Characterization of Seven Genes Affecting Caenorhabditis elegans Hindgut Development

Abstract We have identified and characterized 12 mutations in seven genes that affect the development of the Caenorhabditis elegans hindgut. We find that the mutations can disrupt the postembryonic development of the male-specific blast cells within the hindgut, the hindgut morphology in both males and hermaphrodites, and in some cases, the expression of a hindgut marker in hermaphrodite animals. Mutations in several of the genes also affect viability. On the basis of their mutant phenotypes, we propose that the genes fall into four distinct classes: (1) egl-5 is required for regional identity of the tail; (2) sem-4 is required for a variety of ectodermal and mesodermal cell types, including cells in the hindgut; (3) two genes, lin-49 and lin-59, affect development of many cells, including hindgut; and (4) three genes, mab-9, egl-38, and lin-48, are required for patterning fates within the hindgut, making certain hindgut cells different from others. We also describe a new allele of the Pax gene egl-38 that is temperature sensitive and affects the conserved β-hairpin of the EGL-38 paired domain. Our results suggest that a combination of different factors contribute to normal C. elegans hindgut development.

Download Full-text

A Deficiency Screen for Zygotic Loci Required for Establishment and Patterning of the Epidermis in Caenorhabditis elegans

Genetics ◽

10.1093/genetics/146.1.185 ◽

1997 ◽

Vol 146 (1) ◽

pp. 185-206 ◽

Cited By ~ 1

Author(s):

Rebecca M Terns ◽

Peggy Kroll-Conner ◽

Jiangwen Zhu ◽

Sooyoun Chung ◽

Joel H Rothman

Keyword(s):

Caenorhabditis Elegans ◽

Cell Types ◽

Epidermal Cells ◽

Epidermal Differentiation ◽

Apparent Effect ◽

Internal Organs ◽

C Elegans ◽

Seam Cell ◽

Genomic Regions ◽

Caenorhabditis Elegans Genome

To identify genomic regions required for establishment and patterning of the epidermis, we screened 58 deficiencies that collectively delete at least ∼67% of the Caenorhabditis elegans genome. The epidermal pattern of deficiency homozygous embryos was analyzed by examining expression of a marker specific for one of the three major epidermal cell types, the seam cells. The organization of the epidermis and internal organs was also analyzed using a monoclonal antibody specific for epithelial adherens junctions. While seven deficiencies had no apparent effect on seam cell production, 21 were found to result in subnormal, and five in excess numbers of these cells. An additional 23 deficiencies blocked expression of the seam cell marker, in some cases without preventing cell proliferation. Two deficiencies result in multinucleate seam cells. Deficiencies were also identified that result in subnormal numbers of epidermal cells, hyperfusion of epidermal cells into a large syncytium, or aberrant epidermal differentiation. Finally, analysis of internal epithelia revealed deficiencies that cause defects in formation of internal organs, including circularization of the intestine and bifurcation of the pharynx lumen. This study reveals that many regions of the C. elegans genome are required zygotically for patterning of the epidermis and other epithelia.

Download Full-text

Goα Regulates Volatile Anesthetic Action in Caenorhabditis elegans

Genetics ◽

10.1093/genetics/158.2.643 ◽

2001 ◽

Vol 158 (2) ◽

pp. 643-655 ◽

Cited By ~ 1

Author(s):

Bruno van Swinderen ◽

Laura B Metz ◽

Laynie D Shebester ◽

Jane E Mendel ◽

Paul W Sternberg ◽

...

Keyword(s):

Caenorhabditis Elegans ◽

Novel Mutation ◽

Volatile Anesthetic ◽

Loss Of Function ◽

Wild Type ◽

Α Subunit ◽

C Elegans ◽

Missense Mutant ◽

Anesthetic Action ◽

Mutant Phenotypes

Abstract To identify genes controlling volatile anesthetic (VA) action, we have screened through existing Caenorhabditis elegans mutants and found that strains with a reduction in Go signaling are VA resistant. Loss-of-function mutants of the gene goa-1, which codes for the α-subunit of Go, have EC50s for the VA isoflurane of 1.7- to 2.4-fold that of wild type. Strains overexpressing egl-10, which codes for an RGS protein negatively regulating goa-1, are also isoflurane resistant. However, sensitivity to halothane, a structurally distinct VA, is differentially affected by Go pathway mutants. The RGS overexpressing strains, a goa-1 missense mutant found to carry a novel mutation near the GTP-binding domain, and eat-16(rf) mutants, which suppress goa-1(gf) mutations, are all halothane resistant; goa-1(null) mutants have wild-type sensitivities. Double mutant strains carrying mutations in both goa-1 and unc-64, which codes for a neuronal syntaxin previously found to regulate VA sensitivity, show that the syntaxin mutant phenotypes depend in part on goa-1 expression. Pharmacological assays using the cholinesterase inhibitor aldicarb suggest that VAs and GOA-1 similarly downregulate cholinergic neurotransmitter release in C. elegans. Thus, the mechanism of action of VAs in C. elegans is regulated by Goα, and presynaptic Goα-effectors are candidate VA molecular targets.

Download Full-text

A normally attractive cell interaction is repulsive in two C. elegans mesodermal cell migration mutants

Development ◽

10.1242/dev.113.3.797 ◽

1991 ◽

Vol 113 (3) ◽

pp. 797-803 ◽

Cited By ~ 4

Author(s):

M.J. Stern ◽

H.R. Horvitz

Keyword(s):

Cell Migration ◽

Caenorhabditis Elegans ◽

Premature Termination ◽

Cell Interaction ◽

Egg Laying ◽

Wild Type ◽

Mesodermal Cell ◽

C Elegans ◽

Somatic Gonad ◽

Sex Myoblasts

In wild-type Caenorhabditis elegans hermaphrodites, two bilaterally symmetric sex myoblasts (SMs) migrate anteriorly to flank the precise center of the gonad, where they divide to generate the muscles required for egg laying (J. E. Sulston and H. R. Horvitz (1977) Devl Biol. 56, 110–156). Although this migration is largely independent of the gonad, a signal from the gonad attracts the SMs to their precise final positions (J. H. Thomas, M. J. Stern and H. R. Horvitz (1990) Cell 62, 1041–1052). Here we show that mutations in either of two genes, egl-15 and egl-17, cause the premature termination of the migrations of the SMs. This incomplete migration is caused by the repulsion of the SMs by the same cells in the somatic gonad that are the source of the attractive signal in wild-type animals.

Download Full-text

Tissue-Specific Transcription Footprinting Using RNA PoI DamID (RAPID) in Caenorhabditis elegans

Genetics ◽

10.1534/genetics.120.303774 ◽

2020 ◽

Vol 216 (4) ◽

pp. 931-945 ◽

Cited By ~ 1

Author(s):

Georgina Gómez-Saldivar ◽

Jaime Osuna-Luque ◽

Jennifer I. Semple ◽

Dominique A. Glauser ◽

Sophie Jarriault ◽

...

Keyword(s):

Caenorhabditis Elegans ◽

Rna Polymerase ◽

Cell Types ◽

Neuroendocrine Cells ◽

Cell Physiology ◽

Specific Gene ◽

Cell Content ◽

Tissue Specific ◽

C Elegans ◽

Active Transcription

Differential gene expression across cell types underlies development and cell physiology in multicellular organisms. Caenorhabditis elegans is a powerful, extensively used model to address these biological questions. A remaining bottleneck relates to the difficulty to obtain comprehensive tissue-specific gene transcription data, since available methods are still challenging to execute and/or require large worm populations. Here, we introduce the RNA Polymerase DamID (RAPID) approach, in which the Dam methyltransferase is fused to a ubiquitous RNA polymerase subunit to create transcriptional footprints via methyl marks on the DNA of transcribed genes. To validate the method, we determined the polymerase footprints in whole animals, in sorted embryonic blastomeres and in different tissues from intact young adults by driving tissue-specific Dam fusion expression. We obtained meaningful transcriptional footprints in line with RNA-sequencing (RNA-seq) studies in whole animals or specific tissues. To challenge the sensitivity of RAPID and demonstrate its utility to determine novel tissue-specific transcriptional profiles, we determined the transcriptional footprints of the pair of XXX neuroendocrine cells, representing 0.2% of the somatic cell content of the animals. We identified 3901 candidate genes with putatively active transcription in XXX cells, including the few previously known markers for these cells. Using transcriptional reporters for a subset of new hits, we confirmed that the majority of them were expressed in XXX cells and identified novel XXX-specific markers. Taken together, our work establishes RAPID as a valid method for the determination of RNA polymerase footprints in specific tissues of C. elegans without the need for cell sorting or RNA tagging.

Download Full-text

Inducible Systemic RNA Silencing in Caenorhabditis elegans

Molecular Biology of the Cell ◽

10.1091/mbc.e03-01-0858 ◽

2003 ◽

Vol 14 (7) ◽

pp. 2972-2983 ◽

Cited By ~ 86

Author(s):

Lisa Timmons ◽

Hiroaki Tabara ◽

Craig C. Mello ◽

Andrew Z. Fire

Keyword(s):

Rna Interference ◽

Caenorhabditis Elegans ◽

Rna Silencing ◽

Molecular Mechanisms ◽

Normal Animal ◽

Cell Types ◽

Animal Cells ◽

Tissue Specific ◽

C Elegans ◽

Systemic Rna

Introduction of double-stranded RNA (dsRNA) can elicit a gene-specific RNA interference response in a variety of organisms and cell types. In many cases, this response has a systemic character in that silencing of gene expression is observed in cells distal from the site of dsRNA delivery. The molecular mechanisms underlying the mobile nature of RNA silencing are unknown. For example, although cellular entry of dsRNA is possible, cellular exit of dsRNA from normal animal cells has not been directly observed. We provide evidence that transgenic strains of Caenorhabditis elegans transcribing dsRNA from a tissue-specific promoter do not exhibit comprehensive systemic RNA interference phenotypes. In these same animals, modifications of environmental conditions can result in more robust systemic RNA silencing. Additionally, we find that genetic mutations can influence the systemic character of RNA silencing in C. elegans and can separate mechanisms underlying systemic RNA silencing into tissue-specific components. These data suggest that trafficking of RNA silencing signals in C. elegans is regulated by specific physiological and genetic factors.

Download Full-text

The Caenorhabditis elegans Replication Licensing Factor CDT-1 Is Targeted for Degradation by the CUL-4/DDB-1 Complex

Molecular and Cellular Biology ◽

10.1128/mcb.00736-06 ◽

2006 ◽

Vol 27 (4) ◽

pp. 1394-1406 ◽

Cited By ~ 35

Author(s):

Youngjo Kim ◽

Edward T. Kipreos

Keyword(s):

Caenorhabditis Elegans ◽

Ubiquitin Ligase ◽

S Phase ◽

Null Mutant ◽

Wild Type ◽

C Elegans ◽

Licensing Factor ◽

Ubiquitin Ligase E3 ◽

Blast Cells ◽

Temporal Restriction

ABSTRACT The replication of genomic DNA is strictly regulated to occur only once per cell cycle. This regulation centers on the temporal restriction of replication licensing factor activity. Two distinct ubiquitin ligase (E3) complexes, CUL4/DDB1 and SCFSkp2, have been reported to target the replication licensing factor Cdt1 for ubiquitin-mediated proteolysis. However, it is unclear to what extent these two distinct Cdt1 degradation pathways are conserved. Here, we show that Caenorhabditis elegans DDB-1 is required for the degradation of CDT-1 during S phase. DDB-1 interacts specifically with CUL-4 but not with other C. elegans cullins. A ddb-1 null mutant exhibits extensive DNA rereplication in postembryonic BLAST cells, similar to what is observed in cul-4(RNAi) larvae. DDB-1 physically associates with CDT-1, suggesting that CDT-1 is a direct substrate of the CUL-4/DDB-1 E3 complex. In contrast, a deletion mutant of the C. elegans Skp2 ortholog, skpt-1, appears overtly wild type with the exception of an impenetrant gonad migration defect. There is no appreciable role for SKPT-1 in the degradation of CDT-1 during S phase, even in a sensitized ddb-1 mutant background. We propose that the CUL-4/DDB-1 ubiquitin ligase is the principal E3 for regulating the extent of DNA replication in C. elegans.

Download Full-text

FHOD-1 is the only formin in Caenorhabditis elegans that promotes striated muscle growth and Z-line organization in a cell autonomous manner

10.1101/2020.06.18.159582 ◽

2020 ◽

Cited By ~ 1

Author(s):

Sumana Sundaramurthy ◽

SarahBeth Votra ◽

Arianna Laszlo ◽

Tim Davies ◽

David Pruyne

Keyword(s):

Caenorhabditis Elegans ◽

Muscle Cell ◽

Muscle Development ◽

Striated Muscle ◽

Muscle Growth ◽

Temperature Sensitive ◽

Direct Role ◽

C Elegans ◽

Simple Model System ◽

Body Wall Muscles

AbstractThe striated body wall muscles of Caenorhabditis elegans are a simple model system with well-characterized sarcomeres that have many vertebrate protein homologs. Previously, we observed deletion mutants for two formin genes, fhod-1 and cyk-1, developed thin muscles with abnormal dense bodies/sarcomere Z-lines. However, the nature of the cyk-1 mutation necessitated maternal CYK-1 expression for viability of the examined animals. Here, we tested the effects of complete loss of CYK-1 using a fast acting temperature-sensitive cyk-1(ts) mutant. Surprisingly, neither post-embryonic loss of CYK-1 nor acute loss of CYK-1 during embryonic sarcomerogenesis caused muscle defects, suggesting CYK-1 might not play a direct role in muscle development. Consistent with this, examination of cyk-1(Δ) mutants re-expressing CYK-1 in a mosaic pattern showed CYK-1 cannot rescue muscle defects in a muscle cell autonomous manner, suggesting muscle phenotypes caused by cyk-1 deletion are likely indirect. Conversely, mosaic re-expression of FHOD-1 in fhod-1(Δ) mutants promoted muscle cell growth, as well as proper Z-line organization, in a muscle cell autonomous manner. As we can observe no effect of loss of any other worm formin on muscle development, we conclude that FHOD-1 is the only formin that directly promotes striated muscle development in C. elegans.

Download Full-text

A lineage-resolved molecular atlas of C. elegans embryogenesis at single-cell resolution

Science ◽

10.1126/science.aax1971 ◽

2019 ◽

Vol 365 (6459) ◽

pp. eaax1971 ◽

Cited By ~ 65

Author(s):

Jonathan S. Packer ◽

Qin Zhu ◽

Chau Huynh ◽

Priya Sivaramakrishnan ◽

Elicia Preston ◽

...

Keyword(s):

Nervous System ◽

Caenorhabditis Elegans ◽

Single Cell ◽

Molecular Basis ◽

Cell Types ◽

Embryonic Cells ◽

Cell Type ◽

C Elegans ◽

Exact Position ◽

Sister Cells

Caenorhabditis elegans is an animal with few cells but a wide diversity of cell types. In this study, we characterize the molecular basis for their specification by profiling the transcriptomes of 86,024 single embryonic cells. We identify 502 terminal and preterminal cell types, mapping most single-cell transcriptomes to their exact position in C. elegans’ invariant lineage. Using these annotations, we find that (i) the correlation between a cell’s lineage and its transcriptome increases from middle to late gastrulation, then falls substantially as cells in the nervous system and pharynx adopt their terminal fates; (ii) multilineage priming contributes to the differentiation of sister cells at dozens of lineage branches; and (iii) most distinct lineages that produce the same anatomical cell type converge to a homogenous transcriptomic state.

Download Full-text

Roles of Actin in the Morphogenesis of the Early Caenorhabditis elegans Embryo

International Journal of Molecular Sciences ◽

10.3390/ijms21103652 ◽

2020 ◽

Vol 21 (10) ◽

pp. 3652

Author(s):

Dureen Samandar Eweis ◽

Julie Plastino

Keyword(s):

Cell Division ◽

Caenorhabditis Elegans ◽

Asymmetric Cell Division ◽

Cell Types ◽

Actin Dynamics ◽

Actin Binding ◽

Asymmetric Cell Divisions ◽

C Elegans ◽

Asymmetric Divisions ◽

Different Cell Types

The cell shape changes that ensure asymmetric cell divisions are crucial for correct development, as asymmetric divisions allow for the formation of different cell types and therefore different tissues. The first division of the Caenorhabditis elegans embryo has emerged as a powerful model for understanding asymmetric cell division. The dynamics of microtubules, polarity proteins, and the actin cytoskeleton are all key for this process. In this review, we highlight studies from the last five years revealing new insights about the role of actin dynamics in the first asymmetric cell division of the early C. elegans embryo. Recent results concerning the roles of actin and actin binding proteins in symmetry breaking, cortical flows, cortical integrity, and cleavage furrow formation are described.

Download Full-text

The lysosomal cathepsin protease CPL-1 plays a leading role in phagosomal degradation of apoptotic cells in Caenorhabditis elegans

Molecular Biology of the Cell ◽

10.1091/mbc.e14-01-0015 ◽

2014 ◽

Vol 25 (13) ◽

pp. 2071-2083 ◽

Cited By ~ 16

Author(s):

Meng Xu ◽

Yubing Liu ◽

Liyuan Zhao ◽

Qiwen Gan ◽

Xiaochen Wang ◽

...

Keyword(s):

Caenorhabditis Elegans ◽

Apoptotic Cell ◽

Cell Types ◽

Apoptotic Cells ◽

C Elegans ◽

Lysosomal Protease ◽

Leading Role ◽

Lysosomal Proteases ◽

Cell Corpse

During programmed cell death, the clearance of apoptotic cells is achieved by their phagocytosis and delivery to lysosomes for destruction in engulfing cells. However, the role of lysosomal proteases in cell corpse destruction is not understood. Here we report the identification of the lysosomal cathepsin CPL-1 as an indispensable protease for apoptotic cell removal in Caenorhabditis elegans. We find that loss of cpl-1 function leads to strong accumulation of germ cell corpses, which results from a failure in degradation rather than engulfment. CPL-1 is expressed in a variety of cell types, including engulfment cells, and its mutation does not affect the maturation of cell corpse–containing phagosomes, including phagosomal recruitment of maturation effectors and phagosome acidification. Of importance, we find that phagosomal recruitment and incorporation of CPL-1 occurs before digestion of cell corpses, which depends on factors required for phagolysosome formation. Using RNA interference, we further examine the role of other candidate lysosomal proteases in cell corpse clearance but find that they do not obviously affect this process. Collectively, these findings establish CPL-1 as the leading lysosomal protease required for elimination of apoptotic cells in C. elegans.

Download Full-text