Involvement of the sonic hedgehog, patched 1 and bmp2 genes in patterning of the zebrafish dermal fin rays

Development ◽  
1998 ◽  
Vol 125 (21) ◽  
pp. 4175-4184 ◽  
Author(s):  
L. Laforest ◽  
C.W. Brown ◽  
G. Poleo ◽  
J. Geraudie ◽  
M. Tada ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Sonic Hedgehog ◽  
Bone Matrix ◽  
Basal Layer ◽  
Pectoral Fin ◽  
Expression Domain ◽  
Fin Regeneration ◽  
Fin Rays ◽  
Dermal Bone ◽  
Fish Fins

The signaling molecule encoded by Sonic hedgehog (shh) participates in the patterning of several embryonic structures including limbs. During early fin development in zebrafish, a subset of cells in the posterior margin of pectoral fin buds express shh. We have shown that regulation of shh in pectoral fin buds is consistent with a role in mediating the activity of a structure analogous to the zone of polarizing activity (ZPA) (Akimenko and Ekker (1995) Dev. Biol. 170, 243–247). During growth of the bony rays of both paired and unpaired fins, and during fin regeneration, there does not seem to be a region equivalent to the ZPA and one would predict that shh would play a different role, if any, during these processes specific to fish fins. We have examined the expression of shh in the developing fins of 4-week old larvae and in regenerating fins of adults. A subset of cells in the basal layer of the epidermis in close proximity to the newly formed dermal bone structures of the fin rays, the lepidotrichia, express shh, and ptc1 which is thought to encode the receptor of the SHH signal. The expression domain of ptc1 is broader than that of shh and adjacent blastemal cells releasing the dermal bone matrix also express ptc1. Further observations indicate that the bmp2 gene, in addition to being expressed in the same cells of the basal layer of the epidermis as shh, is also expressed in a subset of the ptc1-expressing cells of the blastema. Amputations of caudal fins immediately after the first branching point of the lepidotrichia, and global administration of all-trans-retinoic acid, two procedures known to cause fusion of adjacent rays, result in a transient decrease in the expression of shh, ptc1 and bmp2. The effects of retinoic acid on shh expression occur within minutes after the onset of treatment suggesting direct regulation of shh by retinoic acid. These observations suggest a role for shh, ptc1 and bmp2 in patterning of the dermoskeleton of developing and regenerating teleost fins.

scholarly journals Skeletal geometry and niche transitions restore organ size and shape during zebrafish fin regeneration

2019 ◽  
Author(s):  
Scott Stewart ◽  
Gabriel A. Yette ◽  
Heather K. Le Bleu ◽  
Astra L. Henner ◽  
Joshua A. Braunstein ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Positional Information ◽  
State Transitions ◽  
Injury Site ◽  
Fin Regeneration ◽  
Size And Shape ◽  
Fin Rays ◽  
Fish Fins ◽  
Original Size ◽  
Skeletal Geometry

ABSTRACTRegenerating fish fins return to their original size and shape regardless of the nature or extent of injury. Prevailing models for this longstanding mystery of appendage regeneration speculate fin cells maintain uncharacterized positional identities that instruct outgrowth after injury. Using zebrafish, we find differential Wnt production correlates with the extent of regeneration across the caudal fin. We identify Dachshund transcription factors as markers of distal blastema cells that produce Wnt and thereby promote a pro-progenitor and -proliferation environment. We show these Dach-expressing “niche cells” derive from mesenchyme populating cylindrical and progressively tapered fin rays. The niche pool, and consequently Wnt, steadily dissipates as regeneration proceeds; once exhausted, ray and fin growth stops. Supported by mathematical modeling, we show longfint2 zebrafish regenerate exceptionally long fins due to a perdurant niche, representing a “broken countdown timer”. We propose regenerated fin size is dictated by the amount of niche formed upon damage, which simply depends on the availability of intra-ray mesenchyme defined by skeletal girth at the injury site. Likewise, the fin reestablishes a tapered ray skeleton because progenitor osteoblast output reflects diminishing niche size. This “transpositional scaling” model contends mesenchyme-niche state transitions and positional information provided by self-restoring skeletal geometry rather than cell memories determine a regenerated fin’s size and shape.

Transient establishment of anteroposterior polarity in the zebrafish pectoral fin bud in the absence of sonic hedgehog activity

Development ◽  
1999 ◽  
Vol 126 (21) ◽  
pp. 4817-4826 ◽  
Author(s):  
C.J. Neumann ◽  
H. Grandel ◽  
W. Gaffield ◽  
S. Schulte-Merker ◽  
C. Nusslein-Volhard
Keyword(s):  
Retinoic Acid ◽  
Sonic Hedgehog ◽  
Limb Development ◽  
Normal Development ◽  
Limb Bud ◽  
Pectoral Fin ◽  
Anteroposterior Patterning ◽  
Vertebrate Limb ◽  
Anteroposterior Polarity

Sonic hedgehog (Shh) is expressed in the posterior vertebrate limb bud mesenchyme and directs anteroposterior patterning and growth during limb development. Here we report an analysis of the pectoral fin phenotype of zebrafish sonic you mutants, which disrupt the shh gene. We show that Shh is required for the establishment of some aspects of anteroposterior polarity, while other aspects of anteroposterior polarity are established independently of Shh, and only later come to depend on Shh for their maintenance. We also demonstrate that Shh is required for the activation of posterior HoxD genes by retinoic acid. Finally, we show that Shh is required for normal development of the apical ectodermal fold, for growth of the fin bud, and for formation of the fin endoskeleton.

The Expression of Alkaline Phosphatase, Osteopontin, Osteocalcin, and Chondroitin Sulfate during Pectoral Fin Regeneration in Carassius auratus gibelio: A Combined Histochemical and Immunohistochemical Study

2013 ◽  
Vol 19 (1) ◽  
pp. 233-242 ◽  
Author(s):  
Simona Stavri ◽  
Otilia Zarnescu
Keyword(s):  
Alkaline Phosphatase ◽  
Chondroitin Sulfate ◽  
Carassius Auratus ◽  
Matrix Protein ◽  
Type I ◽  
Carassius Auratus Gibelio ◽  
Pectoral Fin ◽  
Fin Regeneration ◽  
Fin Rays ◽  
Inorganic Components

AbstractDermal bone is an important component of the teleost fins, and its ability to regenerate after fin amputation appears to be unlimited. The organic bone matrix contain type I collagen fibers, proteoglycans enriched in chondroitin sulfate, and noncollagenous matrix protein such as osteocalcin, osteopontin, and osteonectin. These molecules are synthesized by fin osteoblasts. Inorganic components chiefly consist of calcium and phosphate that form crystals of hydroxyapatite. Fin rays are described as models to study ossification. Due to this, the identification of the components involved in the synthesis of the organic and inorganic components of lepidotrichial bone are of great interest for the analysis of skeletal disorders in fish ossification. The present study investigates expression of alkaline phosphatase, osteopontin, osteocalcin, and chondroitin sulfate during pectoral fin regeneration in Carassius auratus gibelio. Alkaline phosphatase reaction has been found in the epidermis covering the wound, proximal blastema, near the cells that surround newly-formed lepidotrichia matrix and the tips of regenerating fin rays. Osteopontin has been observed throughout the regeneration blastema but excluded from the scleroblasts lining the inner side of the lepidotrichia. Osteocalcin and chondroitin sulfate expression coincides with the onset of mineralization of lepidotrichial matrix, suggesting its involvement in bone mineralization.

scholarly journals Resurrection of the genus Homalopteroides (Teleostei: Balitoridae) with a redescription of H. modestus (Vinciguerra 1890)

Zootaxa ◽  
2012 ◽  
Vol 3586 (1) ◽  
pp. 329 ◽  
Author(s):  
ZACHARY S. RANDALL ◽  
LAWRENCE M. PAGE
Keyword(s):  
Lateral Line ◽  
Head Length ◽  
Pectoral Fin ◽  
Caudal Fin ◽  
Dorsal Fin ◽  
Interorbital Width ◽  
Fin Rays ◽  
Orbital Rim ◽  
Pectoral Fin Rays ◽  
Pelvic Fin

The genus Homalopteroides Fowler 1905 is resurrected and distinguished from the genus Homaloptera van Hasselt 1823based on a combination of characters including a unique mouth morphology, dorsal-fin origin over pelvic fin,≤60 lateral-line scales, and≤30 predorsal scales. Species included in Homalopteroides are H. wassinkii (Bleeker 1853), H. modestus(Vinciguerra 1890), H. rupicola (Prashad & Mukerji 1929), H. smithi (Hora 1932), H. stephensoni (Hora 1932), H. weberi(Hora 1932), H. tweediei (Herre 1940), H. indochinensis (Silas 1953), H. nebulosus (Alfred 1969), H. yuwonoi (Kottelat1998), and possibly H. manipurensis (Arunkumar 1999). Homalopteroides modestus (Vinciguerra 1890) is a poorlyknown species that was originally described from the Meekalan and Meetan rivers of southern Myanmar. It occurs in theSalween, Mae Khlong, and Tenasserim basins, and can be distinguished from all other species of Homalopteroides by thecombination of caudal-fin pattern (black proximal and distal bars, median blotch), 15 pectoral-fin rays, pectoral-fin lengthgreater than head length, 5½–6½ scales above and 5–6 scales below the lateral line (to the pelvic fin), 39–44 total lateral-line pores, no axillary pelvic-fin lobe, pelvic fin not reaching anus, orbital length less than interorbital width in adult, and maxillary barbel reaching to or slightly past the anterior orbital rim.

Expression of the atrial-specific myosin heavy chain AMHC1 and the establishment of anteroposterior polarity in the developing chicken heart

Development ◽  
1994 ◽  
Vol 120 (4) ◽  
pp. 871-883 ◽  
Author(s):  
K.E. Yutzey ◽  
J.T. Rhee ◽  
D. Bader
Keyword(s):  
Gene Expression ◽  
Retinoic Acid ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Cardiac Myocyte ◽  
Anterior Segment ◽  
Heart Cells ◽  
Heart Tube ◽  
Expression Domain ◽  
Chicken Heart

A unique myosin heavy chain cDNA (AMHC1), which is expressed exclusively in the atria of the developing chicken heart, was isolated and used to study the generation of diversified cardiac myocyte cell lineages. The pattern of AMHC1 gene expression during heart formation was determined by whole-mount in situ hybridization. AMHC1 is first activated in the posterior segment of the heart when these myocytes initially differentiate (Hamburger and Hamilton stage 9+). The anterior segment of the heart at this stage does not express AMHC1 although the ventricular myosin heavy chain isoform is strongly expressed beginning at stage 8+. Throughout chicken development, AMHC1 continues to be expressed in the posterior heart tube as it develops into the diversified atria. The early activation of AMHC1 expression in the posterior cardiac myocytes suggests that the heart cells are diversified when they differentiate initially and that the anterior heart progenitors differ from the posterior heart progenitors in their myosin isoform gene expression. The expression domain of AMHC1 can be expanded anteriorly within the heart tube by treating embryos with retinoic acid as the heart primordia fuse. Embryos treated with retinoic acid prior to the initiation of fusion of the heart primordia express AMHC1 throughout the entire heart-forming region and fusion of the heart primordia is inhibited. These data indicate that retinoic acid treatment produces an expansion of the posterior (atrial) domain of the heart and suggests that diversified fates of cardiomyogenic progenitors can be altered.

Ituglanis compactus, a new species of catfish (Siluriformes: Trichomycteridae) from the rio Jari drainage, lower Amazon, Brazil 

Zootaxa ◽  
2017 ◽  
Vol 4244 (2) ◽  
pp. 207 ◽  
Author(s):  
ÍTHALO DA SILVA CASTRO ◽  
WOLMAR BENJAMIN WOSIACKI
Keyword(s):  
New Species ◽  
Body Size ◽  
Head Length ◽  
New Taxon ◽  
Pectoral Fin ◽  
Reduced Body ◽  
Weberian Apparatus ◽  
Fin Rays ◽  
A New Species ◽  
Pectoral Fin Rays

A new species of Ituglanis is described from rio Iratapuru, near the rio Jari, Amapá, Brazil. The new species is distinguished from all congeners by the reduced number of post-Weberian apparatus vertebrae (36 or 37); the low number of paired ribs (2); the low number of interopercular odontodes (12–15); the number of branchiostegal rays (7 or 8); the presence of elongated fontanel in parieto-supraoccipital; the pectoral-fin rays (i,5); head length (18.9–25.0); and the presence of pores supraorbital s1, infraorbitals i1 and i3 of the laterosensory system. The new taxon has a reduced body size and fully ossified skeleton, but does not display a large number of paedomorphic traits compared to congeners. Comments about taxonomy and intrageneric comparisons are made, and paedomorphic in Ituglanis is discussed. Thoughts about conservation of the new species are presented. 

VIII.—On the Pectoral Fin of Cœlacanthus

1901 ◽  
Vol 8 (2) ◽  
pp. 71-72 ◽  
Author(s):  
Edgar D. Wellburn
Keyword(s):  
New South ◽  
New South Wales ◽  
Geological Survey ◽  
Pectoral Fin ◽  
Anterior Border ◽  
Pectoral Fins ◽  
Anterior Half ◽  
South Wales ◽  
Fin Rays ◽  
Distal Border

Among the fossil fishes of the Talbragar Beds (Jurassic?) described by Dr. A. Smith Woodward in a memoir of the Geological Survey of New South Wales (1895), there is the ventral portion of the abdominal region of a Cœlacanth fish, having one of the pectoral fins well shown. The fin is shown in counterpart, and is thus described:— “It exhibits, as usual, the characteristic obtuse lobation and the large fringe of articulated attenuated dermal rays, and is unique in displaying some of the eudoskeletal supporting bones. These elements seem to have been well ossified, though with persistent cartilage internally. At the base of the fin there occurs a broken fragment of bone1 incapable of determination; but in the lobe of the fin itself there is a series of four well-defined, hourglass-shaped supports. Of these bones the anterior three are much elongated, and nearly equally slender, while the fourth is much more robust and expanded at its distal end. The four elements radiate from the anterior half of the base of the fin; and it seems very probable that some smaller cartilage behind and near the distal border of the lobe have disappeared from lack of ossification. The fin-rays gradually increase in length from the anterior border to the middle of the lobe, whence they decrease again backwards, and finally become extremely delicate.”

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