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Brammer-Robbins E, Cowart JR, Calderon M, Burgess EA, Larkin IV, Martyniuk CJ. Sirenian (manatees and dugongs) reproductive endocrinology. Gen Comp Endocrinol 2024; 356:114575. [PMID: 38908455 DOI: 10.1016/j.ygcen.2024.114575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Accepted: 06/19/2024] [Indexed: 06/24/2024]
Abstract
Reproductive hormones are essential to mating systems, behavior, fertility, gestation, parturition, and lactation in mammals and understanding the role of hormones in these processes is essential for species conservation. Sirenia is a unique order of marine mammals that include manatees, dugongs, and the extinct Steller's sea cow. Extant Sirenian species are all listed as vulnerable due to habitat loss, cold stress, boat strike trauma, harmful algal bloom toxicity, entanglements, and illegal hunting. Therefore, successful reproduction is essential to maintaining and increasing Sirenian populations. Understanding Sirenian reproductive behavior, endocrinology, and mating strategies will aid conservation and management efforts to protect and provide the proper conditions for successful reproduction. The objectives of this review were to synthesize the current knowledge regarding reproductive cycles and endocrinology of Sirenians and identify knowledge gaps for future investigation. The current literature on Sirenian reproductive physiology reports reproductive seasonality, sexual maturation, estrous cyclicity and acyclicity, pregnancy, and sex differences. However, there remain significant knowledge gaps on the cyclicity and pulsatile release of gonadotropins, maturation in females, and characterization of pregnancy hormone profiles throughout gestation. To date, there is no explanation for confirmed pattern for ovarian acyclicity, nor understanding of the function of the numerous accessory corpus luteum described in manatees. Research including a greater number of longitudinal and postmortem studies on a wider variety of wild manatee populations are important first steps. Taken together, understanding the reproductive endocrinology of these vulnerable and threatened species is critical for policy and management decisions to better inform protection initiatives.
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Affiliation(s)
- Elizabeth Brammer-Robbins
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA; Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL, USA; Aquatic Animal Health Program, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.
| | - Jonathan R Cowart
- Aquatic Animal Health Program, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA
| | - Monica Calderon
- Aquatic Animal Health Program, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA
| | | | - Iskande V Larkin
- Aquatic Animal Health Program, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA
| | - Christopher J Martyniuk
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA; Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL, USA
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2
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Pyenson ND. How teeth, tusks and horny pads evolved together in sea cows. Proc Biol Sci 2024; 291:20241154. [PMID: 39137887 PMCID: PMC11321848 DOI: 10.1098/rspb.2024.1154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2024] [Revised: 06/13/2024] [Accepted: 07/23/2024] [Indexed: 08/15/2024] Open
Affiliation(s)
- Nicholas D. Pyenson
- Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC20013-7012, USA
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3
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Tian R, Zhang Y, Kang H, Zhang F, Jin Z, Wang J, Zhang P, Zhou X, Lanyon JM, Sneath HL, Woolford L, Fan G, Li S, Seim I. Sirenian genomes illuminate the evolution of fully aquatic species within the mammalian superorder afrotheria. Nat Commun 2024; 15:5568. [PMID: 38956050 PMCID: PMC11219930 DOI: 10.1038/s41467-024-49769-x] [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: 08/23/2023] [Accepted: 06/12/2024] [Indexed: 07/04/2024] Open
Abstract
Sirenians of the superorder Afrotheria were the first mammals to transition from land to water and are the only herbivorous marine mammals. Here, we generated a chromosome-level dugong (Dugong dugon) genome. A comparison of our assembly with other afrotherian genomes reveals possible molecular adaptations to aquatic life by sirenians, including a shift in daily activity patterns (circadian clock) and tolerance to a high-iodine plant diet mediated through changes in the iodide transporter NIS (SLC5A5) and its co-transporters. Functional in vitro assays confirm that sirenian amino acid substitutions alter the properties of the circadian clock protein PER2 and NIS. Sirenians show evidence of convergent regression of integumentary system (skin and its appendages) genes with cetaceans. Our analysis also uncovers gene losses that may be maladaptive in a modern environment, including a candidate gene (KCNK18) for sirenian cold stress syndrome likely lost during their evolutionary shift in daily activity patterns. Genomes from nine Australian locations and the functionally extinct Okinawan population confirm and date a genetic break ~10.7 thousand years ago on the Australian east coast and provide evidence of an associated ecotype, and highlight the need for whole-genome resequencing data from dugong populations worldwide for conservation and genetic management.
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Affiliation(s)
- Ran Tian
- Integrative Biology Laboratory, Nanjing Normal University, Nanjing, 210023, China
| | - Yaolei Zhang
- BGI Research, Qingdao, 266555, China
- BGI Research, Shenzhen, 518083, China
- Qingdao Key Laboratory of Marine Genomics BGI Research, Qingdao, 266555, China
| | - Hui Kang
- Marine Mammal and Marine Bioacoustics Laboratory, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, 572000, China
- The Innovation Research Center for Aquatic Mammals, and Key Laboratory of Aquatic Biodiversity and Conservation of the Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Fan Zhang
- Integrative Biology Laboratory, Nanjing Normal University, Nanjing, 210023, China
| | - Zhihong Jin
- Integrative Biology Laboratory, Nanjing Normal University, Nanjing, 210023, China
| | - Jiahao Wang
- BGI Research, Qingdao, 266555, China
- BGI Research, Shenzhen, 518083, China
| | - Peijun Zhang
- Marine Mammal and Marine Bioacoustics Laboratory, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, 572000, China
| | - Xuming Zhou
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- School of Life Sciences, University of Science and Technology of China, Hefei, 230027, China
| | - Janet M Lanyon
- School of the Environment, The University of Queensland, Lucia, 4072, Australia
| | - Helen L Sneath
- School of the Environment, The University of Queensland, Lucia, 4072, Australia
| | - Lucy Woolford
- School of Veterinary Sciences, The University of Adelaide, Roseworthy, 5371, Australia
| | - Guangyi Fan
- BGI Research, Qingdao, 266555, China.
- BGI Research, Shenzhen, 518083, China.
- Qingdao Key Laboratory of Marine Genomics BGI Research, Qingdao, 266555, China.
- State Key Laboratory of Agricultural Genomics, BGI Research, Shenzhen, 518083, China.
| | - Songhai Li
- Marine Mammal and Marine Bioacoustics Laboratory, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, 572000, China.
- The Innovation Research Center for Aquatic Mammals, and Key Laboratory of Aquatic Biodiversity and Conservation of the Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.
| | - Inge Seim
- Integrative Biology Laboratory, Nanjing Normal University, Nanjing, 210023, China.
- Marine Mammal and Marine Bioacoustics Laboratory, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, 572000, China.
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Steinbinder J, Sachslehner AP, Holthaus KB, Eckhart L. Comparative genomics of sirenians reveals evolution of filaggrin and caspase-14 upon adaptation of the epidermis to aquatic life. Sci Rep 2024; 14:9278. [PMID: 38653760 PMCID: PMC11039687 DOI: 10.1038/s41598-024-60099-2] [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: 12/23/2023] [Accepted: 04/18/2024] [Indexed: 04/25/2024] Open
Abstract
The mammalian epidermis has evolved to protect the body in a dry environment. Genes of the epidermal differentiation complex (EDC), such as FLG (filaggrin), are implicated in the barrier function of the epidermis. Here, we investigated the molecular evolution of the EDC in sirenians (manatees and dugong), which have adapted to fully aquatic life, in comparison to the EDC of terrestrial mammals and aquatic mammals of the clade Cetacea (whales and dolphins). We show that the main subtypes of EDC genes are conserved or even duplicated, like late cornified envelope (LCE) genes of the dugong, whereas specific EDC genes have undergone inactivating mutations in sirenians. FLG contains premature stop codons in the dugong, and the ortholog of human CASP14 (caspase-14), which proteolytically processes filaggrin, is pseudogenized in the same species. As FLG and CASP14 have also been lost in whales, these mutations represent convergent evolution of skin barrier genes in different lineages of aquatic mammals. In contrast to the dugong, the manatee has retained functional FLG and CASP14 genes. FLG2 (filaggrin 2) is truncated in both species of sirenians investigated. We conclude that the land-to-water transition of sirenians was associated with modifications of the epidermal barrier at the molecular level.
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Affiliation(s)
- Julia Steinbinder
- Department of Dermatology, Medical University of Vienna, Vienna, Austria
| | | | | | - Leopold Eckhart
- Department of Dermatology, Medical University of Vienna, Vienna, Austria.
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Hautier L, Gomes Rodrigues H, Ferreira-Cardoso S, Emerling CA, Porcher ML, Asher RJ, Portela Miguez R, Delsuc F. From teeth to pad: tooth loss and development of keratinous structures in sirenians. Proc Biol Sci 2023; 290:20231932. [PMID: 38018114 PMCID: PMC10685118 DOI: 10.1098/rspb.2023.1932] [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: 08/29/2023] [Accepted: 11/03/2023] [Indexed: 11/30/2023] Open
Abstract
Sirenians are a well-known example of morphological adaptation to a shallow-water grazing diet characterized by a modified feeding apparatus and orofacial morphology. Such adaptations were accompanied by an anterior tooth reduction associated with the development of keratinized pads, the evolution of which remains elusive. Among sirenians, the recently extinct Steller's sea cow represents a special case for being completely toothless. Here, we used μ-CT scans of sirenian crania to understand how motor-sensor systems associated with tooth innervation responded to innovations such as keratinized pads and continuous dental replacement. In addition, we surveyed nine genes associated with dental reduction for signatures of loss of function. Our results reveal how patterns of innervation changed with modifications of the dental formula, especially continuous replacement in manatees. Both our morphological and genomic data show that dental development was not completely lost in the edentulous Steller's sea cows. By tracing the phylogenetic history of tooth innervation, we illustrate the role of development in promoting the innervation of keratinized pads, similar to the secondary use of dental canals for innervating neomorphic keratinized structures in other tetrapod groups.
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Affiliation(s)
- Lionel Hautier
- Institut des Sciences de l’Évolution, Université Montpellier, CNRS, IRD, EPHE, Montpellier 34095, France
- Mammal Section, Life Sciences, Vertebrate Division, The Natural History Museum, London, UK
| | - Helder Gomes Rodrigues
- Centre de Recherche en Paléontologie—Paris (CR2P), UMR CNRS 7207, Muséum National d'Histoire Naturelle, Sorbonne Université, Paris, France
| | - Sérgio Ferreira-Cardoso
- Institut des Sciences de l’Évolution, Université Montpellier, CNRS, IRD, EPHE, Montpellier 34095, France
| | | | - Marie-Lou Porcher
- Institut des Sciences de l’Évolution, Université Montpellier, CNRS, IRD, EPHE, Montpellier 34095, France
| | - Robert J. Asher
- Department of Zoology, University of Cambridge, Cambridge, UK
| | - Roberto Portela Miguez
- Mammal Section, Life Sciences, Vertebrate Division, The Natural History Museum, London, UK
| | - Frédéric Delsuc
- Institut des Sciences de l’Évolution, Université Montpellier, CNRS, IRD, EPHE, Montpellier 34095, France
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Antar MS, Gohar AS, El-Desouky H, Seiffert ER, El-Sayed S, Claxton AG, Sallam HM. A diminutive new basilosaurid whale reveals the trajectory of the cetacean life histories during the Eocene. Commun Biol 2023; 6:707. [PMID: 37563270 PMCID: PMC10415296 DOI: 10.1038/s42003-023-04986-w] [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: 04/16/2023] [Accepted: 05/25/2023] [Indexed: 08/12/2023] Open
Abstract
Soon after whales originated from small terrestrial artiodactyl ancestors, basal stem forms (archaeocetes) came to inhabit more specialized aquatic ecologies and underwent a tremendous adaptive radiation that culminated in the adoption of a fully aquatic lifestyle. This adaptive strategy is first documented by the geographically widespread extinct family Basilosauridae. Here we report a new basilosaurid genus and species, Tutcetus rayanensis, from the middle Eocene of Fayum, Egypt. This new whale is not only the smallest known basilosaurid, but it is also one of the oldest records of this family from Africa. Tutcetus allows us to further test hypotheses regarding basilosaurids' early success in the aquatic ecosystem, which lasted into the latest Eocene, and their ability to outcompete amphibious stem whales and opportunistically adapt to new niches after they completely severed their ties to the land. Tutcetus also significantly expands the size range of the basilosaurids and reveals new details about their life histories, phylogeny, and paleobiogeography.
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Affiliation(s)
- Mohammed S Antar
- Mansoura University Vertebrate Paleontology Center (MUVP), Mansoura University, Mansoura, 35516, Egypt.
- Nature Conservation Sector, Egyptian Environmental Affairs Agency, Cairo, 11728, Egypt.
| | - Abdullah S Gohar
- Mansoura University Vertebrate Paleontology Center (MUVP), Mansoura University, Mansoura, 35516, Egypt
- Institute of Global Health and Human Ecology (I-GHHE), School of Sciences and Engineering, American University in Cairo, New Cairo, 11835, Egypt
| | - Heba El-Desouky
- Mansoura University Vertebrate Paleontology Center (MUVP), Mansoura University, Mansoura, 35516, Egypt
- Department of Geology, Faculty of Science, Mansoura University, Mansoura, 35516, Egypt
| | - Erik R Seiffert
- Department of Integrative Anatomical Sciences, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, 90033, USA
| | - Sanaa El-Sayed
- Mansoura University Vertebrate Paleontology Center (MUVP), Mansoura University, Mansoura, 35516, Egypt
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Alexander G Claxton
- Department of Anatomy and Cell Biology, Oklahoma State University Center for Health Sciences, Tulsa, OK, 74107, USA
| | - Hesham M Sallam
- Mansoura University Vertebrate Paleontology Center (MUVP), Mansoura University, Mansoura, 35516, Egypt
- Institute of Global Health and Human Ecology (I-GHHE), School of Sciences and Engineering, American University in Cairo, New Cairo, 11835, Egypt
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7
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Beck RMD, de Vries D, Janiak MC, Goodhead IB, Boubli JP. Total evidence phylogeny of platyrrhine primates and a comparison of undated and tip-dating approaches. J Hum Evol 2023; 174:103293. [PMID: 36493598 DOI: 10.1016/j.jhevol.2022.103293] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 10/21/2022] [Accepted: 10/21/2022] [Indexed: 12/12/2022]
Abstract
There have been multiple published phylogenetic analyses of platyrrhine primates (New World monkeys) using both morphological and molecular data, but relatively few that have integrated both types of data into a total evidence approach. Here, we present phylogenetic analyses of recent and fossil platyrrhines, based on a total evidence data set of 418 morphological characters and 10.2 kilobases of DNA sequence data from 17 nuclear genes taken from previous studies, using undated and tip-dating approaches in a Bayesian framework. We compare the results of these analyses with molecular scaffold analyses using maximum parsimony and Bayesian approaches, and we use a formal information theoretic approach to identify unstable taxa. After a posteriori pruning of unstable taxa, the undated and tip-dating topologies appear congruent with recent molecular analyses and support largely similar relationships, with strong support for Stirtonia as a stem alouattine, Neosaimiri as a stem saimirine, Cebupithecia as a stem pitheciine, and Lagonimico as a stem callitrichid. Both analyses find three Greater Antillean subfossil platyrrhines (Xenothrix, Antillothrix, and Paralouatta) to form a clade that is related to Callicebus, congruent with a single dispersal event by the ancestor of this clade to the Greater Antilles. They also suggest that the fossil Proteropithecia may not be closely related to pitheciines, and that all known platyrrhines older than the Middle Miocene are stem taxa. Notably, the undated analysis found the Early Miocene Panamacebus (currently recognized as the oldest known cebid) to be unstable, and the tip-dating analysis placed it outside crown Platyrrhini. Our tip-dating analysis supports a late Oligocene or earliest Miocene (20.8-27.0 Ma) age for crown Platyrrhini, congruent with recent molecular clock analyses.
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Affiliation(s)
- Robin M D Beck
- Ecosystems and Environment Research Centre, School of Science, Engineering and Environment, University of Salford, Manchester, UK.
| | - Dorien de Vries
- Ecosystems and Environment Research Centre, School of Science, Engineering and Environment, University of Salford, Manchester, UK
| | - Mareike C Janiak
- Ecosystems and Environment Research Centre, School of Science, Engineering and Environment, University of Salford, Manchester, UK
| | - Ian B Goodhead
- Ecosystems and Environment Research Centre, School of Science, Engineering and Environment, University of Salford, Manchester, UK
| | - Jean P Boubli
- Ecosystems and Environment Research Centre, School of Science, Engineering and Environment, University of Salford, Manchester, UK
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How did the sea cow cross the Pacific? At a ponderous paddle. Nature 2022. [DOI: 10.1038/d41586-022-02899-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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