Seahorse brood pouch morphology and control of male parturition in Hippocampus abdominalis.

Autor: Dudley JS; The University of Sydney, School of Life and Environmental Sciences, Heydon-Laurence Building (A08), Sydney, NSW, 2006, Australia., Paul JW; School of Medicine and Public Health, College of Health, Medicine and Wellbeing, University of Newcastle, Callaghan, NSW, 2308, Australia; Hunter Medical Research Institute, 1 Kookaburra Circuit, New Lambton Heights, NSW, 2305, Australia., Teh V; The University of Sydney, School of Life and Environmental Sciences, Heydon-Laurence Building (A08), Sydney, NSW, 2006, Australia., Mackenzie TE; The University of Sydney, School of Life and Environmental Sciences, Heydon-Laurence Building (A08), Sydney, NSW, 2006, Australia., Butler TA; School of Medicine and Public Health, College of Health, Medicine and Wellbeing, University of Newcastle, Callaghan, NSW, 2308, Australia; Hunter Medical Research Institute, 1 Kookaburra Circuit, New Lambton Heights, NSW, 2305, Australia., Tolosa JM; School of Medicine and Public Health, College of Health, Medicine and Wellbeing, University of Newcastle, Callaghan, NSW, 2308, Australia; Hunter Medical Research Institute, 1 Kookaburra Circuit, New Lambton Heights, NSW, 2305, Australia., Smith R; School of Medicine and Public Health, College of Health, Medicine and Wellbeing, University of Newcastle, Callaghan, NSW, 2308, Australia; Hunter Medical Research Institute, 1 Kookaburra Circuit, New Lambton Heights, NSW, 2305, Australia., Foley M; Sydney Microscopy & Microanalysis, The University of Sydney, NSW, 2006, Australia., Dowland S; The University of Sydney, School of Medical Sciences, Sydney, New South Wales, Australia., Thompson MB; The University of Sydney, School of Life and Environmental Sciences, Heydon-Laurence Building (A08), Sydney, NSW, 2006, Australia., Whittington CM; The University of Sydney, School of Life and Environmental Sciences, Heydon-Laurence Building (A08), Sydney, NSW, 2006, Australia. Electronic address: camilla.whittington@sydney.edu.au.
Jazyk: angličtina
Zdroj: Placenta [Placenta] 2022 Sep; Vol. 127, pp. 88-94. Date of Electronic Publication: 2022 Aug 06.
DOI: 10.1016/j.placenta.2022.07.015
Abstrakt: Introduction: Syngnathids (seahorses, pipefishes and seadragons) are among the few vertebrates that display male pregnancy. During seahorse pregnancy, males incubate developing embryos embedded in a placenta within a fleshy brood pouch, before expelling fully developed neonates at parturition. The mechanisms underpinning seahorse parturition are poorly understood.
Methods: We examined the morphology of the brood pouch using microcomputed tomography and histological techniques, in combination with physiological assays, to examine how male pot-bellied seahorses (Hippocampus abdominalis) control labour. In female-pregnant vertebrates, nonapeptide hormones (such as vasopressin- and oxytocin-like hormones) produce contractions of gestational smooth muscle to produce labour.
Results: Histological analysis of the seahorse brood pouch reveals only scattered small smooth muscle bundles in the brood pouch, and in-vitro application of isotocin (a teleost nonapeptide hormone) to the brood pouch do not produce measurable muscle contractions. Micro-computed tomography shows differences in size and orientation of the anal fin assembly between male and female pot-bellied seahorses, and histological analysis reveals large skeletal muscle bundles attached to the anal fin bones at the male brood pouch opening.
Discussion: We conclude that seahorse parturition may be facilitated by contraction of these muscles, which, in combination with body movements, serves to gape open the pouch and expel the neonates. Future biomechanical studies are needed to test this hypothesis.
(Copyright © 2022 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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