Characterizing the Effect of Static Magnetic Fields on &amp;lt;i&amp;gt;C. elegans&amp;lt;/i&amp;gt; Using Microfluidics

Njus, Zach; Feldmann, Douglas; Brien, Riley; Kong, Taejoon; Kalwa, Upender; Pandey, Santosh

doi:10.4236/abb.2015.69061

Cited by 13 publications

(13 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In nematology, the development of microfluidic assays have been primarily focused on the behavioral modeling of Caenorhabditis elegans (Saldanha et al 2013) and some parasites of veterinary importance (Chen et al 2011). These studies have also used image analysis combined with microfluidics to aid in data acquisition (Njus et al 2015;Saldanha et al 2013).…”

mentioning

confidence: 99%

Chip Technologies for Screening Chemical and Biological Agents Against Plant-Parasitic Nematodes

et al. 2016

Self Cite

View full text Add to dashboard Cite

Plant-parasitic nematodes cause substantial damage to agricultural crops worldwide. Long-term management of these pests requires novel strategies to reduce infection of host plants. Disruption of nematode chemotaxis to root systems has been proposed as a potential management approach, and novel assays are needed to test the chemotactic behavior of nematodes against a wide range of synthetic chemicals and root exudates. Two microfluidic chips were developed that measure the attraction or repulsion of nematodes to chemicals ("chemical chip") and young plant roots ("root chip"). The chip designs allowed for chemical concentration gradients to be maintained up to 24 h, the nematodes to remain physically separate from the chemical reservoirs, and for images of nematode populations to be captured using either a microscope or a flatbed scanner. In the experiments using the chemical chips, seven ionic solutions were tested on second-stage juveniles (J2s) of Meloidogyne incognita and Heterodera glycines. Results were consistent with previous reports of repellency of M. incognita to a majority of the ionic solutions, including NHNO, KNO, KCl, MgCl, and CaCl. H. glycines was found to be attracted to both NHNO and KNO, which has not been reported previously. A software program was written to aid in monitoring the location of nematodes at regular time intervals using the root chip. In experiments with the root chip, H. glycines J2s were attracted to roots of 3-day-old, susceptible (cultivar Williams 82) soybean seedlings, and attraction of H. glycines to susceptible soybean was similar across the length of the root. Attraction to resistant (cultivar Jack) soybean seedlings relative to the water only control was inconsistent across runs, and H. glycines J2s were not preferentially attracted to the roots of resistant or susceptible cultivars when both were placed on opposite sides of the same root chip. The chips developed allow for direct tests of plant-parasitic nematode chemotaxis to chemicals and roots with minimal human intervention.

show abstract

mentioning

confidence: 99%

Chip Technologies for Screening Chemical and Biological Agents Against Plant-Parasitic Nematodes

et al. 2016

Self Cite

View full text Add to dashboard Cite

show abstract

“…Not surprisingly, no test condition was significantly different from such a variable control. Therefore, in our view, the Njus et al (2015) study appears to offer little evidence to counter the idea that C. elegans orients to magnetic fields.…”

Section: New Behavioral Experiments Support Original Study Replicatiomentioning

confidence: 71%

“…Consistent with our original study that found that magnetic orientation required a cGMP-dependent signaling cascade including the cation channel TAX-4, Caldart and Golombek found that mutation of the TAX-4-obligate subunit TAX-2 abolished this migration (Fig 2B, p = 0.39, n = 12 in the presence of a magnet, p = 0.59, n = 12 when no magnet was present). Landler et al (2017) notes that a study by Njus et al (2015) reported that worms failed to respond to magnetic fields. Njus et al restricted their study to crawling velocity and omega bends and not orientation.…”

Section: New Behavioral Experiments Support Original Study Replicatiomentioning

confidence: 99%

Temporal and spatial factors that influence magnetotaxis in C. elegans

Vidal-Gadea

Caldart

Bainbridge

et al. 2018

Preprint

View full text Add to dashboard Cite

Many animals can orient using the earth's magnetic field. In a recent study, we performed three distinct behavioral assays providing evidence that the nematode Caenorhabditis elegans orients to earth-strength magnetic fields (Vidal-Gadea et al., 2015). In addition to these behavioral assays, we found that magnetic orientation in C. elegans depends on the AFD sensory neurons and conducted subsequent physiological experiments showing that AFD neurons respond to earth-strength magnetic fields. A new behavioral study by Landler et al. (2017) suggested that C. elegans does not orient to magnetic fields and raises issues that cast doubt on our study. Here we reanalyze Lander et al.'s data to show how they appear to have missed observing positive results, and we highlight differences in experimental methods and interpretations that may explain our different results and conclusions. Moreover, we present new data from our labs together with replication by an independent lab to show how temporal and spatial factors influence the unique spatiotemporal trajectory that worms make during magnetotaxis. Together, these findings provide guidance on how to achieve robust magnetotaxis and reinforce our original finding that C. elegans is a suitable model system to study magnetoreception.

show abstract

“…For instance, this feature could be used for quantifying cell viability with spatial resolution within each well. It is worth noting that microplates with fewer wells (and consequently bigger ones) would allow experiments with small model animals such as C. elegans [25][26][27] and Planarians 18,28 where, we emphasize, the interpretation of any finding should take into careful consideration the nonnegligible field variations within each well.…”

Section: Discussionmentioning

confidence: 99%

A novel system of coils for magnetobiology research

Makinistian

2016

Review of Scientific Instruments

View full text Add to dashboard Cite

A novel system of coils for testing in vitro magnetobiological effects was designed, simulated, and built. Opposite to what is usual, the system generates a controlled gradient of magnetic field. This feature is introduced to allow the assessment of multiple values of the field in a single experiment. The apparatus consists of two flattened orthogonal coils, which permit independent control of two of the spatial components of the field. Geometry of design, combined with the use of a standard multi-well microplate for cellular culture, allows for simultaneous testing of 96 different field conditions. The system, intended to increase the efficiency of evaluating biological effects throughout ranges of the field parameters, was fully characterized injecting DC currents to the coils (i.e., generating static magnetic fields) in order to assess the spatial distribution of both the field's and field-gradient's components. Temperature load was carefully evaluated and the maximum values of 350 μT and 9 μT/mm (for the field and its gradient) could be generated without excessive heating of the cellular cultures.

show abstract

Characterizing the Effect of Static Magnetic Fields on <i>C. elegans</i> Using Microfluidics

Cited by 13 publications

References 23 publications

Chip Technologies for Screening Chemical and Biological Agents Against Plant-Parasitic Nematodes

Chip Technologies for Screening Chemical and Biological Agents Against Plant-Parasitic Nematodes

Temporal and spatial factors that influence magnetotaxis in C. elegans

A novel system of coils for magnetobiology research

Contact Info

Product

Resources

About