Cain NE et al. (2015) Nucleus "SUN proteins and nuclear envelope spacing."

Cain NE, Starr DA

[Nucleus, 2015]

The nuclear envelope consists of 2 membranes separated by 30-50 nm, but how the 2 membranes are evenly spaced has been an open question in the field. Nuclear envelope bridges composed of inner nuclear membrane SUN proteins and outer nuclear membrane KASH proteins have been proposed to set and regulate nuclear envelope spacing. We tested this hypothesis directly by examining nuclear envelope spacing in Caenorhabditis elegans animals lacking UNC-84, the sole somatic SUN protein. SUN/KASH bridges are not required to maintain even nuclear envelope spacing in most tissues. However, UNC-84 is required for even spacing in body wall muscle nuclei. Shortening UNC-84 by 300 amino acids did not narrow the nuclear envelope space. While SUN proteins may play a role in maintaining nuclear envelope spacing in cells experiencing forces, our data suggest they are dispensable in most cells.

Zhou K et al. (2010) Dev Dyn "Movers and shakers or anchored: Caenorhabditis elegans nuclei achieve it with KASH/SUN."

Zhou K, Hanna-Rose W

[Dev Dyn, 2010]

The invariant cell division patterns that characterize Caenorhabditis elegans development make it an ideal system to study the mechanisms that control nuclear movement and positioning. Forward genetic screens in this system allowed identification of the key molecular machinery for connecting the nucleus to the cytoskeleton; pairs of protein partners, consisting of a KASH domain protein and a SUN domain protein, bridge the nuclear envelope to connect the nucleus to cytoskeletal components. The C. elegans genome encodes several KASH/SUN pairs, and mutant phenotypes as well as tissue-specific expression patterns suggest a diversity of functions. These functions include moving the nucleus but have been extended to effects on the chromosomes inside the nucleus as well. We review the impact of the C. elegans system in pioneering this field as well as the functions of these KASH/SUN protein pairs across spatial and temporal C. elegans development.

Ernst IM et al. (2013) Ageing Res Rev "Vitamin E supplementation and lifespan in model organisms."

Nikolai S, Rimbach G, Pallauf K, Ernst IM, Roeder T, Bendall JK, Paulsen L, Huebbe P

[Ageing Res Rev, 2013]

We have conducted a comprehensive literature review regarding the effect of vitamin E on lifespan in model organisms including single-cell organisms, rotifers, Caenorhabditis elegans, Drosophila melanogaster and laboratory rodents. We searched Pubmed and ISI Web of knowledge for studies up to 2011 using the terms "tocopherols", "tocotrienols", "lifespan" and "longevity" in the above mentioned model organisms. Twenty-four studies were included in the final analysis. While some studies suggest an increase in lifespan due to vitamin E, other studies did not observe any vitamin E-mediated changes in lifespan in model organisms. Furthermore there are several studies reporting a decrease in lifespan in response to vitamin E supplementation. Different outcomes between studies may be partly related to species-specific differences, differences in vitamin E concentrations and the vitamin E congeners administered. The findings of our literature review suggest that there is no consistent beneficial effect of vitamin E on lifespan in model organisms which is consistent with reports in human intervention studies.

Horn HF (2014) Curr Top Dev Biol "LINC complex proteins in development and disease."

Horn HF

[Curr Top Dev Biol, 2014]

The LINC complex spans the nuclear envelope and plays critical roles in coordinating nuclear and cytoplasmic activities and in organizing nuclear and cytoskeletal features. LINC complexes are assembled from KASH and SUN-domain proteins, which interact in the nuclear envelope and form a physical link between the cytoskeleton and the nuclear interior. A number of diseases have been associated with mutations in genes coding for LINC complex proteins. Mouse models of LINC complex protein have provided valuable insight into LINC complex functions and into how these proteins contribute to the various diseases with which they have been associated.

Felix MA et al. (2002) Hermann, Editeurs des Sciences et des Arts. Paris, France. "Caenorhabditis elegans. Un organisme modele en biologie."

Labouesse M, Segalat L, Felix MA

[Hermann, Editeurs des Sciences et des Arts. Paris, France., 2002]

L'espce Caenorhabditis elegans fut dcrite en 1900 Alger par E. Maupas, qui s'intressait son mode de reproduction hermaphrodite. Plus tard, vers le milieu du vingtime sicle, V. Nigon et ses collaboratuers Lyon tudirent les reorganizations cellulaires accompagnant la fecundation et les premiers clivages. J. Brun isola les preiers mutants morpholgiques.

Lewis E et al. (1994) Parasite "Cuticulin genes of nematodes."

Bazzicalupo P, Zei F, Lassandro F, Lewis E, Ristoratore F, Nola M, Sebastiano M, Favre R, Cermola M

[Parasite, 1994]

Two genes coding for cuticlin components of Coenorhabditis elegans have been cloned and their structure is described. Recombinant proteins have been produced in E. coli and antibodies raised against them. Nucleic acid and specific antibodies are being used to isolate the homologues from the parasitic species Ascaris lumbricoides and Brugia pahangi.

Bucher EA et al. (1994) Seminars in Developmental Biology "Gastrulation in the nematode Caenorhabditis elegans."

Bucher EA, Seydoux GC

[Seminars in Developmental Biology, 1994]

Gastrulation in Caenorhabditis elegans has been described by following the movements of individual nuclei in living embryos by Nomarski microscopy. Gastrulation starts in the 26-cell stage when the two gut precursors, Ea and Ep, move into the blastocoele. The migration of Ea and Ep does not depend on interactions with specific neighboring cells and appears to rely on the earlier fate specification of the E lineage. In particular, the long cell cycle length of Ea and Ep appears important for gastrulation. Later in embryogenesis, the precursors to the germline, muscle and pharynx join the E descendants in the interior. As in other organisms, the movement of gastrulation permit novel cell contacts that are important for the specification of certain cell fates.

Starr DA et al. (2003) J Cell Sci "ANChors away: an actin based mechanism of nuclear positioning."

Han M, Starr DA

[J Cell Sci, 2003]

Mechanisms for nuclear migration and nuclear anchorage function together to control nuclear positioning. Both tubulin and actin networks play important roles in nuclear positioning. The actin cytoskeleton. has been shown to position nuclei in a variety of systems from yeast to plants and animals. It can either act as a stable skeleton to anchor nuclei or supply the active force to move nuclei. Two C elegans genes and their homologues play important roles in these processes. Syne/ANC-1 anchors nuclei by directly tethering the nuclear envelope to the actin cytoskeleton, and UNC-84/SUN functions at the nuclear envelope to recruit Syne/ANC-1.

McGhee JD (2013) Wiley Interdiscip Rev Dev Biol "The Caenorhabditis elegans intestine."

McGhee JD

[Wiley Interdiscip Rev Dev Biol, 2013]

The transcriptional regulatory hierarchy that controls development of the Caenorhabditis elegans endoderm begins with the maternally provided SKN-1 transcription factor, which determines the fate of the EMS blastomere of the four-cell embryo. EMS divides to produce the posterior E blastomere (the clonal progenitor of the intestine) and the anterior MS blastomere, a major contributor to mesoderm. This segregation of lineage fates is controlled by an intercellular signal from the neighboring P2 blastomere and centers on the HMG protein POP-1. POP-1 would normally repress the endoderm program in both E and MS but two consequences of the P2-to-EMS signal are that POP-1 is exported from the E-cell nucleus and the remaining POP-1 is converted to an endoderm activator by complexing with SYS-1, a highly diverged -catenin. In the single E cell, a pair of genes encoding small redundant GATA-type transcription factors, END-1 and END-3, are transcribed under the combined control of SKN-1, the POP-1/SYS-1 complex, as well as the redundant pair of MED-1/2 GATA factors, themselves direct zygotic targets of SKN-1 in the EMS cell. With the expression of END-1/END-3, the endoderm is specified. END-1 and END-3 then activate transcription of a further set of GATA-type transcription factors that drive intestine differentiation and function. One of these factors, ELT-2, appears predominant; a second factor, ELT-7, is partially redundant with ELT-2. The mature intestine expresses several thousand genes, apparently all controlled, at least in part, by cis-acting GATA-type motifs.

Elliott TS et al. (2014) Curr Opin Chem Biol "Genetic code expansion and bioorthogonal labelling enables cell specific proteomics in an animal."

Chin JW, Elliott TS, Bianco A

[Curr Opin Chem Biol, 2014]

The site specific, co-translational introduction of unnatural amino acids into proteins produced in cells has been facilitated by the development of the pyrrolysyl-tRNA synthetase/tRNACUA pair. This pair can now be used to direct the site-specific incorporation of designer amino acids in E. coli, yeast, mammalian cells, and animals (the worm, C. elegans and the fly, D. melanogaster). Developments in encoding components of rapid bioorthogonal reactions are providing new opportunities for labelling and visualising proteins. A new method called stochastic orthogonal recoding of translation with chemoselective modification (SORT-M) leverages advances in genetic code expansion and bioorthogonal chemistry to label proteomes with diverse chemistry at diverse codons in E. coli, mammalian cells, and in spatially and temporally defined sets of cells in the fly. Proteomes in targeted sets of cells have been visualised by SORT-M and proteins in targeted cells have been identified by SORT-M.