Wang, John et al. (2009) International Worm Meeting "Life is not fair: larger chromosomes are transmitted to males in C. elegans."

Herr, Winship, Chen, Pei-Jiun, Keller, Laurent, Wang, John, Wang, George

[International Worm Meeting, 2009]

The genome is typically viewed as a collection of cooperating genes whose alleles, in sexual eukaryotes, are segregated fairly during sexual reproduction. However, underneath the veneer of the harmonious and egalitarian genome, conflicts among genes exist and the lottery of gene transmission is sometimes biased. Aside from transposable elements and sperm competition, these topics have been underexplored in C. elegans. We decided to investigate if genetic inheritance in C. elegans is also biased. We tested whether chromosomal aberrations in a heterozygous state are transmitted unequally to offspring using strains carrying transgene insertions or deficiencies. For 4/4 integrated transgene strains tested, we found that heterozygote males (GFP/+) transmitted the insertion-bearing chromosome preferentially to male progeny. The magnitude of the transmission skew was large and differed among the lines (ranging from 2:1 to 6:1 ratio of GFP:non-GFP males). In parallel, we observed a skew of equivalent magnitude in transmission of the non-GFP bearing chromosome to hermaphrodites. We also tested two large deficiencies (tDf1 and nDf24). For both, heterozygote males transmitted the wild-type and deficiency alleles preferentially to the male and hermaphrodite progeny, respectively. These results show that the genetic inheritance in C. elegans is indeed biased, with the larger chromosomes preferentially transmitted to males. To examine the sensitivity of the mechanisms responsible for this transmission skew, we then tested if smaller chromosomal aberrations would exhibit the same phenotype. Thus far, we have tested single gene deletions in unc-47 (gk192) and unc-63 (gk234). For both we observed small (~5%) but significant biases in transmission. This suggests that the skewing mechanism may be able to detect very small chromosomal differences in the range of a few kb. As an entry to understanding transmission skew, we first asked if the skew is sex-specific. We examined transgene transmission in XO her-1 mutants and found that sperm, but not oocytes, display transmission skew. This suggests that transmission skew may happen during spermatogenesis. Transmission skew has important implications and poses interesting questions. This effect could play an important role in genome evolution and reveals an unexpected genetic linkage between autosomes and the X chromosome. More interestingly, the insertion-bearing chromosomes could serve as a model for birth of Y-chromosomes and for understanding how rapid evolution of sex determination systems occurs.

John Wang et al. (2001) International C. elegans Meeting "Global Analysis of Gene Expression Patterns in the Dauer Larvae of Caenorhabditis elegans"

Stuart K Kim, John Wang

[International C. elegans Meeting, 2001]

We are using the full-genome microarrays to profile gene expression differences associated with exit from dauer larvae. In principle, by examining gene expression differences on the whole-genome level, we will be able to illuminate the complete set of genes that are implicated for dauer-specific attributes. Identification of dauer-enriched genes would provide a framework for understanding dauer-specific characteristics, such as altered energy metabolism, certain aspects of aging, stress resistance, and the coordinated execution of a complex morphological change. To identify genes involved with dauer exit, we performed DNA microarray experiments with RNA isolated at different time points after addition of food to a dauer population. Each RNA sample was compared to a common reference RNA, and multiple RNA samples were prepared for each time point. Since some of the genes regulated upon dauer exit might be in response to the introduction of food rather than a dauer-specific developmental response, we also examined the feeding of starved L1's over a similar timecourse. We have identified and begun to analyze about 2700 and 1900 genes that are reproducibly altered during dauer exit and L1 feeding, respectively. Examination of the kinetic profiles of these genes reveals several temporally distinct expression groups, defining a developmental cascade of events that occur during dauer exit or L1 feeding. We find about 400 genes that have similar expression patterns in both timecourses and that constitute a common feeding response. Approximately 900 genes have different expression profiles in the two timecourse. Most are regulated only in the dauer timecourse. These likely represent the dauer-specific developmental response. We have separated the genes, identified above, into different groups based on their expression patterns by hierarchical clustering. Since genes that function together in a common process tend to be placed in the same cluster, we are currently pursuing in-depth analysis of the different clusters to ascertain what types of processes occur during dauer exit and L1 feeding. We found that stress genes (such as heat shock proteins and superoxide dismutases) are highly expressed in the dauer larvae. We also find that detoxification genes are enriched in the dauer larvae. Another interesting and unexpected discovery is that some Major Sperm Proteins (MSPs) are expressed in dauers. MSPs were previously reported to be only expressed in males or L4 and young adult hermaphrodites and to function only as components of sperm. Expression of MSPs in the dauer larvae may reveal an alternative function for a subset of the MSPs.

Infarinato N (2019) J Cell Biol "Xiaochen Wang: Building up our understanding of breaking down."

Infarinato N

[J Cell Biol, 2019]

Wang studies lysosomal degradation pathways using <i>C. elegans</i> as a model system.

Plenefisch JD et al. (1994) Worm Breeder's Gazette "Cloning mua-3: Some Observations on the New Molecular Era"

Plenefisch JD, Hedgecock EM

[Worm Breeder's Gazette, 1994]

Cloning mua-3: some observations on the new Molecular Era John Plenefisch and Edward Hedgecock, Dept. of Biology, Johns Hopkins University, Baltimore MD 21218

Wang JT et al. (2014) Curr Biol "P granules."

Seydoux G, Wang JT

[Curr Biol, 2014]

Wang and Seydoux discuss the functional importance of P granules - the germline-specific RNA granules of C. elegans.

Parham C et al. (1994) Worm Breeder's Gazette "Tc4 and Tc5: What Makes Them Move and Why It Matters"

Beinhorn J, Collins JJ, Butze K, Parham C

[Worm Breeder's Gazette, 1994]

Tc4 and Tc5: what makes them move and why it matters Christi Parham, Kristie Butze, Joanna Beinhorn and John Collins. Dept. of Biochemistry and Molecular Biology, University of New Hampshire. Durham, NH 03824

Almeida CA et al. (1994) Worm Breeder's Gazette "Function of a Domain of the Myosin Heavy Chain Implicated in Familial Hypertrophic Cardiomyopathy"

Collins JJ, Almeida CA, Swift KE

[Worm Breeder's Gazette, 1994]

Function of a Domain of the Myosin Heavy Chain Implicated in Familial Hypertrophic Cardiomyopathy Craig A. Almeida, Kerry E. Swift and John J. Collins Department of Biochemistry and Molecular, University of New Hampshire, Durham, NH 03820

Chalfie M (1993) J Neurobiol "Touch receptor development and function in Caenorhabditis elegans."

Chalfie M

[J Neurobiol, 1993]

Mutations causing a touch-insensitive phenotype in the nematode Caenorhabditis elegans have been the basis of studies on the specification of neuronal cell fate, inherited neurodegeneration, and the molecular nature of mechanosensory transduction. (C) 1993 John Wiley & sons, Inc.

Maine EM et al. (1994) Worm Breeder's Gazette "Mutations That Enhance glp-1 Identify Genes Required For Various Aspects of Germline Development."

Gelber MB, Smardon AM, Shu P, Qiao L, Maine EM, Lissemore JL

[Worm Breeder's Gazette, 1994]

Mutations that enhance glp-1 identify genes required for various aspects of germline development. Eleanor Maine, Li Qiao, Jim Lissemore-, Pei Shu, Anne Smardon, and Melanie Gelber. Biology Dept., Syracuse University, Syracuse, NY 13244 and Biology Dept., John Carroll University, Cleveland, OH 44118.

Chalfie M (1998) Nature "Genome sequencing. The worm revealed."

Chalfie M

[Nature, 1998]

In 1983, John Sulston and Alan Coulson began to construct a complete physical map of the genome of the nematode worm Caenorhabditis elegans, and started what became known as the C. elegans Genome Project. At the time, several people wondered why John, who had just described all of the cell divisions in C. elegans (the cell lineage), was interested in this project rather than in a more 'biological' problem. He replied by joking that he had a "weakness for grandiose, meaningless projects". In 1989, as the physical map approached completion, the Genome Project, now including Bob Waterston and his group, embarked on the even more ambitious goal of obtaining the complete genomic sequence