scholarly journals Current Understanding on Tail Regeneration in Green Anoles (Anolis carolinensis)

2016 ◽  
Author(s):  
Zulkar Nain ◽  
Md Ariful Islam ◽  
Sadrul Hasan Chowdhury ◽  
Sadia Afroza
Keyword(s):  
Medical Science ◽  
Model Organism ◽  
Anolis Carolinensis ◽  
Current Understanding ◽  
Tail Regeneration ◽  
Tail Autotomy ◽  
Vital Functions ◽  
Evolutionarily Conserved ◽  
Genetic Level ◽  
Regeneration Study

Regeneration of lost tail is of great importance to lizards. Anolis carolinensis, a green lizard, is capable of regenerating its tail efficiently after autotomy. Hence, it is considered as a model organism in regeneration study. A. carolinensis shed its tail in order to distract the predator’s attention and thus makes a way to escape. Restoring of the amputated tail takes several days and the mechanism is currently clearly understood. Although save its life, tail regeneration is associated with the impairment of several vital functions in Anoles. In addition, various differences have been observed between original and regenerated tail in terms of mechanism and structure. To date, very little work has been conducted on tail autotomy and regeneration at molecular and genetic level. The genes responsible for regeneration in anoles are identified recently. These genes are evolutionarily conserved through all tetrapod vertebrates. They are, however, in a state of ‘switched-off’ in other vertebrates including humans. Consequently, a throughout study of these so called ‘switched-off’ genes may provide a way of restoring lost organs in human, and thus could revolutionize the modern medical science.

Another potential cost of tail autotomy: tail loss may result in high ectoparasite loads in Sceloporus lizards

2018 ◽  
Vol 39 (2) ◽  
pp. 191-202 ◽  
Author(s):  
Víctor Argaez ◽  
Israel Solano-Zavaleta ◽  
J. Jaime Zúñiga-Vega
Keyword(s):  
Body Condition ◽  
Rainy Season ◽  
Lizard Species ◽  
Potential Cost ◽  
Tail Regeneration ◽  
Tail Loss ◽  
Tail Autotomy ◽  
Vital Functions ◽  
Trade Offs ◽  
Ectoparasite Load

Abstract Tail autotomy is a common phenomenon in lizards that increases the chances of immediate survival during a predation event or agonistic encounter. However, despite short-term benefits, tail regeneration may also impose costs. Several studies have demonstrated that tail loss compromises other vital functions such as lipid storage, reproduction, and the immune system. Several lizard species are hosts of mites and ticks. Here we evaluated in three lizard species from the genus Sceloporus, whether individuals that have lost their tails and invested energy in tail regeneration are more susceptible to ectoparasites. Using a multimodel inference framework, we examined if tail loss and regeneration, as well as sex, body condition, and season (dry or rainy) predict ectoparasite load. Our results indicate that investing energy and resources in tail regeneration compromises defence against ectoparasites. These costs differed between sexes and among species. Overall, ectoparasite load increases during the rainy season and is on average higher in males. In S. grammicus, during the rainy season, males with regenerated tails and in poor body condition had more ectoparasites than males with intact tails in good body condition. In S. megalepidurus, we observed the same effect during the rainy season but in females rather than males. In S. torquatus, we found no effect of tail loss on ectoparasite load. We discuss the possibility that differences observed among species reflect differences in both species-specific physiological trade-offs and local environmental conditions.

Synchronizing the Neurospora crassa circadian clock with the rhythmic environment

2005 ◽  
Vol 33 (5) ◽  
pp. 949-952 ◽  
Author(s):  
N. Price-Lloyd ◽  
M. Elvin ◽  
C. Heintzen
Keyword(s):  
Light Intensity ◽  
Circadian Clock ◽  
Neurospora Crassa ◽  
Model Organism ◽  
Circadian Clocks ◽  
Current Understanding ◽  
Signalling Pathways ◽  
Selection Pressures ◽  
The Earth ◽  
Natural Cycles

The metronomic predictability of the environment has elicited strong selection pressures for the evolution of endogenous circadian clocks. Circadian clocks drive molecular and behavioural rhythms that approximate the 24 h periodicity of our environment. Found almost ubiquitously among phyla, circadian clocks allow preadaptation to rhythms concomitant with the natural cycles of the Earth. Cycles in light intensity and temperature for example act as important cues that couple circadian clocks to the environment via a process called entrainment. This review summarizes our current understanding of the general and molecular principles of entrainment in the model organism Neurospora crassa, a simple eukaryote that has one of the best-studied circadian systems and light-signalling pathways.

scholarly journals An Evolutionarily Conserved Pathway Essential for Orsay Virus Infection of Caenorhabditis elegans

mBio ◽  
2017 ◽  
Vol 8 (5) ◽  
Author(s):  
Hongbing Jiang ◽  
Kevin Chen ◽  
Luis E. Sandoval ◽  
Christian Leung ◽  
David Wang
Keyword(s):  
Caenorhabditis Elegans ◽  
Virus Infection ◽  
Tyrosine Kinase ◽  
Model Organism ◽  
Wiskott Aldrich Syndrome ◽  
C Elegans ◽  
Evolutionarily Conserved ◽  
Conserved Genes ◽  
Orsay Virus ◽  
Syndrome Protein

ABSTRACT Many fundamental biological discoveries have been made in Caenorhabditis elegans. The discovery of Orsay virus has enabled studies of host-virus interactions in this model organism. To identify host factors critical for Orsay virus infection, we designed a forward genetic screen that utilizes a virally induced green fluorescent protein (GFP) reporter. Following chemical mutagenesis, two Viro (virus induced reporter off) mutants that failed to express GFP were mapped to sid-3, a nonreceptor tyrosine kinase, and B0280.13 (renamed viro-2), an ortholog of human Wiskott-Aldrich syndrome protein (WASP). Both mutants yielded Orsay virus RNA levels comparable to that of the residual input virus, suggesting that they are not permissive for Orsay virus replication. In addition, we demonstrated that both genes affect an early prereplication stage of Orsay virus infection. Furthermore, it is known that the human ortholog of SID-3, activated CDC42-associated kinase (ACK1/TNK2), is capable of phosphorylating human WASP, suggesting that VIRO-2 may be a substrate for SID-3 in C. elegans. A targeted RNA interference (RNAi) knockdown screen further identified the C. elegans gene nck-1, which has a human ortholog that interacts with TNK2 and WASP, as required for Orsay virus infection. Thus, genetic screening in C. elegans identified critical roles in virus infection for evolutionarily conserved genes in a known human pathway. IMPORTANCE Orsay virus is the only known virus capable of naturally infecting the model organism Caenorhabditis elegans, which shares many evolutionarily conserved genes with humans. We exploited the robust genetic tractability of C. elegans to identify three host genes, sid-3, viro-2, and nck-1, which are essential for Orsay virus infection. Mutant animals that lack these three genes are highly defective in viral replication. Strikingly, the human orthologs of these three genes, activated CDC42-associated kinase (TNK2), Wiskott-Aldrich syndrome protein (WASP), and noncatalytic region of tyrosine kinase adaptor protein 1 (NCK1) are part of a known signaling pathway in mammals. These results suggest that TNK2, WASP, and NCK1 may play important roles in mammalian virus infection. IMPORTANCE Orsay virus is the only known virus capable of naturally infecting the model organism Caenorhabditis elegans, which shares many evolutionarily conserved genes with humans. We exploited the robust genetic tractability of C. elegans to identify three host genes, sid-3, viro-2, and nck-1, which are essential for Orsay virus infection. Mutant animals that lack these three genes are highly defective in viral replication. Strikingly, the human orthologs of these three genes, activated CDC42-associated kinase (TNK2), Wiskott-Aldrich syndrome protein (WASP), and noncatalytic region of tyrosine kinase adaptor protein 1 (NCK1) are part of a known signaling pathway in mammals. These results suggest that TNK2, WASP, and NCK1 may play important roles in mammalian virus infection.

scholarly journals A reference translatome map reveals two modes of protein evolution

2021 ◽  
Author(s):  
Aaron Wacholder ◽  
Omer Acar ◽  
Anne-Ruxandra Carvunis
Keyword(s):  
Model Organism ◽  
Great Majority ◽  
High Sensitivity ◽  
Ribosome Profiling ◽  
Computational Framework ◽  
Protein Coding ◽  
Biologically Relevant ◽  
Protein Coding Genes ◽  
Representative Subset ◽  
Evolutionarily Conserved

Ribosome profiling experiments demonstrate widespread translation of eukaryotic genomes outside of annotated protein-coding genes. However, it is unclear how much of this "noncanonical" translation contributes biologically relevant microproteins rather than insignificant translational noise. Here, we developed an integrative computational framework (iRibo) that leverages hundreds of ribosome profiling experiments to detect signatures of translation with high sensitivity and specificity. We deployed iRibo to construct a reference translatome in the model organism S. cerevisiae. We identified ~19,000 noncanonical translated elements outside of the ~5,400 canonical yeast protein-coding genes. Most (65%) of these non-canonical translated elements were located on transcripts annotated as non-coding, or entirely unannotated, while the remainder were located on the 5' and 3' ends of mRNA transcripts. Only 14 non-canonical translated elements were evolutionarily conserved. In stark contrast with canonical protein-coding genes, the great majority of the yeast noncanonical translatome appeared evolutionarily transient and showed no signatures of selection. Yet, we uncovered phenotypes for 53% of a representative subset of evolutionarily transient translated elements. The iRibo framework and reference translatome described here provide a foundation for further investigation of a largely unexplored, but biologically significant, evolutionarily transient translatome.

scholarly journals The role of FLOWERING LOCUS C in vernalization of Brassica: the importance of vernalization research in the face of climate change

2018 ◽  
Vol 69 (1) ◽  
pp. 30 ◽  
Author(s):  
Daniel J. Shea ◽  
Etsuko Itabashi ◽  
Satoko Takada ◽  
Eigo Fukai ◽  
Tomohiro Kakizaki ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Model Organism ◽  
Climatic Changes ◽  
Environmental Cues ◽  
Plant Responses ◽  
Agricultural Crops ◽  
Regulatory Pathways ◽  
Evolutionarily Conserved ◽  
The Face

As climatic changes occur over the coming decades, our scientific understanding of plant responses to environmental cues will become an increasingly important consideration in the breeding of agricultural crops. This review provides a summary of the literature regarding vernalization research in Brassicaceae, covering both the historical origins of vernalization research and current understanding of the molecular mechanisms behind the regulatory pathways involved in vernalization and subsequent inflorescence. We discuss the evolutionarily conserved biology between the model organism Arabidopsis thaliana and the Brassica genus of crop cultivars and contrast the differences between the genera to illustrate the importance of Brassica-specific research into vernalization.

scholarly journals The Nematode Caenorhabditis elegans A Model Animal “Made for Microscopy”

2004 ◽  
Vol 12 (2) ◽  
pp. 8-13
Author(s):  
David H. Hall
Keyword(s):  
Caenorhabditis Elegans ◽  
System Development ◽  
Scientific Discovery ◽  
Medical Science ◽  
Model Organism ◽  
Small Animal ◽  
Single Species ◽  
Fruit Fly ◽  
Nervous System Development ◽  
Model Animal

The small unassuming nematode, Caenorhabditis elegans is only one millimeter long and lives in the soil munching on bacteria. While many nematode (roundworm) species are parasites with medical or agricultural importance, C. elegans seems to harm no one. Yet, this animal has attained a status in medical science that compares to more complex organisms such as the mouse or fruit fly in its utility for scientific discovery. It has been the subject of thousands of studies dealing with topics as diverse as nutrition, aging, and nervous system development. About 5000 scientists are now pursuing this single species in hundreds of laboratories worldwide. In 2002, the Nobel Prize in Medicine was awarded to three of the pioneers in establishing C. elegans as a “model organism“: Sydney Brenner, John Sulston, and H. Robert Horvitz. Why study worms?Sydney Brenner first turned his attention to C. elegans in the 1960's. Working at the Medical Research Council in England, he was looking for a small animal with inexpensive tastes that could be easily cultured in the laboratory.

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