scholarly journals Growth and Maturation in Development: A Fly’s Perspective

2020 ◽  
Vol 21 (4) ◽  
pp. 1260 ◽  
Author(s):  
Renald Delanoue ◽  
Nuria M. Romero

In mammals like humans, adult fitness is improved due to resource allocation, investing energy in the developmental growth process during the juvenile period, and in reproduction at the adult stage. Therefore, the attainment of their target body height/size co-occurs with the acquisition of maturation, implying a need for coordination between mechanisms that regulate organismal growth and maturation timing. Insects like Drosophila melanogaster also define their adult body size by the end of the juvenile larval period. Recent studies in the fly have shown evolutionary conservation of the regulatory pathways controlling growth and maturation, suggesting the existence of common coordinator mechanisms between them. In this review, we will present an overview of the significant advancements in the coordination mechanisms ensuring developmental robustness in Drosophila. We will include (i) the characterization of feedback mechanisms between maturation and growth hormones, (ii) the recognition of a relaxin-like peptide Dilp8 as a central processor coordinating juvenile regeneration and time of maturation, and (iii) the identification of a novel coordinator mechanism involving the AstA/KISS system.

2003 ◽  
Vol 6 (5) ◽  
pp. 399-408 ◽  
Author(s):  
Karri Silventoinen ◽  
Sampo Sammalisto ◽  
Markus Perola ◽  
Dorret I. Boomsma ◽  
Belinda K. Cornes ◽  
...  

2006 ◽  
Vol 57 (4) ◽  
pp. 477 ◽  
Author(s):  
R. De la Rosa ◽  
A. I. Kiran ◽  
D. Barranco ◽  
L. León

The juvenile period represents a serious impediment in olive breeding programs. Seedlings with long juvenile period are of very low interest for the breeder because their evaluation considerably delays the first stages of the breeding process. For this reason, the influence of seedling vigour (measured as plant height or stem diameter) on the characteristics at the adult stage was studied to establish useful negative preselection criteria on the basis of that relationship. Olive progenies from crosses and open pollinations of 12 different parents carried out in 1998 and 1999 were evaluated in the greenhouse and, afterwards, during the first 3 years of bearing in the open field. The results obtained indicate that early evaluation and selection for juvenile period can be performed at the seedling stage in olive progenies on the basis of vigour measurements. Selection for short juvenile period was valid irrespective of parentage and, therefore, could be efficient in a general context. No relationship between juvenile period and yield or fruit traits was found so that this preselection criterion would have no adverse effects on these characters.


2014 ◽  
Vol 23 (24) ◽  
pp. 6607-6615 ◽  
Author(s):  
Mengmeng Du ◽  
Paul L. Auer ◽  
Shuo Jiao ◽  
Jeffrey Haessler ◽  
David Altshuler ◽  
...  

2019 ◽  
Author(s):  
Sonia Balyan ◽  
Sombir Rao ◽  
Sarita Jha ◽  
Chandni Bansal ◽  
Jaishri Rubina Das ◽  
...  

AbstractThe footprint of tomato cultivation, a cool region crop that exhibits heat stress (HS) sensitivity, is increasing in the tropics/sub-tropics. Knowledge of novel regulatory hot-spots from varieties growing in the Indian sub-continent climatic zones could be vital for developing HS-resilient crops. Comparative transcriptome-wide signatures of a tolerant (CLN1621L) and sensitive (CA4) cultivar-pair short-listed from a pool of varieties exhibiting variable thermo-sensitivity using physiological, survival and yield-related traits revealed redundant to cultivar-specific HS-regulation with more up-regulated genes for CLN1621L than CA4. The anatgonisiticly-expressing genes include enzymes; have roles in plant defense and response to different abiotic stresses. Functional characterization of three antagonistic genes by overexpression and TRV-VIGS silencing established Solyc09g014280 (Acylsugar acyltransferase) and Solyc07g056570 (Notabilis), that are up-regulated in tolerant cultivar, as positive regulators of HS-tolerance and Solyc03g020030 (Pin-II proteinase inhibitor), that is down-regulated in CLN1621L, as negative regulator of thermotolerance. Transcriptional assessment of promoters of these genes by SNPs in stress-responsive cis-elements and promoter swapping experiments in opposite cultivar background showed inherent cultivar-specific orchestration of transcription factors in regulating transcription. Moreover, overexpression of three ethylene response transcription factors (ERF.C1/F4/F5) also improved HS-tolerance in tomato. This study identifies several novel HS-tolerance genes and provides proof of their utility in tomato-thermotolerance.HighlightNovel heat stress regulatory pathways uncovered by comparative transcriptome profiling between contrasting tomato cultivars from Indian sub-continent for improving thermotolerance. (20/30)


Author(s):  
Pat Rasmussen ◽  
Christine Levesque ◽  
Jianjun Niu ◽  
Howard Gardner ◽  
Gregory Nilsson ◽  
...  

A pilot study was undertaken to characterize the concentration, duration and particle size distribution of the talc cloud that forms in the personal breathing zone (PBZ) during application of certain talc-containing cosmetics. Multiple direct-reading instruments were employed to simultaneously monitor PM4 concentrations (particulate matter with aerodynamic diameter < 4 µm; mg/m3) at different distances from each of three subjects while they applied talc products. Results indicated that the purpose and method of applying the talc product, combined with behavioral and physical differences amongst subjects, all strongly influenced airborne talc concentrations and the duration of the cloud. Air concentrations of talc in the PBZ averaged around 1.0 mg/m3, and the duration of exposure varied from less than one minute to more than ten minutes. The real-time monitors captured the occasional formation of secondary clouds, likely caused by resuspension of talc particles from skin or other surfaces. Measurements of aerosolized baby powder, face powder, and two adult body powders indicated that the median aerodynamic diameter of the talc cloud ranged from 1.7 to 2.0 µm. These direct-reading approaches were valuable for providing detailed characterization of short duration exposures to airborne talc particles, and will be useful to support future exposure assessments of talc and other powders in consumer products.


2003 ◽  
Vol 81 (4) ◽  
pp. 574-581 ◽  
Author(s):  
Robert Poulin ◽  
A David M. Latham

For ectotherms, temperature is an important correlate of variation in body size within species. Variation in body size among related species could also be attributable in part to temperature if the different species grow under different thermal regimes. The roles of both initial (larval) size and host body temperature on final (adult) size of parasitic trematodes were investigated in a comparative analysis. Trematodes are a good model group for such a study, with almost half of known species growing at high and constant temperatures in endothermic vertebrates and the rest at lower and fluctuating temperatures in ectothermic vertebrates. The relative growth of trematodes, i.e., their growth relative to the size of their larvae, varied greatly among species. Increases in body size from the cercarial larval stage to the adult stage averaged almost 40-fold (maximum 1300-fold), whereas increases in size from the metacercarial stage to the adult stage averaged 6-fold (maximum 110-fold). There were no differences between trematodes in ectothermic hosts and trematodes in endothermic hosts with respect to these measures of relative growth, however, which suggests that host type and the thermal regime provided by the host have no effect on the growth of trematodes from larval to adult stages. In contrast, the final (adult) body size of trematodes appears to be determined to some extent by their initial (larval) size, independently of the type of host in which they developed.


2013 ◽  
Vol 81 (9) ◽  
pp. 3068-3076 ◽  
Author(s):  
Carolyn R. Morris ◽  
Christen L. Grassel ◽  
Julia C. Redman ◽  
Jason W. Sahl ◽  
Eileen M. Barry ◽  
...  

ABSTRACTShigellaspecies Gram-negative bacteria which cause a diarrheal disease, known as shigellosis, by invading and destroying the colonic mucosa and inducing a robust inflammatory response. With no vaccine available, shigellosis annually kills over 600,000 children in developing countries. This study demonstrates the utility of combining high-throughput bioinformatic methods within vitroandin vivoassays to provide new insights into pathogenesis. Comparisons ofin vivoandin vitrogene expression identified genes associated with intracellular growth. Additional bioinformatics analyses identified genes that are present inS. flexneriisolates but not in the three otherShigellaspecies. Comparison of these two analyses revealed nine genes that are differentially expressed during invasion and that are specific toS. flexneri. One gene, a DeoR family transcriptional regulator with decreased expression during invasion, was further characterized and is now designatedicgR, forintracellulargrowthregulator. Deletion oficgRcaused no difference in growthin vitrobut resulted in increased intracellular replication in HCT-8 cells. Furtherin vitroandin vivostudies using high-throughput sequencing of RNA transcripts (RNA-seq) of an isogenic ΔicgRmutant identified 34 genes that were upregulated under both growth conditions. This combined informatics and functional approach has allowed the characterization of a gene and pathway previously unknown inShigellapathogenesis and provides a framework for further identification of novel virulence factors and regulatory pathways.


1999 ◽  
Vol 28 (5) ◽  
pp. 911-918 ◽  
Author(s):  
K. Silventoinen ◽  
E. Lahelma ◽  
O. Rahkonen

2008 ◽  
Vol 4 (3) ◽  
pp. 282-285 ◽  
Author(s):  
A Chinsamy ◽  
L Codorniú ◽  
L Chiappe

Life-history parameters of pterosaurs such as growth and ontogenetic development represent an enigma. This aspect of pterosaur biology has remained perplexing because few pterosaur taxa are represented by complete ontogenetic series. Of these, Pterodaustro is unique in that besides being represented by hundreds of individuals with wing spans ranging from 0.3 to 2.5 m, it includes an embryo within an egg. Here we present a comprehensive osteohistological assessment of multiple skeletal elements of a range of ontogenetic sizes of Pterodaustro , and we provide unparalleled insight into its growth dynamics. We show that, upon hatching, Pterodaustro juveniles grew rapidly for approximately 2 years until they reached approximately 53% of their mature body size, whereupon they attained sexual maturity. Thereafter, growth continued for at least another 3–4 years at comparatively slower rates until larger adult body sizes were attained. Our analysis further provides definitive evidence that Pterodaustro had a determinate growth strategy.


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