scholarly journals Differential gene expression in seasonal sympatry: mechanisms involved in diverging life histories

2016 ◽  
Vol 12 (3) ◽  
pp. 20160069 ◽  
Author(s):  
Adam M. Fudickar ◽  
Mark P. Peterson ◽  
Timothy J. Greives ◽  
Jonathan W. Atwell ◽  
Eli S. Bridge ◽  
...  
Keyword(s):  
Gene Expression ◽  
Life History ◽  
Life Histories ◽  
Pectoral Muscle ◽  
Early Spring ◽  
Timing Of Reproduction ◽  
Muscle Genes ◽  
Differential Gene ◽  
Reproductive Processes

In an era of climate change, understanding the genetic and physiological mechanisms underlying flexibility in phenology and life history has gained greater importance. These mechanisms can be elucidated by comparing closely related populations that differ in key behavioural and physiological traits such as migration and timing of reproduction. We compared gene expression in two recently diverged dark-eyed Junco (  Junco hyemalis ) subspecies that live in seasonal sympatry during winter and early spring, but that differ in behaviour and physiology, despite exposure to identical environmental cues. We identified 547 genes differentially expressed in blood and pectoral muscle. Genes involved in lipid transport and metabolism were highly expressed in migrant juncos, while genes involved in reproductive processes were highly expressed in resident breeders. Seasonal differences in gene expression in closely related populations residing in the same environment provide significant insights into mechanisms underlying variation in phenology and life history, and have potential implications for the role of seasonal timing differences in gene flow and reproductive isolation.

Hormones and Behavior

2019 ◽  
pp. 11-26
Author(s):  
Maren N. Vitousek ◽  
Laura A. Schoenle
Keyword(s):  
Life History ◽  
Life Histories ◽  
Life History Traits ◽  
Developmental Plasticity ◽  
Endocrine System ◽  
Phenotypic Traits ◽  
Social Environments ◽  
Trade Offs ◽  
And Behavior

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.

scholarly journals CsrA (BB0184) Is Not Involved in Activation of the RpoN-RpoS Regulatory Pathway in Borrelia burgdorferi

2014 ◽  
Vol 82 (4) ◽  
pp. 1511-1522 ◽  
Author(s):  
Zhiming Ouyang ◽  
Jianli Zhou ◽  
Michael V. Norgard
Keyword(s):  
Gene Expression ◽  
Borrelia Burgdorferi ◽  
Animal Studies ◽  
Expression System ◽  
Regulatory Pathway ◽  
Content Type ◽  
Mouse Tissues ◽  
Differential Gene ◽  
Carbon Storage Regulator

ABSTRACTBorrelia burgdorferiencodes a homologue of the bacterial carbon storage regulator A (CsrA). Recently, it was reported that CsrA contributes toB. burgdorferiinfectivity and is required for the activation of the central RpoN-RpoS regulatory pathway. However, many questions concerning the function of CsrA inB. burgdorferigene regulation remain unanswered. In particular, there are conflicting reports concerning the molecular details of how CsrA may modulaterpoSexpression and, thus, how CsrA may influence the RpoN-RpoS pathway inB. burgdorferi. To address these key discrepancies, we examined the role of CsrA in differential gene expression in the Lyme disease spirochete. Upon engineering an induciblecsrAexpression system inB. burgdorferi, controlled hyperexpression of CsrA in a merodiploid strain did not significantly alter the protein and transcript levels ofbosR,rpoS, and RpoS-dependent genes (such asospCanddbpA). In addition, we constructed isogeniccsrAmutants in two widely used infectiousB. burgdorferistrains. When expression ofbosR,rpoS,ospC, anddbpAwas compared between thecsrAmutants and their wild-type counterparts, no detectable differences were observed. Finally, animal studies indicated that thecsrAmutants remained infectious for and virulent in mice. Analyses ofB. burgdorferigene expression in mouse tissues showed comparable levels ofrpoStranscripts by thecsrAmutants and the parental strains. Taken together, these results constitute compelling evidence that CsrA is not involved in activation of the RpoN-RpoS pathway and is dispensable for mammalian infectious processes carried out byB. burgdorferi.

Individual Growth and Reproduction

2019 ◽  
pp. 38-56
Author(s):  
Ken H. Andersen
Keyword(s):  
Life History ◽  
Growth Model ◽  
Life Histories ◽  
Maximum Size ◽  
Individual Growth ◽  
Energy Budgets ◽  
Asymptotic Size ◽  
The Individual ◽  
Growth And Reproduction

This chapter develops descriptions of how individuals grow and reproduce. More specifically, the chapter seeks to determine the growth and reproduction rates from the consumption rate, by developing an energy budget of the individual as a function of size. To that end, the chapter addresses the question of how an individual makes use of the energy acquired from consumption. It sets up the energy budgets of individuals by formulating the growth model using so-called life-history invariants, which are parameters that do not vary systematically between species. While the formulation of the growth model in terms of life-history invariants is largely successful, there is in particular one parameter that is not invariant between life histories: the asymptotic size (maximum size) of individuals in the population. This parameter plays the role of a master trait that characterizes most of the variation between life histories.

scholarly journals DNA Methylation Patterns in the Social Spider, Stegodyphus dumicola

Genes ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 137 ◽  
Author(s):  
Shenglin Liu ◽  
Anne Aagaard ◽  
Jesper Bechsgaard ◽  
Trine Bilde
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Sequence Data ◽  
Social Spider ◽  
The Social ◽  
Genome Bisulfite Sequencing ◽  
Differential Gene ◽  
Methylation Patterns ◽  
Comparative Phylogenetic Analysis

Variation in DNA methylation patterns among genes, individuals, and populations appears to be highly variable among taxa, but our understanding of the functional significance of this variation is still incomplete. We here present the first whole genome bisulfite sequencing of a chelicerate species, the social spider Stegodyphus dumicola. We show that DNA methylation occurs mainly in CpG context and is concentrated in genes. This is a pattern also documented in other invertebrates. We present RNA sequence data to investigate the role of DNA methylation in gene regulation and show that, within individuals, methylated genes are more expressed than genes that are not methylated and that methylated genes are more stably expressed across individuals than unmethylated genes. Although no causal association is shown, this lends support for the implication of DNA CpG methylation in regulating gene expression in invertebrates. Differential DNA methylation between populations showed a small but significant correlation with differential gene expression. This is consistent with a possible role of DNA methylation in local adaptation. Based on indirect inference of the presence and pattern of DNA methylation in chelicerate species whose genomes have been sequenced, we performed a comparative phylogenetic analysis. We found strong evidence for exon DNA methylation in the horseshoe crab Limulus polyphemus and in all spider and scorpion species, while most Parasitiformes and Acariformes species seem to have lost DNA methylation.

The role of dispersal and retention in the early life stages of shrimp in a lowland river

2010 ◽  
Vol 67 (4) ◽  
pp. 720-729 ◽  
Author(s):  
Amina E. Price ◽  
Paul Humphries
Keyword(s):  
Life History ◽  
Life Histories ◽  
Movement Patterns ◽  
Early Ontogeny ◽  
Small Scale ◽  
Lowland River ◽  
Southeastern Australia ◽  
Stage Of Development ◽  
Paratya Australiensis

This study investigated the importance of dispersal and retention processes during early ontogeny for three caridean shrimp species that complete their entire life history in freshwater. Directional traps were used to examine the small-scale movement patterns of shrimp into and out of nursery habitat patches (slackwaters) in a small lowland river in southeastern Australia. Movement patterns provided evidence for two contrasting life history based dispersal and retention strategies. For the two smaller atyid species, Paratya australiensis and Caridina mccullochi , the majority of larvae remained within the slackwater in which they were hatched until the final stage of development, at which point dispersal, either among slackwaters or out of slackwaters to faster-flowing pool and run habitats, occurred. For the larger palaemonid species, Macrobrachium australiense , larvae were hatched into slackwaters and dispersal occurred predominately during the first stage of larval development and then decreased as development progressed. Despite the differences in dispersal strategies among species, movement was mostly associated with a particular larval stage and thus emphasizes the importance of retention during critical developmental periods and of the potential impact that flow alteration could have on these and other species with similar life histories.

scholarly journals Friends or Foes—Microbial Interactions in Nature

Biology ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 496
Author(s):  
Nancy Weiland-Bräuer
Keyword(s):  
Gene Expression ◽  
Cell Communication ◽  
Microbial Interactions ◽  
Basic Unit ◽  
Associated Bacteria ◽  
Community Behavior ◽  
Successful Establishment ◽  
Differential Gene ◽  
Abiotic Stimuli

Microorganisms are present in nearly every niche on Earth and mainly do not exist solely but form communities of single or mixed species. Within such microbial populations and between the microbes and a eukaryotic host, various microbial interactions take place in an ever-changing environment. Those microbial interactions are crucial for a successful establishment and maintenance of a microbial population. The basic unit of interaction is the gene expression of each organism in this community in response to biotic or abiotic stimuli. Differential gene expression is responsible for producing exchangeable molecules involved in the interactions, ultimately leading to community behavior. Cooperative and competitive interactions within bacterial communities and between the associated bacteria and the host are the focus of this review, emphasizing microbial cell–cell communication (quorum sensing). Further, metagenomics is discussed as a helpful tool to analyze the complex genomic information of microbial communities and the functional role of different microbes within a community and to identify novel biomolecules for biotechnological applications.

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