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Yao A, Nakamura M, Kohtsuka H, Sunobe T, Miura T. Gonadal and cellular dynamics during protogynous sex change in the harlequin sandsmelt Parapercis pulchella. JOURNAL OF FISH BIOLOGY 2023; 103:1347-1356. [PMID: 37621220 DOI: 10.1111/jfb.15534] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 07/19/2023] [Accepted: 08/23/2023] [Indexed: 08/26/2023]
Abstract
Some teleost fishes change their sex, and some of these fishes have specific gonads known as "ovotestes," that is, gonads containing both ovarian and testicular tissues. In this study, we revealed the gonadal transformation process and cell dynamics during the female-to-male sex change in the harlequin sandsmelt, Parapercis pulchella (Pinguipetidae), in which females possess ovotestes. Histological observations revealed that although female ovotestes were composed of oocytes, a few cysts of male germ cells were observed among them. At the initial phase of sex change, male germ cells increased, and spermatogenesis proceeded. After that, oocytes decreased and finally disappeared, and the gonads became functional testes. Immunohistochemistry using antibodies against Pcna (proliferating cell nuclear antigen) as a cell proliferation marker revealed that spermatogonia were Pcna positive, whereas spermatocytes were negative, in female ovotestes. This suggests that spermatogenesis is arrested at the spermatocyte stage. In addition, some somatic cells surrounding oocytes, which were thought to be the female follicle cells, were Pcna positive during sex change, indicating that these cells proliferate during sex change and are reused in male testes after sex change. Also, immunostaining using antibodies against active cleaved-Caspase3a as an apoptosis marker demonstrated that oocytes degenerated through apoptotic cell death at the late transition stage. Together with previous findings in other fishes, these findings suggested that the histological processes in gonads during sex change, such as the order of developmental events, developmental fates of ovarian cavities, and ovotestis structures, are diversified among fish species. In contrast, cellular dynamics of female germ and somatic cells during sex change are common among protogynous species.
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Affiliation(s)
- Akifumi Yao
- Misaki Marine Biological Station, School of Science, The University of Tokyo, Miura, Japan
| | - Mayuko Nakamura
- Misaki Marine Biological Station, School of Science, The University of Tokyo, Miura, Japan
| | - Hisanori Kohtsuka
- Misaki Marine Biological Station, School of Science, The University of Tokyo, Miura, Japan
| | - Tomoki Sunobe
- Laboratory of Fish Behavioral Ecology, Tateyama Station, Field Science Center, Tokyo University of Marine Science and Technology, Tateyama, Japan
| | - Toru Miura
- Misaki Marine Biological Station, School of Science, The University of Tokyo, Miura, Japan
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2
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Oyama T, Sonoyama T, Kasai M, Sakai Y, Sunobe T. Bidirectional sex change and plasticity of gonadal phases in the goby Lubricogobius exiguus. JOURNAL OF FISH BIOLOGY 2023; 102:1079-1087. [PMID: 36856167 DOI: 10.1111/jfb.15363] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 02/24/2023] [Indexed: 05/13/2023]
Abstract
Of the ca. 500 known hermaphroditic fish species, bidirectional sex change and simultaneous hermaphroditism are currently known in 69 and 57 species, respectively. Both bidirectional sex change and simultaneous hermaphroditism are predicted to evolve when mating opportunities are limited, such as in cases of low-density distribution and low mobility of individuals. However, the plasticity of sex is adaptive in obtaining mating opportunities, especially when there is mate loss. Pair-rearing experiments and histological observations of gonads of the goby Lubricogobius exiguus, which has low-density distributions and low mobility, showed bidirectional sex change. The male-role individuals in pairs had gonads in which only the testis was functional (male-phase), whereas the female-role individuals had two types of gonads: only the ovary was functional (female-phase) or both testis and ovary were functional (simultaneously hermaphroditic phase, SH-phase). In addition, single-rearing experiments showed SH-phase gonads in all individuals, and some cyclic spawning but no self-fertilization occurred. These results revealed that L. exiguus has an unusual sexual pattern among hermaphroditic fishes because they undergo bidirectional sex change and some maintain SH-phase gonads. These findings indicate that the low-density distribution and low mobility of L. exiguus in their natural habitat may have influenced the evolution of this unique sexual pattern.
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Affiliation(s)
- Takumi Oyama
- Laboratory of Fish Behavioral Ecology, Tateyama Station, Field Science Center, Tokyo University of Marine Science and Technology, Tateyama, Chiba, Japan
- Laboratory of Biology of Aquatic Resources, Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan
| | | | - Miku Kasai
- Shimonoseki Marine Science Museum, Shimonoseki, Yamaguchi, Japan
| | - Yoichi Sakai
- Laboratory of Biology of Aquatic Resources, Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan
| | - Tomoki Sunobe
- Laboratory of Fish Behavioral Ecology, Tateyama Station, Field Science Center, Tokyo University of Marine Science and Technology, Tateyama, Chiba, Japan
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Goldsworthy NC, Srinivasan M, Smallhorn‐West P, Cheah L, Munday PL, Jones GP. Life-history constraints, short adult life span and reproductive strategies in coral reef gobies of the genus Trimma. JOURNAL OF FISH BIOLOGY 2022; 101:996-1007. [PMID: 35818109 PMCID: PMC9796689 DOI: 10.1111/jfb.15161] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 07/05/2022] [Indexed: 05/26/2023]
Abstract
Body size influences many life-history traits, with small-bodied animals tending to have short life spans, high mortality and greater reproductive effort early in life. In this study, the authors investigated the life-history traits and reproductive strategies of three small-bodied coral reef gobies of the genus Trimma: Trimma benjamini, Trimma capostriatum and Trimma yanoi. The authors found all Trimma species studied attained a small body size of <25 mm, had a short life span of <140 days and experienced high estimated daily mortality of 3.0%-6.7%. Furthermore, the pelagic larval phase accounted for 25.3%-28.5% of the maximum life span, and maturation occurred between 74.1 and 82.1 days at 15.2-15.8 mm, leaving only 35%-43% of the total life span as a reproductively viable adult. All mature individuals had gonad structures consistent with bidirectional sex change, with bisexual gonads including both ovarian and testicular portions separated by a thin wall of connective tissue. In the female and male phases, only ovaries or testes were mature, whereas gonadal tissue of the non-active sex remained. One T. benjamini individual and one T. yanoi individual had ovarian and testicular tissue active simultaneously. The results of this study highlight the life-history challenges small CRFs face on their path to reproduction and reproductive strategies that could be beneficial in fishes with high and unpredictable mortality and short reproductive life spans.
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Affiliation(s)
- Nisha C. Goldsworthy
- Australian Research Council Centre of Excellence for Coral Reef StudiesJames Cook UniversityTownsvilleQueenslandAustralia
- Marine Biology and AquacultureJames Cook UniversityTownsvilleQueenslandAustralia
- College of Science and EngineeringJames Cook UniversityTownsvilleQueenslandAustralia
| | - Maya Srinivasan
- Marine Biology and AquacultureJames Cook UniversityTownsvilleQueenslandAustralia
- College of Science and EngineeringJames Cook UniversityTownsvilleQueenslandAustralia
| | - Patrick Smallhorn‐West
- Australian Research Council Centre of Excellence for Coral Reef StudiesJames Cook UniversityTownsvilleQueenslandAustralia
- WorldFishBayan LepasPenangMalaysia
| | - Lit‐Chien Cheah
- Division of Tropical Environments & SocietiesJames Cook UniversityTownsvilleQueenslandAustralia
| | - Philip L. Munday
- Australian Research Council Centre of Excellence for Coral Reef StudiesJames Cook UniversityTownsvilleQueenslandAustralia
| | - Geoffrey P. Jones
- Australian Research Council Centre of Excellence for Coral Reef StudiesJames Cook UniversityTownsvilleQueenslandAustralia
- Marine Biology and AquacultureJames Cook UniversityTownsvilleQueenslandAustralia
- College of Science and EngineeringJames Cook UniversityTownsvilleQueenslandAustralia
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Renn SC, Hurd PL. Epigenetic Regulation and Environmental Sex Determination in Cichlid Fishes. Sex Dev 2021; 15:93-107. [PMID: 34433170 PMCID: PMC8440468 DOI: 10.1159/000517197] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Accepted: 05/12/2021] [Indexed: 12/14/2022] Open
Abstract
Studying environmental sex determination (ESD) in cichlids provides a phylogenetic and comparative approach to understand the evolution of the underlying mechanisms, their impact on the evolution of the overlying systems, and the neuroethology of life history strategies. Natural selection normally favors parents who invest equally in the development of male and female offspring, but evolution may favor deviations from this 50:50 ratio when environmental conditions produce an advantage for doing so. Many species of cichlids demonstrate ESD in response to water chemistry (temperature, pH, and oxygen concentration). The relative strengths of and the exact interactions between these factors vary between congeners, demonstrating genetic variation in sensitivity. The presence of sizable proportions of the less common sex towards the environmental extremes in most species strongly suggests the presence of some genetic sex-determining loci acting in parallel with the ESD factors. Sex determination and differentiation in these species does not seem to result in the organization of a final and irreversible sexual fate, so much as a life-long ongoing battle between competing male- and female-determining genetic and hormonal networks governed by epigenetic factors. We discuss what is and is not known about the epigenetic mechanism behind the differentiation of both gonads and sex differences in the brain. Beyond the well-studied tilapia species, the 2 best-studied dwarf cichlid systems showing ESD are the South American genus Apistogramma and the West African genus Pelvicachromis. Both species demonstrate male morphs with alternative reproductive tactics. We discuss the further neuroethology opportunities such systems provide to the study of epigenetics of alternative life history strategies and other behavioral variation.
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Affiliation(s)
| | - Peter L Hurd
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, CA
- Department of Psychology, University of Alberta, Edmonton, AB, CA
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Testicular inducing steroidogenic cells trigger sex change in groupers. Sci Rep 2021; 11:11117. [PMID: 34045599 PMCID: PMC8160332 DOI: 10.1038/s41598-021-90691-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 05/12/2021] [Indexed: 11/08/2022] Open
Abstract
Vertebrates usually exhibit gonochorism, whereby their sex is fixed throughout their lifetime. However, approximately 500 species (~ 2%) of extant teleost fishes change sex during their lifetime. Although phylogenetic and evolutionary ecological studies have recently revealed that the extant sequential hermaphroditism in teleost fish is derived from gonochorism, the evolution of this transsexual ability remains unclear. We revealed in a previous study that the tunica of the ovaries of several protogynous hermaphrodite groupers contain functional androgen-producing cells, which were previously unknown structures in the ovaries of gonochoristic fishes. Additionally, we demonstrated that these androgen-producing cells play critical roles in initiating female-to-male sex change in several grouper species. In the present study, we widened the investigation to include 7 genera and 18 species of groupers and revealed that representatives from most major clades of extant groupers commonly contain these androgen-producing cells, termed testicular-inducing steroidogenic (TIS) cells. Our findings suggest that groupers acquired TIS cells in the tunica of the gonads for successful sex change during their evolution. Thus, TIS cells trigger the evolution of sex change in groupers.
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Qu M, Ding S, Schartl M, Adolfi MC. Spatial and temporal expression pattern of sex-related genes in ovo-testis of the self-fertilizing mangrove killifish (Kryptolebias marmoratus). Gene 2020; 742:144581. [PMID: 32173540 DOI: 10.1016/j.gene.2020.144581] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 03/10/2020] [Accepted: 03/11/2020] [Indexed: 01/23/2023]
Abstract
In vertebrates, sex determination and differentiation comprehend a fine balance between female and male factors, leading the bipotential anlage to develop towards ovary or testis, respectively. Nevertheless, the mangrove killifish, (Kryptolebias marmoratus) a simultaneous hermaphroditic species, could overcome those antagonistic pathways and evolved to develop and maintain reproductively active ovarian and testicular tissues in the same organ. Morphological and mRNA localization analyzes of developing and adult gonads demonstrate that genes related to testis (dmrt1 and amh) and ovary differentiation (foxl2 and sox9a) follow the same expression pattern observed in gonochoristic species, thus functioning as two independent organs. In addition, Amh expression patterns make it a strong candidate for initiation of the formation and maintenance of the testicular tissue in the hermaphroditic gonad. Differently from described so far, foxl3 seems to have an important role in oogenesis as well as spermatogenesis and gonadal structure.
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Affiliation(s)
- Meng Qu
- University of Wuerzburg, Physiological Chemistry, Biocenter, Am Hubland, D-97074 Wuerzburg, Germany; State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Science, Xiamen University, Xiamen 361102, China; CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Guangzhou 510220, China
| | - Shaoxiong Ding
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Science, Xiamen University, Xiamen 361102, China
| | - Manfred Schartl
- University of Wuerzburg, Physiological Chemistry, Biocenter, Am Hubland, D-97074 Wuerzburg, Germany; University of Wuerzburg, Developmental Biochemistry, Biocenter, Am Hubland, D-97074 Wuerzburg, Germany; The Xiphophorus Genetic Stock Center, Department of Chemistry and Biochemistry, Texas State University, San Marcos, TX, USA
| | - Mateus Contar Adolfi
- University of Wuerzburg, Physiological Chemistry, Biocenter, Am Hubland, D-97074 Wuerzburg, Germany; University of Wuerzburg, Developmental Biochemistry, Biocenter, Am Hubland, D-97074 Wuerzburg, Germany.
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Pla S, Benvenuto C, Capellini I, Piferrer F. A phylogenetic comparative analysis on the evolution of sequential hermaphroditism in seabreams (Teleostei: Sparidae). Sci Rep 2020; 10:3606. [PMID: 32107416 PMCID: PMC7046777 DOI: 10.1038/s41598-020-60376-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 01/28/2020] [Indexed: 01/25/2023] Open
Abstract
The Sparids are an ideal group of fishes in which to study the evolution of sexual systems since they exhibit a great sexual diversity, from gonochorism (separate sexes) to protandrous (male-first) and protogynous (female-first) sequential hermaphroditism (sex change). According to the size-advantage model (SAM), selection should favour sex change when the second sex achieves greater reproductive success at a larger body size than the first sex. Using phylogenetic comparative methods and a sample of 68 sparid species, we show that protogyny and protandry evolve from gonochorism but evolutionary transitions between these two forms of sequential hermaphroditism are unlikely to happen. Using male gonadosomatic index (GSI) as a measure of investment in gametes and proxy for sperm competition, we find that, while gonochoristic and protogynous species support the predictions of SAM, protandrous species do not, as they exhibit higher GSI values than expected even after considering mating systems and spawning modes. We suggest that small males of protandrous species have to invest disproportionally more in sperm production than predicted not only when spawning in aggregations, with high levels of sperm competition, but also when spawning in pairs due to the need to fertilize highly fecund females, much larger than themselves. We propose that this compensatory mechanism, together with Bateman’s principles in sequential hermaphrodites, should be formally incorporated in the SAM.
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Affiliation(s)
- Susanna Pla
- Institut de Ciències del Mar, Spanish National Research Council (CSIC), Barcelona, Spain
| | - Chiara Benvenuto
- Ecosystems and Environment Research Centre, School of Science, Engineering and Environment, University of Salford, Salford, UK
| | - Isabella Capellini
- School of Biological Sciences, Queen's University of Belfast, 19 Chlorine Gardens, Belfast, BT9 5DL, UK
| | - Francesc Piferrer
- Institut de Ciències del Mar, Spanish National Research Council (CSIC), Barcelona, Spain.
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