scholarly journals Insertion Hot Spots of DIRS1 Retrotransposon and Chromosomal Diversifications among the Antarctic Teleosts Nototheniidae

2019 ◽  
Vol 20 (3) ◽  
pp. 701 ◽  
Author(s):  
Juliette Auvinet ◽  
Paula Graça ◽  
Laura Ghigliotti ◽  
Eva Pisano ◽  
Agnès Dettaï ◽  
...  
Keyword(s):  
Hot Spots ◽  
Chromosomal Rearrangements ◽  
Antarctic Fish ◽  
Wide Distribution ◽  
Suitable Model ◽  
Fish Family ◽  
The Antarctic ◽  
Antarctic Teleosts

By their faculty to transpose, transposable elements are known to play a key role in eukaryote genomes, impacting both their structuration and remodeling. Their integration in targeted sites may lead to recombination mechanisms involved in chromosomal rearrangements. The Antarctic fish family Nototheniidae went through several waves of species radiations. It is a suitable model to study transposable element (TE)-mediated mechanisms associated to genome and chromosomal diversifications. After the characterization of Gypsy (GyNoto), Copia (CoNoto), and DIRS1 (YNoto) retrotransposons in the genomes of Nototheniidae (diversity, distribution, conservation), we focused on their chromosome location with an emphasis on the three identified nototheniid radiations (the Trematomus, the plunderfishes, and the icefishes). The strong intrafamily TE conservation and wide distribution across species of the whole family suggest an ancestral acquisition with potential secondary losses in some lineages. GyNoto and CoNoto (including Hydra and GalEa clades) mostly produced interspersed signals along chromosomal arms. On the contrary, insertion hot spots accumulating in localized regions (mainly next to centromeric and pericentromeric regions) highlighted the potential role of YNoto in chromosomal diversifications as facilitator of the fusions which occurred in many nototheniid lineages, but not of the fissions.

scholarly journals Evolution in the cold

2000 ◽  
Vol 12 (3) ◽  
pp. 257-257 ◽  
Author(s):  
Andrew Clarke
Keyword(s):  
Evolutionary Biology ◽  
Antarctic Fish ◽  
The Arctic ◽  
Polar Regions ◽  
Evolutionary Studies ◽  
Adaptive Radiations ◽  
The Antarctic ◽  
The Impact ◽  
Insight Into

Theodosius Dobzhansky once remarked that nothing in biology makes sense other than in the light of evolution, thereby emphasising the central role of evolutionary studies in providing the theoretical context for all of biology. It is perhaps surprising then that evolutionary biology has played such a small role to date in Antarctic science. This is particularly so when it is recognised that the polar regions provide us with an unrivalled laboratory within which to undertake evolutionary studies. The Antarctic exhibits one of the classic examples of a resistance adaptation (antifreeze peptides and glycopeptides, first described from Antarctic fish), and provides textbook examples of adaptive radiations (for example amphipod crustaceans and notothenioid fish). The land is still largely in the grip of major glaciation, and the once rich terrestrial floras and faunas of Cenozoic Gondwana are now highly depauperate and confined to relatively small patches of habitat, often extremely isolated from other such patches. Unlike the Arctic, where organisms are returning to newly deglaciated land from refugia on the continental landmasses to the south, recolonization of Antarctica has had to take place by the dispersal of propagules over vast distances. Antarctica thus offers an insight into the evolutionary responses of terrestrial floras and faunas to extreme climatic change unrivalled in the world. The sea forms a strong contrast to the land in that here the impact of climate appears to have been less severe, at least in as much as few elements of the fauna show convincing signs of having been completely eradicated.

Chromosome-wide distribution of haplotype blocks and the role of recombination hot spots

2003 ◽  
Vol 33 (3) ◽  
pp. 382-387 ◽  
Author(s):  
M.S. Phillips ◽  
R. Lawrence ◽  
R. Sachidanandam ◽  
A.P. Morris ◽  
D.J. Balding ◽  
...  
Keyword(s):  
Hot Spots ◽  
Wide Distribution ◽  
Haplotype Blocks ◽  
Recombination Hot Spots

scholarly journals The role of iceberg scours in niche separation within the Antarctic fish genus Trematomus

Polar Biology ◽  
2001 ◽  
Vol 24 (7) ◽  
pp. 502-507 ◽  
Author(s):  
Brenner M. ◽  
Buck B. ◽  
Cordes S. ◽  
Dietrich L. ◽  
Jacob U. ◽  
...  
Keyword(s):  
Antarctic Fish ◽  
Niche Separation ◽  
The Antarctic

scholarly journals Characterization of Four Liver-Expressed Antimicrobial Peptides from Antarctic Fish and Their Antibacterial Activity

2019 ◽  
Vol 9 (20) ◽  
pp. 4299 ◽  
Author(s):  
Shweta Borkar ◽  
Sondavid Nandanwar ◽  
Jun Lee ◽  
Hak Kim
Keyword(s):  
Antibacterial Activity ◽  
Antimicrobial Peptides ◽  
Antarctic Fish ◽  
Effect Of Temperature ◽  
Dissostichus Mawsoni ◽  
Sytox Green ◽  
Uptake Assay ◽  
The Antarctic ◽  
Β Sheet

Liver-expressed antimicrobial peptides (LEAPs) are cysteine-containing cationic peptides. LEAP-1 and LEAP-2 are eight- and four-cysteine containing antimicrobial peptides found in animals, respectively. LEAP-1 is widely known as antibacterial peptide involved in the innate immunity of fish, but the roles of LEAP-1 and LEAP-2 in Antarctic fish species are unknown. In the present study, we synthesized and characterized novel LEAPs with four and eight cysteine residues, derived from Antarctic notothenioid (Dissostichus mawsoni) and Antarctic eelpout (Lycodichthys dearborni). Circular dichroism spectroscopy of these peptides showed a typical β-sheet conformation. The LEAPs were found to be bactericidal against gram-positive as well as gram-negative bacteria. In the SYTOX green uptake assay, LEAPs did not trigger any significant increase in fluorescence. However, LEAPs competitively bound to DNA and replaced the ethidium bromide (EB) dye. To determine the effect of temperature on the activity of LEAPs, we evaluated the antibacterial activity against Listeria monocytogenes at 5, 15, 25, and 35 °C. The results showed that the antibacterial activity of LEAPs increased with a decrease in temperature, which may indicate that the Antarctic fish LEAP are evolutionarily adapted. Taken together, our results suggest that novel Antarctic LEAPs are bactericidal peptides with the likely mode of action being DNA binding and may be evolved to adapt to cold temperature.

Molecular adaptation of the blood of Antarctic teleosts to environmental conditions

1989 ◽  
Vol 1 (2) ◽  
pp. 119-124 ◽  
Author(s):  
Guido Di Prisco ◽  
Rossana D'Avino
Keyword(s):  
Haemoglobin Concentration ◽  
Oxygen Binding ◽  
Root Effect ◽  
Physiological Relevance ◽  
Antarctic Convergence ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
The Antarctic ◽  
The Relationship ◽  
Antarctic Teleosts

Following the break-up of Gondwana, the drift of Antarctica to its present position and the establishment of the Antarctic Convergence, fish evolution was characterized by adaptation to progressive cooling of the environment. The decrease of erythrocyte number and haemoglobin concentration in the blood of Antarctic teleosts raises several questions concerning the physiology of respiration and the enzymatic role of erythrocytes. Our study of the molecular basis of cold adaptation includes the relationship between molecular structure and biological function of haemoglobins. Species of the suborder Notothenioidei, largely confined within the Convergence, have only one major haemoglobin, which displays the Root effect in oxygen binding; on the other hand, Zoarcidae (a family found at all latitudes) have four or five haemoglobins, only one of which displays the Root effect. In addition, our data indicate that the physiological relevance of erythrocyte-like cells, present in very small number in the blood of haemoglobinless Channichthyidae, may be linked to higher content of enzymes, such as glucose-6-phosphate dehydrogenase, in comparison with erythrocytes of red-blooded fishes.

The role of icebeg scours in niche separation within the Antarctic fish genus Trematomus

2002 ◽  
pp. 215-220
Author(s):  
M. Brenner ◽  
B. H. Buck ◽  
S. Cordes ◽  
L. Dietrich ◽  
U. Jacob ◽  
...  
Keyword(s):  
Antarctic Fish ◽  
Niche Separation ◽  
The Antarctic

Characterization of the cytoplasmic chaperonin containing TCP-1 from the Antarctic fish Notothenia coriiceps

Extremophiles ◽  
2006 ◽  
Vol 10 (6) ◽  
pp. 537-549 ◽  
Author(s):  
Sandra Pucciarelli ◽  
Sandra K. Parker ◽  
H. William Detrich ◽  
Ronald Melki
Keyword(s):  
Antarctic Fish ◽  
Notothenia Coriiceps ◽  
The Antarctic

scholarly journals Molecular and functional characterization of the mouse intracardiac nervous system

2021 ◽  
Author(s):  
Guenaelle Lizot ◽  
Come Pasqualin ◽  
Audrey Tissot ◽  
Stephane Pages ◽  
Aurelien Chatelier
Keyword(s):  
Nervous System ◽  
Cardiac Arrhythmias ◽  
Suitable Model ◽  
Patch Clamp Technique ◽  
Pharmacological Characterization ◽  
Cart Peptide ◽  
Intracardiac Nervous System ◽  
Intracardiac Neurons

Background: The intracardiac nervous system (ICNS) refers to clusters of neurons, located within the heart, that participate to the neuronal regulation of cardiac functions and are involved in the initiation of cardiac arrhythmias. Therefore, deciphering the role of the ICNS in cardiac physiology and physiopathology is mandatory. Whereas transgenic mouse models represent powerful tools to reach this goal, the mouse ICNS is still poorly characterized. Objective: The objective of the present study was to provide a phenotypic, electrophysiological and pharmacological characterization of the mouse ICNS. Methods: Global cardiac innervation and phenotypic diversity was investigated by performing immunohistochemistry on cleared murine heart and on tissue sections. Patch clamp technique was used for electrophysiological and pharmacological characterization of isolated mouse intracardiac neurons. Results: We identified the expression of 7 distinct neuronal markers within mouse intracardiac neurons demonstrating the neurochemical diversity of this network. Of note, we described for the first time in mouse, the existence of neuron expressing the calcium binding protein calbindin, the neuropeptide Y (NPY) and the cocain and amphetamine regulated transcript (CART) peptide. Electrophysiological studies also revealed the existence of two different neuronal population based on their electrical behavior. Finally, we demonstrated that these neurons can be modulated by several neuromodulators. Conclusion: This study demonstrated that mouse ICNS shares similar molecular and functional complexity to that of other species and therefore is a suitable model to decipher the role of individual neuronal subtypes in the modulation of cardiac function and in the initiation of cardiac arrhythmias.

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