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Draeger TN, Rey MD, Hayta S, Smedley M, Martin AC, Moore G. DMC1 stabilizes crossovers at high and low temperatures during wheat meiosis. FRONTIERS IN PLANT SCIENCE 2023; 14:1208285. [PMID: 37615022 PMCID: PMC10442654 DOI: 10.3389/fpls.2023.1208285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 07/17/2023] [Indexed: 08/25/2023]
Abstract
Effective chromosome synapsis and crossover formation during meiosis are essential for fertility, especially in grain crops such as wheat. These processes function most efficiently in wheat at temperatures between 17-23 °C, although the genetic mechanisms for such temperature dependence are unknown. In a previously identified mutant of the hexaploid wheat reference variety 'Chinese Spring' lacking the long arm of chromosome 5D, exposure to low temperatures during meiosis resulted in asynapsis and crossover failure. In a second mutant (ttmei1), containing a 4 Mb deletion in chromosome 5DL, exposure to 13 °C led to similarly high levels of asynapsis and univalence. Moreover, exposure to 30 °C led to a significant, but less extreme effect on crossovers. Previously, we proposed that, of 41 genes deleted in this 4 Mb region, the major meiotic gene TaDMC1-D1 was the most likely candidate for preservation of synapsis and crossovers at low (and possibly high) temperatures. In the current study, using RNA-guided Cas9, we developed a new Chinese Spring CRISPR mutant, containing a 39 bp deletion in the 5D copy of DMC1, representing the first reported CRISPR-Cas9 targeted mutagenesis in Chinese Spring, and the first CRISPR mutant for DMC1 in wheat. In controlled environment experiments, wild-type Chinese Spring, CRISPR dmc1-D1 and backcrossed ttmei1 mutants were exposed to either high or low temperatures during the temperature-sensitive period from premeiotic interphase to early meiosis I. After 6-7 days at 13 °C, crossovers decreased by over 95% in the dmc1-D1 mutants, when compared with wild-type plants grown under the same conditions. After 24 hours at 30 °C, dmc1-D1 mutants exhibited a reduced number of crossovers and increased univalence, although these differences were less marked than at 13 °C. Similar results were obtained for ttmei1 mutants, although their scores were more variable, possibly reflecting higher levels of background mutation. These experiments confirm our previous hypothesis that DMC1-D1 is responsible for preservation of normal crossover formation at low and, to a certain extent, high temperatures. Given that reductions in crossovers have significant effects on grain yield, these results have important implications for wheat breeding, particularly in the face of climate change.
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Affiliation(s)
| | - María-Dolores Rey
- Agroforestry and Plant Biochemistry, Proteomics and Systems Biology, Department of Biochemistry and Molecular Biology, University of Córdoba, Córdoba, Spain
| | - Sadiye Hayta
- John Innes Centre, Norwich Research Park, Norwich, United Kingdom
| | - Mark Smedley
- John Innes Centre, Norwich Research Park, Norwich, United Kingdom
| | - Azahara C. Martin
- Department of Plant Genetic Improvement, Institute for Sustainable Agriculture, Spanish National Research Council (CSIC), Córdoba, Spain
| | - Graham Moore
- John Innes Centre, Norwich Research Park, Norwich, United Kingdom
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Ruan SL, Xie L, Ou JW, Sun XS, Zhang YP, Hu JR. Molecular cloning, the characterization of metallothionein and catalase, and the evaluation of testicular toxicity of Cd in the Chinese fire-bellied newt (Cynops orientalis). ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 208:111731. [PMID: 33396062 DOI: 10.1016/j.ecoenv.2020.111731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 11/24/2020] [Accepted: 11/25/2020] [Indexed: 06/12/2023]
Abstract
Cadmium (Cd) is an environmental toxicant and a nonessential metal. Cd can attack a wide range of organs, such as the liver, kidney, lung, ovary, testis, brain, and muscle in vertebrates. Among these organs, the testis might be the most sensitive organ to Cd toxicity. Metallothionein (MT) is a cysteine-rich protein with a low molecular weight, that can bind with Cd and eliminate reactive oxygen species (ROSs). Hydrogen peroxide, which as a crucial type of ROS that is induced by Cd, can be eliminated by catalase (CAT) in the self-protection of cells and to realize Cd toxicity resistance. To investigate the functions of MT and CAT in the testis of Cynops orientalis, we cloned the full-length MT and CAT genes of C. orientalis for the first time. Immunofluorescence results demonstrated that MT and CAT were expressed in Sertoli cells and all spermatogenic cells in the testis of C. orientalis. The results of the ultrastructural damage assay demonstrated that there were various impairments, which included organelle vacuolization, abnormal chromatin distribution, and apoptotic bodies, in somatic cells that were exposed to Cd. However, the anomalies of spermatozoa were located mainly in the mid-piece and head, many of which showed severely impaired structures. The results demonstrated that MT and CAT expression had distinct patterns in response to various Cd concentrations: an increase in MT mRNA levels with elevated Cd levels and a persistent increase in CAT mRNA levels with elevated Cd levels. These results suggested that MT and CAT play roles in Cd toxicity resistance in the testis and that the expression of CAT may be a better biomarker than the expression of MT for assessing Cd pollution.
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Affiliation(s)
- Shi-Long Ruan
- College of Life and Environmental Science, Hangzhou Normal University, Hangzhou 310036, PR China
| | - Lei Xie
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, PR China; National and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, Wenzhou University, Wenzhou 325035, PR China
| | - Jun-Wei Ou
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, PR China; National and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, Wenzhou University, Wenzhou 325035, PR China
| | - Xue-Song Sun
- College of Life and Environmental Science, Hangzhou Normal University, Hangzhou 310036, PR China
| | - Yong-Pu Zhang
- College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, PR China; National and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, Wenzhou University, Wenzhou 325035, PR China.
| | - Jian-Rao Hu
- College of Life and Environmental Science, Hangzhou Normal University, Hangzhou 310036, PR China.
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Draeger T, C Martin A, Alabdullah AK, Pendle A, Rey MD, Shaw P, Moore G. Dmc1 is a candidate for temperature tolerance during wheat meiosis. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2020; 133:809-828. [PMID: 31853574 PMCID: PMC7021665 DOI: 10.1007/s00122-019-03508-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 12/10/2019] [Indexed: 05/21/2023]
Abstract
KEY MESSAGE The meiotic recombination gene Dmc1 on wheat chromosome 5D has been identified as a candidate for the maintenance of normal chromosome synapsis and crossover at low and possibly high temperatures. We initially assessed the effects of low temperature on meiotic chromosome synapsis and crossover formation in the hexaploid wheat (Triticum aestivum L.) variety 'Chinese Spring'. At low temperatures, asynapsis and chromosome univalence have been observed before in Chinese Spring lines lacking the long arm of chromosome 5D (5DL), which led to the proposal that 5DL carries a gene (Ltp1) that stabilises wheat chromosome pairing at low temperatures. In the current study, Chinese Spring wild type and 5DL interstitial deletion mutant plants were exposed to low temperature in a controlled environment room during a period from premeiotic interphase to early meiosis I. A 5DL deletion mutant was identified whose meiotic chromosomes exhibit extremely high levels of asynapsis and chromosome univalence at metaphase I after 7 days at 13 °C, suggesting that Ltp1 is deleted in this mutant. Immunolocalisation of the meiotic proteins ASY1 and ZYP1 on ltp1 mutants showed that low temperature results in a failure to complete synapsis at pachytene. KASP genotyping revealed that the ltp1 mutant has a 4-Mb deletion in 5DL. Of 41 genes within this deletion region, the strongest candidate for the stabilisation of chromosome pairing at low temperatures is the meiotic recombination gene Dmc1. The ltp1 mutants were subsequently treated at 30 °C for 24 h during meiosis and exhibited a reduced number of crossovers and increased univalence, though to a lesser extent than at 13 °C. We therefore renamed our ltp1 mutant 'ttmei1' (temperature-tolerant meiosis 1) to reflect this additional loss of high temperature tolerance.
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Affiliation(s)
- Tracie Draeger
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK.
| | | | | | - Ali Pendle
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - María-Dolores Rey
- Agroforestry and Plant Biochemistry, Proteomics and Systems Biology, Department of Biochemistry and Molecular Biology, University of Cordoba, Cordoba, Spain
| | - Peter Shaw
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Graham Moore
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
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Cruz Vieira AB, Weber AA, Ribeiro YM, Luz RK, Bazzoli N, Rizzo E. Influence of salinity on spermatogenesis in adult Nile tilapia (Oreochromis niloticus) testis. Theriogenology 2019; 131:1-8. [PMID: 30921633 DOI: 10.1016/j.theriogenology.2019.03.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 02/14/2019] [Accepted: 03/18/2019] [Indexed: 01/12/2023]
Abstract
Continental waters salinisation is a global threat that has grown because of climate change and human activities, but little is known about how and what biological tracts are affected. The aim of this study was to investigate the influence of different water salinities on the expression of HSP70, PCNA and caspase-3 during spermatogenesis of Nile tilapia. Adult males were submitted to four salinity treatments: (S0) fresh water, (S7) 7 g L-1, (S14) 14 g L-1, and (S21) 21 g L-1 for 1, 4, and 9 days. All specimens were in spermatogenic activity and the highest values of the gonadosomatic index (GSI) occurred in the S0 and S7. In the morphometric analysis, spermatocytes were the most frequent germ cell detected in all treatments (>50%) and spermatids achieved about 20% of the testicular proportion, with few variations among treatments. Spermatozoa were significantly reduced only in S14 compared to S7. Leydig cells were significantly increased in S14 when compared to S7 but plasma concentrations of 11-KT showed no significant difference among treatments. ELISA assay showed higher testicular expression of HSP70 at 1 day in all groups, followed by a significant decrease at days 4 and 9 in S14 and S21. The expression of PCNA was significantly lower while the activity of caspase-3 was higher in S14 and S21 when compared to S0 and S7. These results indicate that higher salinities in S14 and S21 interfere with the relationship between testicular HSP70, PCNA, and caspase-3, but with few effects over spermatogenesis dynamics of Nile tilapia.
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Affiliation(s)
- Augusto Bicalho Cruz Vieira
- Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, UFMG, Belo Horizonte, Caixa Postal 486, 30161-970, Minas Gerais, Brazil
| | - André Alberto Weber
- Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, UFMG, Belo Horizonte, Caixa Postal 486, 30161-970, Minas Gerais, Brazil
| | - Yves Moreira Ribeiro
- Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, UFMG, Belo Horizonte, Caixa Postal 486, 30161-970, Minas Gerais, Brazil
| | - Ronald Kennedy Luz
- Laboratório de Aquacultura, Escola de Veterinária, Universidade Federal de Minas Gerais, UFMG, Belo Horizonte, Caixa Postal 567, 30123-970, Minas Gerais, Brazil
| | - Nilo Bazzoli
- Programa de Pós-Graduação em Zoologia dos Vertebrados, Pontifícia Universidade Católica de Minas Gerais, PUC Minas, Belo Horizonte, Caixa Postal 500, 30535-610, Minas Gerais, Brazil
| | - Elizete Rizzo
- Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, UFMG, Belo Horizonte, Caixa Postal 486, 30161-970, Minas Gerais, Brazil.
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Morgan CH, Zhang H, Bomblies K. Are the effects of elevated temperature on meiotic recombination and thermotolerance linked via the axis and synaptonemal complex? Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0470. [PMID: 29109229 PMCID: PMC5698628 DOI: 10.1098/rstb.2016.0470] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/05/2017] [Indexed: 12/23/2022] Open
Abstract
Meiosis is unusual among cell divisions in shuffling genetic material by crossovers among homologous chromosomes and partitioning the genome into haploid gametes. Crossovers are critical for chromosome segregation in most eukaryotes, but are also an important factor in evolution, as they generate novel genetic combinations. The molecular mechanisms that underpin meiotic recombination and chromosome segregation are well conserved across kingdoms, but are also sensitive to perturbation by environment, especially temperature. Even subtle shifts in temperature can alter the number and placement of crossovers, while at greater extremes, structural failures can occur in the linear axis and synaptonemal complex structures which are essential for recombination and chromosome segregation. Understanding the effects of temperature on these processes is important for its implications in evolution and breeding, especially in the context of global warming. In this review, we first summarize the process of meiotic recombination and its reliance on axis and synaptonemal complex structures, and then discuss effects of temperature on these processes and structures. We hypothesize that some consistent effects of temperature on recombination and meiotic thermotolerance may commonly be two sides of the same coin, driven by effects of temperature on the folding or interaction of key meiotic proteins. This article is part of the themed issue ‘Evolutionary causes and consequences of recombination rate variation in sexual organisms’.
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Affiliation(s)
| | - Huakun Zhang
- John Innes Centre, Colney Lane, Norwich NR4 7UH, UK
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Kon S, Sato T, Endo D, Takahashi T, Takaku A, Nakauchi Y, Toyama F, Meyer-Rochow VB, Takayama-Watanabe E, Watanabe A. Sperm storage influences the potential for spontaneous acrosome reaction of the sperm in the newt Cynops pyrrhogaster. Mol Reprod Dev 2017; 84:1314-1322. [PMID: 29235206 DOI: 10.1002/mrd.22932] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 11/13/2017] [Indexed: 11/08/2022]
Abstract
Sperm storage is supposed to influence sperm quality, although the details remain unclear. In the present study, we found that sperm stored in a sperm storage site, the vas deferens of Cynops pyrrhogaster, spontaneously undergo acrosome reaction following incubation in Steinberg's salt solution (ST). Percentages of acrosome-reacted sperm increased time-dependently to about 60% in 24 hr. The concentration of cyclic adenosine monophosphate (cAMP) was elevated after incubating sperm in ST, while dibutylyl cAMP induced an acrosome reaction. Chelating of extracellular Ca2+ suppressed the dibutylyl cAMP-induced acrosome reaction as well as spontaneous acrosome reaction in ST. These results suggest that cAMP elevation driven by Ca2+ influx can be a cue for spontaneous acrosome reaction. Relatively low Ca2+ concentration and pH in the vas deferens were sufficient to suppress spontaneous acrosome reaction within 1 hr. In addition, the cysteine rich secretory protein 2 gene was expressed in the vas deferens, indicating that it may be involved in the continuous suppression of spontaneous acrosome reaction. Sperm that underwent spontaneous acrosome reaction in ST was significantly increased when stored in the vas deferens for longer periods, or by males experiencing temperatures in excess of 12°C during hibernation conditions. Percentages of the spontaneously acrosome-reacted sperm were found to differ among males even though they were of identical genetic background. Taken together, C. pyrrhogaster sperm possess the potential for spontaneous acrosome reaction that does not become obvious in the vas deferens, unless promoted in correlation with sperm storage.
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Affiliation(s)
- Shinnosuke Kon
- Faculty of Science, Department of Biology, Yamagata University, Kojirakawa, Yamagata, Japan
| | - Tae Sato
- Faculty of Science, Department of Biology, Yamagata University, Kojirakawa, Yamagata, Japan
| | - Daisuke Endo
- Faculty of Science, Department of Biology, Yamagata University, Kojirakawa, Yamagata, Japan
| | - Tomoe Takahashi
- Faculty of Science, Department of Biology, Yamagata University, Kojirakawa, Yamagata, Japan
| | - Akio Takaku
- Faculty of Science, Department of Biology, Yamagata University, Kojirakawa, Yamagata, Japan
| | - Yuni Nakauchi
- Faculty of Science, Department of Biology, Yamagata University, Kojirakawa, Yamagata, Japan
| | - Fubito Toyama
- Graduate School of Engineering, Utsunomiya University, Utsunomiya, Tochigi, Japan
| | - Victor B Meyer-Rochow
- Department of Biology, University of Oulu, Oulu, Finland.,Research Institute of Luminous Organisms, Hachijojima, Tokyo, Japan
| | | | - Akihiko Watanabe
- Faculty of Science, Department of Biology, Yamagata University, Kojirakawa, Yamagata, Japan
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Du ZN, Rong CT, Hui S, Peng Z, Jin SH, Li SJ, Wang HY, Li JY. Expression and function of HSP110 family in mouse testis after vasectomy. Asian J Androl 2017; 19:355-361. [PMID: 26952955 PMCID: PMC5427794 DOI: 10.4103/1008-682x.164197] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 02/27/2015] [Accepted: 07/17/2015] [Indexed: 12/21/2022] Open
Abstract
HSP110 functions to protect cells, tissues, and organs from noxious conditions. Vasectomy induces apoptosis in the testis; however, little is known about the reason leading to this outcome. The aim of the present study was to evaluate the expression and function of HSP110 in mouse testis after vasectomy. Following bilateral vasectomy, we used fluorescent Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) to detect apoptosis, Western blotting and immunohistochemistry to examine HSP110 expression and localization. Serum antisperm antibody (AsAb) and testosterone were measured by Enzyme-linked immunosorbent assay (ELISA) and radioimmunoassay, respectively. Expression of endoplasmic reticulum stress (ERS) sensors and downstream signaling components was measured by Reverse Transcription-Polymerase Chain Reaction (RT-PCR), and the phosphorylation of eIF2α and JNK was detected by Western blotting. Vasectomy induced morphologic changes, increased apoptosis in the testis, increased serum AsAb, and decreased testosterone levels. After vasectomy, ORP150 mRNA level was increased first and then decreased, Bcl-2 was decreased, and the expression of HSPA4l, GRP78, GADD153, PERK, ATF6, IRE-1, XBP-1s, Bax, Bak, and caspases and the phosphorylation of eIF2α and JNK were increased. We present that an ER stress-mediated pathway is activated and involved in apoptosis in the testis after vasectomy. HSPA4l and ORP150 may play important roles in maintaining the normal structure and function of testis.
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Affiliation(s)
- Zhen-Ning Du
- Department of Medicine, Yantai University, Yantai 264005, China
| | - Cheng-Ting Rong
- Department of Medicine, Yantai University, Yantai 264005, China
- Pharmacy Department of Fuyang People's Hospital, Fuyang 236001, China
| | - Shi Hui
- Department of Medicine, Yantai University, Yantai 264005, China
| | - Zhu Peng
- Yantai Yuhuangding Hospital, Yantai 264000, China
| | - Shao-Hua Jin
- Yantai Yuhuangding Hospital, Yantai 264000, China
| | - Shi-Jia Li
- Yantai Yuhuangding Hospital, Yantai 264000, China
| | - Hai-Yan Wang
- Department of Medicine, Yantai University, Yantai 264005, China
- Yantai Yuhuangding Hospital, Yantai 264000, China
| | - Jian-Yuan Li
- Department of Medicine, Yantai University, Yantai 264005, China
- Yantai Yuhuangding Hospital, Yantai 264000, China
- Key Laboratory of Male Reproductive Health, National Health and Family Planning Commission, Beijing 100081, China
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Borowiec AS, Sion B, Chalmel F, D Rolland A, Lemonnier L, De Clerck T, Bokhobza A, Derouiche S, Dewailly E, Slomianny C, Mauduit C, Benahmed M, Roudbaraki M, Jégou B, Prevarskaya N, Bidaux G. Cold/menthol TRPM8 receptors initiate the cold-shock response and protect germ cells from cold-shock-induced oxidation. FASEB J 2016; 30:3155-70. [PMID: 27317670 PMCID: PMC5001517 DOI: 10.1096/fj.201600257r] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 05/23/2016] [Indexed: 12/21/2022]
Abstract
Testes of most male mammals present the particularity of being externalized from the body and are consequently slightly cooler than core body temperature (4-8°C below). Although, hypothermia of the testis is known to increase germ cells apoptosis, little is known about the underlying molecular mechanisms, including cold sensors, transduction pathways, and apoptosis triggers. In this study, using a functional knockout mouse model of the cold and menthol receptors, dubbed transient receptor potential melastatine 8 (TRPM8) channels, we found that TRPM8 initiated the cold-shock response by differentially modulating cold- and heat-shock proteins. Besides, apoptosis of germ cells increased in proportion to the cooling level in control mice but was independent of temperature in knockout mice. We also observed that the rate of germ cell death correlated positively with the reactive oxygen species level and negatively with the expression of the detoxifying enzymes. This result suggests that the TRPM8 sensor is a key determinant of germ cell fate under hypothermic stimulation.-Borowiec, A.-S., Sion, B., Chalmel, F., Rolland, A. D., Lemonnier, L., De Clerck, T., Bokhobza, A., Derouiche, S., Dewailly, E., Slomianny, C., Mauduit, C., Benahmed, M., Roudbaraki, M., Jégou, B., Prevarskaya, N., Bidaux, G. Cold/menthol TRPM8 receptors initiate the cold-shock response and protect germ cells from cold-shock-induced oxidation.
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Affiliation(s)
| | - Benoit Sion
- Pharmacologie Fondamentale et Clinique de la Douleur, INSERM, U1107, Neuro-Dol, Clermont Université, Université d'Auvergne, Clermont-Ferrand, France
| | | | | | - Loïc Lemonnier
- Physiologie Cellulaire (PHYCEL), INSERM, U1003, Université Lille, Lille, France
| | - Tatiana De Clerck
- Physiologie Cellulaire (PHYCEL), INSERM, U1003, Université Lille, Lille, France
| | - Alexandre Bokhobza
- Physiologie Cellulaire (PHYCEL), INSERM, U1003, Université Lille, Lille, France
| | - Sandra Derouiche
- Physiologie Cellulaire (PHYCEL), INSERM, U1003, Université Lille, Lille, France
| | - Etienne Dewailly
- Physiologie Cellulaire (PHYCEL), INSERM, U1003, Université Lille, Lille, France
| | - Christian Slomianny
- Physiologie Cellulaire (PHYCEL), INSERM, U1003, Université Lille, Lille, France
| | - Claire Mauduit
- Centre Méditerranéen de Médecine Moléculaire (C3M), Team 5, INSERM, U1065, Nice, France; and
| | - Mohamed Benahmed
- Centre Méditerranéen de Médecine Moléculaire (C3M), Team 5, INSERM, U1065, Nice, France; and
| | - Morad Roudbaraki
- Physiologie Cellulaire (PHYCEL), INSERM, U1003, Université Lille, Lille, France
| | - Bernard Jégou
- INSERM, U1085-Irset, Campus de Beaulieu, Rennes, France
| | - Natalia Prevarskaya
- Physiologie Cellulaire (PHYCEL), INSERM, U1003, Université Lille, Lille, France
| | - Gabriel Bidaux
- Physiologie Cellulaire (PHYCEL), INSERM, U1003, Université Lille, Lille, France; Laboratoire de Physique des Lasers, Atomes et Molécules (PhLAM), UMR8523, Biophotonic Team, Villeneuve d'Ascq, France
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9
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Tattersall GJ, Leite CAC, Sanders CE, Cadena V, Andrade DV, Abe AS, Milsom WK. Seasonal reproductive endothermy in tegu lizards. SCIENCE ADVANCES 2016; 2:e1500951. [PMID: 26844295 PMCID: PMC4737272 DOI: 10.1126/sciadv.1500951] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 11/19/2015] [Indexed: 06/05/2023]
Abstract
With some notable exceptions, small ectothermic vertebrates are incapable of endogenously sustaining a body temperature substantially above ambient temperature. This view was challenged by our observations of nighttime body temperatures sustained well above ambient (up to 10°C) during the reproductive season in tegu lizards (~2 kg). This led us to hypothesize that tegus have an enhanced capacity to augment heat production and heat conservation. Increased metabolic rates and decreased thermal conductance are the same mechanisms involved in body temperature regulation in those vertebrates traditionally acknowledged as "true endotherms": the birds and mammals. The appreciation that a modern ectotherm the size of the earliest mammals can sustain an elevated body temperature through metabolic rates approaching that of endotherms enlightens the debate over endothermy origins, providing support for the parental care model of endothermy, but not for the assimilation capacity model of endothermy. It also indicates that, contrary to prevailing notions, ectotherms can engage in facultative endothermy, providing a physiological analog in the evolutionary transition to true endothermy.
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Affiliation(s)
- Glenn J. Tattersall
- Department of Biological Sciences, Brock University, St. Catharines, Ontario L2S 3A1, Canada
- National Institute of Science and Technology in Comparative Physiology (INCT–Fisiologia Comparada), 13505-060 Rio Claro, São Paulo, Brazil
| | - Cleo A. C. Leite
- National Institute of Science and Technology in Comparative Physiology (INCT–Fisiologia Comparada), 13505-060 Rio Claro, São Paulo, Brazil
- Department of Physiological Sciences, Federal University of São Carlos (UFSCar), São Carlos, São Paulo, Brazil
| | - Colin E. Sanders
- Department of Physiological Sciences, Federal University of São Carlos (UFSCar), São Carlos, São Paulo, Brazil
| | - Viviana Cadena
- Department of Biological Sciences, Brock University, St. Catharines, Ontario L2S 3A1, Canada
| | - Denis V. Andrade
- National Institute of Science and Technology in Comparative Physiology (INCT–Fisiologia Comparada), 13505-060 Rio Claro, São Paulo, Brazil
- Department of Zoology, São Paulo State University (UNESP), 13506-900 Rio Claro, Brazil
| | - Augusto S. Abe
- National Institute of Science and Technology in Comparative Physiology (INCT–Fisiologia Comparada), 13505-060 Rio Claro, São Paulo, Brazil
- Department of Zoology, São Paulo State University (UNESP), 13506-900 Rio Claro, Brazil
| | - William K. Milsom
- National Institute of Science and Technology in Comparative Physiology (INCT–Fisiologia Comparada), 13505-060 Rio Claro, São Paulo, Brazil
- Department of Zoology, University of British Columbia, Vancouver, British Columbia V6T1Z4, Canada
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Bomblies K, Higgins JD, Yant L. Meiosis evolves: adaptation to external and internal environments. THE NEW PHYTOLOGIST 2015; 208:306-23. [PMID: 26075313 DOI: 10.1111/nph.13499] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2015] [Accepted: 05/03/2015] [Indexed: 05/23/2023]
Abstract
306 I. 306 II. 307 III. 312 IV. 317 V. 318 319 References 319 SUMMARY: Meiosis is essential for the fertility of most eukaryotes and its structures and progression are conserved across kingdoms. Yet many of its core proteins show evidence of rapid or adaptive evolution. What drives the evolution of meiosis proteins? How can constrained meiotic processes be modified in response to challenges without compromising their essential functions? In surveying the literature, we found evidence of two especially potent challenges to meiotic chromosome segregation that probably necessitate adaptive evolutionary responses: whole-genome duplication and abiotic environment, especially temperature. Evolutionary solutions to both kinds of challenge are likely to involve modification of homologous recombination and synapsis, probably via adjustments of core structural components important in meiosis I. Synthesizing these findings with broader patterns of meiosis gene evolution suggests that the structural components of meiosis coevolve as adaptive modules that may change in primary sequence and function while maintaining three-dimensional structures and protein interactions. The often sharp divergence of these genes among species probably reflects periodic modification of entire multiprotein complexes driven by genomic or environmental changes. We suggest that the pressures that cause meiosis to evolve to maintain fertility may cause pleiotropic alterations of global crossover rates. We highlight several important areas for future research.
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Affiliation(s)
- Kirsten Bomblies
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - James D Higgins
- Department of Biology, University of Leicester, Leicester, LE1 7RH, UK
| | - Levi Yant
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
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Yokoe M, Sano M, Shibata H, Shibata D, Takayama-Watanabe E, Inaba K, Watanabe A. Sperm proteases that may be involved in the initiation of sperm motility in the newt, Cynops pyrrhogaster. Int J Mol Sci 2014; 15:15210-24. [PMID: 25170808 PMCID: PMC4200841 DOI: 10.3390/ijms150915210] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 07/28/2014] [Accepted: 08/25/2014] [Indexed: 11/17/2022] Open
Abstract
A protease of sperm in the newt Cynops pyrrhogaster that is released after the acrosome reaction (AR) is proposed to lyse the sheet structure on the outer surface of egg jelly and release sperm motility-initiating substance (SMIS). Here, we found that protease activity in the sperm head was potent to widely digest substrates beneath the sperm. The protease activity measured by fluorescein thiocarbamoyl-casein digestion was detected in the supernatant of the sperm after the AR and the activity was inhibited by 4-(2-aminoethyl) benzenesulfonyl fluoride (AEBSF), an inhibitor for serine or cysteine protease, suggesting the release of serine and/or cysteine proteases by AR. In an in silico analysis of the testes, acrosins and 20S proteasome were identified as possible candidates of the acrosomal proteases. We also detected another AEBSF-sensitive protease activity on the sperm surface. Fluorescence staining with AlexaFluor 488-labeled AEBSF revealed a cysteine protease in the principal piece; it is localized in the joint region between the axial rod and undulating membrane, which includes an axoneme and produces powerful undulation of the membrane for forward sperm motility. These results indicate that AEBSF-sensitive proteases in the acrosome and principal piece may participate in the initiation of sperm motility on the surface of egg jelly.
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Affiliation(s)
- Misato Yokoe
- Department of Biology, Faculty of Science, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560, Japan.
| | - Makoto Sano
- Department of Biology, Faculty of Science, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560, Japan.
| | - Honami Shibata
- Department of Biology, Faculty of Science, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560, Japan.
| | - Daisuke Shibata
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1 Shimoda, Shizuoka 415-0025, Japan.
| | - Eriko Takayama-Watanabe
- Institute of Arts and Sciences, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560, Japan.
| | - Kazuo Inaba
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1 Shimoda, Shizuoka 415-0025, Japan.
| | - Akihiko Watanabe
- Department of Biology, Faculty of Science, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560, Japan.
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McClusky LM. The caspase-dependent apoptosis gradient in the testis of the blue shark, Prionace glauca. Reproduction 2013; 145:297-310. [DOI: 10.1530/rep-12-0216] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The severe degenerative phenomena that characterises spermatogenesis in mating blue sharks involves spatially separated germ cell and Sertoli cell apoptosis. Unlike that observed in multilayered type B spermatogonial and spermatocyte cysts caspase-3-dependent apoptosis of single and multinucleate type B spermatogonia in one to three spermatogonial layered cysts resulted in their complete fragmentation, delayed phagocytic removal and displacement of the apoptotic bodies towards the perilumenar Sertoli nuclei. Changes were observed in the immunostaining patterns of proliferating cell nuclear antigen (PCNA), including subtle changes in cytoplasmic and overall intense immunostaining, labelled single and multinucleate cell (MNC) apoptotic spermatogonial masses in premeiotic cysts in different stages of the protracted death process. Initial massive MNC formation at the mitosis–meiosis transition eventually left its imprint in the spermatogenic sequence in the form of vacuolated areas in the affected and subsequent stages. Some of the latter attempted further developmental advance but eventually degenerated. The observed higher PCNA index of spermatogonia in vacuolated testes compared to testes with the MNC type of degeneration indicated that the former testicular morphology represented, in essence, the recovery phase from the pronounced MNC death earlier. Events culminating in the eventual apoptotic demise of the Sertoli cells themselves included the abortion of further development (presumably due to a suboptimal Sertoli:germ cell ratio) of those germ cells left over from the wave of MNC death that swept the cysts. Eventually the Sertoli-cell-only cysts became apoptotic as they were engulfed by the infiltrating lymphomyeloid cells from the epigonal organ associated with the mature pole of the testis.
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Wang DH, Hu JR, Wang LY, Hu YJ, Tan FQ, Zhou H, Shao JZ, Yang WX. The apoptotic function analysis of p53, Apaf1, Caspase3 and Caspase7 during the spermatogenesis of the Chinese fire-bellied newt Cynops orientalis. PLoS One 2012; 7:e39920. [PMID: 22768170 PMCID: PMC3386923 DOI: 10.1371/journal.pone.0039920] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Accepted: 05/29/2012] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Spontaneous and stress-induced germ cell apoptosis during spermatogenesis of multicellular organisms have been investigated broadly in mammals. Spermatogenetic process in urodele amphibians was essentially like that in mammals in spite of morphological differences; however, the mechanism of germ cell apoptosis in urodele amphibians remains unknown. The Chinese fire-belly newt, Cynops orientalis, was an excellent organism for studying germ cell apoptosis due to its sensitiveness to temperature, strong endurance of starvation, and sensitive skin to heavy metal exposure. METHODOLOGY/PRINCIPAL FINDINGS TUNEL result showed that spontaneous germ cell apoptosis took place in normal newt, and severe stress-induced apoptosis occurred to spermatids and sperm in response to heat shock (40°C 2 h), cold exposure (4°C 12 h), cadmium exposure (Cd 36 h), and starvation stress. Quantitative reverse transcription polymerase chain reactions (qRT-PCR) showed that gene expression of Caspase3 or Caspase7 was obviously elevated after stress treatment. Apaf1 was not altered at its gene expression level, and p53 was significantly decreased after various stress treatment. Caspase assay demonstrated that Caspase-3, -8, -9 enzyme activities in newt testis were significantly elevated after heat shock (40°C 2 h), cold exposure (4°C 12 h), and cadmium exposure (Cd 36 h), while Caspase3 and Caspase8 activities were increased with Caspase9 significantly decreased after starvation treatment. CONCLUSIONS/SIGNIFICANCE Severe germ cell apoptosis triggered by heat shock, cold exposure, and cadmium exposure was Caspase3 dependent, which probably involved both extrinsic and intrinsic pathways. Apaf1 may be involved in this process without elevating its gene expression. But starvation-induced germ cell apoptosis was likely mainly through extrinsic pathway. p53 was probably not responsible for stress-induced germ cell apoptosis in newt testis. The intriguing high occurrence of spermatid and sperm apoptosis probably resulted from the sperm morphology and unique reproduction policy of Chinese fire-belly newt, Cynops orientalis.
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Affiliation(s)
- Da-Hui Wang
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou, People's Republic of China
| | - Jian-Rao Hu
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, People's Republic of China
| | - Li-Ya Wang
- Department of Reproductive Endocrinology, The Women’s Hospital, School of Medicine, Zhejiang University, Hangzhou, People's Republic of China
| | - Yan-Jun Hu
- Department of Reproductive Endocrinology, The Women’s Hospital, School of Medicine, Zhejiang University, Hangzhou, People's Republic of China
| | - Fu-Qing Tan
- The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, People's Republic of China
| | - Hong Zhou
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou, People's Republic of China
| | - Jian-Zhong Shao
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou, People's Republic of China
| | - Wan-Xi Yang
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou, People's Republic of China
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Yazawa T, Inanoka Y, Mizutani T, Kuribayashi M, Umezawa A, Miyamoto K. Liver receptor homolog-1 regulates the transcription of steroidogenic enzymes and induces the differentiation of mesenchymal stem cells into steroidogenic cells. Endocrinology 2009; 150:3885-93. [PMID: 19359379 DOI: 10.1210/en.2008-1310] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Steroidogenic factor-1 (SF-1, also known as Ad4BP) has been demonstrated to be a primary transcriptional regulator of steroidogenic-related genes. However, mRNA for liver receptor homolog-1 (LRH-1), which together with SF-1, belongs to the NR5A nuclear receptor family, is expressed at much higher levels than SF-1 mRNA in the human gonad. In our previous studies, we demonstrated that SF-1 induced the differentiation of bone marrow-derived mesenchymal stem cells (MSCs) into steroidogenic cells such as Leydig or adrenocortical cells. The introduction of LRH-1 into human MSCs (hMSCs) with the aid of cAMP also induced the expression of steroidogenic enzymes, including CYP17, and their differentiation into steroid hormone-producing cells. Promoter analysis, EMSA, and chromatin immunoprecipitation assay using LRH-1-transduced hMSCs indicated that three LRH-1 binding sites were responsible for CYP17 transactivation. Immunohistochemical studies showed that LRH-1 protein was expressed in human Leydig cells. The CYP17 promoter region was highly methylated in hMSCs, whereas it was demethylated by the introduction of LRH-1 and cAMP treatment. These results indicate that LRH-1 could represent another key regulator of the steroidogenic lineage in MSCs and play a vital role in steroid hormone production in human Leydig cells.
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MESH Headings
- Adrenal Glands/metabolism
- Animals
- Cell Differentiation/genetics
- Cell Line
- Chromatin Immunoprecipitation
- Cyclic AMP/pharmacology
- DAX-1 Orphan Nuclear Receptor
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/physiology
- Electrophoretic Mobility Shift Assay
- Female
- Gonads/metabolism
- Humans
- Immunohistochemistry
- Male
- Mesenchymal Stem Cells/cytology
- Mesenchymal Stem Cells/metabolism
- Mice
- Mice, Mutant Strains
- Nuclear Receptor Subfamily 4, Group A, Member 1
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/physiology
- Receptors, Retinoic Acid/genetics
- Receptors, Retinoic Acid/physiology
- Receptors, Steroid/genetics
- Receptors, Steroid/physiology
- Repressor Proteins/genetics
- Repressor Proteins/physiology
- Reverse Transcriptase Polymerase Chain Reaction
- Steroid 17-alpha-Hydroxylase/genetics
- Steroidogenic Factor 1/genetics
- Steroidogenic Factor 1/physiology
- Steroids/biosynthesis
- Transduction, Genetic
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Affiliation(s)
- Takashi Yazawa
- Department of Biochemistry, Faculty of Medical Sciences, University of Fukui, Eiheiji-cho, Fukui 910-1193 Japan
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Dumond H, Maufroid JP, Ko CI, Chardard D, Chesnel A, Flament S. Freemartin in the amphibian Pleurodeles waltl: parabiosis between individuals from opposite sex triggers both germ and somatic cells alterations during female gonad development. Mol Reprod Dev 2008; 75:439-49. [PMID: 18008317 DOI: 10.1002/mrd.20750] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Wild type embryos of the newt Pleurodeles waltl were used to realize parabiosis, a useful model to study the effect of endogenous circulating hormones on gonad development. The genotypic sex of each parabiont (ZZ male or ZW female) was determined early from the analysis of the sex chromosome borne marker peptidase-1. In ZZ/ZZ and ZW/ZW associations, gonads develop according to genetic sex. In ZZ/ZW associations, the ZZ gonads differentiate as normal testes while ZW gonads development shows numerous alterations. At the beginning of sex differentiation, these ZW gonads possess a reduced number of germ cells and a reduced expression of steroidogenic factor 1 and P450-aromatase mRNAs when compared to gonads from ZW/ZW associations. During gonad differentiation, conversely to the control situation, these germ cells do not enter meiosis as corroborated by chromatin status and absence of the meiosis entry marker DMC1; the activity of the estradiol-producing enzyme P450-aromatase is as low as in ZZ gonads. At adulthood, no germ cells are observed on histological sections, consistently with the absence of VASA expression. At this stage, the testis-specific marker DMRT1 is expressed only in ZZ gonads, suggesting that the somatic compartment of the ZW gonad is not masculinized. So, when exposed to ZZ hormones, ZW gonads reach the undifferentiated status but the ovary differentiation does not occur. This gonad is inhibited by a process affecting both somatic and germ cells. Additionally, the ZW gonad inhibition does not occur in the case of an exogenous estradiol treatment of larvae.
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Affiliation(s)
- Helene Dumond
- EA 3442 Aspects cellulaires et moléculaires de la reproduction et du développement, Nancy-Université, Nancy, France
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Yazawa T, Uesaka M, Inaoka Y, Mizutani T, Sekiguchi T, Kajitani T, Kitano T, Umezawa A, Miyamoto K. Cyp11b1 is induced in the murine gonad by luteinizing hormone/human chorionic gonadotropin and involved in the production of 11-ketotestosterone, a major fish androgen: conservation and evolution of the androgen metabolic pathway. Endocrinology 2008; 149:1786-92. [PMID: 18162527 DOI: 10.1210/en.2007-1015] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
We have shown previously that Cyp11b1, an 11beta-hydroxylase responsible for glucocorticoid biosynthesis in the adrenal gland, was induced by cAMP in androgen-producing Leydig-like cells derived from mesenchymal stem cells. We found that Cyp11b1 was induced in male Leydig cells, or female theca cells, when human chorionic gonadotropin was administered in immature mice. Expression of Cyp11b1 in rodent gonads caused the production of 11-ketotestosterone (11-KT), a major fish androgen, which induces male differentiation or spermatogenesis in fish. As in teleosts, plasma concentrations of 11-KT were elevated in human chorionic gonadotropin-treated mice. In contrast to teleosts, however, plasma concentrations of 11-KT were similar in both sexes, despite levels of testosterone, a precursor substrate, being about 20 times higher in male mice. Because expression of 11beta-hydroxysteroid dehydrogenase type 2, was much higher in the mouse ovary than in the testis, conversion of testosterone into 11-KT may occur more efficiently in the ovary. In a luciferase reporter system that was responsive to and activated by androgens, 11-KT efficiently activated mammalian androgen receptor-mediated transactivation. Our results suggest that the androgen metabolic pathway is conserved between teleosts and mammals, despite sexual dominance and reproductive functions of 11-KT being altered during evolution.
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Affiliation(s)
- Takashi Yazawa
- Department of Biochemistry, Faculty of Medical Sciences, University of Fukui, Shimoaizuki, Matsuoka, Eiheiji-cho, Fukui, Japan
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Sasso-Cerri E, Cerri PS, Freymüller E, Miraglia SM. Apoptosis during the seasonal spermatogenic cycle of Rana catesbeiana. J Anat 2006; 209:21-9. [PMID: 16822266 PMCID: PMC2100304 DOI: 10.1111/j.1469-7580.2006.00582.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/14/2006] [Indexed: 11/29/2022] Open
Abstract
In the bullfrog Rana catesbeiana, testicular weight is constant throughout the year, but the volume densities of germinative and interstitial compartments undergo inverse changes from winter (non-breeding) to summer (breeding). The occurrence of apoptosis in the seminiferous lobules of bullfrogs was investigated in these two periods using sections stained with haematoxylin and eosin (H&E), the TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling) method and transmission electron microscopy. TUNEL-positive cells were observed in the seminiferous lobules, and ultrastructural morphological details confirmed the occurrence of cell death by apoptosis. In summer, the occurrence of several spermatogenic processes (in addition to spermiogenesis and spermiation), and then the overconsumption of Sertoli cell-derived pro-survival factors, could be responsible for the increased density of apoptotic cells. Alternatively, the low apoptotic frequency in winter could be related to the constant homeostasis in the germinative compartment given that most lobules are filled with primary spermatocytes. As volume densities of interstitial and germinative compartments undergo inverse seasonal variations through the year, the incidence of apoptosis (in summer) could play a part in controlling the spermatogenic process, maintaining the lobular size when interstitial tissue is maximally developed. In winter, the low apoptotic cell density leads to spermatogenic recrudescence and, thereby, the production of an adequate quantity of spermatozoa for the next breeding period. Thus, apoptosis may participate not only in the maintenance of spermatogenic homeostasis, but also in the cyclical control of the different spermatogenic processes according to seasonal changes of the testicular compartments as a whole.
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Affiliation(s)
- Estela Sasso-Cerri
- Department of Morphology, Dental School, São Paulo State University (UNESP), Araraquara, Brazil.
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