scholarly journals Sensitivity to perturbations of a cell migration under temporal regulation

2020 ◽  
Author(s):  
Clément Dubois ◽  
Shivam Gupta ◽  
Andrew Mugler ◽  
Marie-Anne Félix
Keyword(s):  
Body Size ◽  
Long Range ◽  
Body Position ◽  
Size Variation ◽  
Young Larva ◽  
Final Position ◽  
Temporal Regulation ◽  
Natural Genetic Variation ◽  
Body Size Variation ◽  
C Elegans

AbstractFew studies have measured the robustness to perturbations of the final position of a long-range migrating cell. In the nematode Caenorhabditis elegans, the QR neuroblast migrates anteriorly in the young larva, while undergoing three rounds of division. The daughters of QR.pa stop their migration at an anterior body position and acquire a neuronal fate. Previous studies showed that the migration stops upon expression of the Wnt receptor MIG-1, which surprisingly is not induced by positional cues but by a timing mechanism (Mentink et al. 2014). Given this temporal regulation, we wondered 1) how precise QR.pax positioning is when confronted with various challenges, such as stochastic noise, environment or body size variation and 2) whether QR.pax position varies among C. elegans wild isolates. We find that the variance of QR.pax final position is similar to that of other long-range migrating neurons. Its mean position undergoes a slight posterior shift at higher temperature, while its variance is greatly increased following sustained starvation at hatching. We manipulated body size using mutants and tetraploid animals. As expected from the temporal mechanism, smaller mutants display anteriorly shifted QR.pax cells, while longer mutants and tetraploids display posteriorly shifted QR.pax cells. Using a mathematical model, we show however that body size variation is partially compensated. We find that cell speed is indeed altered in body size mutants. Finally, we could detect highly significant variation among C. elegans wild isolates. Overall, this study reveals that the final cell position of QR.pax shows some degree of sensitivity to external perturbations and natural genetic variation.

scholarly journals Temporally regulated cell migration is sensitive to variation in body size

Development ◽  
2021 ◽  
Vol 148 (5) ◽  
pp. dev196949 ◽  
Author(s):  
Clément Dubois ◽  
Shivam Gupta ◽  
Andrew Mugler ◽  
Marie-Anne Félix
Keyword(s):  
Body Size ◽  
Long Range ◽  
Size Variation ◽  
Temperature Shift ◽  
Final Position ◽  
Stochastic Variation ◽  
Timing Mechanism ◽  
C Elegans ◽  
Environmental Perturbations ◽  
The People

ABSTRACTFew studies have measured the robustness to perturbations of the final position of a long-range migrating cell. In the nematodeCaenorhabditis elegans, the QR neuroblast migrates anteriorly, while undergoing three division rounds. We study the final position of two of its great-granddaughters, the end of migration of which was previously shown to depend on a timing mechanism. We find that the variance in their final position is similar to that of other long-range migrating neurons. As expected from the timing mechanism, the position of QR descendants depends on body size, which we varied by changing maternal age or using body size mutants. Using a mathematical model, we show that body size variation is partially compensated for. Applying environmental perturbations, we find that the variance in final position increased following starvation at hatching. The mean position is displaced upon a temperature shift. Finally, highly significant variation was found amongC. eleganswild isolates. Overall, this study reveals that the final position of these neurons is quite robust to stochastic variation, shows some sensitivity to body size and to external perturbations, and varies in the species.This article has an associated ‘The people behind the papers’ interview.

scholarly journals Mammalian body size is determined by interactions between climate, urbanization, and ecological traits

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Maggie M. Hantak ◽  
Bryan S. McLean ◽  
Daijiang Li ◽  
Robert P. Guralnick
Keyword(s):  
Body Size ◽  
Resource Availability ◽  
Critical Role ◽  
Size Variation ◽  
Ecological Factors ◽  
Species Traits ◽  
Body Size Variation ◽  
Resource Availability Hypothesis ◽  
Urban Heat ◽  
Thermal Buffering

AbstractAnthropogenically-driven climate warming is a hypothesized driver of animal body size reductions. Less understood are effects of other human-caused disturbances on body size, such as urbanization. We compiled 140,499 body size records of over 100 North American mammals to test how climate and human population density, a proxy for urbanization, and their interactions with species traits, impact body size. We tested three hypotheses of body size variation across urbanization gradients: urban heat island effects, habitat fragmentation, and resource availability. Our results demonstrate that both urbanization and temperature influence mammalian body size variation, most often leading to larger individuals, thus supporting the resource availability hypothesis. In addition, life history and other ecological factors play a critical role in mediating the effects of climate and urbanization on body size. Larger mammals and species that utilize thermal buffering are more sensitive to warmer temperatures, while flexibility in activity time appears to be advantageous in urbanized areas. This work highlights the value of using digitized, natural history data to track how human disturbance drives morphological variation.

scholarly journals The role of local versus biogeographical processes in influencing diversity and body‐size variation in mammal assemblages

2016 ◽  
Vol 6 (5) ◽  
pp. 1447-1456 ◽  
Author(s):  
Luiz Carlos S. Lopez ◽  
Marcos S. L. Figueiredo ◽  
Maria Paula de Aguiar Fracasso ◽  
Daniel Oliveira Mesquita ◽  
Ulisses Umbelino Anjos ◽  
...  
Keyword(s):  
Body Size ◽  
Size Variation ◽  
Body Size Variation ◽  
Mammal Assemblages

scholarly journals Insights into body size variation in cetaceans from the evolution of body-size-related genes

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Yingying Sun ◽  
Yanzhi Liu ◽  
Xiaohui Sun ◽  
Yurui Lin ◽  
Daiqing Yin ◽  
...  
Keyword(s):  
Body Size ◽  
Size Variation ◽  
Body Size Variation

Geographic variation in body size and sexual size dimorphism of North American Ratsnakes (Pantherophis spp. s.l.)

2018 ◽  
Vol 96 (11) ◽  
pp. 1196-1202 ◽  
Author(s):  
Brett A. DeGregorio ◽  
Gabriel Blouin-Demers ◽  
Gerardo L.F. Carfagno ◽  
J. Whitfield Gibbons ◽  
Stephen J. Mullin ◽  
...  
Keyword(s):  
Body Size ◽  
Large Scale ◽  
Sexual Size Dimorphism ◽  
Size Variation ◽  
Sexually Dimorphic ◽  
Male Body ◽  
Complex Species ◽  
Size Dimorphism ◽  
Body Size Variation ◽  
Female Body Size

Because body size affects nearly all facets of an organism’s life history, ecologists have long been interested in large-scale patterns of body-size variation, as well as why those large-scale patterns often differ between sexes. We explored body-size variation across the range of the sexually dimorphic Ratsnake complex (species of the genus Pantherophis Fitzinger, 1843 s.l.; formerly Elaphe obsoleta (Say in James, 1823)) in North America. We specifically explored whether variation in body size followed latitudinal patterns or varied with climatic variables. We found that body size did not conform to a climatic or latitudinal gradient, but instead, some of the populations with the largest snakes occurred near the core of the geographic range and some with the smallest occurred near the northern, western, and southern peripheries of the range. Males averaged 14% larger than females, although the degree of sexual size dimorphism varied between populations (range: 2%–25%). There was a weak trend for male body size to change in relation to temperature, whereas female body size did not. Our results indicate that relationships between climate and an ectotherm’s body size are more complicated than linear latitudinal clines and likely differ for males and females.

scholarly journals Temperature‐driven color lightness and body size variation scale to local assemblages of European Odonata but are modified by propensity for dispersal

2020 ◽  
Vol 10 (16) ◽  
pp. 8936-8948
Author(s):  
Daniel Acquah‐Lamptey ◽  
Martin Brändle ◽  
Roland Brandl ◽  
Stefan Pinkert
Keyword(s):  
Body Size ◽  
Size Variation ◽  
Body Size Variation

Effects of latitude and allopatry on body size variation in European water shrews

2008 ◽  
Vol 53 (1) ◽  
pp. 39-46 ◽  
Author(s):  
Boris Kryštufek ◽  
Aila Quadracci
Keyword(s):  
Body Size ◽  
Size Variation ◽  
Body Size Variation ◽  
European Water

scholarly journals New footprints from Laetoli (Tanzania) provide evidence for marked body size variation in early hominins

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Fidelis T Masao ◽  
Elgidius B Ichumbaki ◽  
Marco Cherin ◽  
Angelo Barili ◽  
Giovanni Boschian ◽  
...  
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Size Variation ◽  
Single Species ◽  
Australopithecus Afarensis ◽  
Body Size Variation ◽  
Northern Tanzania ◽  
The World ◽  
Marked Body ◽  
Considerable Body

Laetoli is a well-known palaeontological locality in northern Tanzania whose outstanding record includes the earliest hominin footprints in the world (3.66 million years old), discovered in 1978 at Site G and attributed to Australopithecus afarensis. Here, we report hominin tracks unearthed in the new Site S at Laetoli and referred to two bipedal individuals (S1 and S2) moving on the same palaeosurface and in the same direction as the three hominins documented at Site G. The stature estimates for S1 greatly exceed those previously reconstructed for Au. afarensis from both skeletal material and footprint data. In combination with a comparative reappraisal of the Site G footprints, the evidence collected here embodies very important additions to the Pliocene record of hominin behaviour and morphology. Our results are consistent with considerable body size variation and, probably, degree of sexual dimorphism within a single species of bipedal hominins as early as 3.66 million years ago.

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