We are primates and we are fish: Teaching monophyletic organismal biology

1998 ◽  
Vol 1 (3) ◽  
pp. 108-111 ◽  
Author(s):  
Harry W. Greene
Keyword(s):  
Organismal Biology

scholarly journals A champion of organismal biology

2015 ◽  
Vol 201 (6) ◽  
pp. 513-515
Author(s):  
Ken Cheng ◽  
Bernhard Ronacher
Keyword(s):  
Organismal Biology

scholarly journals The genetic paradigms of dietary restriction fail to extend life span in cep-1(gk138) mutant of C. elegans p53 due to possible background mutations

2020 ◽  
Author(s):  
Anita Goyala ◽  
Aiswarya Baruah ◽  
Arnab Mukhopadhyay
Keyword(s):  
Life Span ◽  
Dietary Restriction ◽  
Model Systems ◽  
Regulation Of Expression ◽  
Life Span Extension ◽  
Phenotypic Differences ◽  
C Elegans ◽  
Xenobiotic Detoxification ◽  
Organismal Biology ◽  
Extend Life Span

AbstractDietary restriction (DR) increases life span and improves health in most model systems tested, including non-human primates. In C. elegans, as in other models, DR leads to reprogramming of metabolism, improvements in mitochondrial health, large changes in gene expression, including increase in expression of cytoprotective genes, better proteostasis etc. Understandably, multiple global transcriptional regulators like transcription factors FOXO/DAF-16, FOXA/PHA-4, HSF1/HSF-1 and NRF2/SKN-1 are important for DR longevity. Considering the wide-ranging effects of p53 on organismal biology, we asked whether the C. elegans ortholog, CEP-1 is required for DR-mediated longevity assurance. We employed the widely-used TJ1 strain of cep-1(gk138). We show that cep-1(gk138) suppresses the life span extension of two genetic paradigms of DR, but two non-genetic modes of DR remain unaffected in this strain. We find that in cep-1(gk138), two aspects of DR, increased autophagy and the up-regulation of expression of cytoprotective xenobiotic detoxification program (cXDP) genes are dampened. Importantly, we find that background mutation(s) in the strain may be the actual cause for the phenotypic differences that we observed and cep-1 may not be directly involved in genetic DR-mediated longevity assurance in worms. Identifying these mutation(s) may reveal a novel regulator of longevity required specifically by genetic modes of DR.

scholarly journals Ceramide synthases at the centre of sphingolipid metabolism and biology

2012 ◽  
Vol 441 (3) ◽  
pp. 789-802 ◽  
Author(s):  
Thomas D. Mullen ◽  
Yusuf A. Hannun ◽  
Lina M. Obeid
Keyword(s):  
Cell Death ◽  
De Novo ◽  
Acyl Chain ◽  
Sphingolipid Metabolism ◽  
Sphingoid Base ◽  
Salvage Pathway ◽  
Organismal Biology ◽  
Acyl Chain Length ◽  
Specific Manner ◽  
Ceramide Synthases

Sphingolipid metabolism in metazoan cells consists of a complex interconnected web of numerous enzymes, metabolites and modes of regulation. At the centre of sphingolipid metabolism reside CerSs (ceramide synthases), a group of enzymes that catalyse the formation of ceramides from sphingoid base and acyl-CoA substrates. From a metabolic perspective, these enzymes occupy a unique niche in that they simultaneously regulate de novo sphingolipid synthesis and the recycling of free sphingosine produced from the degradation of pre-formed sphingolipids (salvage pathway). Six mammalian CerSs (CerS1–CerS6) have been identified. Unique characteristics have been described for each of these enzymes, but perhaps the most notable is the ability of individual CerS isoforms to produce ceramides with characteristic acyl-chain distributions. Through this control of acyl-chain length and perhaps in a compartment-specific manner, CerSs appear to regulate multiple aspects of sphingolipid-mediated cell and organismal biology. In the present review, we discuss the function of CerSs as critical regulators of sphingolipid metabolism, highlight their unique characteristics and explore the emerging roles of CerSs in regulating programmed cell death, cancer and many other aspects of biology.

scholarly journals Identifying cryptic diversity with predictive phylogeography

2016 ◽  
Vol 283 (1841) ◽  
pp. 20161529 ◽  
Author(s):  
Anahí Espíndola ◽  
Megan Ruffley ◽  
Megan L. Smith ◽  
Bryan C. Carstens ◽  
David C. Tank ◽  
...  
Keyword(s):  
North America ◽  
Pacific Northwest ◽  
Biological Diversity ◽  
Single Species ◽  
Cryptic Diversity ◽  
Major Goal ◽  
Organismal Biology ◽  
Unknown Species ◽  
The Pacific ◽  
Ecosystem Level

Identifying units of biological diversity is a major goal of organismal biology. An increasing literature has focused on the importance of cryptic diversity, defined as the presence of deeply diverged lineages within a single species. While most discoveries of cryptic lineages proceed on a taxon-by-taxon basis, rapid assessments of biodiversity are needed to inform conservation policy and decision-making. Here, we introduce a predictive framework for phylogeography that allows rapidly identifying cryptic diversity. Our approach proceeds by collecting environmental, taxonomic and genetic data from codistributed taxa with known phylogeographic histories. We define these taxa as a reference set, and categorize them as either harbouring or lacking cryptic diversity. We then build a random forest classifier that allows us to predict which other taxa endemic to the same biome are likely to contain cryptic diversity. We apply this framework to data from two sets of disjunct ecosystems known to harbour taxa with cryptic diversity: the mesic temperate forests of the Pacific Northwest of North America and the arid lands of Southwestern North America. The predictive approach presented here is accurate, with prediction accuracies placed between 65% and 98.79% depending of the ecosystem. This seems to indicate that our method can be successfully used to address ecosystem-level questions about cryptic diversity. Further, our application for the prediction of the cryptic/non-cryptic nature of unknown species is easily applicable and provides results that agree with recent discoveries from those systems. Our results demonstrate that the transition of phylogeography from a descriptive to a predictive discipline is possible and effective.

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