Zhao P et al. (2016) Cell Res "One-step homozygosity in precise gene editing by an improved CRISPR/Cas9 system."

Suehiro Y, Wang X, Gong H, Jiang Y, Lv X, Zhao P, Zhao X, Mitani S, Zhang Z, Xue D

[Cell Res, 2016]

Seydoux GC et al. (1996) Nature "Repression of gene expression in the embryonic germ lineage of C. elegans."

Mello CC, Pettitt J, Priess JR, Seydoux GC, Wood WB, Fire A

[Nature, 1996]

The distinction between soma and germline was recognized more than a century ago: somatic cells form the body of an organism, whereas germ cells serve to produce future generations. In Caenorhabditis elegans, the separation of some and germline occurs through a series of asymmetrical divisions, in which embryonic germline blastomeres divide unequally to produce one somatic daughter and one germline daughter. Here we show that after each asymmetrical division, embryonically transcribed RNAs are detected in somatic, but not germline, blastomeres. This asymmetry depends on the activity of the germline specific factor, PIE-1. In the absence of PIE-1, embryonically transcribed RNAs are detected in both somatic and germline blastomeres. Furthermore, ectopic expression of PIE-1 in somatic blastomeres can significantly reduce the accumulation of new transcripts in these cells. Taken together, these results suggest that germ-cell fate depends on an inhibitory mechanism that blocks new gene expression in the early embryonic germ lineage.

Yin J et al. (2015) Genesis "Multiple cis elements and GATA factors regulate a cuticle collagen gene in Caenorhabditis elegans."

Yin J, Madaan U, Park A, Savage-Dunn C, Aftab N

[Genesis, 2015]

The cuticle of the nematode Caenorhabditis elegans is a specialized extracellular matrix whose major component is collagen. Cuticle collagens are encoded by a large multigene family consisting of more than 150 members. Cuticle collagen genes are expressed in epidermis (hypodermis) and may be stage-specific or cyclically expressed. We identified cuticle collagen genes as transcriptional targets of the DBL-1 TGF--related signaling pathway. These studies prompted us to investigate the cis-regulatory sequences required for transcription of one of the target genes, col-41. We generated reporter constructs that reproduce stage- and tissue-specific expression of fluorescent markers. We identify four conserved sequence elements that are required for transcription of reporters. Finally, we provide evidence that col-41 expression is controlled by a sequence element containing two GATA sites and by the epidermal GATA transcription factors ELT-1 and ELT-3.

Zhao P et al. (2014) Cell Res "Oligonucleotide-based targeted gene editing in C. elegans via the CRISPR/Cas9 system."

Yue Y, Ke H, Zhao P, Xue D, Zhang Z

[Cell Res, 2014]

Burglin TR et al. (1992) Nat Genet "New motif in PBX genes."

Burglin TR, Ruvkun GB

[Nat Genet, 1992]

Human pre-B cell acute lymphoblastic leukaemias are associated with a chimaeric gene that is generated from a t(1;19) chromosomal translocation. This fusion joins the regulatory regions of the lymphoid transcription factor gene, E2A, to the C-terminal region, including the homeodomain, of PBX1 (previously called prl). Tow additional human genes (PBX2 and PBX3) with 77-84% identity to PBX1 have been isolated based on sequence similarity. These genes, however, are too closely related to distinguish between recent divergence and conserved essential motifs, if any, outside the homeodomain. Such conserved domains might be revealed by comparing mammalian sequences with those of more evolutionarily distant organisms, such as the expressed sequence tags (ESTs) generated recently in Caenorhabditis elegans.

Schnabel R et al. (1997) Nature "Hox genes misled by local environments."

Schnabel H, Schnabel R

[Nature, 1997]

Cowing and Kenyon raise an important issue concerning Hox genes by suggesting that these genes may not only be expressed according to position but also according to cell lineage. This suggestion is based on two experiments in which the so-called M cell and two hypodermal V6 cells were manipulated to express a Hox gene, mab-5, outside the posterior region of the Caenorhabditis elegans embryo. Here we propose a less radical interpretation of these data.

Gil-Galvez A et al. (2020) Biotechniques "Cautionary note on the use of Caenorhabditis elegans to study muscle phenotypes caused by mutations in the human MYH7 gene."

Gil-Galvez A, Paradas C, Carbonell-Corvillo P, Miranda-Vizuete A

[Biotechniques, 2020]

Mutations in the human <i>MYH7</i> gene, encoding a slow skeletal muscle/-cardiac myosin heavy chain, cause different types of myopathies. The nematode model <i>Caenorhabditis elegans</i> has frequently been employed to study the molecular and physiological consequences of <i>MYH7</i> mutations in muscle function by introducing mutations into the <i>unc-54</i> gene, the worm <i>MYH7</i> ortholog. We report here that the <i>C. elegans</i> model is not appropriate for such studies if they involve expression of the UNC-54 protein (wild-type or fused to green fluorescent protein) above endogenous levels.

Jin J et al. (2004) Genes Dev "Systematic analysis and nomenclature of mammalian F-box proteins."

Cardozo T, Harper JW, Pagano M, Jin J, Elledge SJ, Lovering RC

[Genes Dev, 2004]

Rajaram S et al. (2000) Genesis "The sequence and associated null phenotype of a C. elegans neurocalcin-like gene."

Sedensky MM, Morgan PG, Rajaram S

[Genesis, 2000]

The neuronal calcium sensor (NCS) proteins belong to a subfamily of the EF-hand calcium binding proteins. These proteins are primarily expressed in the nervous system and currently include more than 20 members across species [Nakayama et al., J Mol Evol 34:416-448, 1992]. Two homologues of the ncs genes, Ce-ncs-1 and Ce-ncs-2, have recently been identified in the nematode C. elegans. Here we report the cDNA sequence of a third C. elegans ncs homologue, Ce-ncs-3. We demonstrate that a null mutation in this gene caused by a large deletion in the locus does not confer a visible phenotype in C. elegans. This, in addition to the strong homology between Ce-NCS-3 and the other C. elegans NCS proteins, may indicate functional redundancy between the three genes.

Mounsey A et al. (2002) Genome Res "Evidence suggesting that a fifth of annotated Caenorhabditis elegans genes may be pseudogenes."

Bauer P, Hope IA, Mounsey A

[Genome Res, 2002]

Only a minority of the genes, identified in the Caenorhabditis elegans genome sequence data by computer analysis, have been characterized experimentally. We attempted to determine the expression patterns for a random sample of the annotated genes using reporter gene fusions. A low success rate was obtained for evolutionarily recently duplicated genes. Analysis of the data suggests that this is not due to conditional or low-level expression. The remaining explanation is that most of the annotated genes in the recently duplicated category are pseudogenes, a proportion corresponding to 20% of all of the annotated C elegans genes. Further Support for this Surprisingly high figure was sought by comparing sequences for families of recently duplicated C elegans genes. Although only a preliminary analysis, clear evidence for a gene having been recently inactivated by genetic drift was found for many genes in the recently duplicated category. At least 4% of the annotated C elegans genes call be recognized as pseudogenes simply from closer inspection of the sequence data. Lessons learned in identifying pseudogenes in C elegans could be of value in the annotation of the genomes of other species where, although there may be fewer pseudogenes, they may be harder to detect.