Moderate heat stress-induced sterility is due to motility defects and reduced mating drive in Caenorhabditis elegans males.

Moderate heat stress negatively impacts fertility in sexually reproducing organisms at sublethal temperatures. These moderate heat stress effects are typically more pronounced in males. In some species, sperm production, quality and motility are the primary cause of male infertility during moderate heat stress.

LIN-35 is necessary in both the soma and germline for preserving fertility in Caenorhabditis elegans under moderate temperature stress.

Maintenance of germline function under stress conditions is crucial for species survival. The germ line in many species is especially sensitive to elevated temperature. We have investigated the role of the pocket protein LIN-35 in preserving fertility in Caenorhabditis elegans under moderate temperature stress.

Temperature stressed males fail to mate successfully and successful males produce very few viable cross progeny.

Exposure to moderate temperature stress can have profoundly negative effects on an organism's reproductive capacity at temperatures where there are minimal or indiscernible effects on the organism as a whole. These negative effects are often more pronounced in males of the species that produce sperm. Previously we showed that few males of wild type strains are able to successfully produce any cross progeny after experiencing temperature stress.

Wnt Signaling Drives Ectopic Gene Expression and Larval Arrest in the Absence of the DREAM Repressor Complex.

Establishment and maintenance of proper gene expression is a requirement for normal growth and development. The DREAM complex in functions as a transcriptional repressor of germline genes in somatic cells. At 26°, DREAM complex mutants show increased misexpression of germline genes in somatic cells and High Temperature Arrest (HTA) of worms at the first larval stage.

Defects in mating behavior and tail morphology are the primary cause of sterility in males at high temperature.

Reproduction is a fundamental imperative of all forms of life. For all the advantages sexual reproduction confers, it has a deeply conserved flaw: it is temperature sensitive. As temperatures rise, fertility decreases.

synMuv B proteins regulate spatial and temporal chromatin compaction during development.

Tissue-specific establishment of repressive chromatin through creation of compact chromatin domains during development is necessary to ensure proper gene expression and cell fate. synMuv B proteins are important for the soma/germline fate decision and mutants demonstrate ectopic germline gene expression in somatic tissue, especially at high temperature. We show that synMuv B proteins regulate developmental chromatin compaction and that the timing of chromatin compaction is temperature sensitive in both wild type and synMuv B mutants.

Repression of Germline Genes in Somatic Tissues by H3K9 Dimethylation of Their Promoters.

Repression of germline-promoting genes in somatic cells is critical for somatic development and function. To study how germline genes are repressed in somatic tissues, we analyzed key histone modifications in three synMuv B mutants, , , and -all of which display ectopic expression of germline genes in the soma. LIN-35 and LIN-37 are members of the conserved DREAM complex.

Copper Oxide Nanoparticles Impact Several Toxicological Endpoints and Cause Neurodegeneration in Caenorhabditis elegans.

Engineered nanoparticles are becoming increasingly incorporated into technology and consumer products. In 2014, over 300 tons of copper oxide nanoparticles were manufactured in the United States. The increased production of nanoparticles raises concerns regarding the potential introduction into the environment or human exposure.

Natural variants of C. elegans demonstrate defects in both sperm function and oogenesis at elevated temperatures.

The temperature sensitivity of the germ line is conserved from nematodes to mammals. Previous studies in C. briggsae and Drosophila showed that isolates originating from temperate latitudes lose fertility at a lower temperature than strains originating from tropical latitudes.

synMuv B proteins antagonize germline fate in the intestine and ensure C. elegans survival.

Previous studies demonstrated that a subset of synMuv B mutants ectopically misexpress germline-specific P-granule proteins in their somatic cells, suggesting a failure to properly orchestrate a soma/germline fate decision. Surprisingly, this fate confusion does not affect viability at low to ambient temperatures. Here, we show that, when grown at high temperature, a majority of synMuv B mutants irreversibly arrest at the L1 stage.

Mononuclear muscle cells in Drosophila ovaries revealed by GFP protein traps.

Genetic analysis of muscle specification, formation and function in model systems has provided valuable insight into human muscle physiology and disease. Studies in Drosophila have been particularly useful for discovering key genes involved in muscle specification, myoblast fusion, and sarcomere organization. The muscles of the Drosophila female reproductive system have received little attention despite extensive work on oogenesis.

The Ovhts polyprotein is cleaved to produce fusome and ring canal proteins required for Drosophila oogenesis.

An essential component of normal development is controlling the transition from cell proliferation to differentiation. One such transition occurs during Drosophila oogenesis. In early oogenesis, germ cells undergo mitotic proliferation and contain a specialized organelle called a fusome, whereas later post-mitotic cells differentiate and lose the fusome as F-actin-rich ring canals form.

Exploring strategies for protein trapping in Drosophila.

The use of fluorescent protein tags has had a huge impact on cell biological studies in virtually every experimental system. Incorporation of coding sequence for fluorescent proteins such as green fluorescent protein (GFP) into genes at their endogenous chromosomal position is especially useful for generating GFP-fusion proteins that provide accurate cellular and subcellular expression data. We tested modifications of a transposon-based protein trap screening procedure in Drosophila to optimize the rate of recovering useful protein traps and their analysis.