan University, Shanghai 200032, China
| | - Yang Zeng
- Institute of Pediatrics, Children's Hospital of Fudan University, the Institutes of Biomedical Sciences, and the State Key Laboratory of Genetic Engineering, Fudan University, Shanghai 200032, China
| | - Yuxi Luo
- Institute of Pediatrics, Children's Hospital of Fudan University, the Institutes of Biomedical Sciences, and the State Key Laboratory of Genetic Engineering, Fudan University, Shanghai 200032, China
| | - Fangzhou Xu
- Institute of Pediatrics, Children's Hospital of Fudan University, the Institutes of Biomedical Sciences, and the State Key Laboratory of Genetic Engineering, Fudan University, Shanghai 200032, China
| | - Lei Wang
- Institute of Pediatrics, Children's Hospital of Fudan University, the Institutes of Biomedical Sciences, and the State Key Laboratory of Genetic Engineering, Fudan University, Shanghai 200032, China
| | - Zhihua Zhang
- Institute of Pediatrics, Children's Hospital of Fudan University, the Institutes of Biomedical Sciences, and the State Key Laboratory of Genetic Engineering, Fudan University, Shanghai 200032, China
| | - Qing Sang
- Institute of Pediatrics, Children's Hospital of Fudan University, the Institutes of Biomedical Sciences, and the State Key Laboratory of Genetic Engineering, Fudan University, Shanghai 200032, China
| |
Collapse
|
4
|
Gurusaran M, Biemans JJ, Wood CW, Davies OR. Molecular insights into LINC complex architecture through the crystal structure of a luminal trimeric coiled-coil domain of SUN1. Front Cell Dev Biol 2023; 11:1144277. [PMID: 37416798 PMCID: PMC10320395 DOI: 10.3389/fcell.2023.1144277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Accepted: 06/09/2023] [Indexed: 07/08/2023] Open
Abstract
The LINC complex, consisting of interacting SUN and KASH proteins, mechanically couples nuclear contents to the cytoskeleton. In meiosis, the LINC complex transmits microtubule-generated forces to chromosome ends, driving the rapid chromosome movements that are necessary for synapsis and crossing over. In somatic cells, it defines nuclear shape and positioning, and has a number of specialised roles, including hearing. Here, we report the X-ray crystal structure of a coiled-coiled domain of SUN1's luminal region, providing an architectural foundation for how SUN1 traverses the nuclear lumen, from the inner nuclear membrane to its interaction with KASH proteins at the outer nuclear membrane. In combination with light and X-ray scattering, molecular dynamics and structure-directed modelling, we present a model of SUN1's entire luminal region. This model highlights inherent flexibility between structured domains, and raises the possibility that domain-swap interactions may establish a LINC complex network for the coordinated transmission of cytoskeletal forces.
Collapse
Affiliation(s)
- Manickam Gurusaran
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | - Jelle J. Biemans
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | - Christopher W. Wood
- Institute of Quantitative Biology, Biochemistry and Biotechnology, University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | - Owen R. Davies
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, Scotland, United Kingdom
| |
Collapse
|
5
|
Liao HQ, Guo ZY, Huang LH, Liu G, Lu JF, Zhang YF, Xing XW. WDR87 interacts with CFAP47 protein in the middle piece of spermatozoa flagella to participate in sperm tail assembly. Mol Hum Reprod 2022; 29:6960929. [PMID: 36571501 DOI: 10.1093/molehr/gaac042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 12/07/2022] [Indexed: 12/27/2022] Open
Abstract
Spermatogenesis is a complex process that includes spermatogonia self-renewal, spermatocyte meiosis and spermatozoa assembly. Recent studies have revealed that WD40-repeat domain-containing (WDR) proteins play important roles in spermatocyte division, spermatozoa flagella assembly and head shaping. In this study, we investigated the expression pattern of WDR87 and found that it was highly expressed in the testis of both humans and mice. Immunofluorescence staining revealed that mouse WDR87 was distributed in the perinuclear cytoplasm of primary spermatocytes, secondary spermatocytes and round spermatids. In the spermiogenesis stage, with extension of the nucleus, WDR87 migrated to the manchette and finally localized to the middle piece of the spermatozoa tail. Furthermore, we identified a cilia- and flagella-associated protein, CFAP47, which interacted with WDR87 in the flagellar midpiece of the spermatozoa, suggesting that WDR87 may be associated with multiple morphological abnormalities of the flagella (MMAF). Subsequently, we screened gene mutations in seven MMAF individuals and found two novel mutations in CFAP47 (c.706G>A, Val236Met; c.1337C>T, Thr446Met) in one case. Immunoblotting and immunofluorescence revealed that CFAP47 was dramatically reduced in spermatozoa from the CFAP47-mutated man. Meanwhile, the expression of WDR87 was also significantly decreased, and weak signals were detected adjacent to the spermatozoa nuclei, indicating that CFAP47 was necessary for WDR87 transportation during spermatozoa flagella biogenesis. These data indicate that WDR87 is located in the middle piece of the sperm tail and interacts with CFAP47 to form a complex which is involved in spermatozoa tail assembly.
Collapse
Affiliation(s)
- Hong-Qing Liao
- The Second Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, China.,Hengyang Nanhua-Xinghui Reproductive Health Hospital, Hengyang, China
| | - Zi-Yi Guo
- The Second Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, China.,Hengyang Nanhua-Xinghui Reproductive Health Hospital, Hengyang, China
| | - Li-Hua Huang
- Center for Experimental Medicine, Third Xiangya Hospital, Central South University, Changsha, China
| | - Gang Liu
- The Institute of Reproduction and Stem Cell Engineering, School of Basic Medical Science, Central South University, Changsha, China
| | - Jin-Feng Lu
- Hengyang Nanhua-Xinghui Reproductive Health Hospital, Hengyang, China
| | - Yun-Fei Zhang
- Center for Experimental Medicine, Third Xiangya Hospital, Central South University, Changsha, China
| | - Xiao-Wei Xing
- Center for Experimental Medicine, Third Xiangya Hospital, Central South University, Changsha, China
| |
Collapse
|
6
|
Song X, Li R, Liu G, Huang L, Li P, Feng W, Gao Q, Xing X. Nuclear Membrane Protein SUN5 Is Highly Expressed and Promotes Proliferation and Migration in Colorectal Cancer by Regulating the ERK Pathway. Cancers (Basel) 2022; 14:5368. [PMID: 36358787 PMCID: PMC9654567 DOI: 10.3390/cancers14215368] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 10/28/2022] [Accepted: 10/28/2022] [Indexed: 09/26/2023] Open
Abstract
SUN5 was first identified as a nuclear envelope protein involved in spermatocyte division. We found that SUN5 was highly expressed in some cancers, but its function and mechanism in cancer development remain unclear. In the present study, we demonstrated that SUN5 was highly expressed in colorectal cancer (CRC) tissues and cells, as indicated by bioinformatics analysis, and SUN5 promoted cell proliferation and migration in vitro. Moreover, the overexpression of SUN5 upregulated phosphorylated ERK1/2 (pERK1/2), whereas the knockdown of SUN5 yielded the opposite results. PD0325901 decreased the level of pERK1/2 to inhibit cell proliferation and migration, which was partially reversed by SUN5 overexpression, indicating that drug resistance existed in patients with high SUN5 expression. The xenograft transplantation experiment showed that SUN5 accelerated tumor formation in vivo. Furthermore, we found that SUN5 regulated the ERK pathway via Nesprin2 mediation and promoted the nuclear translocation of pERK1/2 by interacting with Nup93. Thus, these findings indicated that highly expressed SUN5 promoted CRC proliferation and migration by regulating the ERK pathway, which may contribute to the clinical diagnosis and new treatment strategies for CRC.
Collapse
Affiliation(s)
- Xiaoyue Song
- Center for Experimental Medicine, Third Xiangya Hospital, Central South University, Changsha 410013, China
- Department of Laboratory Medicine, Third Xiangya Hospital, Central South University, Changsha 410013, China
| | - Ruhong Li
- Department of General Surgery, Yanan Hospital Affiliated to Kunming Medical University, Kunming 650051, China
| | - Gang Liu
- The Institute of Reproduction and Stem Cell Engineering, School of Basic Medical Sciences, Central South University, Changsha 410078, China
| | - Lihua Huang
- Center for Experimental Medicine, Third Xiangya Hospital, Central South University, Changsha 410013, China
| | - Peng Li
- Department of General Surgery, Yanan Hospital Affiliated to Kunming Medical University, Kunming 650051, China
| | - Wanjiang Feng
- Center for Experimental Medicine, Third Xiangya Hospital, Central South University, Changsha 410013, China
| | - Qiujie Gao
- Center for Experimental Medicine, Third Xiangya Hospital, Central South University, Changsha 410013, China
- Department of Laboratory Medicine, Third Xiangya Hospital, Central South University, Changsha 410013, China
| | - Xiaowei Xing
- Center for Experimental Medicine, Third Xiangya Hospital, Central South University, Changsha 410013, China
| |
Collapse
|
7
|
Hoyer-Fender S. Development of the Connecting Piece in ODF1-Deficient Mouse Spermatids. Int J Mol Sci 2022; 23:ijms231810280. [PMID: 36142191 PMCID: PMC9499666 DOI: 10.3390/ijms231810280] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 08/30/2022] [Accepted: 09/04/2022] [Indexed: 11/30/2022] Open
Abstract
ODF1 is a major protein of the accessory fibres of the mammalian sperm tail. In addition, ODF1 is found in the connecting piece, a complex structure located at the posterior end of the nucleus that connects the sperm head and tail. The tight coupling of the sperm head and tail is critical for the progressive motility of the sperm to reach the oocyte for fertilisation. The depletion of ODF1 by homologous recombination in mice led to male infertility. Although sperm tails were present in the epididymis, no intact spermatozoa were found. Instead, the depletion of ODF1 resulted in sperm decapitation, suggesting that ODF1 is essential for the formation of the coupling apparatus and the tight linkage of the sperm head and tail. However, the development of the linkage complex in the absence of ODF1 has never been investigated. Here, I analysed the fine structure of the developing connecting piece by transmission electron microscopy. I show that the connecting piece develops as in wild-type spermatids. Structural abnormalities were not observed when ODF1 was absent. Thus, ODF1 is dispensable for the development of the connecting piece. However, the decapitation of ODF1-deficient spermatozoa indicates that the heads and tails of the spermatozoa are not linked, so that they separate when force is applied.
Collapse
Affiliation(s)
- Sigrid Hoyer-Fender
- Johann-Friedrich-Blumenbach-Institute of Zoology and Anthropology-Developmental Biology, GZMB, Ernst-Caspari-Haus, Justus-von-Liebig-Weg 11, Georg-August-Universität Göttingen, 37077 Göttingen, Germany
| |
Collapse
|
8
|
Okada Y. Sperm chromatin condensation: epigenetic mechanisms to compact the genome and spatiotemporal regulation from inside and outside the nucleus. Gene 2022; 97:41-53. [PMID: 35491100 DOI: 10.1266/ggs.21-00065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Sperm chromatin condensation is a critical step in mammalian spermatogenesis to protect the paternal DNA from external damaging factors and to acquire fertility. During chromatin condensation, various events proceed in a chronological order, independently or in sequence, interacting with each other both inside and outside the nucleus to support the dramatic chromatin changes. Among these events, histone-protamine replacement, which is concomitant with acrosome biogenesis and cytoskeletal alteration, is the most critical step associated with nuclear elongation. Failures of not only intranuclear events but also extra-nuclear events severely affect sperm shape and chromatin state and are subsequently linked to infertility. This review focuses on nuclear and non-nuclear factors that affect sperm chromatin condensation and its effects, and further discusses the possible utility of sperm chromatin for clinical applications.
Collapse
Affiliation(s)
- Yuki Okada
- Laboratory of Pathology and Development, Institute for Quantitative Biosciences, The University of Tokyo
| |
Collapse
|
9
|
Tapia Contreras C, Hoyer-Fender S. The Transformation of the Centrosome into the Basal Body: Similarities and Dissimilarities between Somatic and Male Germ Cells and Their Relevance for Male Fertility. Cells 2021; 10:2266. [PMID: 34571916 PMCID: PMC8471410 DOI: 10.3390/cells10092266] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 08/26/2021] [Accepted: 08/30/2021] [Indexed: 12/14/2022] Open
Abstract
The sperm flagellum is essential for the transport of the genetic material toward the oocyte and thus the transmission of the genetic information to the next generation. During the haploid phase of spermatogenesis, i.e., spermiogenesis, a morphological and molecular restructuring of the male germ cell, the round spermatid, takes place that includes the silencing and compaction of the nucleus, the formation of the acrosomal vesicle from the Golgi apparatus, the formation of the sperm tail, and, finally, the shedding of excessive cytoplasm. Sperm tail formation starts in the round spermatid stage when the pair of centrioles moves toward the posterior pole of the nucleus. The sperm tail, eventually, becomes located opposed to the acrosomal vesicle, which develops at the anterior pole of the nucleus. The centriole pair tightly attaches to the nucleus, forming a nuclear membrane indentation. An articular structure is formed around the centriole pair known as the connecting piece, situated in the neck region and linking the sperm head to the tail, also named the head-to-tail coupling apparatus or, in short, HTCA. Finally, the sperm tail grows out from the distal centriole that is now transformed into the basal body of the flagellum. However, a centriole pair is found in nearly all cells of the body. In somatic cells, it accumulates a large mass of proteins, the pericentriolar material (PCM), that together constitute the centrosome, which is the main microtubule-organizing center of the cell, essential not only for the structuring of the cytoskeleton and the overall cellular organization but also for mitotic spindle formation and chromosome segregation. However, in post-mitotic (G1 or G0) cells, the centrosome is transformed into the basal body. In this case, one of the centrioles, which is always the oldest or mother centriole, grows the axoneme of a cilium. Most cells of the body carry a single cilium known as the primary cilium that serves as an antenna sensing the cell's environment. Besides, specialized cells develop multiple motile cilia differing in substructure from the immotile primary cilia that are essential in moving fluids or cargos over the cellular surface. Impairment of cilia formation causes numerous severe syndromes that are collectively subsumed as ciliopathies. This comparative overview serves to illustrate the molecular mechanisms of basal body formation, their similarities, and dissimilarities, in somatic versus male germ cells, by discussing the involved proteins/genes and their expression, localization, and function. The review, thus, aimed to provide a deeper knowledge of the molecular players that is essential for the expansion of clinical diagnostics and treatment of male fertility disorders.
Collapse
Affiliation(s)
| | - Sigrid Hoyer-Fender
- Göttingen Center of Molecular Biosciences, Johann-Friedrich-Blumenbach Institute for Zoology and Anthropology-Developmental Biology, Faculty of Biology and Psychology, Georg-August University of Göttingen, 37077 Göttingen, Germany;
| |
Collapse
|