An official website of the United States government
Abstract Habitat loss and fragmentation have independent impacts on biodiversity; thus, field studies are needed to distinguish their impacts. Moreover, species with different locomotion rates respond differently to fragmentation, complicating direct comparisons of the effects of habitat loss and fragmentation across differing taxa and landscapes. To overcome these challenges, we combined mechanistic mathematical modeling and laboratory experiments to compare how species with different locomotion rates were affected by low (∼80% intact) and high (∼30% intact) levels of habitat loss. In our laboratory experiment, we usedCaenorhabditis elegansstrains with different locomotion rates and subjected them to the different levels of habitat loss and fragmentation by placingEscherichia coli(C. elegansfood) over different proportions of the Petri dish. We developed a partial differential equation model that incorporated spatial and biological phenomena to predict the impacts of habitat arrangement on populations. Only species with low rates of locomotion declined significantly in abundance as fragmentation increased in areas with low (p = 0.0270) and high (p = 0.0243) levels of habitat loss. Despite that species with high locomotion rates changed little in abundance regardless of the spatial arrangement of resources, they had the lowest abundance and growth rates in all environments because the negative effect of fragmentation created a mismatch between the population distribution and the resource distribution. Our findings shed new light on incorporating the role of locomotion in determining the effects of habitat fragmentation.
more »
« less
The mechanoreceptor pezo-1 is required for normal crawling locomotion in the nematode C. elegans
The discovery in 2010 of the PIEZO family of mechanoreceptors revolutionized our understanding of the role of proprioceptive feedback in mammalian physiology. Much remains to be elucidated. This study looks at the role this receptor plays in normal locomotion. Like humans, the nematode C. elegans expresses PIEZO-type channels (encoded by the pezo-1 gene) throughout its somatic musculature. Here we use the unbiased automated behavioral software Tierpsy to characterize the effects that mutations removing PEZO-1 from body wall musculature have on C. elegans crawling. We find that loss of PEZO-1 results in disrupted locomotion and posture, consistent with phenotypes associated with loss of PIEZO2 in human musculature. C. elegans is thus an amenable system to study the role of mechanoreception on muscle physiology and function.
more »
« less
- Award ID(s):
- 1818140
- PAR ID:
- 10553908
- Publisher / Repository:
- microPublication Biology
- Date Published:
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Distinct mechanoreceptor pezo-1 isoforms modulate food intake in the nematode Caenorhabditis elegansnull (Ed.)Two PIEZO mechanosensitive cation channels, PIEZO1 and PIEZO2, have been identified in mammals, where they are involved in numerous sensory processes. While structurally similar, PIEZO channels are expressed in distinct tissues and exhibit unique properties. How different PIEZOs transduce force, how their transduction mechanism varies, and how their unique properties match the functional needs of the distinct tissues where they are expressed remain all-important unanswered questions. The nematode Caenorhabditis elegans has a single PIEZO ortholog (pezo-1) predicted to have twelve isoforms. These isoforms share many transmembrane domains, but differ in those that distinguish PIEZO1 and PIEZO2 in mammals. Here we use translational and transcriptional reporters to show that long pezo-1 isoforms are selectively expressed in mesodermally derived tissues (such as muscle and glands). In contrast, shorter pezo-1 isoforms are primarily expressed in neurons. In the digestive system, different pezo-1 isoforms appear to be expressed in different cells of the same organ. We show that pharyngeal muscles, glands, and valve rely on long pezo-1 isoforms to respond appropriately to the presence of food. The unique pattern of complementary expression of pezo-1 isoforms suggest that different isoforms possess distinct functions. The number of pezo-1 isoforms in C. elegans, their differential pattern of expression, and their roles in experimentally tractable processes make this an attractive system to investigate the molecular basis for functional differences between members of the PIEZO family of mechanoreceptors.more » « less
-
Distinct mechanoreceptor pezo-1 isoforms modulate food intake in the nematode Caenorhabditis elegansZetka, M (Ed.)Abstract Two PIEZO mechanosensitive cation channels, PIEZO1 and PIEZO2, have been identified in mammals, where they are involved in numerous sensory processes. While structurally similar, PIEZO channels are expressed in distinct tissues and exhibit unique properties. How different PIEZOs transduce force, how their transduction mechanism varies, and how their unique properties match the functional needs of the tissues they are expressed in remain all-important unanswered questions. The nematode Caenorhabditis elegans has a single PIEZO ortholog (pezo-1) predicted to have 12 isoforms. These isoforms share many transmembrane domains but differ in those that distinguish PIEZO1 and PIEZO2 in mammals. We used transcriptional and translational reporters to show that putative promoter sequences immediately upstream of the start codon of long pezo-1 isoforms predominantly drive green fluorescent protein (GFP) expression in mesodermally derived tissues (such as muscle and glands). In contrast, sequences upstream of shorter pezo-1 isoforms resulted in GFP expression primarily in neurons. Putative promoters upstream of different isoforms drove GFP expression in different cells of the same organs of the digestive system. The observed unique pattern of complementary expression suggests that different isoforms could possess distinct functions within these organs. We used mutant analysis to show that pharyngeal muscles and glands require long pezo-1 isoforms to respond appropriately to the presence of food. The number of pezo-1 isoforms in C. elegans, their putative differential pattern of expression, and roles in experimentally tractable processes make this an attractive system to investigate the molecular basis for functional differences between members of the PIEZO family of mechanoreceptors.more » « less
-
Caenorhabditis elegans is an excellent model to study host-microbe interactions as it is easy to visualize bacterial presence in their intestine. However, previous studies have shown that utilizing transgenic, fluorescent protein-expressing bacteria is not a reliable method to distinguish living bacteria from dead bacteria in the lumen of C. elegans. In this study, we compared methods for visualizing bacterial presence within the C. elegans intestine and found that RNA fluorescent in situ hybridization (RNA FISH) could distinguish the difference between intact and dead bacteria. Thus, we propose RNA FISH as the preferred method to visualize live bacterial presence in the intestines of C. elegans prior to fixation.more » « less
-
Cellular identity and fate are determined by the proteins synthesized. Initiation of mRNA translation requires an important translation factor, eIF4G (ifg-1 in C. elegans). Embryos use mRNA translational control for spatial and temporal regulation of protein synthesis. Using CRISPR engineering, we added in-frame epitope and fluorescent tags (V5, Myc, Flag, GFP, and mCherry) to IFG-1. Tagged forms containing the V5 epitope caused embryonic arrest. Internal disruption of the V5 tag restored viability at 25°C. This study demonstrates that the molecular nature of a small epitope tag is sufficient to disrupt C. elegans embryogenesis.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Data Paper:
- https://doi.org/10.17912/micropub.biology.001085
