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Wang T, Wang X, Zhao N, Liu Q, Song Z, Li J. Morphology of the urogenital papilla of the male marine teleost Black Rockfish, Sebastes schlegelii (Hilgendorf, 1880), and its role in internal fertilization. J Morphol 2023; 284:e21534. [PMID: 36373244 DOI: 10.1002/jmor.21534] [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: 07/11/2022] [Revised: 09/20/2022] [Accepted: 10/09/2022] [Indexed: 11/16/2022]
Abstract
There are few detailed descriptions of the morphology of the male external genitalia, the urogenital papilla (UGP), of the Black Rockfish (Sebastes schlegelii Hilgendorf, 1880). The purpose of this study was to evaluate this organ histologically and to determine the time of development of the UGP in Black Rockfish. Twelve adult males, three adult females and around 500 juveniles were used in the experiment. The juveniles were divided into normal developmental and androgen groups. The androgen group was exposed to methyltestosterone (100 μg/L) for 2 h daily for 38 days. Samples (N = 10 per sampling) were randomly selected for analysis every 5 days from 30 to 116 days after birth. Parameters assessed included the type of epithelium, composition of connective tissue, muscular tissue, and the timing of UGP development. Differences in these parameters between normal developmental and androgen groups were evaluated. The results indicated that the UGP of the adult fish contains the sperm duct and ureter, which have the function of transporting sperm and urine, respectively. The androgen-treated juvenile fish developed the UGP earlier than the normal development group. This study provides a reference for understanding the external genitalia of other viviparous fishes by studying the UGP of the male Black Rockfish.
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Affiliation(s)
- Tao Wang
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, China.,CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Xueying Wang
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Ning Zhao
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Qinghua Liu
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Zongcheng Song
- Weihai Shenghang Aquatic Product Science and Technology Co. Ltd., Weihai, China
| | - Jun Li
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
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2
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Macaluso L, Carnevale G, Casu R, Pietrocola D, Villa A, Delfino M. Structural and environmental constraints on reduction of paired appendages among vertebrates. Biol J Linn Soc Lond 2019. [DOI: 10.1093/biolinnean/blz097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
AbstractBurrowing habits or complex environments have generally been considered as potential drivers acting on reduction and loss of the appendicular skeleton among vertebrates. Herein, we suggest that this might be the case for lissamphibians and squamates, but that fin loss in fishes is usually prevented by important structural constraints, because pectoral fins are commonly used to control rolling and pitching. We provide an overview of the distribution of paired appendage reduction across vertebrates while examining the ecological affinities of finless and limbless clades. We analysed the correlation between lifestyle and fin or limb loss using the discrete comparative analysis. The resulting Bayesian factors indicate strong evidence of correlation between: (1) pectoral-fin loss and coexistence of anguilliform elongation and burrowing habits or complex habitat in teleost fishes; and (2) limb loss and a burrowing or grass-swimming lifestyle in squamate reptiles and lissamphibians. These correlations suggest that a complex environment or a fossorial habit is a driving force leading to appendage loss. The only style of locomotion that is functional even in the absence of paired appendages is the undulatory one, which is typical of all elongated reptiles and lissamphibians, but certainly less common in teleost fishes.
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Affiliation(s)
- Loredana Macaluso
- Dipartimento di Scienze della Terra, Università degli Studi di Torino, Via Valperga Caluso, Torino, Italy
| | - Giorgio Carnevale
- Dipartimento di Scienze della Terra, Università degli Studi di Torino, Via Valperga Caluso, Torino, Italy
| | - Raffaello Casu
- Dipartimento di Fisica, Università degli Studi di Torino, Via Pietro Giuria, Torino, Italy
| | - Daniel Pietrocola
- Dipartimento di Scienze della Terra, Università degli Studi di Torino, Via Valperga Caluso, Torino, Italy
| | - Andrea Villa
- Dipartimento di Scienze della Terra, Università degli Studi di Torino, Via Valperga Caluso, Torino, Italy
- Bayerische Staatssammlung für Paläontologie und Geologie, Richard-Wagner-Straße, München, Germany
| | - Massimo Delfino
- Dipartimento di Scienze della Terra, Università degli Studi di Torino, Via Valperga Caluso, Torino, Italy
- Institut Català de Paleontologia Miquel Crusafont, Universitat Autònoma de Barcelona, Edifici Z (ICTA-ICP), Carrer de les Columnes s/n, Campus de la UAB, Cerdanyola del Valles, Barcelona, Spain
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3
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Ogino Y, Tohyama S, Kohno S, Toyota K, Yamada G, Yatsu R, Kobayashi T, Tatarazako N, Sato T, Matsubara H, Lange A, Tyler CR, Katsu Y, Iguchi T, Miyagawa S. Functional distinctions associated with the diversity of sex steroid hormone receptors ESR and AR. J Steroid Biochem Mol Biol 2018; 184:38-46. [PMID: 29885351 DOI: 10.1016/j.jsbmb.2018.06.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 05/26/2018] [Accepted: 06/04/2018] [Indexed: 12/13/2022]
Abstract
Sex steroid hormones including estrogens and androgens play fundamental roles in regulating reproductive activities and they act through estrogen and androgen receptors (ESR and AR). These steroid receptors have evolved from a common ancestor in association with several gene duplications. In most vertebrates, this has resulted in two ESR subtypes (ESR1 and ESR2) and one AR, whereas in teleost fish there are at least three ESRs (ESR1, ESR2a and ESR2b) and two ARs (ARα and ARβ) due to a lineage-specific whole genome duplication. Functional distinctions have been suggested among these receptors, but to date their roles have only been characterized in a limited number of species. Sexual differentiation and the development of reproductive organs are indispensable for all animal species and in vertebrates these events depend on the action of sex steroid hormones. Here we review the recent progress in understanding of the functions of the ESRs and ARs in the development and expression of sexually dimorphic characteristics associated with steroid hormone signaling in vertebrates, with representative fish, amphibians, reptiles, birds and mammals.
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Affiliation(s)
- Yukiko Ogino
- Attached Promotive Centre for International Education and Research of Agriculture, Faculty of Agriculture, Kyushu University, Fukuoka, Fukuoka 812-8581, Japan
| | - Saki Tohyama
- Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka, Shizuoka 422-8526, Japan
| | - Satomi Kohno
- Department of Biology, St. Cloud State University, St. Cloud, MN 56301, USA
| | - Kenji Toyota
- Department of Biological Sciences, Kanagawa University, Hiratsuka, Kanagawa 259-1293, Japan; Faculty of Industrial Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan
| | - Gen Yamada
- Institute of Advanced Medicine, Wakayama Medical University, Wakayama, Wakayama 641-8509, Japan
| | - Ryohei Yatsu
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas 78712, USA
| | - Tohru Kobayashi
- Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka, Shizuoka 422-8526, Japan
| | | | - Tomomi Sato
- Graduate School of Nanobioscience, Yokohama City University, Yokohama, Kanagawa 236-0027, Japan
| | - Hajime Matsubara
- Department of Aquatic Biology, Faculty of Bioindustry, Tokyo University of Agriculture, Abashiri, Hokkaido 099-2493, Japan
| | - Anke Lange
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4QD, UK
| | - Charles R Tyler
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4QD, UK
| | - Yoshinao Katsu
- Graduate School of Life Science, Hokkaido University, Sapporo 060-0809, Japan
| | - Taisen Iguchi
- Graduate School of Nanobioscience, Yokohama City University, Yokohama, Kanagawa 236-0027, Japan.
| | - Shinichi Miyagawa
- Faculty of Industrial Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan; Institute of Advanced Medicine, Wakayama Medical University, Wakayama, Wakayama 641-8509, Japan.
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Macagno ALM, Moczek AP. Appendage-patterning genes regulate male and female copulatory structures in horned beetles. Evol Dev 2016; 17:248-53. [PMID: 26174101 DOI: 10.1111/ede.12129] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Explaining the extraordinarily rapid diversification of insect copulatory structures has been a longstanding objective in evolutionary biology. However, remarkably little is known about the developmental genetic underpinnings of their formation. Furthermore, recent work has questioned whether male genitalic structures in beetles are serially homologous to appendages, or even homologous to the genitalia of other orders. Using RNA interference, we demonstrate that several cardinal appendage-patterning genes regulate the formation of copulatory structures in Onthophagus beetles of both sexes. These results are in strong disagreement with previous findings in the model beetle species Tribolium castaneum, but congruent with earlier studies in true bugs and flies. Our results support the hypotheses that genitalic development is largely conserved across insect orders, and that genitalia constitute serial appendage homologues. Moreover, we identify two patterning genes with striking phenotypic effects in both sexes. In these cases, the affected structures are known to interact functionally during copulation, but are not homologous to each other. This suggests that shared developmental regulation of male and female copulatory structures may extend beyond components related by descent to those related by function.
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Affiliation(s)
- Anna L M Macagno
- Department of Biology, Indiana University, 915 East Third Street, 102 Myers Hall, Bloomington, Indiana, 47405-7107, USA
| | - Armin P Moczek
- Department of Biology, Indiana University, 915 East Third Street, 102 Myers Hall, Bloomington, Indiana, 47405-7107, USA
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5
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Ogino Y, Kuraku S, Ishibashi H, Miyakawa H, Sumiya E, Miyagawa S, Matsubara H, Yamada G, Baker ME, Iguchi T. Neofunctionalization of Androgen Receptor by Gain-of-Function Mutations in Teleost Fish Lineage. Mol Biol Evol 2015; 33:228-44. [PMID: 26507457 DOI: 10.1093/molbev/msv218] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Steroid hormone receptor family provides an example of evolution of diverse transcription factors through whole-genome duplication (WGD). However, little is known about how their functions have been evolved after the duplication. Teleosts present a good model to investigate an accurate evolutionary history of protein function after WGD, because a teleost-specific WGD (TSGD) resulted in a variety of duplicated genes in modern fishes. This study focused on the evolution of androgen receptor (AR) gene, as two distinct paralogs, ARα and ARβ, have evolved in teleost lineage after TSGD. ARα showed a unique intracellular localization with a higher transactivation response than that of ARβ. Using site-directed mutagenesis and computational prediction of protein-ligand interactions, we identified two key substitutions generating a new functionality of euteleost ARα. The substitution in the hinge region contributes to the unique intracellular localization of ARα. The substitution on helices 10/11 in the ligand-binding domain possibly modulates hydrogen bonds that stabilize the receptor-ligand complex leading to the higher transactivation response of ARα. These substitutions were conserved in Acanthomorpha (spiny-rayed fish) ARαs, but not in an earlier branching lineage among teleosts, Japanese eel. Insertion of these substitutions into ARs from Japanese eel recapitulates the evolutionary novelty of euteleost ARα. These findings together indicate that the substitutions generating a new functionality of teleost ARα were fixed in teleost genome after the divergence of the Elopomorpha lineage. Our findings provide a molecular explanation for an adaptation process leading to generation of the hyperactive AR subtype after TSGD.
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Affiliation(s)
- Yukiko Ogino
- Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, and Department of Basic Biology, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Japan
| | - Shigehiro Kuraku
- Phyloinformatics Unit, RIKEN Center for Life Science Technologies, Kobe, Japan
| | - Hiroshi Ishibashi
- Department of Life Environmental Conservation, Faculty of Agriculture, Ehime University, Matsuyama, Japan
| | - Hitoshi Miyakawa
- Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, and Department of Basic Biology, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Japan Center for Bioscience Research and Education, Utsunomiya University, Utsunomiya, Japan
| | - Eri Sumiya
- Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, and Department of Basic Biology, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Japan
| | - Shinichi Miyagawa
- Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, and Department of Basic Biology, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Japan
| | - Hajime Matsubara
- Department of Aquatic Biology, Faculty of Bioindustry, Tokyo University of Agriculture, Abashiri, Japan
| | - Gen Yamada
- Department of Developmental Genetics, Institute of Advanced Medicine, Wakayama Medical University, Wakayama, Japan
| | | | - Taisen Iguchi
- Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, and Department of Basic Biology, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Japan
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Ogino Y, Hirakawa I, Inohaya K, Sumiya E, Miyagawa S, Denslow N, Yamada G, Tatarazako N, Iguchi T. Bmp7 and Lef1 are the downstream effectors of androgen signaling in androgen-induced sex characteristics development in medaka. Endocrinology 2014; 155:449-62. [PMID: 24248458 DOI: 10.1210/en.2013-1507] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Androgens play key roles in the morphological specification of male type sex attractive and reproductive organs, whereas little is known about the developmental mechanisms of such secondary sex characters. Medaka offers a clue about sexual differentiation. They show a prominent masculine sexual character for appendage development, the formation of papillary processes in the anal fin, which has been induced in females by exogenous androgen exposure. This current study shows that the development of papillary processes is promoted by androgen-dependent augmentation of bone morphogenic protein 7 (Bmp7) and lymphoid enhancer-binding factor-1 (Lef1). Androgen receptor (AR) subtypes, ARα and ARβ, are expressed in the distal region of outgrowing bone nodules of developing papillary processes. Development of papillary processes concomitant with the induction of Bmp7 and Lef1 in the distal bone nodules by exposure to methyltestosterone was significantly suppressed by an antiandrogen, flutamide, in female medaka. When Bmp signaling was inhibited in methyltestosterone-exposed females by its inhibitor, dorsomorphin, Lef1 expression was suppressed accompanied by reduced proliferation in the distal bone nodules and retarded bone deposition. These observations indicate that androgen-dependent expressions of Bmp7 and Lef1 are required for the bone nodule outgrowth leading to the formation of these secondary sex characteristics in medaka. The formation of androgen-induced papillary processes may provide insights into the mechanisms regulating the specification of sexual features in vertebrates.
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Affiliation(s)
- Yukiko Ogino
- Okazaki Institute for Integrative Bioscience (Y.O., I.H., E.S., S.M., T.I.), National Institute for Basic Biology, National Institutes of Natural Sciences, and Department of Basic Biology (Y.O., I.H., E.S., S.M., T.I.), Faculty of Life Science, The Graduate University for Advanced Studies, Aichi 444-8787, Japan; Department of Biological Information (K.I.), Tokyo Institute of Technology, Yokohama 226-8501, Japan; Department of Physiological Sciences (N.D.), Center for Environmental and Human Toxicology, University of Florida, Gainesville, Florida 32611; Department of Developmental Genetics (G.Y.), Institute of Advanced Medicine, Wakayama Medical University, Wakayama 641-8509, Japan; and National Institute for Environmental Studies (N.T.), Ibaraki, 305-8506, Japan
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7
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Hall BK. Homology, homoplasy, novelty, and behavior. Dev Psychobiol 2012; 55:4-12. [PMID: 22711423 DOI: 10.1002/dev.21039] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Accepted: 03/28/2012] [Indexed: 12/26/2022]
Abstract
Richard Owen coined the modern definition of homology in 1843. Owen's conception of homology was pre-evolutionary, nontransformative (homology maintained basic plans or archetypes), and applied to the fully formed structures of animals. I sketch out the transition to an evolutionary approach to homology in which all classes of similarity are interpreted against the single branching tree of life, and outline the evidence for the application of homology across all levels and features of the biological hierarchy, including behavior. Owen contrasted homology with analogy. While this is not incorrect it is a pre-evolutionary contrast. Lankester [Lankester [1870] Journal of Natural History, 6 (31), 34-43] proposed homoplasy as the class of homology applicable to features formed by independent evolution. Today we identify homology, convergence, parallelism, and novelties as patterns of evolutionary change. A central issue in homology [Owen [1843] Lectures on comparative anatomy and physiology of the invertebrate animals, delivered at the Royal College of Surgeons in 1843. London: Longman, Brown, Green & Longmans] has been whether homology of features-the "same" portion of the brain in different species, for example-depends upon those features sharing common developmental pathways. Owen did not require this criterion, although he observed that homologues often do share developmental pathways (and we now know, often share gene pathways). A similar situation has been explored in the study of behavior, especially whether behaviors must share a common structural, developmental, neural, or genetic basis to be classified as homologous. However, and importantly, development and genes evolve. As shown with both theory and examples, morphological and behavioral features of the phenotype can be homologized as structural or behavioral homologues, respectively, even when their developmental or genetic bases differ (are not homologous).
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Affiliation(s)
- Brian K Hall
- Department of Biology, Dalhousie University, Halifax, NS, Canada.
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8
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Aspiras AC, Smith FW, Angelini DR. Sex-specific gene interactions in the patterning of insect genitalia. Dev Biol 2011; 360:369-80. [DOI: 10.1016/j.ydbio.2011.09.026] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2011] [Revised: 09/23/2011] [Accepted: 09/25/2011] [Indexed: 01/26/2023]
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9
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Kleisner K. The formation of the theory of homology in biological sciences. Acta Biotheor 2007; 55:317-40. [PMID: 17929173 DOI: 10.1007/s10441-007-9023-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2006] [Accepted: 09/07/2007] [Indexed: 11/26/2022]
Abstract
Homology is among the most important comparative concepts in biology. Today, the evolutionary reinterpretation of homology is usually conceived of as the most important event in the development of the concept. This paradigmatic turning point, however important for the historical explanation of life, is not of crucial importance for the development of the concept of homology itself. In the broadest sense, homology can be understood as sameness in reference to the universal guarantor so that in this sense the different concepts of homology show a certain kind of "metahomology". This holds in the old morphological conception, as well as in the evolutionary usage of homology. Depending on what is (or was) taken as a guarantor, different types of homology may be distinguished (as idealistic, historical, developmental etc.). This study represents a historical overview of the development of the homology concept followed by some clues on how to navigate the pluralistic terminology of modern approaches to homology.
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Affiliation(s)
- Karel Kleisner
- Department of History and Philosophy of Science, Charles University, Vinicná 7, Prague, 128 44, Czech Republic.
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10
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Ogino Y, Katoh H, Yamada G. Androgen dependent development of a modified anal fin, gonopodium, as a model to understand the mechanism of secondary sexual character expression in vertebrates. FEBS Lett 2004; 575:119-26. [PMID: 15388345 DOI: 10.1016/j.febslet.2004.08.046] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2004] [Revised: 07/05/2004] [Accepted: 08/25/2004] [Indexed: 12/31/2022]
Abstract
Male external genitalia show structural variations among species. Androgenic hormones are essential for the morphological specification of male type copulatory organs, while little is known about the developmental mechanisms of such secondary sexual characters. Western mosquitofish Gambusia affinis may offer a clue to the sexual differentiation researches, because they show a prominent masculine sexual character for appendage development, anal fin to gonopodium (GP) transition, and its formation could be induced in early juvenile fry by exogenously supplied androgens. We show that GP development is promoted by androgen dependent augmentation of sonic hedgehog (Shh) expression. Two AR cDNAs were cloned and identified as ARalpha and ARbeta from western mosquitofish. Both ARs were predominantly expressed in the distal region of outgrowing anal fin rays. Exposure of fry to androgen caused anal fin outgrowth concomitant with the Shh induction in the distal anal fin ray epithelium. When AR signaling was inhibited by its antagonist flutamide in fry, the initial induction of the Shh was suppressed accompanying retarded anal fin outgrowth. Similar suppression of anal fin outgrowth was induced by treatment with cyclopamine, an inhibitor of Shh signaling. These observations indicate that androgen dependent Shh expression is required for anal fin outgrowth leading to the formation of a genital appendage, the GP in teleost fishes. Androgen-induced GP formation may provide insights into the expression mechanism regulating the specification of sexual features in vertebrates.
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Affiliation(s)
- Yukiko Ogino
- Center for Animal Resources and Development (CARD), Graduate School of Medical and Pharmaceutical Sciences, Kumamoto University, Honjo 2-2-1, Kumamoto 860-0811, Japan
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11
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McCaffery PJ, Adams J, Maden M, Rosa-Molinar E. Too much of a good thing: retinoic acid as an endogenous regulator of neural differentiation and exogenous teratogen. Eur J Neurosci 2003; 18:457-72. [PMID: 12911743 DOI: 10.1046/j.1460-9568.2003.02765.x] [Citation(s) in RCA: 143] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Retinoic acid (RA) is essential for both embryonic and adult growth, activating gene transcription via specific nuclear receptors. It is generated, via a retinaldehyde intermediate, from retinol (vitamin A). RA levels require precise regulation by controlled synthesis and catabolism, and when RA concentrations deviate from normal, in either direction, abnormal growth and development occurs. This review describes: (i) how the pattern of RA metabolic enzymes controls the actions of RA; and (ii) the type of abnormalities that result when this pattern breaks down. Examples are given of RA control of the anterior/posterior axis of the hindbrain, the dorsal/ventral axis of the spinal cord, as well as certain sex-specific segments of the spinal cord, using varied animal models including mouse, quail and mosquitofish. These functions are highly sensitive to abnormal changes in RA concentration. In rodents, the control of neural patterning and differentiation are disrupted when RA concentrations are lowered, whereas inappropriately high concentrations of RA result in abnormal development of cerebellum and hindbrain nuclei. The latter parallels the malformations seen in the human embryo exposed to RA due to treatment of the mother with the acne drug Accutane (13-cis RA) and, in cases where the child survives beyond birth, a particular set of behavioural anomalies can be described. Even the adult brain may be susceptible to an imbalance of RA, particularly the hippocampus. This report shows how the properties of RA as a neural induction agent and organizer of segmentation can explain the consequences of RA depletion and overexpression.
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12
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Bejder L, Hall BK. Limbs in whales and limblessness in other vertebrates: mechanisms of evolutionary and developmental transformation and loss. Evol Dev 2002; 4:445-58. [PMID: 12492145 DOI: 10.1046/j.1525-142x.2002.02033.x] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We address the developmental and evolutionary mechanisms underlying fore- and hindlimb development and progressive hindlimb reduction and skeletal loss in whales and evaluate whether the genetic, developmental, and evolutionary mechanisms thought to be responsible for limb loss in snakes "explain" loss of the hindlimbs in whales. Limb loss and concurrent morphological and physiological changes associated with the transition from land to water are discussed within the context of the current whale phylogeny. Emphasis is placed on fore- and hindlimb development, how the forelimbs transformed into flippers, and how the hindlimbs regressed, leaving either no elements or vestigial skeletal elements. Hindlimbs likely began to regress only after the ancestors of whales entered the aquatic environment: Hindlimb function was co-opted by the undulatory vertical axial locomotion made possible by the newly evolved caudal flukes. Loss of the hindlimbs was associated with elongation of the body during the transition from land to water. Limblessness in most snakes is also associated with adoption of a new (burrowing) lifestyle and was driven by developmental changes associated with elongation of the body. Parallels between adaptation to burrowing or to the aquatic environment reflect structural and functional changes associated with the switch to axial locomotion. Because they are more fully studied and to determine whether hindlimb loss in lineages that are not closely related could result from similar genetically controlled developmental pathways, we discuss developmental (cellular and genetic) processes that may have driven limb loss in snakes and leg-less lizards and compare these processes to the loss of hindlimbs in whales. In neither group does ontogenetic or phylogenetic limb reduction result from failure to initiate limb development. In both groups limb loss results from arrested development at the limb bud stage, as a result of inability to maintain necessary inductive tissue interactions and enhanced cell death over that seen in limbed tetrapods. An evolutionary change in Hox gene expression--as occurs in snakes--or in Hox gene regulation--as occurs in some limbless mutants--is unlikely to have initiated loss of the hindlimbs in cetaceans. Selective pressures acting on a wide range of developmental processes and adult traits other than the limbs are likely to have driven the loss of hindlimbs in whales.
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Affiliation(s)
- Lars Bejder
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4J1.
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13
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Burke AC, Rosa-Molinar E. Starting from fins: parallelism in the evolution of limbs and genitalia. The fin-to-limb transition. Evol Dev 2002; 4:375-7. [PMID: 12356267 DOI: 10.1046/j.1525-142x.2002.02024.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The March/April 2002 issue of Evolution and Development focused on three presentations made at the Starting from Fins: Parallelism in the Evolution of Limbs and Genitalia symposium held as part of the 2001 Chicago meeting of the Society of Integrative and Comparative Biology. The intention of the symposium and the publication of the presentations was to extend discussion of the potential and the limits of using serial homologues to understand developmental aspects of morphological evolution. The March/April 2002 issue concentrated on unpaired fin to genitalia transitions. This issue focuses on paired fins to limbs and highlights the need for developmental data to be integrated with data from fossil materal, phylogenetic analysis, and explicitly comparative studies. Coates et al. use phylogenetic methods to explore the limb/fin characters of taxa, but their analysis departs somewhat from the usual in that the reference group for organisms includes sister group taxa not usually considered true tetrapods. They state that including finned taxa from the stem group permits an attempt to distinguish the primitive condition of the characteristics demonstrated by the crown group, that is, "limbed tetrapods." In focusing on limb characters specifically and including aspects of the appendicular girdles, Coates et al. highlight morphological details and trends within a given phylogeny. They also demonstrate the degree of relevance of limb characters during the establishment of lineages and their branching patterns by using only limb characters to generate a tree and use a direct comparison of serial versus special homologies to explore the degree of evolutionary parallelism between fore-and hindlimbs. The preliminary conclusions indicate a high level of independence between the serially homologous fore-and hindlimb. Innes et al. present outcomes from the use of cutting edge molecular genetic approaches to understand developmental aspects of limb morphology. In a manner conceptually similar to Coates et al.'s use of fossil characters, Innes et al. use the serial analysis of gene expression to sort differences from similarities in the gene expression profiles of fore-and hindlimbs of the same embryos. Although these gene expression pattems are likely to reflect the serial homology of the paired limbs, they are silent in terms of our understanding both the profound and subtle differences between fore- and hindlimbs in any given species. Innes et al. point out the volume of data generated by SAGE far exceeds our ability to interpret its biological meaning. The studies presented here and in the March/April issue are excellent examples of the need to interpret complex data in light of collective knowledge of evolutionary history. We hope the insights gained from the symposium and papers contribute to a dialogue on how to integrate different approaches and assist in moving forward the field of Evolution and Development.
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Affiliation(s)
- Ann Campbell Burke
- Department of Biology, Wesleyan University, Middletown, CT 06459-0170, USA.
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