Jaynes Research

Contact

Name: James B. Jaynes, PhD
Position: Professor

Jefferson Alumni Hall, Room 479
1020 Locust Street
Philadelphia, PA 19107

Contact Number(s):

Highlighted Publications

Smith, S.T. and Jaynes, J.B.  (1996). A conserved region of engrailed, shared among all en-, gsc‑, Nk1-, Nk2-, and msh-class homeoproteins, mediates active transcriptional repression in vivo, Development 122, 3141-3150.

Here, the conserved repressor domain of Engrailed was defined and characterized.  This domain has been used by many laboratories to convert other transcription factors into repressors, helping to reveal their target genes and their modes of action in vivo.

Fujioka, M., Emi-Sarker, Y., Yusibova, G.L., Goto, T., and Jaynes, J.B.  (1999). Analysis of an even-skipped rescue transgene reveals both composite and discrete neuronal and early blastoderm enhancers, and multi-stripe positioning by gap gene repressor gradients, Development 126, 2527-2538.

Here it is shown that the complex spatial and temporal pattern of expression of the even skipped gene can be dissected into an array of discrete enhancers, one for each major pattern element.  This serves as a textbook example of how genes are regulated in higher eukaryotic organisms, including humans.

Miki Fujioka, Galina L. Yusibova, Jian Zhou, and James B. Jaynes  (2008). The DNA binding Polycomb-group protein Pleiohomeotic maintains both active and repressed transcriptional states through a single site;  Development 135: 4131-4139.  Cited by 12.  http://dev.biologists.org/cgi/content/full/135/24/4131

This paper describes the discovery of the bifunctional role of one of the DNA-binding Polycomb-group proteins, Pleiohomeotic (Pho), which is required to maintain either the active or the repressed state of a gene in an epigenetic fashion, depending on whether the gene was activated or repressed earlier in development.

Fujioka, M., Sun, G., and Jaynes, J.B.  (2013). The Drosophila eve Insulator Homie Promotes eve Expression and Protects the Adjacent Gene from Repression by Polycomb Spreading.  PLoS-Genetics 9(10): e1003883.  doi:10.1371/journal.pgen.1003883.  http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1003883

This work showed that chromatin insulators block Polycomb-mediated repression from spreading along a chromosome, preventing the repression 

Miki Fujioka, Hemlata Mistry, Paul Schedl, and James B. Jaynes  (2016).  Determinants of Chromosome Architecture: Insulator Pairing in cis and in trans. PLoS Genet 12(2): e1005889.   doi:10.1371/journal.pgen.1005889
http://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1005889

Here, the modes of action of the even skipped chromatin insulators homie and nhomie are analyzed using long-range gene regulation in cis and in trans, along with chromosome conformation capture, to show how directional pairing of insulators dictates which enhancers interact with which promoters, thereby orchestrating genome function.

D. Chetverina, M. Fujioka, M. Erokhin, P. Georgiev, J. B. Jaynes, and P. Schedl (2017). Boundaries of loop domains (insulators): Determinants of chromosome form and function in multicellular eukaryotes. Bioessays 38: 1600233, DOI 10.1002/bies.201600233

This paper reviews recent insights into the interplay between gene regulation and chromosome architecture in 3 dimensions.

Jacob Peacock, James B. Jaynes (2017)  Using competition assays to quantitatively model cooperative binding by transcription factors and other ligands, Biochimica et Biophysica Acta (BBA) - General Subjects, ISSN 0304-4165, doi:10.1016/j.bbagen.2017.07.024
http://www.sciencedirect.com/search?qs=&authors=jaynes&pub=Biochimica%20et%20Biophysica%20Acta%20%28BBA%29%20-%20General%20Subjects&volume=&issue=&page=&origin=journal&zone=qSearch&publicationTitles=271022&withinJournalBook=true

This work describes novel methods for analyzing cooperativity in sequence-specific DNA binding by transcription factors in eukaryotic organisms.

Recent Publications

A β-Catenin-TCF-Sensitive Locus Control Region Mediates GUCY2C Ligand Loss in Colorectal Cancer

An insulator blocks access to enhancers by an illegitimate promoter, preventing repression by transcriptional interference

Analysis of the DNA-binding properties of Alx1, an evolutionarily conserved regulator of skeletogenesis in echinoderms

Defining the boundaries of polycomb domains in drosophila

Dynamic interplay between enhancer–promoter topology and gene activity

Using competition assays to quantitatively model cooperative binding by transcription factors and other ligands

Boundaries of loop domains (insulators): Determinants of chromosome form and function in multicellular eukaryotes

Determinants of Chromosome Architecture: Insulator Pairing in cis and in trans

Genome-wide identification of Drosophila Hb9 targets reveals a pivotal role in directing the transcriptome within eight neuronal lineages, including activation of Nitric oxide synthase and Fd59a/Fox-D

The Drosophila eve Insulator Homie Promotes eve Expression and Protects the Adjacent Gene from Repression by Polycomb Spreading

Engrailed cooperates directly with Extradenticle and Homothorax on a distinct class of homeodomain binding sites to repress sloppy paired

Regulation of a duplicated locus: Drosophila sloppy paired is replete with functionally overlapping enhancers

Ecdysone- and NO-Mediated Gene Regulation by Competing EcR/Usp and E75A Nuclear Receptors during Drosophila Development

A chromatin insulator mediates transgene homing and very long-range enhancer-promoter communication

The DNA-binding Polycomb-group protein Pleiohomeotic maintains both active and repressed transcriptional states through a single site

The interaction of DIAP1 with dOmi/HtrA2 regulates cell death in Drosophila

Transcription of bxd Noncoding RNAs Promoted by Trithorax Represses Ubx in cis by Transcriptional Interference

Embryonic even skipped-dependent muscle and heart cell fates are required for normal adult activity, heart function, and lifespan

Erratum: Drawing lines in the sand: Even skipped et al. and parasegment boundaries (Developmental Biology (2004) 269 (609-622) DOI: 10.1016/j.ydbio. 2004.03.001)

Drawing lines in the sand: Even skipped et al. and parasegment boundaries

Embryonic origins of a motor system: Motor dendrites form a myotopic map in Drosophila

Methylation at lysine 4 of histone H3 in ecdysone-dependent development of Drosophila

Even-skipped, acting as a repressor, regulates axonal projections in Drosophila

Specification of Motoneuron Fate in Drosophila: Integration of Positive and Negative Transcription Factor Inputs by a Minimal eve Enhancer

Engrailed cooperates with extradenticle and homothorax to repress target genes in Drosophila