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Chen Y, Renfree MB. Hormonal and Molecular Regulation of Phallus Differentiation in a Marsupial Tammar Wallaby. Genes (Basel) 2020; 11:genes11010106. [PMID: 31963388 PMCID: PMC7017150 DOI: 10.3390/genes11010106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 12/24/2019] [Accepted: 01/14/2020] [Indexed: 11/16/2022] Open
Abstract
Congenital anomalies in phalluses caused by endocrine disruptors have gained a great deal of attention due to its annual increasing rate in males. However, the endocrine-driven molecular regulatory mechanism of abnormal phallus development is complex and remains largely unknown. Here, we review the direct effect of androgen and oestrogen on molecular regulation in phalluses using the marsupial tammar wallaby, whose phallus differentiation occurs after birth. We summarize and discuss the molecular mechanisms underlying phallus differentiation mediated by sonic hedgehog (SHH) at day 50 pp and phallus elongation mediated by insulin-like growth factor 1 (IGF1) and insulin-like growth factor binding protein 3 (IGFBP3), as well as multiple phallus-regulating genes expressed after day 50 pp. We also identify hormone-responsive long non-coding RNAs (lncRNAs) that are co-expressed with their neighboring coding genes. We show that the activation of SHH and IGF1, mediated by balanced androgen receptor (AR) and estrogen receptor 1 (ESR1) signalling, initiates a complex regulatory network in males to constrain the timing of phallus differentiation and to activate the downstream genes that maintain urethral closure and phallus elongation at later stages.
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Affiliation(s)
- Yu Chen
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL 32603, USA
- School of BioSciences, The University of Melbourne, Parkville, VIC 3010, Australia
- Correspondence: (Y.C.); (M.B.R.)
| | - Marilyn B. Renfree
- School of BioSciences, The University of Melbourne, Parkville, VIC 3010, Australia
- Correspondence: (Y.C.); (M.B.R.)
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2
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Modepalli V, Hinds LA, Sharp JA, Lefevre C, Nicholas KR. Marsupial tammar wallaby delivers milk bioactives to altricial pouch young to support lung development. Mech Dev 2016; 142:22-29. [PMID: 27639961 PMCID: PMC5161226 DOI: 10.1016/j.mod.2016.08.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 08/26/2016] [Accepted: 08/26/2016] [Indexed: 11/27/2022]
Abstract
Our research is exploiting the marsupial as a model to understand the signals required for lung development. Marsupials have a unique reproductive strategy, the mother gives birth to altricial neonate with an immature lung and the changes in milk composition during lactation in marsupials appears to provide bioactives that can regulate diverse aspects of lung development, including branching morphogenesis, cell proliferation and cell differentiation. These effects are seen with milk collected between 25 and 100days postpartum. To better understand the temporal effects of milk composition on postnatal lung development we used a cross-fostering technique to restrict the tammar pouch young to milk composition not extending beyond day 25 for 45days of its early postnatal life. These particular time points were selected as our previous study showed that milk protein collected prior to ~day 25 had no developmental effect on mouse embryonic lungs in culture. The comparative analysis of the foster group and control young at day 45 postpartum demonstrated that foster pouch young had significantly reduced lung size. The lungs in fostered young were comprised of large intermediate tissue, had a reduced size of airway lumen and a higher percentage of parenchymal tissue. In addition, expression of marker genes for lung development (BMP4, WNT11, AQP-4, HOPX and SPB) were significantly reduced in lungs from fostered young. Further, to identify the potential bioactive expressed by mammary gland that may have developmental effect on pouch young lungs, we performed proteomics analysis on tammar milk through mass-spectrometry and listed the potential bioactives (PDGF, IGFBP5, IGFBPL1 and EGFL6) secreted in milk that may be involved in regulating pouch young lung development. The data suggest that postnatal lung development in the tammar young is most likely regulated by maternal signalling factors supplied through milk.
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Affiliation(s)
- Vengamanaidu Modepalli
- Department of Ecology, Evolution and Behavior, Institute of Life Science, Hebrew University, Edmund J Safra Campus, Jerusalem, Israel.
| | - Lyn A Hinds
- CSIRO Ecosystem Sciences, GPO Box 1700, Canberra, ACT 2601, Australia.
| | - Julie A Sharp
- School of Medicine, Deakin University, Pigdons Road, Geelong, VIC, Australia.
| | - Christophe Lefevre
- Walter Eliza Hall Institute, 1G Royal Parade, Parkville, Victoria 3052, Australia.
| | - Kevin R Nicholas
- School of Medicine, Deakin University, Pigdons Road, Geelong, VIC, Australia.
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3
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Hetz JA, Menzies BR, Shaw G, Stefanidis A, Cowley MA, Renfree MB. Effects of nutritional manipulation on body composition in the developing marsupial, Macropus eugenii. Mol Cell Endocrinol 2016; 428:148-60. [PMID: 27032712 DOI: 10.1016/j.mce.2016.03.030] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 03/22/2016] [Accepted: 03/23/2016] [Indexed: 01/18/2023]
Abstract
When 60-day-old tammar wallaby pouch young (Macropus eugenii) are fostered to mothers at 120 days of lactation, their growth, developmental rate and maturation of their GH/IGF axes are markedly accelerated. To determine the effect of fostering on energy intake, body composition and fat accretion, we first measured total body fat and lean mass in these young. Next, we mimicked the triglyceride oleic and palmitic acid composition of 120-day milk by supplementing 60 day young with these fatty acids and comparing their growth with that of growth accelerated young. There was no difference in the weight or growth axis maturation of supplemented young but there was significantly more body fat in these and in the growth-accelerated fostered young than in controls. We conclude that the accelerated growth and GH/IGF axis maturation observed previously in fostered young is most likely due to increased milk consumption and earlier access to specific nutrients.
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Affiliation(s)
- Jennifer A Hetz
- School of BioSciences, The University of Melbourne, Victoria, 3010, Australia
| | - Brandon R Menzies
- School of BioSciences, The University of Melbourne, Victoria, 3010, Australia
| | - Geoffrey Shaw
- School of BioSciences, The University of Melbourne, Victoria, 3010, Australia
| | - Aneta Stefanidis
- Department of Physiology, Monash University, Victoria, 3800, Australia
| | - Michael A Cowley
- Department of Physiology, Monash University, Victoria, 3800, Australia
| | - Marilyn B Renfree
- School of BioSciences, The University of Melbourne, Victoria, 3010, Australia.
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4
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Cripps JK, Martin JK, Coulson G. Anthelmintic Treatment Does Not Change Foraging Strategies of Female Eastern Grey Kangaroos, Macropus giganteus. PLoS One 2016; 11:e0147384. [PMID: 26784582 PMCID: PMC4718527 DOI: 10.1371/journal.pone.0147384] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2015] [Accepted: 01/04/2016] [Indexed: 11/18/2022] Open
Abstract
Large mammalian herbivores are commonly infected with gastrointestinal helminths. Heavily parasitised hosts are likely to have increased nutritional requirements and would be predicted to increase their food intake to compensate for costs of being parasitised, but experimental tests of the impacts of these parasites on the foraging efficiency of hosts are lacking, particularly in free-ranging wildlife. We conducted a field experiment on a population of free-ranging eastern grey kangaroos (Macropus giganteus) to test this prediction, removing nematodes from one group of adult females using an anthelmintic treatment. We then carried out observations before and following treatment to assess the influence of parasites on foraging behaviour. Contrary to our predictions, the manipulation of parasite burdens did not result in changes in any of the key foraging variables we measured. Our results suggest that despite carrying large burdens of gastrointestinal parasites, the foraging strategy of female kangaroos is likely be driven by factors unrelated to parasitism, and that kangaroos in high nutritional environments may be able acquire sufficient nutrients to offset the costs of parasitism. We conclude that the drivers of forage intake likely differ between domesticated and free-ranging herbivores, and that free-ranging hosts are likely more resilient to parasitism.
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Affiliation(s)
- Jemma K. Cripps
- School of BioSciences, The University of Melbourne, Melbourne, Victoria, Australia
- Faculty of Veterinary Science, The University of Melbourne, Veterinary Clinical Centre, Werribee, Victoria, Australia
- * E-mail:
| | - Jennifer K. Martin
- School of BioSciences, The University of Melbourne, Melbourne, Victoria, Australia
| | - Graeme Coulson
- School of BioSciences, The University of Melbourne, Melbourne, Victoria, Australia
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5
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Hetz JA, Menzies BR, Shaw G, Rao A, Clarke IJ, Renfree MB. Growth axis maturation is linked to nutrition, growth and developmental rate. Mol Cell Endocrinol 2015; 411:38-48. [PMID: 25896544 DOI: 10.1016/j.mce.2015.04.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Revised: 04/09/2015] [Accepted: 04/13/2015] [Indexed: 10/23/2022]
Abstract
Maturation of the mammalian growth axis is thought to be linked to the transition from fetal to post-natal life at birth. However, in an altricial marsupial, the tammar wallaby (Macropus eugenii), this process occurs many months after birth but at a time when the young is at a similar developmental stage to that of neonatal eutherian mammals. Here we manipulate growth rates and demonstrate in slow, normal and fast growing tammar young that nutrition and growth rate affect the time of maturation of the growth axis. Maturation of GH/IGF-I axis components occurred earlier in fast growing young, which had significantly increased hepatic GHR, IGF1 and IGFALS expression, plasma IGF-I concentrations, and significantly decreased plasma GH concentrations compared to age-matched normal young. These data support the hypothesis that the time of maturation of the growth axis depends on the growth rate and maturity of the young, which can be accelerated by changing their nutritional status.
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Affiliation(s)
- Jennifer A Hetz
- School of BioSciences, The University of Melbourne, Vic. 3010, Australia
| | - Brandon R Menzies
- School of BioSciences, The University of Melbourne, Vic. 3010, Australia.
| | - Geoffrey Shaw
- School of BioSciences, The University of Melbourne, Vic. 3010, Australia
| | - Alexandra Rao
- Department of Physiology, Monash University, Vic. 3800, Australia
| | - Iain J Clarke
- Department of Physiology, Monash University, Vic. 3800, Australia
| | - Marilyn B Renfree
- School of BioSciences, The University of Melbourne, Vic. 3010, Australia
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6
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Cunha GR. Exotic animals in development. Differentiation 2014; 87:1-3. [PMID: 24655574 DOI: 10.1016/j.diff.2014.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 02/27/2014] [Indexed: 11/19/2022]
Affiliation(s)
- Gerald R Cunha
- Department of Urology, University of California - San Francisco, 400 Parnassus Avenue, Box A610, San Francisco, CA 94143, United States.
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7
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Duncan LG, Nair SV, Deane EM. Immunohistochemical localization of T-lymphocyte subsets in the developing lymphoid tissues of the tammar wallaby (Macropus eugenii). Dev Comp Immunol 2012; 38:475-486. [PMID: 22929957 DOI: 10.1016/j.dci.2012.06.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Revised: 06/25/2012] [Accepted: 06/29/2012] [Indexed: 06/01/2023]
Abstract
Research into marsupial adaptive immunity during ontogeny has been hampered by the lack of antibodies that react to marsupial immunological cell populations. In this study, newly synthesised polyclonal antibodies to the T cell marker, CD8, have been developed and used to investigate the ontogeny and distribution of this T cell population in the tammar wallaby. Immunohistochemical analysis indicated that the distribution of the CD8 lymphocytes in the lymphoid tissues of tammar neonates during the first 144 days of pouch life was similar to that of the eutherian mammals. However, CD8α(+) lymphocytes were observed in the intestines of tammar neonates prior to their first appearance in the cervical thymus, an observation that has not been found in eutherians. A dual labelling immunohistochemical approach was used for the indirect demonstration of CD4 and enabled the simultaneous detection in the tammar wallaby tissues of the two major T-lymphocyte populations, CD4 and CD8 that are associated with adaptive immunity. As in eutherian mammals, CD4(+) cells were the predominant T cell lymphocyte subset observed in the spleen while in the nodal tissues, an age-related decrease in the CD4(+)/CD8(+) ratio was noted. These antibodies provide a new immunological tool to study the role of T cell subsets in marsupial immunity and disease pathogenesis studies.
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Affiliation(s)
- Louise G Duncan
- Department of Biological Sciences, Faculty of Science, Macquarie University, NSW, Australia
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8
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Menzies BR, Shaw G, Fletcher TP, Pask AJ, Renfree MB. Maturation of the growth axis in marsupials occurs gradually during post-natal life and over an equivalent developmental stage relative to eutherian species. Mol Cell Endocrinol 2012; 349:189-94. [PMID: 22056413 DOI: 10.1016/j.mce.2011.10.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Revised: 10/12/2011] [Accepted: 10/16/2011] [Indexed: 11/26/2022]
Abstract
The separation of a nutrition-responsive insulin-like growth factor (IGF) system and a growth hormone (GH) responsive IGF system to control pre- and post-natal growth of developing mammals may originate from the constraints imposed by intra-uterine development. In eutherian species that deliver relatively precocial young, maturation of the GH regulatory system is coincident with the time of birth. We measured the hepatic expression of the four key growth axis genes GH-receptor, IGF-1 and -2, and IGFBBP-3, and plasma protein concentrations of IGF-1 from late fetal life through to adult stages of a marsupial, the tammar wallaby. The data clearly show that maturation of GH-regulated growth in marsupials occurs gradually over the course of post-natal life at an equivalent developmental stage to that of precocial eutherian mammals. This suggests that the timing of GH-regulated growth in marsupials is not related to parturition but instead to the relative developmental stage.
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Affiliation(s)
- Brandon R Menzies
- ARC Centre of Excellence for Kangaroo Genomics, Department of Zoology, The University of Melbourne, Victoria 3010, Australia.
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9
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Renfree MB, Papenfuss AT, Deakin JE, Lindsay J, Heider T, Belov K, Rens W, Waters PD, Pharo EA, Shaw G, Wong ESW, Lefèvre CM, Nicholas KR, Kuroki Y, Wakefield MJ, Zenger KR, Wang C, Ferguson-Smith M, Nicholas FW, Hickford D, Yu H, Short KR, Siddle HV, Frankenberg SR, Chew KY, Menzies BR, Stringer JM, Suzuki S, Hore TA, Delbridge ML, Mohammadi A, Schneider NY, Hu Y, O'Hara W, Al Nadaf S, Wu C, Feng ZP, Cocks BG, Wang J, Flicek P, Searle SMJ, Fairley S, Beal K, Herrero J, Carone DM, Suzuki Y, Sugano S, Toyoda A, Sakaki Y, Kondo S, Nishida Y, Tatsumoto S, Mandiou I, Hsu A, McColl KA, Lansdell B, Weinstock G, Kuczek E, McGrath A, Wilson P, Men A, Hazar-Rethinam M, Hall A, Davis J, Wood D, Williams S, Sundaravadanam Y, Muzny DM, Jhangiani SN, Lewis LR, Morgan MB, Okwuonu GO, Ruiz SJ, Santibanez J, Nazareth L, Cree A, Fowler G, Kovar CL, Dinh HH, Joshi V, Jing C, Lara F, Thornton R, Chen L, Deng J, Liu Y, Shen JY, Song XZ, Edson J, Troon C, Thomas D, Stephens A, Yapa L, Levchenko T, Gibbs RA, Cooper DW, Speed TP, Fujiyama A, M Graves JA, O'Neill RJ, Pask AJ, Forrest SM, Worley KC. Genome sequence of an Australian kangaroo, Macropus eugenii, provides insight into the evolution of mammalian reproduction and development. Genome Biol 2011; 12:R81. [PMID: 21854559 PMCID: PMC3277949 DOI: 10.1186/gb-2011-12-8-r81] [Citation(s) in RCA: 147] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Revised: 07/22/2011] [Accepted: 08/19/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND We present the genome sequence of the tammar wallaby, Macropus eugenii, which is a member of the kangaroo family and the first representative of the iconic hopping mammals that symbolize Australia to be sequenced. The tammar has many unusual biological characteristics, including the longest period of embryonic diapause of any mammal, extremely synchronized seasonal breeding and prolonged and sophisticated lactation within a well-defined pouch. Like other marsupials, it gives birth to highly altricial young, and has a small number of very large chromosomes, making it a valuable model for genomics, reproduction and development. RESULTS The genome has been sequenced to 2 × coverage using Sanger sequencing, enhanced with additional next generation sequencing and the integration of extensive physical and linkage maps to build the genome assembly. We also sequenced the tammar transcriptome across many tissues and developmental time points. Our analyses of these data shed light on mammalian reproduction, development and genome evolution: there is innovation in reproductive and lactational genes, rapid evolution of germ cell genes, and incomplete, locus-specific X inactivation. We also observe novel retrotransposons and a highly rearranged major histocompatibility complex, with many class I genes located outside the complex. Novel microRNAs in the tammar HOX clusters uncover new potential mammalian HOX regulatory elements. CONCLUSIONS Analyses of these resources enhance our understanding of marsupial gene evolution, identify marsupial-specific conserved non-coding elements and critical genes across a range of biological systems, including reproduction, development and immunity, and provide new insight into marsupial and mammalian biology and genome evolution.
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Affiliation(s)
- Marilyn B Renfree
- The Australian Research Council Centre of Excellence in Kangaroo Genomics, Australia
- Department of Zoology, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Anthony T Papenfuss
- The Australian Research Council Centre of Excellence in Kangaroo Genomics, Australia
- Bioinformatics Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
- Department of Mathematics and Statistics, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Janine E Deakin
- The Australian Research Council Centre of Excellence in Kangaroo Genomics, Australia
- Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia
| | - James Lindsay
- Department of Molecular and Cell Biology, Center for Applied Genetics and Technology, University of Connecticut, Storrs, CT 06269, USA
| | - Thomas Heider
- Department of Molecular and Cell Biology, Center for Applied Genetics and Technology, University of Connecticut, Storrs, CT 06269, USA
| | - Katherine Belov
- The Australian Research Council Centre of Excellence in Kangaroo Genomics, Australia
- Faculty of Veterinary Science, University of Sydney, Sydney, NSW 2006, Australia
| | - Willem Rens
- Department of Veterinary Medicine, University of Cambridge, Madingley Rd, Cambridge, CB3 0ES, UK
| | - Paul D Waters
- The Australian Research Council Centre of Excellence in Kangaroo Genomics, Australia
- Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia
| | - Elizabeth A Pharo
- Department of Zoology, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Geoff Shaw
- The Australian Research Council Centre of Excellence in Kangaroo Genomics, Australia
- Department of Zoology, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Emily SW Wong
- The Australian Research Council Centre of Excellence in Kangaroo Genomics, Australia
- Faculty of Veterinary Science, University of Sydney, Sydney, NSW 2006, Australia
| | - Christophe M Lefèvre
- Institute for Technology Research and Innovation, Deakin University, Geelong, Victoria, 3214, Australia
| | - Kevin R Nicholas
- Institute for Technology Research and Innovation, Deakin University, Geelong, Victoria, 3214, Australia
| | - Yoko Kuroki
- RIKEN Institute, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Matthew J Wakefield
- The Australian Research Council Centre of Excellence in Kangaroo Genomics, Australia
- Bioinformatics Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
| | - Kyall R Zenger
- The Australian Research Council Centre of Excellence in Kangaroo Genomics, Australia
- Faculty of Veterinary Science, University of Sydney, Sydney, NSW 2006, Australia
- School of Marine and Tropical Biology, James Cook University, Townsville, Queensland 4811, Australia
| | - Chenwei Wang
- The Australian Research Council Centre of Excellence in Kangaroo Genomics, Australia
- Faculty of Veterinary Science, University of Sydney, Sydney, NSW 2006, Australia
| | - Malcolm Ferguson-Smith
- Department of Veterinary Medicine, University of Cambridge, Madingley Rd, Cambridge, CB3 0ES, UK
| | - Frank W Nicholas
- Faculty of Veterinary Science, University of Sydney, Sydney, NSW 2006, Australia
| | - Danielle Hickford
- The Australian Research Council Centre of Excellence in Kangaroo Genomics, Australia
- Department of Zoology, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Hongshi Yu
- The Australian Research Council Centre of Excellence in Kangaroo Genomics, Australia
- Department of Zoology, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Kirsty R Short
- Department of Microbiology and Immunology, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Hannah V Siddle
- The Australian Research Council Centre of Excellence in Kangaroo Genomics, Australia
- Faculty of Veterinary Science, University of Sydney, Sydney, NSW 2006, Australia
| | - Stephen R Frankenberg
- The Australian Research Council Centre of Excellence in Kangaroo Genomics, Australia
- Department of Zoology, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Keng Yih Chew
- The Australian Research Council Centre of Excellence in Kangaroo Genomics, Australia
- Department of Zoology, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Brandon R Menzies
- The Australian Research Council Centre of Excellence in Kangaroo Genomics, Australia
- Department of Zoology, The University of Melbourne, Melbourne, Victoria 3010, Australia
- Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Str. 17, Berlin 10315, Germany
| | - Jessica M Stringer
- The Australian Research Council Centre of Excellence in Kangaroo Genomics, Australia
- Department of Zoology, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Shunsuke Suzuki
- The Australian Research Council Centre of Excellence in Kangaroo Genomics, Australia
- Department of Zoology, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Timothy A Hore
- The Australian Research Council Centre of Excellence in Kangaroo Genomics, Australia
- Laboratory of Developmental Genetics and Imprinting, The Babraham Institute, Cambridge, CB22 3AT, UK
| | - Margaret L Delbridge
- The Australian Research Council Centre of Excellence in Kangaroo Genomics, Australia
- Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia
| | - Amir Mohammadi
- The Australian Research Council Centre of Excellence in Kangaroo Genomics, Australia
- Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia
| | - Nanette Y Schneider
- The Australian Research Council Centre of Excellence in Kangaroo Genomics, Australia
- Department of Zoology, The University of Melbourne, Melbourne, Victoria 3010, Australia
- Department of Molecular Genetics, German Institute of Human Nutrition, Potsdam-Rehbruecke, Arthur-Scheunert-Allee 114-116, 14558 Nuthetal, Germany
| | - Yanqiu Hu
- The Australian Research Council Centre of Excellence in Kangaroo Genomics, Australia
- Department of Zoology, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - William O'Hara
- Department of Molecular and Cell Biology, Center for Applied Genetics and Technology, University of Connecticut, Storrs, CT 06269, USA
| | - Shafagh Al Nadaf
- The Australian Research Council Centre of Excellence in Kangaroo Genomics, Australia
- Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia
| | - Chen Wu
- Faculty of Veterinary Science, University of Sydney, Sydney, NSW 2006, Australia
| | - Zhi-Ping Feng
- Bioinformatics Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
- Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Benjamin G Cocks
- Biosciences Research Division, Department of Primary Industries, Victoria, 1 Park Drive, Bundoora 3083, Australia
| | - Jianghui Wang
- Biosciences Research Division, Department of Primary Industries, Victoria, 1 Park Drive, Bundoora 3083, Australia
| | - Paul Flicek
- European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, UK
| | - Stephen MJ Searle
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, UK
| | - Susan Fairley
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, UK
| | - Kathryn Beal
- European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, UK
| | - Javier Herrero
- European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, UK
| | - Dawn M Carone
- Department of Molecular and Cell Biology, Center for Applied Genetics and Technology, University of Connecticut, Storrs, CT 06269, USA
- Department of Cell Biology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Yutaka Suzuki
- Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8560, Japan
| | - Sumio Sugano
- Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8560, Japan
| | - Atsushi Toyoda
- National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
| | - Yoshiyuki Sakaki
- RIKEN Institute, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Shinji Kondo
- RIKEN Institute, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Yuichiro Nishida
- RIKEN Institute, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Shoji Tatsumoto
- RIKEN Institute, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Ion Mandiou
- Department of Computer Science and Engineering, University of Connecticut, Storrs, CT 06269, USA
| | - Arthur Hsu
- Bioinformatics Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
- Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Kaighin A McColl
- Bioinformatics Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
| | - Benjamin Lansdell
- Bioinformatics Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
| | - George Weinstock
- Human Genome Sequencing Center, Department of Molecular and Human Genetics Baylor College of Medicine, Houston, TX 77030, USA
| | - Elizabeth Kuczek
- The Australian Research Council Centre of Excellence in Kangaroo Genomics, Australia
- Australian Genome Research Facility, Melbourne, Victoria, 3052 and the University of Queensland, St Lucia, Queensland 4072, Australia
- Westmead Institute for Cancer Research, University of Sydney, Westmead, New South Wales 2145, Australia
| | - Annette McGrath
- Australian Genome Research Facility, Melbourne, Victoria, 3052 and the University of Queensland, St Lucia, Queensland 4072, Australia
| | - Peter Wilson
- Australian Genome Research Facility, Melbourne, Victoria, 3052 and the University of Queensland, St Lucia, Queensland 4072, Australia
| | - Artem Men
- Australian Genome Research Facility, Melbourne, Victoria, 3052 and the University of Queensland, St Lucia, Queensland 4072, Australia
| | - Mehlika Hazar-Rethinam
- Australian Genome Research Facility, Melbourne, Victoria, 3052 and the University of Queensland, St Lucia, Queensland 4072, Australia
| | - Allison Hall
- Australian Genome Research Facility, Melbourne, Victoria, 3052 and the University of Queensland, St Lucia, Queensland 4072, Australia
| | - John Davis
- Australian Genome Research Facility, Melbourne, Victoria, 3052 and the University of Queensland, St Lucia, Queensland 4072, Australia
| | - David Wood
- Australian Genome Research Facility, Melbourne, Victoria, 3052 and the University of Queensland, St Lucia, Queensland 4072, Australia
| | - Sarah Williams
- Australian Genome Research Facility, Melbourne, Victoria, 3052 and the University of Queensland, St Lucia, Queensland 4072, Australia
| | - Yogi Sundaravadanam
- Australian Genome Research Facility, Melbourne, Victoria, 3052 and the University of Queensland, St Lucia, Queensland 4072, Australia
| | - Donna M Muzny
- Human Genome Sequencing Center, Department of Molecular and Human Genetics Baylor College of Medicine, Houston, TX 77030, USA
| | - Shalini N Jhangiani
- Human Genome Sequencing Center, Department of Molecular and Human Genetics Baylor College of Medicine, Houston, TX 77030, USA
| | - Lora R Lewis
- Human Genome Sequencing Center, Department of Molecular and Human Genetics Baylor College of Medicine, Houston, TX 77030, USA
| | - Margaret B Morgan
- Human Genome Sequencing Center, Department of Molecular and Human Genetics Baylor College of Medicine, Houston, TX 77030, USA
| | - Geoffrey O Okwuonu
- Human Genome Sequencing Center, Department of Molecular and Human Genetics Baylor College of Medicine, Houston, TX 77030, USA
| | - San Juana Ruiz
- Human Genome Sequencing Center, Department of Molecular and Human Genetics Baylor College of Medicine, Houston, TX 77030, USA
| | - Jireh Santibanez
- Human Genome Sequencing Center, Department of Molecular and Human Genetics Baylor College of Medicine, Houston, TX 77030, USA
| | - Lynne Nazareth
- Human Genome Sequencing Center, Department of Molecular and Human Genetics Baylor College of Medicine, Houston, TX 77030, USA
| | - Andrew Cree
- Human Genome Sequencing Center, Department of Molecular and Human Genetics Baylor College of Medicine, Houston, TX 77030, USA
| | - Gerald Fowler
- Human Genome Sequencing Center, Department of Molecular and Human Genetics Baylor College of Medicine, Houston, TX 77030, USA
| | - Christie L Kovar
- Human Genome Sequencing Center, Department of Molecular and Human Genetics Baylor College of Medicine, Houston, TX 77030, USA
| | - Huyen H Dinh
- Human Genome Sequencing Center, Department of Molecular and Human Genetics Baylor College of Medicine, Houston, TX 77030, USA
| | - Vandita Joshi
- Human Genome Sequencing Center, Department of Molecular and Human Genetics Baylor College of Medicine, Houston, TX 77030, USA
| | - Chyn Jing
- Human Genome Sequencing Center, Department of Molecular and Human Genetics Baylor College of Medicine, Houston, TX 77030, USA
| | - Fremiet Lara
- Human Genome Sequencing Center, Department of Molecular and Human Genetics Baylor College of Medicine, Houston, TX 77030, USA
| | - Rebecca Thornton
- Human Genome Sequencing Center, Department of Molecular and Human Genetics Baylor College of Medicine, Houston, TX 77030, USA
| | - Lei Chen
- Human Genome Sequencing Center, Department of Molecular and Human Genetics Baylor College of Medicine, Houston, TX 77030, USA
| | - Jixin Deng
- Human Genome Sequencing Center, Department of Molecular and Human Genetics Baylor College of Medicine, Houston, TX 77030, USA
| | - Yue Liu
- Human Genome Sequencing Center, Department of Molecular and Human Genetics Baylor College of Medicine, Houston, TX 77030, USA
| | - Joshua Y Shen
- Human Genome Sequencing Center, Department of Molecular and Human Genetics Baylor College of Medicine, Houston, TX 77030, USA
| | - Xing-Zhi Song
- Human Genome Sequencing Center, Department of Molecular and Human Genetics Baylor College of Medicine, Houston, TX 77030, USA
| | - Janette Edson
- Australian Genome Research Facility, Melbourne, Victoria, 3052 and the University of Queensland, St Lucia, Queensland 4072, Australia
| | - Carmen Troon
- Australian Genome Research Facility, Melbourne, Victoria, 3052 and the University of Queensland, St Lucia, Queensland 4072, Australia
| | - Daniel Thomas
- Australian Genome Research Facility, Melbourne, Victoria, 3052 and the University of Queensland, St Lucia, Queensland 4072, Australia
| | - Amber Stephens
- Australian Genome Research Facility, Melbourne, Victoria, 3052 and the University of Queensland, St Lucia, Queensland 4072, Australia
| | - Lankesha Yapa
- Australian Genome Research Facility, Melbourne, Victoria, 3052 and the University of Queensland, St Lucia, Queensland 4072, Australia
| | - Tanya Levchenko
- Australian Genome Research Facility, Melbourne, Victoria, 3052 and the University of Queensland, St Lucia, Queensland 4072, Australia
| | - Richard A Gibbs
- Human Genome Sequencing Center, Department of Molecular and Human Genetics Baylor College of Medicine, Houston, TX 77030, USA
| | - Desmond W Cooper
- The Australian Research Council Centre of Excellence in Kangaroo Genomics, Australia
- Department of Biological, Earth and Environmental Sciences, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Terence P Speed
- The Australian Research Council Centre of Excellence in Kangaroo Genomics, Australia
- Bioinformatics Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
| | - Asao Fujiyama
- National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
- National Institute of Informatics, 2-1-2 Hitotsubashi, Chiyoda-ku, Tokyo 101-8430, Japan
| | - Jennifer A M Graves
- The Australian Research Council Centre of Excellence in Kangaroo Genomics, Australia
- Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia
| | - Rachel J O'Neill
- Department of Molecular and Cell Biology, Center for Applied Genetics and Technology, University of Connecticut, Storrs, CT 06269, USA
| | - Andrew J Pask
- The Australian Research Council Centre of Excellence in Kangaroo Genomics, Australia
- Department of Zoology, The University of Melbourne, Melbourne, Victoria 3010, Australia
- Department of Molecular and Cell Biology, Center for Applied Genetics and Technology, University of Connecticut, Storrs, CT 06269, USA
| | - Susan M Forrest
- The Australian Research Council Centre of Excellence in Kangaroo Genomics, Australia
- Australian Genome Research Facility, Melbourne, Victoria, 3052 and the University of Queensland, St Lucia, Queensland 4072, Australia
| | - Kim C Worley
- Human Genome Sequencing Center, Department of Molecular and Human Genetics Baylor College of Medicine, Houston, TX 77030, USA
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10
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Abstract
The developing marsupial is an ideal animal for use in biomedical research. Marsupials are mammals that have been separated from eutherian mammals for over 130-140 million years. They all deliver altricial young that complete their growth and development after birth usually in a pouch, but not all marsupials have a pouch. Their lactation changes dynamically throughout the period of pouch life, and the mother controls their growth via the production of milk that is tailor-made for each stage of development. The tammar wallaby, Macropus eugenii, has been the experimental marsupial of choice for over five decades, as it is highly amendable to handling and breeds well in captivity. The tammar is especially interesting because it has both a lactational and a seasonal control of its reproduction and embryonic diapause that normally lasts 11 months. Standard molecular techniques can be used for most manipulations in marsupials. However, there are several special techniques for treating the young for experimental surgery and for organ culture that we detail below.
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Affiliation(s)
- Marilyn B Renfree
- Department of Zoology, The University of Melbourne, Melbourne, VIC 3010, Australia.
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11
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Leamey CA, Flett DL, Ho SM, Marotte LR. Development of structural and functional connectivity in the thalamocortical somatosensory pathway in the wallaby. Eur J Neurosci 2007; 25:3058-70. [PMID: 17561819 DOI: 10.1111/j.1460-9568.2007.05556.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Neuronal activity is implicated as a driving force in the development of sensory systems. In order for it to play a developmental role, however, the pathways involved must be capable of transmitting this activity. The relationship between afferent arrival, synapse formation and the onset of chemical neurotransmission has been examined using the advantageous model of a marsupial mammal, the wallaby (Macropus eugenii), to determine at what stage activity has the capacity to influence cortical development. It is known that thalamocortical afferents arrive in the somatosensory cortex on postnatal day (P)15 and that their growth cones reach to the base of the compact cell zone of the cortical plate. However, electronmicroscopy showed that thalamocortical synapses were absent at this stage. Glutamatergic responses were recorded in the cortex following stimulation of the thalamus in slices at this time but only in magnesium-free conditions. The responses were mediated entirely by N-methyl-d-aspartate (NMDA) receptors. From P28, responses could be recorded in normal magnesium and comprised a dominant NMDA-mediated component and a non-NMDA mediated component. At this time thalamocortical synapses were first identified and they were in the cortical plate. By P63 the non-NMDA-mediated component had increased relative to the NMDA-mediated component, and by P70 layer IV began to emerge and contained thalamocortical synapses. By P76 a fast non-NMDA-mediated peak dominated the response. This coincides with the appearance of cortical whisker-related patches and the onset in vivo of responses to peripheral stimulation of the whiskers.
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Affiliation(s)
- C A Leamey
- Departments of Physiology and Anatomy & Histology, School of Medical Sciences and Bosch Institute for Medical Research, University of Sydney, Sydney, New South Wales, 2006, Australia.
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12
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Kim Y, Lucas CA, Zhong WWH, Hoh JFY. Developmental changes in ventricular myosin isoenzymes of the tammar wallaby. J Comp Physiol B 2007; 177:701-5. [PMID: 17541602 DOI: 10.1007/s00360-007-0168-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2007] [Revised: 04/21/2007] [Accepted: 05/01/2007] [Indexed: 10/23/2022]
Abstract
Ventricular myosin in eutherian mammals undergoes a perinatal change in response to a sharp rise in thyroid hormone levels during development. In this investigation, changes in ventricular myosin heavy chains (MyHCs) of the tammar wallaby (Macropus eugenii) from early pouch life to adulthood were analysed using native gel electrophoresis, SDS-PAGE and western blotting. Adult wallaby ventricle showed three myosin isoenzymes, V(1), V(2) and V(3); western blots using specific anti-alpha-MyHC and anti-beta-MyHC antibodies showed their MyHC compositions to be alphaalpha, alphabeta and betabeta, respectively. Ventricular muscle in early pouch joeys expressed predominantly beta-MyHC. Up to 200 days, the time of initial pouch exit, alpha-MyHC content was around 5%. Thereafter, there was a sharp increase of alpha-MyHC expression to 35% by 242 days of age, eventually falling back to 23% in the adult. These changes correlate with known surges in plasma levels of thyroid hormones around pouch exit. The results suggest that ventricular myosins in a marsupial mammal also undergo a developmental change, and that marsupial ventricular myosins are thyroid responsive as in eutherians. The increased alpha-MyHC expression empowers the heart to meet the enhanced cardiovascular demands of out-of-pouch activity and the thermogenic action of thyroid hormones.
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Affiliation(s)
- Yoonah Kim
- Discipline of Physiology and the Bosch Institute, F13, School of Medical Sciences, Faculty of Medicine, The University of Sydney, Sydney, NSW 2006, Australia
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13
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Herbert CA, Eckery DC, Trigg TE, Cooper DW. Chronic Treatment of Male Tammar Wallabies with Deslorelin Implants During Pouch Life: Effects on Development, Puberty, and Reproduction in Adulthood1. Biol Reprod 2007; 76:1054-61. [PMID: 17329593 DOI: 10.1095/biolreprod.107.059915] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
The present study evaluated the effects of chronic GnRH agonist (deslorelin) treatment on sexual maturation in the male tammar wallaby. Slow-release deslorelin or placebo implants were administered to male pouch young (n = 10/group) when they were between 180 and 200 days old, to determine if disruption of the pituitary-testicular axis during development altered the timing of sexual maturation or had long-term effects on adult reproductive function. Deslorelin treatment caused retardation of testicular growth and reduced the serum FSH and testosterone concentrations between 12 and 24 mo of age. Maturation of the hypothalamic-pituitary-testicular axis was also delayed in treated animals at 13 and 19 mo of age. Despite these alterations in the pattern and timing of neuroendocrine development, sexual maturation was not permanently blocked in these animals and deslorelin-treated animals reached sexual maturity at the same age as treated animals, as evidenced by a fully functional pituitary-testicular axis and proven fertility at 25 mo of age. The ability of the treated animals to reach puberty at the same time as control animals, despite delayed maturation of the hypothalamic-pituitary-testicular axis, suggests that puberty in the male tammar wallaby is additionally regulated by other, gonadotropin-independent factors.
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Affiliation(s)
- C A Herbert
- School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia.
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14
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Schultz DJ, Whitehead PJ, Taggart DA. Review of surrogacy program for endangered victorian brush-tailed rock wallaby (Petrogale penicillata) with special reference to animal husbandry and veterinary considerations. J Zoo Wildl Med 2007; 37:33-9. [PMID: 17312809 DOI: 10.1638/04-027.1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A surrogacy program to increase the reproductive rate of the critically endangered Victorian brush-tailed rock wallaby (Petrogale penicillata), initially developed in semicaptive conditions, was established in close captivity at Adelaide Zoological Gardens in 1998. Pouch young were removed from their mothers on days 8-20 or 40-45 after parturition and placed onto the teat of a tammar wallaby (Macropus eugenii) or yellow-footed rock wallaby (Petrogale xanthopus xanthopus) surrogate mother. During the early years of the program, mortality of brush-tail pouch young was high (12/16, 75%), both before transfer while still on their mother (5/16) and after transfer to a surrogate mother (7/11). Changing pouch young transfer methodology and improving the health status of the surrogate animals during the later years of the program significantly reduced the mortality of brush-tail pouch young (8/29). Under the new methodology, no mortality of brush-tail pouch young was observed between birth and the time of transfer, (0/29), and after transfer, pouch young mortality rate was eight of 29 (28%). Factors implicated in the improved success of the program included 1) the early transfer (between days 8 and 20) of brush-tail pouch young from mother to surrogate mother, 2) review of the veterinary history and health of the animals selected to act as surrogate mothers, and 3) increased access to grazing pasture for foster mothers. The reproductive rate of the brush-tail females in the later years of the breeding program was sixfold above natural birthing rates. These and other factors important in establishing a breeding program of this nature are discussed.
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Affiliation(s)
- David J Schultz
- Adelaide Zoological Gardens, Frome Road, Adelaide, South Australia 5000, Australia
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15
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Paplinska JZ, Moyle RLC, Temple-Smith PDM, Renfree MB. Reproduction in female swamp wallabies, Wallabia bicolor. Reprod Fertil Dev 2007; 18:735-43. [PMID: 17032581 DOI: 10.1071/rd06024] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2006] [Accepted: 05/09/2006] [Indexed: 11/23/2022] Open
Abstract
The swamp wallaby (Wallabia bicolor) is a common, medium-sized, browsing macropodid marsupial that is unique in many ways. Relatively little is known about the reproductive biology of this species. Previous studies have proposed that the swamp wallaby has a pre-partum oestrus because the gestation period (x = 35.5 days, n = 4) is on average longer than the oestrus period (x = 31.0 days, n = 5) and the period from the removal of pouch young (RPY) to mating (x = 26.0 days, n = 3). In the current study, the period from RPY to birth was confirmed at x = 31.25 days (n = 4) in captive animals, consistent with a pre-partum oestrus. A growth curve for swamp wallaby pouch young was constructed from the progeny of captive animals to estimate the age and date of birth of young in a wild, culled population in South Gippsland, Victoria, and the reproduction of females in the wild throughout the year was examined. Young were born in every month of the year, with no statistically significant variation in the number of young born in each month. Females did not have a period of seasonal anoestrus and conceived throughout the year. Female swamp wallabies in South Gippsland bred continuously throughout the period of this study.
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16
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Yu H, Pask AJ, Shaw G, Renfree MB. Differential expression of WNT4 in testicular and ovarian development in a marsupial. BMC Dev Biol 2006; 6:44. [PMID: 17014734 PMCID: PMC1609105 DOI: 10.1186/1471-213x-6-44] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2006] [Accepted: 10/03/2006] [Indexed: 12/14/2022]
Abstract
Background WNT4 is a key regulator of gonadal differentiation in humans and mice, playing a pivotal role in early embryogenesis. Using a marsupial, the tammar wallaby, in which most gonadal differentiation occurs after birth whilst the young is in the pouch, we show by quantitative PCR during early testicular and ovarian development that WNT4 is differentially expressed ingonads. Results Before birth, WNT4 mRNA expression was similar in indifferent gonads of both sexes. After birth, in females WNT4 mRNA dramatically increased during ovarian differentiation, reaching a peak by day 9–13 post partum (pp) when the ovarian cortex and medulla are first distinguishable. WNT4 protein was localised in the ovarian cortex and at the medullary boundary. WNT4 mRNA then steadily decreased to day 49, by which time all the female germ cells have entered meiotic arrest. In males, WNT4 mRNA was down-regulated in testes immediately after birth, coincident with the time that seminiferous cords normally form, and rose gradually after day 8. By day 49, when testicular androgen production normally declines, WNT4 protein was restricted to the Leydig cells. Conclusion This is the first localisation of WNT4 protein in developing gonads and is consistent with a role for WNT4 in steroidogenesis. Our data provide strong support for the suggestion that WNT4 not only functions as an anti-testis gene during early development, but is also necessary for later ovarian and testicular function.
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MESH Headings
- Amino Acid Sequence
- Animals
- Blotting, Southern
- Blotting, Western
- Cloning, Molecular
- DNA/genetics
- DNA/isolation & purification
- DNA, Complementary/chemistry
- DNA, Complementary/genetics
- Female
- Gene Expression Profiling
- Gene Expression Regulation, Developmental/genetics
- Immunohistochemistry
- Macropodidae/embryology
- Macropodidae/genetics
- Macropodidae/growth & development
- Male
- Molecular Sequence Data
- Ovary/embryology
- Ovary/growth & development
- Ovary/metabolism
- Phylogeny
- Proto-Oncogene Proteins/genetics
- Proto-Oncogene Proteins/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Testis/embryology
- Testis/growth & development
- Testis/metabolism
- Time Factors
- Wnt Proteins/genetics
- Wnt Proteins/metabolism
- Wnt4 Protein
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Affiliation(s)
- Hongshi Yu
- Department of Zoology, The University of Melbourne, Victoria 3010, Australia
| | - Andrew J Pask
- Department of Zoology, The University of Melbourne, Victoria 3010, Australia
| | - Geoffrey Shaw
- Department of Zoology, The University of Melbourne, Victoria 3010, Australia
| | - Marilyn B Renfree
- Department of Zoology, The University of Melbourne, Victoria 3010, Australia
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17
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Lentle RG, Dey D, Hulls C, Mellor DJ, Moughan PJ, Stafford KJ, Nicholas K. A quantitative study of the morphological development and bacterial colonisation of the gut of the tammar wallaby Macropus eugenii eugenii and brushtail possum Trichosurus vulpecula during in-pouch development. J Comp Physiol B 2006; 176:763-74. [PMID: 16819652 DOI: 10.1007/s00360-006-0097-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2006] [Revised: 05/15/2006] [Accepted: 05/23/2006] [Indexed: 10/24/2022]
Abstract
We compared the rates of change of various morphological parameters of the stomach, small intestine, caecum and colon of tammar wallabies and brushtail possums with body mass during in-pouch development. These were correlated with changes in the numbers of bacterial species in the various gut segments. In the pouch-young of both species, the wet tissue masses of all gut segments increased with body mass in a positively allometric manner (i.e. with a body mass exponent > 1), suggesting that the mass of each component was disproportionately low at birth, but increased disproportionately rapidly postnatally. However, the lengths of the wallaby stomach and small intestine scaled isometrically with respect to body mass (i.e. with a body mass exponent around 0.33), which may indicate that the shape of these components changes to the adult form during early neonatal development. Conversely, the length of the caecum and colon of both wallabies and possums scaled in a positively allometric manner with respect to body mass, showing area to volume compensation. This may indicate a more general pattern of disproportionately rapid postnatal enlargement in areas that are distal to the principal sites of neonatal digestion (i.e. the stomach). The numbers of bacterial species present in the various gastrointestinal segments of both species were low in animals aged 100 days or less but there was a significant increase in microbial diversity in the caecum of brushtail possums aged over 100 days. The possum caecum also showed the greatest rate of increase in wet tissue mass relative to body mass. It is postulated that caecal development may act as a nidus for establishment of communities of commensal microflora in the developing marsupial.
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Affiliation(s)
- R G Lentle
- Institute of Food, Nutrition and Human Health, Massey University, Private bag 11222, Palmerston North, New Zealand.
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18
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Yamamoto Y, McKinley MJ, Nakazato M, Yamashita H, Shirahata A, Ueta Y. Postnatal development of orexin-A and orexin-B like immunoreactivities in the Eastern grey kangaroo (Macropus giganteus) hypothalamus. Neurosci Lett 2005; 392:124-8. [PMID: 16188385 DOI: 10.1016/j.neulet.2005.09.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2005] [Revised: 09/01/2005] [Accepted: 09/02/2005] [Indexed: 11/16/2022]
Abstract
The Eastern grey kangaroo (Macropus giganteus) is a marsupial, which is born in an extremely undeveloped state and has a long suckling period in the mother's pouch. In the present study, we examined the immunoreactivities of orexin-A (OXA) and orexin-B (OXB) in the hypothalamus of the Eastern grey kangaroo during the preweaning period, postweaning period and adulthood. In the preweaning period, only a few OXA- and OXB-like immunoreactive (LI) neurons and fibers were present and the intensity of staining was very weak. In the postweaning period, there was a pronounced increase in the numbers of OXA- and OXB-LI neurons and fibers and the intensity of the immunoreactivity was considerably stronger in comparison to the preweaning period. In the adult, the numbers of OXA- and OXB-LI neurons and fibers appeared to be slightly increased and the intensity was slightly stronger in comparison to the postweaning period. At all time periods, the distributions of OXA- and OXB-LI neurons was similar. The postnatal development of hypothalamic orexin neurons may be associated with developmental changes, including feeding behavior.
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Affiliation(s)
- Yukiyo Yamamoto
- Department of Pediatrics, School of Medicine, University of Occupational and Environmental Health, Kitakyushu 807-8555, Japan.
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19
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Waite R, Giraud A, Old J, Howlett M, Shaw G, Nicholas K, Familari M. Cross-fostering inMacropus eugenii leads to increased weight but not accelerated gastrointestinal maturation. ACTA ACUST UNITED AC 2005; 303:331-44. [PMID: 15828013 DOI: 10.1002/jez.a.174] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Stomach and small intestine development was characterized in tammar wallaby (Macropus eugenii) pouch young (PY) using both morphological and immunohistological criteria. At birth, the stomach is undeveloped in comparison to the well-developed intestinal mucosa. The stomach maintains a uniform morphology in both the forestomach and hindstomach regions until the specialization of cardiac and gastric glands are seen at PY170. Parietal cells, found throughout the mucosa are downregulated in the forestomach as cardiac glandular stomach is developing prior to the transition of the offspring to a diet that includes herbage. In the small intestine, mature-type villi are present at birth but the muscularis externa is immature and undergoes significant development around PY120 onwards. We investigated the effects of changes in maternal milk on gut development in the tammar wallaby using a cross fostering approach that provided younger pouch young with older stage milk. Younger PY (average age 67 days postpartum, n = 5) were transferred onto teats vacated by older stage PY (average age 100 days postpartum, n = 6) for 34 days before gut development was assessed. In addition milk analysis was performed before and after fostering events. Cross-fostered PY animals receiving older stage milk were found to be 31% heavier than controls. There was no difference between carbohydrate and protein concentrations however, fostered PY milk had a higher concentration of lipid than that of controls that may have contributed to heavier fostered PY. No difference was found in stomach or small intestine development between these groups using the criteria employed in this study.
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Affiliation(s)
- Rosemary Waite
- Department of Zoology, University of Melbourne, Victoria, 3010, Australia
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20
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Ashwell KWS, Mai JK, Andressen C. CD15 immunoreactivity in the developing brain of a marsupial, the tammar wallaby ( Macropus eugenii). Anat Embryol (Berl) 2004; 209:157-68. [PMID: 15597195 DOI: 10.1007/s00429-004-0430-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/02/2004] [Indexed: 10/26/2022]
Abstract
We have studied the distribution of the CD15 epitope in the developing brain of an Australian diprotodontid metatherian mammal, the tammar wallaby ( Macropus eugenii), using immunohistochemistry in conjunction with hematoxylin and eosin staining. At the time of birth (28 days after conception), CD15 immunoreactivity labeled somata in the primordial plexiform layer of the parietal cortex in a similar position to that seen in the early fetal eutherian brain. CD15 immunoreactivity in the brain of the developing pouch-young wallaby was found to be localized on the surface of radial glia at boundaries between developmentally significant forebrain compartments in a similar distribution to that seen in developing eutherian brain. These were best seen in the developing diencephalon, delineating epithalamus, ventral and dorsal thalamus and hypothalamic anlage, and in the striatum. Immunoreactivity for CD15 identified radial glia marking the lateral migratory stream at the striatopallial boundary, peaking in intensity at P19 to P25. From P37 to P54, CD15 immunoreactivity also demarcated patch compartments in the developing striatum. In contrast, CD15 immunoreactivity in hindbrain structures showed some differences from the temporospatial pattern seen in eutherian brain. These may reflect the relatively early brainstem maturation required for the newborn wallaby to be able to traverse the distance from the maternal genital tract to the pouch. The wallaby provides a convenient model for testing hypotheses concerning the role of CD15 in forebrain development because all events in which CD15 may play a critical role in forebrain morphogenesis occur during pouch life, when the young wallaby is accessible to experimental manipulation.
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Affiliation(s)
- K W S Ashwell
- Department of Anatomy, School of Medical Sciences, The University of New South Wales, Sydney, 2052, New South Wales, Australia.
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Rose RW, Kuswanti N. Thyroid function and the development of endothermy in a marsupial, the Tasmanian bettong, Bettongia gaimardi (Demarest 1822). Gen Comp Endocrinol 2004; 136:17-22. [PMID: 14980792 DOI: 10.1016/j.ygcen.2003.11.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2003] [Revised: 11/11/2003] [Accepted: 11/20/2003] [Indexed: 10/26/2022]
Abstract
The Tasmanian bettong (Bettongia gaimardi) is a small rat-kangaroo (marsupial) found only in Tasmania, Australia. The duration of pouch life is 15 weeks. Adults and older young display non-shivering thermogenesis and this paper examines the role of thyroxine in the development of endothermy in pouch young. Free thyroxine (T4) concentrations varied throughout pouch life. The mean (+/-SE) concentration was 6.2+/-1.9 pmol L(-1) in week 7, increased and peaked at 19.2+/-4.3 pmol L(-1) in week 12, and declined to 5.6+/-0.4 pmol L(-1) by week 20. This was similar to adult levels (3.2+/-3.8 pmol L(-1)). These concentrations showed significant differences. From pouch week 12 onwards, T4 injection raised oxygen consumption. Maximum levels of VO2 after T4 injection occurred at weeks 14-15. Although adult levels were lower, the increase in adult oxygen consumption after T4 injection was about 50%. Peak free T4 levels and metabolic responses to nor-adrenalin occur at week 12 and we hypothesize that thyroid hormone may facilitate the development of adrenergic-receptors in this species. The data presented in the paper further attest to the likely important role of the thyroid gland in the development of endothermy in marsupial pouch young.
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Affiliation(s)
- R W Rose
- School of Zoology, University of Tasmania, Private Bag 5, Hobart, Tasmania 7001, Australia.
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Magarey GM, Mate KE. Comparison of glucose metabolism in in vivo- and in vitro-matured tammar wallaby oocytes and its relationship to developmental potential following intracytoplasmic sperm injection. Reprod Fertil Dev 2004; 16:617-23. [PMID: 15740684 DOI: 10.1071/rd03062] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2003] [Accepted: 04/30/2004] [Indexed: 11/23/2022] Open
Abstract
Although marsupial oocytes undergo nuclear maturation in vitro, there is, at present, no indication of their developmental potential, largely owing to the lack of in vitro fertilisation and related technologies for marsupials. Glucose metabolism has proven a useful indicator of oocyte cytoplasmic maturation and developmental potential in several eutherian species. Therefore, the aims of the present study were to compare: (1) the rates of glycolysis and glucose oxidation in immature, in vitro-matured and in vivo-matured tammar wallaby oocytes; and (2) the metabolic rate of individual oocytes with their ability to form pronuclei after intracytoplasmic sperm injection. The rates of glycolysis measured in immature (2.18 pmol oocyte–1 h–1), in vitro-matured (0.93 pmol oocyte–1 h–1) and in vivo-matured tammar wallaby oocytes (0.54 pmol oocyte–1 h–1) were within a similar range to values obtained in eutherian species. However, unlike the trend observed in eutherian oocytes, the glycolytic rate was significantly higher in immature oocytes compared with either in vivo- or in vitro-matured oocytes (P < 0.001) and significantly higher in in vitro-matured oocytes compared with in vivo-matured oocytes (P < 0.001). No relationship was identified between glucose metabolism and the developmental capacity of oocytes after intracytoplasmic sperm injection when assessed after 17–19 h. Oocytes that became fertilised (two pronuclei) or activated (one or more pronucleus) were not distinguished from others by their metabolic rates. Longer culture after intracytoplasmic sperm injection (e.g. blastocyst stage) may show oocyte glucose metabolism to be predictive of developmental potential; however, culture to the single-cell stage did not reveal any significant differences in normally developing embryos.
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Affiliation(s)
- Genevieve M Magarey
- Cooperative Research Centre for Conservation and Management of Marsupials, Macquarie University, Sydney, NSW, Australia
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Vidovic M, Marotte LR. Analysis of EphB receptors and their ligands in the developing retinocollicular system of the wallaby reveals dynamic patterns of expression in the retina. Eur J Neurosci 2003; 18:1549-58. [PMID: 14511334 DOI: 10.1046/j.1460-9568.2003.02882.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The expression of EphB1 and B2 receptors and ephrins-B1, -B2 and -B3 in the retina and superior colliculus of the wallaby (Macropus eugenii) was examined during the development of the retinocollicular projection, using reverse transcription-polymerase chain reaction and immunohistochemistry. There was an early transient differential expression of EphB2 that was higher in ventral retina and restricted to the outer neuroblast layer, whereas a high ventral to low dorsal gradient of ephrin-B2 expression occurred there throughout the study period. However, there was no dorsoventral gradient of receptors or ligands in retinal ganglion cells or a mediolateral gradient of ephrins in the colliculus. These findings suggest a limited role for these molecules in topographic mapping across the mediolateral colliculus in the wallaby. Early in retinal development there is a complementary pattern of expression of ephrin-B1 and -B2 in the outer neuroblast layer that overlaps with expression of EphB2. Ganglion and amacrine cells also express EphB2. As development proceeds subpopulations of putative horizontal and bipolar cells, also expressing EphB2, come to reside in the inner nuclear layer and ephrin-B1 is expressed throughout the outer nuclear layer. At the same time cells expressing ephrin-B2, and subpopulations of horizontal and bipolar cells come to reside in the inner nuclear layer and there is a corresponding decrease in ephrin-B2 expression in the outer nuclear layer. This pattern of coexpression of receptors and ligands suggests a role for them in cell migration and maintenance of laminar boundaries.
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Affiliation(s)
- Maria Vidovic
- Developmental Biology Group, Research School of Biological Sciences, Australian National University, Canberra, ACT 0200, Australia
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24
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Munn AJ, Dawson TJ. Energy requirements of the red kangaroo (Macropus rufus): impacts of age, growth and body size in a large desert-dwelling herbivore. J Comp Physiol B 2003; 173:575-82. [PMID: 12879349 DOI: 10.1007/s00360-003-0367-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/30/2003] [Indexed: 11/29/2022]
Abstract
Generally, young growing mammals have resting metabolic rates (RMRs) that are proportionally greater than those of adult animals. This is seen in the red kangaroo ( Macropus rufus), a large (>20 kg) herbivorous marsupial common to arid and semi-arid inland Australia. Juvenile red kangaroos have RMRs 1.5-1.6 times those expected for adult marsupials of an equivalent body mass. When fed high-quality chopped lucerne hay, young-at-foot (YAF) kangaroos, which have permanently left the mother's pouch but are still sucking, and recently weaned red kangaroos had digestible energy intakes of 641+/-27 kJ kg(-0.75) day(-1) and 677+/-26 kJ kg(-0.75) day(-1), respectively, significantly higher than the 385+/-37 kJ kg(-0.75) day(-1) ingested by mature, non-lactating females. However, YAF and weaned red kangaroos had maintenance energy requirements (MERs) that were not significantly higher than those of mature, non-lactating females, the values ranging between 384 kJ kg(-0.75) day(-1) and 390 kJ kg(-0.75) day(-1) digestible energy. Importantly, the MER of mature female red kangaroos was 84% of that previously reported for similarly sized, but still growing, male red kangaroos. Growth was the main factor affecting the proportionally higher energy requirements of the juvenile red kangaroos relative to non-reproductive mature females. On a good quality diet, juvenile red kangaroos from permanent pouch exit until shortly after weaning (ca. 220-400 days) had average growth rates of 55 g body mass day(-1). At this level of growth, juveniles had total daily digestible energy requirements (i.e. MER plus growth energy requirements) that were 1.7-1.8 times the MER of mature, non-reproductive females. Our data suggest that the proportionally higher RMR of juvenile red kangaroos is largely explained by the additional energy needed for growth. Energy contents of the tissue gained by the YAF and weaned red kangaroos during growth were estimated to be 5.3 kJ g(-1), within the range found for most young growing mammals.
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Affiliation(s)
- A J Munn
- School of Biological Earth and Environmental Sciences, University of New South Wales, 2052, Sydney, NSW, Australia.
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Pearce AR, Marotte LR. The first thalamocortical synapses are made in the cortical plate in the developing visual cortex of the wallaby (Macropus eugenii). J Comp Neurol 2003; 461:205-16. [PMID: 12724838 DOI: 10.1002/cne.10681] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The time course of development and laminar distribution of thalamocortical synapses in the visual cortex of the marsupial mammal the wallaby (Macropus eugenii) has been studied by electron microscopy from the time of afferent ingrowth to the appearance of layer 4, the main target for thalamic axons. Axons were labeled from the thalamus by a fluorescent carbocyanine dye in fixed tissue or by transneuronal transport of horseradish peroxidase conjugated to wheat germ agglutinin from the eye. Thalamic axons first reached the cortex 2 weeks after birth and grew into the developing cortical plate without a waiting period in the subplate. The first thalamocortical synapses were detected 2 weeks later solely throughout the loosely packed zone of the cortical plate, where layer 6 cells previously have been shown to reside. As the thickness of the cortex increased with age, thalamocortical synapses were increasingly prevalent in the loosely packed zone of the cortical plate. With the appearance of layer 4, thalamocortical synapses were found there as well as in the marginal zone and layer 6. There was no evidence for an early population of thalamocortical synapses in the subplate. The first synapses made by thalamic axons were in a region containing layer 6 cells, one of their normal targets in the mature cortex.
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Affiliation(s)
- Amy R Pearce
- Developmental Neurobiology and Endocrinology Group, Research School of Biological Sciences, Australian National University, Canberra, ACT 0200, Australia
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Suzuki M, Ushijima N, Kohno A, Sawa Y, Yoshida S, Sekikawa M, Ohtaishi N. Plastic casts and confocal laser scanning microscopy applied to the observation of enamel tubules in the red Kangaroo (Macropus rufus). Anat Sci Int 2003; 78:53-61. [PMID: 12680470 DOI: 10.1046/j.0022-7722.2003.00039.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Scanning electron microscopy for plastic casts and confocal laser scanning microscopy for Villanueva bone-stained ground sections were used together to observe enamel tubules in red kangaroo molars. Although the tubular structures such as terminals, bends, expansions, splits, divergences and rejoinings in this species were within the variations of marsupial species, their morphological characteristics were demonstrated with extremely clear and persuasive images. Thus, the combined observations of plastic casts by scanning electron microscopy and Villanueva bone-stain sections by confocal laser scanning microscopy were found to be of value for the investigation of enamel tubules and tubular structures in other hard tissues.
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Affiliation(s)
- Masatsugu Suzuki
- Laboratory of Wildlife Biology, Department of Environmental Veterinary Sciences, The Graduate School of Veterinary Medicine, Hokkaido University, Hokkaido, Japan.
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Abstract
Red kangaroos (Macropus rufus) are large (>20 kg) herbivorous marsupials common to the arid and semi-arid regions of inland Australia, where drought is frequent. Young-at-foot (YAF) red kangaroos are the age/size class usually most affected by drought. Kangaroos at this YAF stage are making the transition from a milk-based diet to one of herbivory and an inability to adequately digest high-fibre feeds may contribute to their high mortalities during drought. We examined the role of milk in the nutrition of YAF red kangaroos fed forages of different fibre content and evaluated it as an extra energy and/or nitrogen source. Milk intake had little impact on the digestion of herbage by YAF red kangaroos fed low-fibre chopped lucerne (alfalfa) hay. Organic matter (OM) intake was 210+/-20 g day(-1) and 228+/-22 g day(-1), respectively, by YAF fed lucerne and lucerne with milk. Apparent digestibility of lucerne OM was ca. 55%, regardless of milk intake. Fed lucerne, with and without milk, YAF sustained growth rates of ca. 45 g day(-1). Conversely, even with a milk supplement, YAF red kangaroos ingested only 90+/-11 g day(-1) of high-fibre chopped oaten hay, of which they digested only ca. 36%. Despite milk intake, YAF fed chopped oaten hay lost between 0 and 75 g body mass day(-1) and were in negative nitrogen balance (-0.40+/-0.11 g N day(-1)). On all diets nitrogen loss was primarily as endogenous nitrogen (urinary and faecal) rather than as dietary nitrogen. Endogenous nitrogen losses were elevated in YAF fed chopped oaten hay, primarily as non-dietary faecal nitrogen. Overall, when high-quality feed was available, YAF were not markedly dependent on milk. However, YAF fed poor-quality chopped oaten hay would require up to 540 ml day(-1) of late-stage kangaroo milk to attain intakes of energy and nitrogen, and hence growth rates, comparable with those YAF fed lucerne.
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Affiliation(s)
- A J Munn
- School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia.
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28
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Rose RW, Morahan TM, Mulchay JE, Ratkowsky DA. Milk composition and growth in wild and captive Tasmanian bettongs, Bettongia gaimardi (Marsupialia). J Comp Physiol B 2003; 173:125-33. [PMID: 12624650 DOI: 10.1007/s00360-002-0315-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/18/2002] [Indexed: 10/25/2022]
Abstract
Changes in milk composition (total solids, carbohydrate, protein, lipid and calculated gross energy content) during lactation in three groups of Tasmanian bettongs ( Bettongia gaimardi): free-living animals (wild group), captive animals offered a diet of dry dog food and apples ad libitum (ad lib group), and captive animals fed restricted amounts of the same diet (maintenance group) were related to growth rates (measured as body mass and head length) of their young. There were no significant differences in the concentration of milk solids among the three groups, but the wild group had higher lipid concentrations and the maintenance group had higher carbohydrate but lower protein concentrations. For all three groups, milk total solids increased through lactation from ca. 25% to ca. 45% and carbohydrate concentrations decreased from ca. 18% to about 3%. Protein concentrations increased from ca. 5% to ca. 10% in the wild and ad lib groups, but only from 4% to 8% in the maintenance group. Lipid concentrations increased in the wild and ad lib groups from ca. 4% to ca. 18%, but in the maintenance group only to ca. 7%. Calculated gross energy content of milk increased through lactation in the wild and ad lib groups (from ca. 500 kJ.100 ml(-1) to ca. 1,000 kJ.100 ml(-1)), but there was no significant increase in the maintenance group. The volume of milk produced increased to a peak just prior to permanent pouch vacation by the young, when the gross energy output in milk was 120-150 kJ.3 h(-1) in the wild and ad lib groups. On a daily basis this is equivalent to the milk energy output of larger wallabies, and helps to explain the relatively high growth rates of young Tasmanian bettongs. There were significant differences in growth rates among the groups, with the heaviest young always in the ad lib group. Thus differences in milk composition resulting from different planes of nutrition can lead to differences in growth rates of marsupial young.
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Affiliation(s)
- R W Rose
- School of Zoology, University of Tasmania, GPO Box 252-05, 7001 Hobart, Tasmania, Australia.
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29
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Makanya AN, Haenni B, Burri PH. Morphometry and allometry of the postnatal lung development in the quokka wallaby (Setonix brachyurus): a light microscopic study. Respir Physiol Neurobiol 2003; 134:43-55. [PMID: 12573880 DOI: 10.1016/s1569-9048(02)00204-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The postnatally developing lungs of the quokka wallaby, Setonix brachyurus, were investigated macroscopically and by light microscopic morphometry. Lung, parenchymal and non-parenchymal volumes as well as the components of the latter two were analysed by regression analysis. The lungs comprised a single undivided left lung and a right lung with an adherent accessory lobe. Septal tissue growth was most remarkable in the canalicular and saccular stages. Between mid-canalicular stage and the saccular stage, the lung volume increased 2-fold, mainly due to airspace expansion, coupled with septal tissue thinning. The non-parenchymal vascular volume increase accelerated in the successive developmental stages while the airway and connective tissue volumes progressed in a decreasing order, being highest in the canalicular and saccular stages and lowest in the alveolar stage. Growth and remodelling of the alveolar septa occurred simultaneously with airspace subdivision. Airspace expansion accelerated during the stage of microvascular maturation, when most other parameters showed the least rate of increase.
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Affiliation(s)
- A N Makanya
- Institute of Anatomy, University of Berne, Buehlstrasse 26, CH-3000 Berne 9, Switzerland
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Liu GB. Functional development of the auditory brainstem in the tammar wallaby (Macropus eugenii): the superior olivary complex and its relationship with the auditory brainstem response (ABR). Hear Res 2003; 175:152-64. [PMID: 12527133 DOI: 10.1016/s0378-5955(02)00733-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Twenty pouch-young tammar wallabies (Macropus eugenii) were used to determine the generator of the auditory brainstem response (ABR) during development through ABR and focal superior olivary complex (SO) recordings. A click response from the SO in the wallaby was recorded from postnatal day (PND) 112 when the ABR was only a positive-negative deflection. Before PND 120, the SO response did not contribute to the ABR as it occurred outside the ABR time-span. After PND 140, the SO response was correlated with multiple waves of the ABR with its dominant component corresponding to the ABR P3 wave. The latency, threshold, and amplitude of the SO response developed to the adult-like level at PND 140, while the rate-following ability in the SO response reached the adult level at PND 160. Presumably this was due to more complicated mechanisms underlying the auditory adaptation. The adaptation of the SO response was directly proportional to the stimulus rate and intensity as well as developmental status. Developmental comparison between the ABR and the focal responses from four auditory brainstem nuclei indicated that each ABR component may have a dominant contributor from the auditory brainstem, but there was no simple and exclusive association between the ABR component and the auditory brainstem nuclei.
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Affiliation(s)
- Guang B Liu
- Vision, Touch and Hearing Research Centre, School of Biomedical Sciences, The University of Queensland, St Lucia, Brisbane, Qld 4072, Australia.
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Zhang X, Lin M. Tracing sperm acrosome differentiation in the testis and maturation in the epididymis of the tammar wallaby (Macropus eugenii) with a 45-kDa acrosome-membrane-associated protein. Reprod Fertil Dev 2002; 14:69-77. [PMID: 12051525 DOI: 10.1071/rd01116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2001] [Accepted: 12/10/2001] [Indexed: 11/23/2022] Open
Abstract
A 45-kDa protein was originally extracted from a depression, where the acrosome is lodged, on the anterior end of the sperm nucleus of ejaculated wallaby spermatozoa. Using immunofluorescent and confocal microscopes, this study demonstrates that the 45-kDa protein is persistently localized to the sperm acrosome throughout the periods of spermiogenesis, spermiation, epididymal maturation and ejaculation in the tammar wallaby. The distribution of the 45-kDa protein is always on the perimeter of the acrosome and associated with the acrosomal membrane, so that changes in the shape of the 45-kDa immunofluorescent labelling mirror changes in the shape of the acrosome during its differentiation in the testis and epididymis. Thus, the 45-kDa protein may be used as a molecular marker to study the marsupial acrosome differentiation and to chart the events of testicular and epididymal maturation of the spermatozoa. Furthermore, the behaviour of the 45-kDa protein during the immunostaining process suggests that this protein is a largely insoluble and detergent-resistant protein and may play an important role in attachment of the acrosome to the nucleus during sperm formation, similar to those inner acrosomal-membrane-associated proteins that have been reported in eutherian spermatozoa.
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Affiliation(s)
- Xiyi Zhang
- Cooperative Research Centre for the Conservation and Management of Marsupials, The University of Newcastle, NSW, Australia
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Abstract
We have studied the development of the hypothalamus of an Australian marsupial, the tammar wallaby (Macropus eugenii), to provide an initial anatomic framework for future research on the developing hypothalamus of diprotodontid metatheria. Cytoarchitectural (hematoxylin and eosin), immunohistochemical (CD 15 and growth associated protein, GAP-43), tritiated thymidine autoradiography, and carbocyanine dye tracing techniques were applied. Until 12 days after birth (P12), the developing hypothalamus consisted of mainly a ventricular germinal zone with a thin marginal layer, but by P25, most hypothalamic nuclei were well differentiated, indicating that the bulk of hypothalamic cytoarchitectural development occurs between P12 and P25. Strong CD 15 immunoreactivity was found in radial glial fibers in the rostral hypothalamus during early developmental ages, separating individual hypothalamic compartments. Immunoreactivity for GAP-43 was used to reveal developing fiber bundles. The medial forebrain bundle was apparent by P0, and the fornix appeared at P12. Tritiated thymidine autoradiography revealed lateral-to-medial and dorsal-to-ventral neurogenetic gradients similar to those seen in rodents. Dye tracing showed that projections to the posterior pituitary arose from the supraoptic nucleus at P5 and from the paraventricular nucleus at P10. Projections to the medulla were first found from the lateral hypothalamic area at P0 and paraventricular nucleus at P10. In conclusion, the pattern of development of the wallaby hypothalamus is broadly similar to that found in eutheria, with comparable neurogenetic compartments to those identified in rodents. Because most hypothalamic maturation takes place after birth, wallabies provide a useful model for experimentally manipulating the developing mammalian hypothalamus.
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Affiliation(s)
- Gang Cheng
- Department of Anatomy, School of Medical Sciences, The University of New South Wales, 2052 New South Wales, Australia.
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Richardson SJ, Aldred AR, Leng SL, Renfree MB, Hulbert AJ, Schreiber G. Developmental profile of thyroid hormone distributor proteins in a marsupial, the tammar wallaby Macropus eugenii. Gen Comp Endocrinol 2002; 125:92-103. [PMID: 11825038 DOI: 10.1006/gcen.2001.7729] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The ontogeny of thyroxine distributor proteins in serum of the marsupial Macropus eugenii (tammar wallaby) was investigated from day 3 after birth until adulthood. The thyroxine distributor proteins in the serum of adult M. eugenii are transthyretin and albumin. Northern analysis of RNA prepared from liver showed that transthyretin mRNA levels were initially high (about adult levels at the earliest ages tested), reduced to about 60% adult levels (between days 50 and 150), and then steadily increased to adult levels (by days 200 to 250). Albumin mRNA levels were initially about 50% of adult levels (day 3) and steadily rose to 90% of adult levels by days 175 to 220. A globulin, "wallaby thyroxine-binding protein" (W-TBP), bound [(125)I]thyroxine from day 3 until about day 200. Of the protein-bound thyroxine, the proportion bound by transthyretin had a similar pattern to the transthyretin mRNA levels. From day 26 onward, about half of the protein-bound thyroxine was bound to albumin. On day 3, less than 10% was bound to W-TBP and the proportion steadily increased to a maximum of about 46% by about day 120 and then reduced to undetectable levels by around day 250. The developmentally regulated W-TBP was present throughout pouch life, when the pouch young is dependent on obtaining thyroxine required for normal growth and development from the mother. After the young tammar wallaby leaves its mother's pouch, a time when it has reached a level of physiological development approximately equivalent to that at the time of birth in precocious eutherian mammals such as cattle and sheep, W-TBP was no longer detected as a thyroxine distributor protein in serum.
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Affiliation(s)
- Samantha J Richardson
- Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria 3010, Australia.
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Miller NJ, Orgeig S, Daniels CB, Baudinette RV. Postnatal development and control of the pulmonary surfactant system in the tammar wallaby Macropus eugenii. J Exp Biol 2001; 204:4031-42. [PMID: 11809778 DOI: 10.1242/jeb.204.23.4031] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
Marsupials are born at an early stage of development and are adapted for future development inside the pouch. Whether the pulmonary surfactant system is fully established at this altricial stage is unknown. This study correlates the presence of surfactant proteins (SP-A, SP-B and SP-D), using immunohistochemistry, with the ex-utero development of the lung in the tammar wallaby Macropus eugenii and also investigates the control of phosphatidylcholine (PC) secretion from developing alveolar type II cells. All three surfactant proteins were found at the site of gas exchange in the lungs of joeys at all ages, even at birth when the lungs are in the early stages of the terminal air-sac phase. Co-cultures of alveolar type II cells and fibroblasts were isolated from the lungs of 30- and 70-day-old joeys and incubated with the hormones dexamethasone (10 μmol l–1), prolactin (1 μmol l–1) or triiodothyronine (100 μmol l–1) or with the autonomic secretagogues isoproterenol (100 μmol l–1) or carbamylcholine chloride (100 μmol l–1). Basal secretion of PC was greater at 30 days of age than at 70 days. Co-cultures responded to all five agonists at 30 days of age, but only the autonomic secretagogues caused a significant increase in PC secretion at 70 days of age. This demonstrates that, as the cells mature, their activity and responsiveness are reduced. The presence of the surfactant proteins at the site of gas exchange at birth suggests that the system is fully functional. It appears that surfactant development is coupled with the terminal air-sac phase of lung development rather than with birth, the length of gestation or the onset of air-breathing.
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Affiliation(s)
- N J Miller
- Department of Environmental Biology, Adelaide University, Adelaide, SA 5005, Australia
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35
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Munn AJ, Dawson TJ. Thermoregulation in juvenile red kangaroos (Macropus rufus) after pouch exit: higher metabolism and evaporative water requirements. Physiol Biochem Zool 2001; 74:917-27. [PMID: 11731983 DOI: 10.1086/324568] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/20/2001] [Indexed: 11/03/2022]
Abstract
The population dynamics of red kangaroos (Macropus rufus) in the Australian arid zone is tightly linked with environmental factors, which partly operate via the survival of juvenile animals. A crucial stage is the young-at-foot (YAF) stage when kangaroos permanently exit the pouch. We have examined the thermal biology of YAF red kangaroos during ages from permanent pouch exit until weaning. Over a wide range of environmental temperatures (ambient temperature [T(a)] -5 degrees to 45 degrees C), YAF red kangaroos had a mass-specific metabolism that was generally twice that of adults, considerably higher than would be expected for an adult marsupial of their body size. The total energy requirements of YAF red kangaroos were 60%-70% of those of adult females, which were three times their size. Over the same range in T(a), YAF red kangaroos also had total evaporative water losses equal to those of adult females. At the highest T(a) (45 degrees C), differences were noted in patterns of dry heat loss (dry conductance) between YAF red kangaroos and adult females, which may partially explain the relatively high levels of evaporative cooling by YAF. By weaning age, young kangaroos showed little change in their basal energy and water requirements (at T(a) 25 degrees C) but did show reduced mass-specific costs in terms of energy and water use at extremes of T(a) (-5 degrees and 45 degrees C, respectively). In their arid environment, typified by unpredictable rainfall and extremes of T(a), young red kangaroos may need to remain close to water points, which, in turn, may restrict their ability to find the high-quality forage needed to meet their high energy demands.
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Affiliation(s)
- A J Munn
- School of Biological Science, University of New South Wales, Sydney, New South Wales 2052, Australia.
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36
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Abstract
The role of genes in the differentiation of the testis and ovary has been extensively studied in the human and the mouse. Despite over a decade of investigations, the precise roles of genes and their interactions in the pathway of sex determination are still unclear. We have chosen to take a comparative look at sex determination and differentiation to gain insights into the evolution and the conserved functions of these genes. To achieve this, we have examined a wide variety of eutherian sex determining genes in a marsupial, the tammar wallaby, to determine which genes have a conserved and fundamental mammalian sex determining role. These investigations have provided many unique insights. Here, we review the recent molecular and endocrine investigations into sexual development in marsupials, and highlight how these studies have shed light on the roles of genes and hormones in mammalian sex determination and differentiation.
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Affiliation(s)
- A Pask
- Department of Zoology, The University of Melbourne, Victoria, 3010, Australia.
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Whitworth DJ, Pask AJ, Shaw G, Marshall Graves JA, Behringer RR, Renfree MB. Characterization of steroidogenic factor 1 during sexual differentiation in a marsupial. Gene 2001; 277:209-19. [PMID: 11602358 DOI: 10.1016/s0378-1119(01)00677-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In eutherian mammals, such as mice and humans, steroidogenic factor 1 (SF1) plays important roles in the development of the gonad and in its steroidogenic activity. Marsupial and eutherian mammals have been evolving independently for at least 100 million years and so we were interested in comparing SF1 of a marsupial with that of eutherians. To this end, we have cloned SF1 from an Australian marsupial, the tammar wallaby. Although the amino acid sequence of SF1 is highly conserved among vertebrate species, tammar SF1 appears to have diverged less from the ancestral SF1 than have eutherian SF1 proteins. Tammar SF1 is expressed by both ovaries and testes on the day of birth, just prior to the onset of testicular differentiation, until at least 8 days after birth by which time the ovary also has begun to sexually differentiate. SF1 transcripts are localized predominantly to the pre-granulosa and Sertoli cells of the ovary and testis, respectively. In the testis SF1 transcripts are also present in the interstitial cells, although at a lower level than that which is observed in the Sertoli cells. SF1 is also transcribed in adult testis and ovary. In the adult ovary SF1 is expressed in the interstitial gland, and in the granulosa cells and theca interna of small to medium-sized antral follicles, but is not expressed in large antral follicles. Thus, although the structure of tammar SF1 is divergent from that of eutherians, its expression profile is similar, supporting a conserved role in gonadal development and steroidogenesis.
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MESH Headings
- Amino Acid Sequence
- Animals
- Animals, Newborn
- Blotting, Northern
- Chromosome Mapping
- Cloning, Molecular
- DNA, Complementary/chemistry
- DNA, Complementary/genetics
- DNA-Binding Proteins/genetics
- Female
- Fushi Tarazu Transcription Factors
- Gene Expression
- Gene Expression Regulation, Developmental
- Homeodomain Proteins
- In Situ Hybridization
- In Situ Hybridization, Fluorescence
- Macropodidae/genetics
- Macropodidae/growth & development
- Male
- Molecular Sequence Data
- Ovary/growth & development
- Ovary/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, Cytoplasmic and Nuclear
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Sex Differentiation/genetics
- Steroidogenic Factor 1
- Testis/growth & development
- Testis/metabolism
- Tissue Distribution
- Transcription Factors/genetics
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Affiliation(s)
- D J Whitworth
- Department of Molecular Genetics, Box 45, The University of Texas, M.D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA.
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38
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Abstract
The androgen 5alpha-androstane-3alpha,17beta-diol (5alpha-adiol) is synthesized in testes and secreted into plasma of male tammar wallaby pouch young and appears to virilize the urogenital sinus. To provide insight into its mechanism of action, a dose response study showed that administration of 1 microg 5alpha-adiol monoenanthate per g body wt. per week for 3 weeks to 24-day-old female pouch young induced prostate bud formation equivalent to that of males of the same age. Administration of this same dose of the enanthates of testosterone, dihydrotestosterone, and 5alpha-adiol to female pouch young caused equivalent virilization of the urogenital sinus. The fact that 5alpha-adiol does not exert a unique effect, together with our earlier findings in this species that 5alpha-adiol and testosterone are converted to dihydrotestosterone in the urogenital sinus and that virilization of the urogenital sinus is prevented by the androgen receptor antagonist flutamide, suggest that 5alpha-adiol is a circulating precursor for dihydrotestosterone formation in this tissue.
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Affiliation(s)
- M W Leihy
- Department of Zoology, University of Melbourne, Victoria 3010, Parkville, Australia
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39
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Liu GB, Mark RF. Functional development of the inferior colliculus (IC) and its relationship with the auditory brainstem response (ABR) in the tammar wallaby (Macropus eugenii). Hear Res 2001; 157:112-23. [PMID: 11470191 DOI: 10.1016/s0378-5955(01)00289-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To discover the developmental relationship between the auditory brainstem response (ABR) and the focal inferior colliculus (IC) response, 32 young tammar wallabies were used, by the application of simultaneous ABR and focal brainstem recordings, in response to acoustic clicks and tone bursts of seven frequencies. The IC of the tammar wallaby undergoes a rapid functional development from postnatal day (PND) 114 to 160. The earliest (PND 114) auditory evoked response was recorded from the rostral IC. With development, more caudal parts of the IC became functional until age about PND 127, when all parts of the IC were responsive to sound. Along a dorsoventral direction, the duration of the IC response decreased, the peak latency shortened, while the amplitude increased, reaching a maximum value at the central IC, then decreased. After PND 160, the best frequency (BF) of the ventral IC was the highest, with values between 12.5 and 16 kHz, the BF of the dorsal IC was the lowest, varying between 3.2 and 6.4 kHz, while the BF of the central IC was between 6.4 and 12.5 kHz. Between PND 114 and 125, the IC response did not have temporal correlation with the ABR. Between PND 140 and 160, only the early components of the responses from the ventral and central IC correlated with the P4 waves of the ABR. After PND 160, responses recorded from different depths of the IC had a temporal correlation with the ABR.
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Affiliation(s)
- G B Liu
- Vision, Touch and Hearing Research Centre, The University of Queensland, St. Lucia, Brisbane, Australia.
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40
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Abstract
We investigated the events that take place during the postnatal morphogenesis of the lung of the quokka wallaby, Setonix brachyurus, using the light microscope and both the scanning and transmission electron microscopes. The lung of term, newborn babies (joeys) at 3-days of postnatal life was at late canalicular stage and comprised large airways and tubules separated by thick mesenchymal interstitium. The tubules were lined by a low cuboidal epithelium but had few portions with true gas exchange barrier where capillaries came into close contact with squamous type of epithelium. By the fifth day postpartum, the lung entered the early saccular stage characterised by large air sacs, thinner septa, a better developed double capillary system and conversion of the cuboidal epithelium into a squamous one of type I cells interrupted by groups of cuboidal type II cells with lamellar bodies. Transitory respiratory bronchioles were recognisable toward the end of this stage. Formation of secondary septa started by Day 15, dividing the saccules into several generations of smaller air spaces. There were alternating and concurrent periods of tissue proliferation and air space expansion, followed by septal thinning. Alveolization started from about 125 days postpartum when the first burst of small sized air spaces bounded by septa with a single capillary layer were encountered. By Day 180 the process of alveolization was completed with only occasional septa showing a double capillary system and by Day 210 postnatally, the lung resembled that of an adult. For the first time in a mammal, the canalicular stage was encountered postnatally during lung development.
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Affiliation(s)
- A N Makanya
- Institute of Anatomy, University of Berne, Switzerland
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41
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Stubbs J, Palmer A, Vidovic M, Marotte LR. Graded expression of EphA3 in the retina and ephrin-A2 in the superior colliculus during initial development of coarse topography in the wallaby retinocollicular projection. Eur J Neurosci 2000; 12:3626-36. [PMID: 11029633 DOI: 10.1046/j.1460-9568.2000.00251.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We describe the expression of EphA3 and EphA7 receptors and ephrin-A2 ligand in the retina and the superior colliculus during the development of the retinocollicular projection in the marsupial wallaby (Macropus eugenii), using immunoblotting and immunohistochemistry. EphA3 in the retina was in a striking, low central to high peripheral gradient, superimposed on which was a high temporal to low nasal level of expression. This distribution was evident from postnatal day 30, when axons are growing into the colliculus and forming a coarsely organized topographic projection, to postnatal day 65, when axons have arborized in their correct retinotopic positions. EphA7 showed a shallow centroperipheral gradient with no nasotemporal differences in expression. In the superior colliculus no rostrocaudal differences in distribution were detected for either of these receptors. Ephrin-A2 was distributed in a gradient increasing from the rostral to the caudal pole in the superficial layers of the superior colliculus only up to postnatal day 30. Ephrin-A2 was evenly distributed in the retina throughout development of the projection. Expression of EphA3 in the retina increased, while the expression of ephrin-A2 in the colliculus was downregulated over time. The graded expression of EphA3 and ephrin-A2 early in the development of the projection suggests that they play a role in establishment of coarse topography of retinal axons along the rostrocaudal axis of the superior colliculus. However, the gradients were not complementary, meaning that EphA3 alone cannot mediate the repulsive interactions with ephrin-A2 that have been postulated to underlie formation of the topographic map.
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Affiliation(s)
- J Stubbs
- Developmental Neurobiology and Endocrinology Group, Research School of Biological Sciences, Australian National University, Canberra, ACT 0200, Australia
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Runciman SI, Baudinette RV, Gannon BJ, Lipsett J. Morphometric analysis of postnatal lung development in a marsupial: transmission electron microscopy. Respir Physiol 1999; 118:61-75. [PMID: 10568420 DOI: 10.1016/s0034-5687(99)00068-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Postnatal lung development in the tammar wallaby was investigated using transmission electron microscopy and stereological morphometry. Volume densities of interstitial, epithelial and endothelial tissue and capillaries in the parenchymal septa were measured as were surface densities of the airspaces and gas exchange capillaries. Absolute changes in these parameters were related to body mass. Three phases of development were identified. During the ectothermic period, in the first 70 days after birth when the lung was in the terminal air sac phase, the most marked change was an increase in volume density of septal interstitium. The transitional period between ectothermy and endothermy, between 70 and 180 days after birth, corresponded to the alveolar phase and was characterised by accelerated increase in air space surface area. Maturation of the parenchymal septa and establishment of the mature capillary system occurred largely after 180 days when endothermy was established. The anatomical diffusion factor in the tammar wallaby adult is similar to that for eutherians.
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Affiliation(s)
- S I Runciman
- Department of Anatomy and Histology, School of Medicine, The Flinders University of South Australia, Adelaide, Australia.
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Kent AR, Harman AM. The effects of a transient increase in temperature on cell generation and cell death in the hippocampus and amygdala of the wallaby, Setonix brachyurus (quokka). Exp Brain Res 1998; 122:301-8. [PMID: 9808303 DOI: 10.1007/s002210050518] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We examined the effects of a single exposure to a temperature elevation of 2 degrees C for a 2 h period on the developmental processes of cell division and cell death in the hippocampus and the amygdala of the quokka. Animals aged postnatal day (P) 4045 were injected with tritiated (3H-) thymidine and then exposed to either 37 degrees C (normal) or 39 degrees C (+/-0.2 degrees C) in an incubator for a duration of 2 h. The young were then returned to the nipple and, after a period of 24 h, were sacrificed. Brains were sectioned and selected sections processed for autoradiography, and some were counterstained. Cell division taking place at the time of heating was estimated by counting 3H-thymidine-labelled cells and at the time of sacrifice by counting mitotic figures. Dying cells were visualised as pyknotic profiles in cresyl-violet-stained sections. In both the amygdala and the hippocampus, the number of 3H-thymidine-labelled cells (cells dividing in situ during the heating period) was significantly lower in the experimental than the control group. Such cells were glia in the amygdala and granule cells and glia in the hippocampus. However, the number of dying cells or mitotic figures (cells dividing at the time of sacrifice) did not differ significantly between the two groups. By comparison, the number of 3H-thymidine-labelled cells, dying cells or mitotic figures did not significantly differ in the diencephalon. Therefore, a brief exposure to a slight elevation in temperature results in an immediate alteration in cell division in the hippocampus and amygdala. These findings have implications for the role played by raised temperature, such as during virus infection, in producing developmental anomalies of the brain.
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Affiliation(s)
- A R Kent
- Department of Psychology, University of Western Australia, Nedlands, Australia
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44
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Simpson K, Shaw D, Nicholas K. Developmentally-regulated expression of a putative protease inhibitor gene in the lactating mammary gland of the tammar wallaby, Macropus eugenii. Comp Biochem Physiol B Biochem Mol Biol 1998; 120:535-41. [PMID: 9787813 DOI: 10.1016/s0305-0491(98)10040-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A novel milk protein, which is secreted only in the early stage of lactation, has been identified in the whey fraction of milk from the tammar wallaby (Macropus eugenii). The amino acid sequence currently available suggests the protein comprises 71 amino acids. The protein migrates at 18 kDa when analysed by SDS polyacrylamide gel electrophoresis but has a calculated molecular weight of 8 kDa. A partial cDNA clone of 153 bp has been isolated by reverse transcriptase PCR. Northern analysis of mammary gland RNA extracted from various stages throughout the entire lactation period showed a messenger RNA transcript of approximately 500 bp present only in the first third of lactation. The protein shares 74.5% similarity at the amino acid level with early lactation protein (ELP) from the brush-tailed possum (Trichosurus vulpecula) and 37% with bovine colostrum trypsin inhibitor, a member of the Kunitz family of protease inhibitors. We hypothesise that the expression of this gene may be controlled by changes in the sucking patterns of the dependent pouch young.
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Affiliation(s)
- K Simpson
- Division of Molecular Biology and Genetics, Victorian Institute of Animal Science, Attwood, Australia
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45
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Abstract
The development of muscle afferents in the tammar wallaby was examined to address whether proprioceptive input contributes to the marked asymmetry of the fore and hindlimb movement. Anatomical tracing with biocytin showed that the muscle afferents had reached the brachial motor horn by postnatal day (P1), but were less advanced in the lumbar region. Labelled cells lying outside the motor horn, presumably filled via gap junctions, were evident in the neonatal lumbar cord. By the 4th postnatal week, the afferent innervation of both brachial and lumbar cords became similar. Afferent discharges from stretching the biceps muscle could be recorded at birth, but not until P4 from the hindlimb gastrocnemius muscle. The discharges were predominantly phasic until P35 when tonic activity could also be recorded. Short latency spinal reflex responses superimposed upon a longer lasting potential were present in the brachial cord at birth, appearing in the lumbar cord at P4. By the 3rd postnatal week, spinal reflex became comparable in both segmental levels. The time course of muscle afferent development was compared to the progression of natural cell death in the lumbar cord. Sensorimotor connections were established towards the end of the rapid phase cell death as observed in other vertebrates.
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Affiliation(s)
- S M Ho
- Developmental Neurobiology, Research School of Biological Sciences, Australian National University, Canberra, Australia.
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46
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Abstract
Development and cell generation in the hippocampus of the marsupial, the quokka wallaby, has been examined. Cells in this brain region are similar in morphology to those in eutherian species, with predominantly pyramidal and granule cells. In the quokka, development of the hippocampus takes place postnatally; this region is first seen just after birth on postnatal day 1 (P1) as an out-pouching of the medial cortical wall into the lateral ventricle. The cornu ammonis (CA) region first appears at P20 as a line of denser cells and by P30, CA3 and the granule cell layer of the dentate gyrus (DG) can be defined. A specific region of the ventricle, near to the developing fimbria, produces the granule cells destined for the dentate gyrus. These cells initially migrate in a curved trajectory into the hilus, following the path of thick, vimentin-positive glial fibres. Cells are generated in the hippocampus from around P5 until at least P85 when some cells in the hilus and also glial cells are labelled with [3H]thymidine. In the cell sparse region around the hippocampal fissure there is a peak of neuron production before P20 followed by a decline and subsequent increase in the production of probably glial cells after P60. The peak of cell generation in the CA region and the granule cell layer of the DG is around P40. Cells continue to be produced in the hilus of the DG much later, with numbers still high at P85, presumably these cells are destined to reach the granule cell layer later in development.
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Affiliation(s)
- A M Harman
- Department of Psychology, University of Western Australia, Nedlands.
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47
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Abstract
We have examined the development of the laminar and areal distribution of cortical commissural neurons in a marsupial mammal, the wallaby Macropus eugenii. In this species, commissural axons approach the major cerebral commissure, the anterior commissure, via either the internal capsule or the external capsule and first cross the midline at postnatal day 14 (P14). By retrogradely labelling these axons with 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine (DiI) at P15, we show here that the cell bodies of these neurons are restricted to a region of cortex adjacent to the rhinal fissure. Most of these labelled neurons are located in the compact cell zone of the cortical plate, with only a few labelled cells found in the zone of loosely packed cells deep to this layer. Over the subsequent 66 days, commissural neurons are found progressively more dorsally, rostrally, and caudally, so that, by P80, they are present throughout the extent of the neocortex. At this age, they are mainly pyramidal in morphology and form a single band within the deeper part of layer 5 of the developing cortex. From P80 to adulthood, the distribution of commissural neurons has been assessed in the visual cortex by using retrograde transport of horseradish peroxidase. At P80, labelled neurons with immature pyramidal morphology are present throughout the occipital cortex; as in DiI material, somata are located in deep layer 5. At P165, previously shown to be the age when commissural axon numbers peak, widespread labelling is present in the occipital region, with labelled cells now found in two bands corresponding to layers 3 and 5. After this age, neurons become more restricted in distribution, so that, by adulthood, commissural neurons are no longer apparent throughout area 17 but are restricted to a localised region around the area 17/18 boundary. Within this region, labelling is still present in layers 3 and 5 but is more dense in layer 3. The gradual restriction of commissural fields seen here in the wallaby is similar to that reported in the neocortex in many eutherians. These findings also support studies in eutheria, suggesting that subplate neurons do not appear to play a major role in commissural development.
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Affiliation(s)
- F Shang
- School of Anatomy, University of New South Wales, Sydney, Australia
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48
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Abstract
The development of trigeminal projections between the thalamus and cortex has been investigated in the marsupial mammal, the wallaby, by using a carbocyanine dye, horseradish peroxidase conjugated to wheat germ agglutinin (WGA-HRP), Neurobiotin, and biocytin as pathway tracers. The appearance of whisker-related patterns in the cortex in relation to their appearance in the brainstem and thalamus was examined, as was the presence or absence of a waiting period for thalamocortical afferents and the identity of the first cortical cells to project to the thalamus. Thalamic afferents first reached the cortex at postnatal day (P) 15 and were distributed up to the deep edge of the compact cell zone in the superficial cortical plate throughout development, in both dye and WGA-HRP labelled material, with no evidence of a waiting period. The initial corticothalamic projection, detected by retrograde transport of WGA-HRP from the thalamus, occurred at P60 from layer 5 cells. This was confirmed by labelling of corticothalamic axons after cortical injections of Neurobiotin and biocytin. Scattered, labelled cells seen before P60 after dye labelling from the thalamus presumably resulted from transcellular labelling via thalamic afferents. Clustering of afferents in layer 4 and cell bodies and their dendrites in layers 5 and 6 first occurred simultaneously at P76. There is a sequential onset of pattern formation, first in brainstem, then in thalamus, and finally in cortex, with a long delay between afferent arrival and pattern formation at each level. Independent regulation at each level, likely depending on target maturation, is suggested.
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Affiliation(s)
- L R Marotte
- Developmental Neurobiology Group, RSBS, Australian National University, Canberra.
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49
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Nicholas K, Simpson K, Wilson M, Trott J, Shaw D. The tammar wallaby: a model to study putative autocrine-induced changes in milk composition. J Mammary Gland Biol Neoplasia 1997; 2:299-310. [PMID: 10882313 DOI: 10.1023/a:1026392623090] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The marsupial newborn is immature and the mother has the capacity to alter milk composition significantly during lactation, presumably to meet the nutritional requirements of the developing young. Furthermore, macropodid marsupials may practice asynchronous concurrent lactation (ACL)7 whereby the mother provides milk which differs in all the major components from adjacent mammary glands for two young of different ages. This phenomenon suggests that local regulation of mammary function, in addition to endocrine stimuli, is likely to be important for controlling milk composition. This paper explores the possibility that changes in sucking patterns of the young represent the first step in a mechanism to signal the mammary gland for putative autocrine-induced changes in milk composition.
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Affiliation(s)
- K Nicholas
- Division of Molecular Biology and Genetics, Victorian Institute of Animal Science, Attwood, Australia.
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50
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Abstract
1. The forelimb motor behaviour of developing wallaby was studied. A clock-like alternating movement was reactivated whenever the animal was removed from the pouch. 2. Forelimb stepping frequency increased during the first 3 weeks of development, while the phase relationship remained constant. Forelimb activity could be affected by altering the afferent feedback from the contralateral limb, or an increase in ambient temperature. 3. In vitro experiments were performed using an isolated brainstem-spinal cord preparation from animals up to 6 weeks postnatal. Fictive locomotor activity could be evoked by electrical stimulation or bath-applied NMDA (< 10 microM). 4. Bath-applied strychnine (10-25 microM) and bicuculline (10-50 microM) disrupted the phase relationship between motor pools, while rhythmic motor discharge remained in the absence of these inhibitory pathways. 5. The present findings indicate that the pattern generator that underlies the robust forelimb movement during the first journey to the pouch is retained for different motor functions during in-pouch development. The neural network that underlies such behaviour can be divided into two major components, a rhythm generator within each hemicord, and a pattern co-ordinating pathway which involve both glycinergic and GABAergic interneurones.
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Affiliation(s)
- S M Ho
- Developmental Neurobiology Group, Research School of Biological Sciences, Australian National University, Canberra, Australia.
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