Apoptosis contributes to protect germ cells from the oogenic germline starvation response but is not essential for the gonad shrinking or recovery observed during adult reproductive diapause in C. elegans

AbstractCaenorhabditis elegans typically feeds on rotting fruit and plant material in a fluctuating natural habitat, a boom-and-bust lifestyle. Moreover, stage specific developmental responses to low food concentration suggest that starvation-like conditions are a regular occurrence. In order to assess variation in the C. elegans starvation response under precisely controlled conditions and simultaneously phenotype a large number of individuals with high precision, we have developed a microfluidic device that, when combined with image scanning technology, allows for high-throughput assessment at a temporal resolution not previously feasible and applied this to a large mapping panel of fully sequenced intercross lines. Under these conditions worms exhibit a markedly reduced adult lifespan with strain-dependent variation in starvation resistance, ranging from <24 hours to ∼120 hours. Genome-wide mapping of the responses of more than 7,855 individuals identified four quantitative trait loci (QTL) of large effects. Three of these loci are associated with single genes (ash-2, exc-6, and dpy-28) and the fourth is a ∼26 KB region on Chromosome V encompassing several genes. Backcross with selection confirmed the effect of the Chromosome V locus. Segregating natural variation for starvation response in this species suggests that different isolates may use different strategies (facultative vivipary versus reproductive diapause) for dealing with extreme food deprivation.

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Faculty Opinions recommendation of C. elegans germ cells show temperature and age-dependent expression of Cer1, a Gypsy/Ty3-related retrotransposon.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.717197869.792452870 ◽

2012 ◽

Author(s):

Andrew Chisholm

Keyword(s):

Germ Cells ◽

C Elegans ◽

Age Dependent

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glp-3 Is Required for Mitosis and Meiosis in the Caenorhabditis elegans Germ Line

Genetics ◽

10.1093/genetics/145.1.111 ◽

1997 ◽

Vol 145 (1) ◽

pp. 111-121 ◽

Cited By ~ 1

Author(s):

Lisa C Kadyk ◽

Eric J Lambie ◽

Judith Kimble

Keyword(s):

Caenorhabditis Elegans ◽

Germ Cells ◽

Germ Line ◽

Stem Cell Population ◽

Phenotypic Characterization ◽

Loss Of Function ◽

Dapi Staining ◽

Cell Cycles ◽

C Elegans ◽

Mitosis And Meiosis

The germ line is the only tissue in Caenorhabditis elegans in which a stem cell population continues to divide mitotically throughout life; hence the cell cycles of the germ line and the soma are regulated differently. Here we report the genetic and phenotypic characterization of the glp-3 gene. In animals homozygous for each of five recessive loss-of-function alleles, germ cells in both hermaphrodites and males fail to progress through mitosis and meiosis, but somatic cells appear to divide normally. Germ cells in animals grown at 15° appear by DAPI staining to be uniformly arrested at the G2/M transition with <20 germ cells per gonad on average, suggesting a checkpoint-mediated arrest. In contrast, germ cells in mutant animals grown at 25° frequently proliferate slowly during adulthood, eventually forming small germ lines with several hundred germ cells. Nevertheless, cells in these small germ lines never undergo meiosis. Double mutant analysis with mutations in other genes affecting germ cell proliferation supports the idea that glp-3 may encode a gene product that is required for the mitotic and meiotic cell cycles in the C. elegans germ line.

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Perinuclear P granules are the principal sites of mRNA export in adult C. elegans germ cells

Development ◽

10.1242/dev.044255 ◽

2010 ◽

Vol 137 (8) ◽

pp. 1305-1314 ◽

Cited By ~ 102

Author(s):

U. Sheth ◽

J. Pitt ◽

S. Dennis ◽

J. R. Priess

Keyword(s):

Germ Cells ◽

Mrna Export ◽

P Granules ◽

C Elegans

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Genetic control of programmed cell death in the Caenorhabditis elegans hermaphrodite germline

Development ◽

10.1242/dev.126.5.1011 ◽

1999 ◽

Vol 126 (5) ◽

pp. 1011-1022 ◽

Cited By ~ 8

Author(s):

T.L. Gumienny ◽

E. Lambie ◽

E. Hartwieg ◽

H.R. Horvitz ◽

M.O. Hengartner

Keyword(s):

Cell Death ◽

Caenorhabditis Elegans ◽

Germ Cell ◽

Somatic Cell ◽

Cell Fate ◽

Germ Cells ◽

Mapk Pathway ◽

Apoptotic Cell ◽

C Elegans ◽

Pathway Activation

Development of the nematode Caenorhabditis elegans is highly reproducible and the fate of every somatic cell has been reported. We describe here a previously uncharacterized cell fate in C. elegans: we show that germ cells, which in hermaphrodites can differentiate into sperm and oocytes, also undergo apoptotic cell death. In adult hermaphrodites, over 300 germ cells die, using the same apoptotic execution machinery (ced-3, ced-4 and ced-9) as the previously described 131 somatic cell deaths. However, this machinery is activated by a distinct pathway, as loss of egl-1 function, which inhibits somatic cell death, does not affect germ cell apoptosis. Germ cell death requires ras/MAPK pathway activation and is used to maintain germline homeostasis. We suggest that apoptosis eliminates excess germ cells that acted as nurse cells to provide cytoplasmic components to maturing oocytes.

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DEPS-1 promotes P-granule assembly and RNA interference in C. elegans germ cells

Development ◽

10.1242/dev.015552 ◽

2008 ◽

Vol 135 (5) ◽

pp. 983-993 ◽

Cited By ~ 49

Author(s):

C. A. Spike ◽

J. Bader ◽

V. Reinke ◽

S. Strome

Keyword(s):

Rna Interference ◽

Germ Cells ◽

C Elegans

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Analysis of RNA associated with P granules in germ cells of C. elegans adults

Development ◽

10.1242/dev.128.8.1287 ◽

2001 ◽

Vol 128 (8) ◽

pp. 1287-1298 ◽

Cited By ~ 4

Author(s):

J.A. Schisa ◽

J.N. Pitt ◽

J.R. Priess

Keyword(s):

Germ Cells ◽

Rna Binding ◽

Nuclear Surface ◽

Binding Motifs ◽

P Granules ◽

C Elegans ◽

Specific Mrnas ◽

Tubulin Mrna ◽

Protein Components ◽

Cytoplasmic Structures

P granules are cytoplasmic structures of unknown function that are associated with germ nuclei in the C. elegans gonad, and are localized exclusively to germ cells, or germ cell precursors, throughout the life cycle. All the known protein components of P granules contain putative RNA-binding motifs, suggesting that RNA is involved in either the structure or function of the granules. However, no specific mRNAs have been identified within P granules in the gonad. We show here that P granules normally contain a low level of RNA, and describe conditions that increase this level. We present evidence that several, diverse mRNAs, including pos-1, mex-1, par-3, skn-1, nos-2 and gld-1 mRNA, are present at least transiently within P granules. In contrast, actin and tubulin mRNA and rRNA are either not present in P granules, or are present at relatively low levels. We show that pgl-1 and the glh (Vasa-related) gene family, which encode protein components of P granules, do not appear essential for RNA to concentrate in P granules; these proteins may instead function in events that are a prerequisite for RNAs to be transported efficiently from the nuclear surface.

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C. elegans germ cells divide and differentiate in a folded tissue

Developmental Biology ◽

10.1016/j.ydbio.2018.07.013 ◽

2018 ◽

Vol 442 (1) ◽

pp. 173-187 ◽

Cited By ~ 8

Author(s):

Hannah S. Seidel ◽

Tilmira A. Smith ◽

Jessica K. Evans ◽

Jarred Q. Stamper ◽

Thomas G. Mast ◽

...

Keyword(s):

Germ Cells ◽

C Elegans

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Melting dsDNA donor molecules potentiates precision genome editing in C. elegans

10.1101/2020.08.03.235036 ◽

2020 ◽

Author(s):

Krishna S. Ghanta ◽

Craig C. Mello

Keyword(s):

Caenorhabditis Elegans ◽

Genome Editing ◽

Germ Cells ◽

Multiple Injections ◽

C Elegans ◽

Homology Directed Repair ◽

Selection Strategies ◽

Double Stranded Dna ◽

Adult Hermaphrodite

ABSTRACTCRISPR genome editing has revolutionized genetics in many organisms. In the nematode Caenorhabditis elegans one injection into each of the two gonad arms of an adult hermaphrodite exposes hundreds of meiotic germ cells to editing mixtures, permitting the recovery of multiple indels or small precision edits from each successfully injected animal. Unfortunately, particularly for long insertions, editing efficiencies can vary widely, necessitating multiple injections, and often requiring co-selection strategies. Here we show that melting double stranded DNA (dsDNA) donor molecules prior to injection increases the frequency of precise homology-directed repair (HDR) by several fold for longer edits. We describe troubleshooting strategies that enable consistently high editing efficiencies resulting, for example, in up to 100 independent GFP knock-ins from a single injected animal. These efficiencies make C. elegans by far the easiest metazoan to genome edit, removing barriers to the use and adoption of this facile system as a model for understanding animal biology.

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