scholarly journals nkx3.2 mutant zebrafish accommodate jaw joint loss through a phenocopy of the head shapes of Paleozoic jawless fish

2020 ◽  
Vol 223 (15) ◽  
pp. jeb216945 ◽  
Author(s):  
Tetsuto Miyashita ◽  
Pranidhi Baddam ◽  
Joanna Smeeton ◽  
A. Phil Oel ◽  
Natasha Natarajan ◽  
...  
Keyword(s):  
Jaw Joint ◽  
Jawless Fish

scholarly journals nkx3.2 mutant zebrafish accommodate jaw joint loss through a phenocopy of the head shapes of Paleozoic jawless fish

2019 ◽  
Author(s):  
Tetsuto Miyashita ◽  
Pranidhi Baddam ◽  
Joanna Smeeton ◽  
Adam Phillip Oel ◽  
Natasha Natarajan ◽  
...  
Keyword(s):  
Marker Gene ◽  
Null Alleles ◽  
Ancestral State ◽  
Feeding Behaviors ◽  
Lower Jaw ◽  
Unique Model ◽  
Jaw Joint ◽  
Joint Ankylosis ◽  
Jawless Fish ◽  
Branchial Region

The vertebrate jaw is a versatile feeding apparatus that facilitated explosive diversification. To function, it requires a joint between the upper and lower jaws, so jaw joint defects - such as osteoarthritis or even ankylosis - are often highly disruptive and difficult to study. To describe consequences of jaw-joint dysfunction, we engineered two independent null alleles of a single jaw-joint marker gene, nkx3.2, in zebrafish. These mutations caused zebrafish to become functionally jawless via fusion of the upper and lower jaw cartilages (ankylosis). Despite lacking jaw joints, nkx3.2 mutants survive to adulthood and accommodate this defect by: a) remodeling their skulls; and b) altering their behavior from suction feeding to ram feeding. As a result of remodeling, nkx3.2 mutants developed superficial similarities to the skull shapes observed in two lineages of ancient jawless vertebrates (anaspids and furcacaudiid thelodonts), including: a fixed open gape, reduced snout, and enlarged branchial region. However, no homology exists in individual skull elements between these taxa, and most of the modified elements in the mutant zebrafish occur outside known expression domains of nkx3.2. Therefore, we interpret the adult nkx3.2 phenotype not as a reversal to an ancestral state, but as convergence due to similar functional requirement of feeding without moveable jaws. This remarkable convergence strongly suggests that jaw movements themselves dramatically influence the development of jawed vertebrate skulls, which implies that functionally viable skull morphologies are finite, with or without functional jaws. Because nkx3.2 null zebrafish display prominent joint ankylosis, drastically modified skull shape, and altered feeding behaviors, these mutants provide a unique model with which to investigate mechanisms of skeletal remodeling and joint diseases.

Adaptation of DICOM 3.0 to jaw joint movement images

2000 ◽  
Author(s):  
Tohru Negishi ◽  
Tsuguhisa Katoh ◽  
Masahiro Fukushi ◽  
Atsushi Senoo ◽  
Yukihiro Nomura ◽  
...  
Keyword(s):  
Joint Movement ◽  
Jaw Joint

Contracture of the jaw joint, formed during severe angina and associated peritonsillar abscess

1930 ◽  
Vol 26 (9) ◽  
pp. 940-940
Author(s):  
B. Goland
Keyword(s):  
Underlying Disease ◽  
Severe Form ◽  
Peritonsillar Abscess ◽  
Jaw Joint

Abstracts. Otorhinolaryngology. Forschner (M. med. Woch., 1929, No. 48) describes the contracture of the jaw joint, formed during a severe form of angina and associated peritonsillar abscess. Despite the fact that all the phenomena of the underlying disease had passed and the patient felt well, the contracture of the jaw joint remained and did not respond to any ordinary treatment.

scholarly journals CTCF binding landscape in jawless fish with reference to Hox cluster evolution

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Mitsutaka Kadota ◽  
Yuichiro Hara ◽  
Kaori Tanaka ◽  
Wataru Takagi ◽  
Chiharu Tanegashima ◽  
...  
Keyword(s):  
Ctcf Binding ◽  
Hox Cluster ◽  
Cluster Evolution ◽  
Jawless Fish ◽  
Hox Cluster Evolution

scholarly journals Mammalian development does not recapitulate suspected key transformations in the evolution of the mammalian middle ear

2015 ◽  
Author(s):  
Héctor Ramirez-Chaves ◽  
Stephen Wroe ◽  
Lynne Selwood ◽  
Lyn Hinds ◽  
Chris Leigh ◽  
...  
Keyword(s):  
Middle Ear ◽  
Mammalian Development ◽  
Positional Change ◽  
Lower Jaw ◽  
Dental Eruption ◽  
Mesozoic Mammals ◽  
Differential Positioning ◽  
Jaw Joint ◽  
Early Mammalian Development ◽  
Land Vertebrates

The tympanic ring, malleus and incus of the mammalian middle ear (MME) derive from the ancestral primary jaw joint of land vertebrates. In Mesozoic mammals, evolutionary detachment of the MME from the lower jaw occurred when Meckel’s cartilage - the last connection between MME and dentary – disappeared. This disappearance is famously recapitulated in early mammalian development. Further developmental recapitulation of Mesozoic MME detachment is thought to occur in the form of negative allometry and posterior/medial replacement of MME bones relative to the jaw joint. However, despite being widely accepted, such detailed recapitulation scenarios have never been quantified. Here we show, based on µCT scans of developmental series of several marsupials and monotremes, that negative allometry of MME bones relative to the skull occurs only after MME detachment, ruling it out as a developmental detachment trigger; additionally, there is no positional change of ectotympanic or malleus relative to the dentary. Differential positioning of MME bones in the two monotreme species is also not developmentally recapitulated. Our results challenge the developmental prerequisites of widely accepted evolutionary scenarios regarding MME detachment. Rather, we observe an association of MME detachment and dental eruption, suggesting a detachment trigger relating to the onset of dentary function.

scholarly journals Fatty-acid derivative acts as a sea lamprey migratory pheromone

2018 ◽  
Vol 115 (34) ◽  
pp. 8603-8608 ◽  
Author(s):  
Ke Li ◽  
Cory O. Brant ◽  
Mar Huertas ◽  
Edward J. Hessler ◽  
Gellert Mezei ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Derivative ◽  
Sea Lamprey ◽  
Olfactory Cues ◽  
Anadromous Fish ◽  
Large Space ◽  
X Ray Crystallography ◽  
Migratory Pheromone ◽  
Sea Lampreys ◽  
Jawless Fish

Olfactory cues provide critical information for spatial orientation of fish, especially in the context of anadromous migrations. Born in freshwater, juveniles of anadromous fish descend to the ocean where they grow into adults before migrating back into freshwater to spawn. The reproductive migrants, therefore, are under selective pressures to locate streams optimal for offspring survival. Many anadromous fish use olfactory cues to orient toward suitable streams. However, no behaviorally active compounds have been identified as migratory cues. Extensive studies have shown that the migratory adult sea lampreys (Petromyzon marinus), a jawless fish, track a pheromone emitted by their stream-dwelling larvae, and, consequently, enter streams with abundant larvae. We fractionated extracts of larval sea lamprey washings with guidance from a bioassay that measures in-stream migratory behaviors of adults and identified four dihydroxylated tetrahydrofuran fatty acids, of which (+)-(2S,3S,5R)-tetrahydro-3-hydroxy-5-[(1R)-1-hydroxyhexyl]-2-furanoctanoic acid was shown as a migratory pheromone. The chemical structure was elucidated by spectroscopies and confirmed by chemical synthesis and X-ray crystallography. The four fatty acids were isomer-specific and enantiomer-specific in their olfactory and behavioral activities. A synthetic copy of the identified pheromone was a potent stimulant of the adult olfactory epithelium, and, at 5 × 10−13 M, replicated the extracts of larval washings in biasing adults into a tributary stream. Our results reveal a pheromone that bridges two distinct life stages and guides orientation over a large space that spans two different habitats. The identified molecule may be useful for control of the sea lamprey.

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