Segmentation pattern of zebrafish caudal fin is affected by developmental temperature and defined by multiple fusions between segments. Issue 6 (29th August 2018)

• Record Type: Journal Article
• Authors: Christou, Maria; Iliopoulou, Maria; Witten, Paul Eckhard; Koumoundouros, George
• Is Part Of: Journal of experimental zoology. Volume 330:Issue 6/7(2018)
• Page Start: 330
• Page End: 340
• Publication Date: 2018-08-29
• Subjects: joints -- lepidotrichia -- phenotypic plasticity -- segments -- teleosts; Developmental biology -- Periodicals; Evolution (Biology) -- Periodicals; Molecular evolution -- Periodicals; Zoology -- Periodicals; Evolution, Molecular -- Periodicals; Developmental Biology -- Periodicals; Zoology -- Periodicals; 591
• DOI: 10.1002/jez.b.22825
• Languages: English
• ISSNs: 1552-5007

Abstract

Abstract: Caudal‐fin lepidotrichia is composed of numerous segments, which are linked to each other by intersegmental joints. During fish growth, lepidotrichia elongate by the addition of new segments at their distal margin, whereas the length of each segment remains constant after it is formed. In the present paper, we examined whether the water temperature affects the segmentation pattern of the juvenile and adult caudal fin. For this purpose, zebrafish ( Danio rerio ) embryos and larvae were exposed to three different temperature conditions (24°C, 28°C, and 32°C) from the pharyngula stage (1 day postfertilization [dpf]) to metamorphosis, whereas the control temperature (28°C) was applied to all the groups before and after this period. Results demonstrated that water temperature had a significant effect on the length of the segments of each lepidotrichium, at both the juvenile and adult stages. Moreover, at higher temperatures, there was a significant proximal shift of the position of the first bifurcation of the second lepidotrichium of the dorsal lobe. At all the experimental conditions, the length of proximal segment was not constant during fish growth, but it followed a discontinuous saltatory growth. Histological analysis of the proximal lepidotrichia segments revealed that the observed apparent growth of segments is the result of fusions between segments. Fusion occurs not by mineralization of the intersegmental joints, but by bone deposition around the joints. Abstract : We examined the effects of water temperature on the phenotypic plasticity of zebrafish caudal fin. We find that the temperature which is experienced by the fish during the embryonic and larval stages has a significant effect on the length of the segments composing each lepidotrichium, as well as on the position of the bifurcations on the lepidotrichia. Our findings on the growth pattern of lepidotrichia show that it is characterized by fusions between the proximal adjacent segments, as well as, between the segments of the sister rays at the origin of bifurcation.