scholarly journals Role of bacterial phenotypic traits in selective feeding of the heterotrophic nanoflagellate Spumella sp.

2002 ◽  
Vol 27 ◽  
pp. 137-148 ◽  
Author(s):  
C Matz ◽  
J Boenigk ◽  
H Arndt ◽  
K Jürgens
Author(s):  
Maren N. Vitousek ◽  
Laura A. Schoenle

Hormones mediate the expression of life history traits—phenotypic traits that contribute to lifetime fitness (i.e., reproductive timing, growth rate, number and size of offspring). The endocrine system shapes phenotype by organizing tissues during developmental periods and by activating changes in behavior, physiology, and morphology in response to varying physical and social environments. Because hormones can simultaneously regulate many traits (hormonal pleiotropy), they are important mediators of life history trade-offs among growth, reproduction, and survival. This chapter reviews the role of hormones in shaping life histories with an emphasis on developmental plasticity and reversible flexibility in endocrine and life history traits. It also discusses the advantages of studying hormone–behavior interactions from an evolutionary perspective. Recent research in evolutionary endocrinology has provided insight into the heritability of endocrine traits, how selection on hormone systems may influence the evolution of life histories, and the role of hormonal pleiotropy in driving or constraining evolution.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Guillermo Velo-Antón ◽  
André Lourenço ◽  
Pedro Galán ◽  
Alfredo Nicieza ◽  
Pedro Tarroso

AbstractExplicitly accounting for phenotypic differentiation together with environmental heterogeneity is crucial to understand the evolutionary dynamics in hybrid zones. Species showing intra-specific variation in phenotypic traits that meet across environmentally heterogeneous regions constitute excellent natural settings to study the role of phenotypic differentiation and environmental factors in shaping the spatial extent and patterns of admixture in hybrid zones. We studied three environmentally distinct contact zones where morphologically and reproductively divergent subspecies of Salamandra salamandra co-occur: the pueriparous S. s. bernardezi that is mostly parapatric to its three larviparous subspecies neighbours. We used a landscape genetics framework to: (i) characterise the spatial location and extent of each contact zone; (ii) assess patterns of introgression and hybridization between subspecies pairs; and (iii) examine the role of environmental heterogeneity in the evolutionary dynamics of hybrid zones. We found high levels of introgression between parity modes, and between distinct phenotypes, thus demonstrating the evolution to pueriparity alone or morphological differentiation do not lead to reproductive isolation between these highly divergent S. salamandra morphotypes. However, we detected substantial variation in patterns of hybridization across contact zones, being lower in the contact zone located on a topographically complex area. We highlight the importance of accounting for spatial environmental heterogeneity when studying evolutionary dynamics of hybrid zones.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alessia Oppezzo ◽  
Filippo Rosselli

AbstractHaematopoiesis, the process by which a restrained population of stem cells terminally differentiates into specific types of blood cells, depends on the tightly regulated temporospatial activity of several transcription factors (TFs). The deregulation of their activity or expression is a main cause of pathological haematopoiesis, leading to bone marrow failure (BMF), anaemia and leukaemia. TFs can be induced and/or activated by different stimuli, to which they respond by regulating the expression of genes and gene networks. Most TFs are highly pleiotropic; i.e., they are capable of influencing two or more apparently unrelated phenotypic traits, and the action of a single TF in a specific setting often depends on its interaction with other TFs and signalling pathway components. The microphthalmia-associated TF (MiTF) is a prototype TF in multiple situations. MiTF has been described extensively as a key regulator of melanocyte and melanoma development because it acts mainly as an oncogene. Mitf-mutated mice show a plethora of pleiotropic phenotypes, such as microphthalmia, deafness, abnormal pigmentation, retinal degeneration, reduced mast cell numbers and osteopetrosis, revealing a greater requirement for MiTF activity in cells and tissue. A growing amount of evidence has led to the delineation of key roles for MiTF in haematopoiesis and/or in cells of haematopoietic origin, including haematopoietic stem cells, mast cells, NK cells, basophiles, B cells and osteoclasts. This review summarizes several roles of MiTF in cells of the haematopoietic system and how MiTFs can impact BM development.


Biomolecules ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 601
Author(s):  
Aditya Saxena ◽  
Nitin Wahi ◽  
Anshul Kumar ◽  
Sandeep Kumar Mathur

The pathogenic mechanisms causing type 2 diabetes (T2D) are still poorly understood; a greater awareness of its causation can lead to the development of newer and better antidiabetic drugs. In this study, we used a network-based approach to assess the cellular processes associated with protein–protein interaction subnetworks of glycemic traits—HOMA-β and HOMA-IR. Their subnetworks were further analyzed in terms of their overlap with the differentially expressed genes (DEGs) in pancreatic, muscle, and adipose tissue in diabetics. We found several DEGs in these tissues showing an overlap with the HOMA-β subnetwork, suggesting a role of these tissues in β-cell failure. Many genes in the HOMA-IR subnetwork too showed an overlap with the HOMA-β subnetwork. For understanding the functional theme of these subnetworks, a pathway-to-pathway complementary network analysis was done, which identified various adipose biology-related pathways, containing genes involved in both insulin secretion and action. In conclusion, network analysis of genes showing an association between T2D and its intermediate phenotypic traits suggests their potential role in beta cell failure. These genes enriched the adipo-centric pathways and were expressed in both pancreatic and adipose tissue and, therefore, might be one of the potential targets for future antidiabetic treatment.


2005 ◽  
Vol 187 (12) ◽  
pp. 4173-4186 ◽  
Author(s):  
Amit Singh ◽  
Radhika Gupta ◽  
R. A. Vishwakarma ◽  
P. R. Narayanan ◽  
C. N. Paramasivan ◽  
...  

ABSTRACT We had recently reported that the mymA operon (Rv3083 to Rv3089) of Mycobacterium tuberculosis is regulated by AraC/XylS transcriptional regulator VirS (Rv3082c) and is important for the cell envelope of M. tuberculosis. In this study, we further show that a virS mutant (MtbΔvirS) and a mymA mutant (Mtbmym::hyg) of M. tuberculosis exhibit reduced contents and altered composition of mycolic acids along with the accumulation of saturated C24 and C26 fatty acids compared to the parental strain. These mutants were markedly more susceptible to major antitubercular drugs at acidic pH and also showed increased sensitivity to detergent (sodium dodecyl sulfate) and to acidic stress than the parental strain. We show that disruption of virS and mymA genes impairs the ability of M. tuberculosis to survive in activated macrophages, but not in resting macrophages, suggesting the importance of the mymA operon in protecting the bacterium against harsher conditions. Infection of guinea pigs with MtbΔvirS, Mtbmym::hyg, and the parental strain resulted in an ∼800-fold-reduced bacillary load of the mutant strains compared with the parental strain in spleens, but not in the lungs, of animals at 20 weeks postinfection. Phenotypic traits were fully complemented upon reintroduction of the virS gene into MtbΔvirS. These observations show the important role of the mymA operon in the pathogenesis of M. tuberculosis at later stages of the disease.


2013 ◽  
Vol 54 (2) ◽  
pp. 123-128 ◽  
Author(s):  
Mahendra Kumar Rai ◽  
Vaibhav V. Tiwari ◽  
László Irinyi ◽  
György János Kövics

Harmful Algae ◽  
2017 ◽  
Vol 68 ◽  
pp. 224-239 ◽  
Author(s):  
Ji Eun Kwon ◽  
Hae Jin Jeong ◽  
So Jin Kim ◽  
Se Hyeon Jang ◽  
Kyung Ha Lee ◽  
...  

2018 ◽  
Author(s):  
Rémi Hocq ◽  
Maxime Bouilloux-Lafont ◽  
Nicolas Lopes Ferreira ◽  
François Wasels

Microbial production of butanol and isopropanol, two high value-added chemicals, is naturally occurring in the solventogenic Clostridium beijerinckii DSM 6423. Despite its ancient discovery, the precise mechanisms controlling alcohol synthesis in this microorganism are poorly understood. In this work, an allyl alcohol tolerant strain obtained by random mutagenesis was characterized. This strain, designated as the AA mutant, shows a dominant production of acids, a severely diminished butanol synthesis capacity, and produces acetone instead of isopropanol. Interestingly, this solvent-deficient strain was also found to have a limited consumption of two carbohydrates and to be still able to form spores, highlighting its particular phenotype. Sequencing of the AA mutant revealed point mutations in several genes including CIBE_0767 (sigL), which encodes the σ54 sigma factor. Complementation with the wild-type sigL gene fully restored solvent production and sugar assimilation, demonstrating that σ54 plays a central role in regulating these pathways in C. beijerinckii DSM 6423. Genomic comparison with other strains further revealed that these functions are probably conserved among the C. beijerinckii strains. The importance of σ54 in C. beijerinckii was further assessed by the characterization of a sigL deletion mutant of the model strain NCIMB 8052 obtained with a CRISPR/Cas9 tool. The resulting mutant exhibited phenotypic traits similar to the AA strain, and was subsequently complemented with the sigL gene from either the wild type or the AA strains. The results of this experiment confirmed the crucial role of σ54 in the regulation of both solventogenesis and sugar consumption pathways in C. beijerinckii.


2017 ◽  
Author(s):  
Rajni Jaiswal ◽  
Shaurya Jauhari ◽  
S.A.M. Rizvi

Abstract.Microarray technology has unlocked doors to a multitude of open analysis problems that if conceived with efficacy may uncover varied genotypic and phenotypic traits. Algorithms belonging to different cultures in computer science have been applied to gene expression data to derive correlation and stratification parameters. While most outcomes are subject to clinical validation, majority of which get declined, the search for the precisely targeted therapeutic agents is still on. This paper is an effort in the similar direction and strives to delineate genes with significant stromal signatures. We suggest a corroborative indulgence of a human laterality disorder gene, CCDC11 in the metastasis, in addition to the role of WDR88 and ARPP21 genes has been further materialized in the analysis. Another standout aspect of the study has been the associated implications of the genes in rare disorders of male breast and female prostate cancers. There is also a threshold proposal that stratifies “safe” expression space for genes. Complimentarily, the manuscript serves as an expedient protocol for anyone seeking microarray data analysis, particularly in R.


2021 ◽  
Author(s):  
Ermeng Yu ◽  
Yichao Li ◽  
Bing Fu ◽  
Junming Zhang ◽  
Jun Xie ◽  
...  

With the rapid development of aquaculture, many fish species are domesticated and brought into cultivation. In the process of domestication, the domesticated fish undergone intense selection pressures and develop some adaptations and phenotypic traits, namely selection signatures, such as growth and metabolism, immunity, foraging and learning behaviors. However, how this selection signatures emerges is still not clear and the knowledge of molecular epigenetic mechanisms underlying selection signatures in fish is still in its infancy. Thus, we used a farmed fish, grass carp (Ctenopharyngodon idellus), as model species to detect these selection signatures and identify the candidate differentially methylated genes that are closely associated with these selection signatures at the level of whole genome, investigating the role of DNA methylation in the emergence of selection signatures during domestication. Our results showed that domesticated grass carp demonstrated four selection signatures, including growth and metabolism, immunity, foraging and learning behaviors, and 38 candidate genes were found associated with these traits. 16 genes are significant candidate genes which play major roles in the growth and metabolism, such as IGF-1 , GK , GYS1, etc. 11 genes are related to immunity, including . The GRM1, TAS1R1 and TAS1R3 genes are essential for the adaptation of domesticated grass carp to commercial feed in artificial rearing condition. The C-FOS, POMC and CBP genes may be responsible for the acquisition of novel feeding habits and contribute to faster growth indirectly by enhancing food intake. The findings here in will provide new insights to expand our understanding about the role of epigenetic modifications in shaping physiological phenotypes in this and other teleost models, which can contribute to efficient breeding of aquaculture stocks and restocking programmes.


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