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Time to match; when do homologous chromosomes become closer? Chromosoma 2022; 131:193-205. [PMID: 35960388 DOI: 10.1007/s00412-022-00777-0] [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: 11/08/2021] [Revised: 05/12/2022] [Accepted: 07/14/2022] [Indexed: 11/03/2022]
Abstract
In most eukaryotes, pairing of homologous chromosomes is an essential feature of meiosis that ensures homologous recombination and segregation. However, when the pairing process begins, it is still under investigation. Contrasting data exists in Mus musculus, since both leptotene DSB-dependent and preleptotene DSB-independent mechanisms have been described. To unravel this contention, we examined homologous pairing in pre-meiotic and meiotic Mus musculus cells using a three-dimensional fluorescence in situ hybridization-based protocol, which enables the analysis of the entire karyotype using DNA painting probes. Our data establishes in an unambiguously manner that 73.83% of homologous chromosomes are already paired at premeiotic stages (spermatogonia-early preleptotene spermatocytes). The percentage of paired homologous chromosomes increases to 84.60% at mid-preleptotene-zygotene stage, reaching 100% at pachytene stage. Importantly, our results demonstrate a high percentage of homologous pairing observed before the onset of meiosis; this pairing does not occur randomly, as the percentage was higher than that observed in somatic cells (19.47%) and between nonhomologous chromosomes (41.1%). Finally, we have also observed that premeiotic homologous pairing is asynchronous and independent of the chromosome size, GC content, or presence of NOR regions.
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Chromosomal positioning in spermatogenic cells is influenced by chromosomal factors associated with gene activity, bouquet formation and meiotic sex chromosome inactivation. Chromosoma 2021; 130:163-175. [PMID: 34231035 DOI: 10.1007/s00412-021-00761-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 06/22/2021] [Accepted: 06/23/2021] [Indexed: 10/20/2022]
Abstract
Chromosome territoriality is not random along the cell cycle and it is mainly governed by intrinsic chromosome factors and gene expression patterns. Conversely, very few studies have explored the factors that determine chromosome territoriality and its influencing factors during meiosis. In this study, we analysed chromosome positioning in murine spermatogenic cells using three-dimensionally fluorescence in situ hybridization-based methodology, which allows the analysis of the entire karyotype. The main objective of the study was to decipher chromosome positioning in a radial axis (all analysed germ-cell nuclei) and longitudinal axis (only spermatozoa) and to identify the chromosomal factors that regulate such an arrangement. Results demonstrated that the radial positioning of chromosomes during spermatogenesis was cell-type specific and influenced by chromosomal factors associated to gene activity. Chromosomes with specific features that enhance transcription (high GC content, high gene density and high numbers of predicted expressed genes) were preferentially observed in the inner part of the nucleus in virtually all cell types. Moreover, the position of the sex chromosomes was influenced by their transcriptional status, from the periphery of the nucleus when its activity was repressed (pachytene) to a more internal position when it is partially activated (spermatid). At pachytene, chromosome positioning was also influenced by chromosome size due to the bouquet formation. Longitudinal chromosome positioning in the sperm nucleus was not random either, suggesting the importance of ordered longitudinal positioning for the release and activation of the paternal genome after fertilisation.
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Ferreiro ME, Amarilla MS, Glienke L, Méndez CS, González C, Jacobo PV, Sobarzo CM, De Laurentiis A, Ferraris MJ, Theas MS. The inflammatory mediators TNFα and nitric oxide arrest spermatogonia GC-1 cell cycle. Reprod Biol 2019; 19:329-339. [PMID: 31757605 DOI: 10.1016/j.repbio.2019.11.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 10/08/2019] [Accepted: 11/02/2019] [Indexed: 01/01/2023]
Abstract
During an inflammatory process of the testis, the network of somatic, immune, and germ cell interactions is altered leading to organ dysfunction. In testicular biopsies of infertile men, spermatogenesis impairment is associated with reduced spermatogonia proliferation, increased number of immune cells, and content of pro-inflammatory cytokines. TNFα-TNFR and nitric oxide (NO)-NO synthase systems are up-regulated in models of testicular damage and in human testis with maturation arrest. The purpose of this study was to test the hypothesis that TNFα-TNFR system and NO alter the function of spermatogonia in the inflamed testis. We studied the effect of TNFα and NO on GC-1 spermatogonia cell cycle progression and death by flow cytometry. GC-1 cells expressed TNFR1 and TNFR2 (immunofluorescence). TNFα (10 and 50 ng/ml) and DETA-Nonoate (0.5 and 2 mM), a NO releaser, increased the percentage of cells in S-phase of the cell cycle and reduced the percentage in G1, inducing also cell apoptosis. TNFα effect was not mediated by oxidative stress unlike NO, since the presence of N-acetyl-l-cysteine (2.5 and 5.0 mM) prevented NO induced cell cycle arrest and death. GC-1 spermatogonia overpass NO induced cell cycle arrest but no TNFα, since after removal of NO, spermatogonia progressed through the cell cycle. We propose TNFα and NO might contribute to impairment of spermatogenesis by preventing adequate functioning of the spermatogonia population. Our results showed that TNFα and NO impaired spermatogonia cell cycle, inducing GC-1 arrest in the S phase.
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Affiliation(s)
- María Eugenia Ferreiro
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Biología Celular, Cátedra II de Histología, Buenos Aires, Argentina, CONICET-Universidad de Buenos Aires, Instituto de Investigaciones Biomédicas (INBIOMED), Buenos Aires, Argentina
| | - María Sofía Amarilla
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Biología Celular, Cátedra II de Histología, Buenos Aires, Argentina, CONICET-Universidad de Buenos Aires, Instituto de Investigaciones Biomédicas (INBIOMED), Buenos Aires, Argentina
| | - Leilane Glienke
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Biología Celular, Cátedra II de Histología, Buenos Aires, Argentina, CONICET-Universidad de Buenos Aires, Instituto de Investigaciones Biomédicas (INBIOMED), Buenos Aires, Argentina
| | - Cinthia Soledad Méndez
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Biología Celular, Cátedra II de Histología, Buenos Aires, Argentina, CONICET-Universidad de Buenos Aires, Instituto de Investigaciones Biomédicas (INBIOMED), Buenos Aires, Argentina
| | - Candela González
- Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y Diagnósticos (CEBBAD), Universidad Maimónides, Buenos Aires, Argentina
| | - Patricia Verónica Jacobo
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Biología Celular, Cátedra II de Histología, Buenos Aires, Argentina, CONICET-Universidad de Buenos Aires, Instituto de Investigaciones Biomédicas (INBIOMED), Buenos Aires, Argentina
| | - Cristian Marcelo Sobarzo
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Biología Celular, Cátedra II de Histología, Buenos Aires, Argentina, CONICET-Universidad de Buenos Aires, Instituto de Investigaciones Biomédicas (INBIOMED), Buenos Aires, Argentina
| | - Andrea De Laurentiis
- Centro de Estudios Farmacológicos y Botánicos (CEFYBO) CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - María Jimena Ferraris
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Biología Celular, Cátedra II de Histología, Buenos Aires, Argentina, CONICET-Universidad de Buenos Aires, Instituto de Investigaciones Biomédicas (INBIOMED), Buenos Aires, Argentina
| | - María Susana Theas
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Biología Celular, Cátedra II de Histología, Buenos Aires, Argentina, CONICET-Universidad de Buenos Aires, Instituto de Investigaciones Biomédicas (INBIOMED), Buenos Aires, Argentina.
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Garcia-Quevedo L, Blanco J, Sarrate Z, Vidal F. Apoptosis mediated by phosphatidylserine externalization in the elimination of aneuploid germ cells during human spermatogenesis. Andrology 2014; 2:892-8. [DOI: 10.1111/j.2047-2927.2014.00272.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 08/01/2014] [Accepted: 08/07/2014] [Indexed: 11/28/2022]
Affiliation(s)
- L. Garcia-Quevedo
- Unitat de Biologia Cel·lular; Facultat de Biociències; Universitat Autònoma de Barcelona; Bellaterra (Cerdanyola del Vallès) Spain
| | - J. Blanco
- Unitat de Biologia Cel·lular; Facultat de Biociències; Universitat Autònoma de Barcelona; Bellaterra (Cerdanyola del Vallès) Spain
| | - Z. Sarrate
- Unitat de Biologia Cel·lular; Facultat de Biociències; Universitat Autònoma de Barcelona; Bellaterra (Cerdanyola del Vallès) Spain
| | - F. Vidal
- Unitat de Biologia Cel·lular; Facultat de Biociències; Universitat Autònoma de Barcelona; Bellaterra (Cerdanyola del Vallès) Spain
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