Byron Williams

Hi!

Welcome to my home page!

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I'm a Research Associate in the Department of Molecular Biology and Genetics at Cornell University, Ithaca, New York. In the laboratory of Michael L. Goldberg, we study mitosis and meiosis in the fruit fly Drosophila melanogaster. We have been collaborating with the laboratory of Maurizio Gatti in the Department of Genetics at the University of Rome "La Sapienza" in Italy.

About me:

Birthday: July 25, 1965.

I grew up in the sunny land of Honolulu, Hawaii, and attended Pauoa Elementary, Kawananakoa Intermediate, then Roosevelt High School, graduating in 1982 (Go Rough Riders!).

Then I left Hawaii going to the mainland and the rainy climate of Reed College in Portland, Oregon. My final year at Reed was spent working with Peter Russell on the bread mold Neurospora. I graduated in 1986 with a B.A. in Biology.

Next, it was off to Graduate School in the Section of Genetics and Development (now the Department of Molecular Biology and Genetics) centered in the Biotechnology Building at Cornell University in Ithaca, New York, getting my Ph.D. in Genetics in 1993. (Finally!). I have survived many unbelievable snowstorms and blizzards here in Ithaca, a far cry from the sunny beaches of Hawaii.

It was also here that I met my wonderful wife, Erika. We were married in 1989. She is also a graduate of Cornell University (class of '86.) Later she ended up working in the Goldberg Lab too! (She made the brain squashes pictured below.) We have a son, Scott, who was born in 1998.

 

Assorted Photos

A picture of Scott and me. (Now, what do you do with this stuff?)

Action Shot! (At Work in the Fly Room.) Too many flies…..!

Max (Our German Shepherd.)

Ithaca Falls. (Just a couple of miles from our home!)

Clematis in our garden.

 

Lab Photos! (Courtesy of Jacklyn Creque.)

Current Lab Members: Jacklyn Creque, Bonnie Bolkan, Jiangtao Yu, Yong Zhao, & Erika Williams.  

The Goldberg Lab (Subset 1). (L-R) Jiangtao Yu, Jackie Creque, Garmay Leung, Bonnie Bolkan, and me.

Goldberg Lab Subset 2. On my birthday. (L-R) Front Row: Jackie Creque, Bonnie Bolkan. Back row: Me, Nate Sylvain, and Erika.

More (Ex-) Goldberg Labmates: Garmay Leung & Zexiao Li. (Now could you please move back from my bench??)

Photos of Cornell

Biotech Building Again

Clock Tower

Johnson Business School

Libe Slope looking down at dorms

Falls near Beebe Lake

 

**** More of My Photos (Fotki.com) ****

 

My work:

Here are some pictures of meiotic cells in prometaphase and metaphase showing the chromosomes (blue) and the ZW10 protein (red.) ZW10 starts off on the kinetochores and then moves to the kinetochore microtubules during metaphase.

Click on the picture to make it bigger.

ZW10 has homologues in higher eukaryotes. We have identified a human homologue of zw10 (hzw10) which is also important in ensuring proper chromosome segregation and preservation of the spindle checkpoint..  The ZW10 protein exists in a large complex with at least two other proteins, ROD and ZWILCH.  These proteins are needed for the localization of other proteins which are important in mitosis: cytoplasmic dynein, a microtubule-based kinetochore motor protein, and MAD2, which functions in the spindle checkpoint to ensure that anaphase does not progress unless chromosomes are properly attached to the spindle at metaphase.  

One place that we can see the effects of mitotic mutations is in the larval brain, fixed, squashed, and stained with orcein to visualize the chromosomes. In the normal Drosophila brain metaphase karyotype, there are four major autosomes (chromosomes 2 and 3), two small dot-like autosomes (chromosome 4) and two sex chromosomes (here the X and Y chromosomes.) In various mutant stocks (such as zw10 mutants) aneuploidy is present.[Aneuploidy refers to a chromosome number that is not simply a multiple of the haploid genome; e.g. 2n+1]. In this case it was likely that chromosome mis-segregation occurred during the previous anaphase. In other mutants, divisions occurring without cytokinesis result in huge polyploid cells containing hundreds of chromosomes.

Mitosis in Brain Neuroblasts can be visualized using anti-tubulin (red), DAPI to stain chromosomes (blue) and anti-centrosomin to see centrosomes (yellow)

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One mutant, we have named mitch for "mitotic chaos", causes defects in congression, or the migration of chromosomes to the metaphase plate. We have discovered the Mitch is yet another occupant of the mitotic centromere/kinetochore.  Another mutant, that we’ve named wip for “wild-pitch”, also results in high levels of aneuploidy and mitotic defects similar to those in mitch.  In preliminary experiments, Wip protein also has been observed  to localize to the kinetochore. 

More Microscopy Photos, Phenotypes click here

I have also studied cytokinesis during meiosis I in Drosophila males, here stained to see the chromosomes (red) and the microtubules (green). During the sequential steps from anaphase (top left) to telophase (bottom right), note the formation of the central spindle between the daughter nuclei, a site of extreme microtubule interdigitation.

A cyst of spermatocytes undergoing meiosis I in the Drosophila mutant quasar, which carry a mutation in the 14-3-3 epsilon gene. The cells have been stained to visualize DNA (red) and microtubules (green). In this mutant, chromosomes are unevenly segregated, resulting in high levels of aneuploidy.

Mutations in the klp3A gene, which encodes a kinesin-like protein, cause defects in cytokinesis (right.) The central spindle (as seen in the wild-type cell, left) does not form in the mutant, together with an absence of cleavage furrow formation. Surprisingly, however, the distance between the separating nuclei, however, remains the same. This indicates that the forces that separate the nuclei during anaphase B stem from the astral microtubules

A sample of papers that describe our research:

 

My favorite links:

FlyBase

Drosophila Genome

PubMed

National Center for Biotechnology Information (NCBI) – all the databases

Scicentral – Interesting science news updated from around the www

 

Online Bio Book – articles about bio topics

 

Tree of Life Web Project – trying to catalogue all life on earth!

 

My e-mail address: bw28@cornell.edu

 

PUBLICATIONS:

Williams, B. C., T. L. Karr, J. M. Montgomery, and M. L. Goldberg (1992). "The Drosophila l(1)zw10 gene product, required for accurate mitotic chromosome segregation, is redistributed at anaphase onset." J. Cell Biol. 118: 759-773.

Williams, B. C. (1993)."Studies on the Drosophila l(1)zw10 gene and its product." Thesis, Cornell University, Ithaca, NY.

Williams, B. C. and M. L. Goldberg. (1994). "Determinants of Drosophila zw10 protein localization and function." J.Cell Sci. 107:785-798.

Williams, B. C., M. F. Riedy, E.V. Williams, M. Gatti, and M. L. Goldberg. (1995). "The Drosophila kinesin-like protein KLP3A is a midbody component required for central spindle assembly and initiation of cytokinesis." J. Cell Biol. 129:709-723.

Williams, B. C., M. Gatti, and M. L. Goldberg. (1996). "Bipolar spindle attachments affect redistributions of ZW10, a Drosophila centromere/kinetochore component required for accurate chromosome segregation." J. Cell Biol. 134, 1127-1140.

Giansanti, M. G., S. Bonaccorsi, B. C. Williams, K. C. Gunsalus, M. L. Goldberg, M. Gatti. (1996). "Genes controlling cytokinesis during meiosis in Drosophlia melanogaster males." In Proceedings on Chromosome Segregation and Aneuploidy (ed. A. Abbondandolo, B.K. Vig, and R. Roi.) pp.304-316.

Williams, B. C., A. F. Dernburg, J. Puro, S. Nokkala, and M.L. Goldberg. (1997) "The Drosophila kinesin-like protein KLP3A is required for pronuclear migration." Development 124(12), 2365-2376.

Starr, D., B. C. Williams, Z. Li, B. Etemad-Moghadam, R. K. Dawe, and M. L. Goldberg. (1997). "Conservation of the centromere/kinetochore protein ZW10." J. Cell Biol. 138 (6), 1289-1301.

Williams, B. C., T. Murphy, M. L. Goldberg, and G. Karpen. (1998). "Neocentromere activity of structurally acentric minichromosomes in Drosophila." Nature Genetics 18, 30l-27.

Basu, J., B. C. Williams, Z. Li, E. V. Williams, and M. L. Goldberg. (1998) "Depletion of a Drosophila homolog of yeast Sup35p disrupts spindle assembly, chromosome segregation, and cytokinesis during male meiosis." Cell Motil Cytoskeleton 39, 286-302.

Giansanti, M. G., S. Bonaccorsi, B. C. Williams, E. V. Williams, C. Santolamazza, M. L. Goldberg, and M. Gatti. (1998) "Cooperative interactions between the central spindle and the contractile ring during Drosophila cytokinesis." Genes Dev 12, 396-410.

Starr, D.A.*, Williams, B.C.*, Hays, T.S. and Goldberg, M.L. (1998) "ZW10 helps recruit dynactin and dynein to the kinetochore."J. Cell Biol. 142:763-74 *These authors contributed equally to this work.

Basu J, Bousbaa H, Logarinho E, Li Z, Williams BC, Lopes C, Sunkel CE, Goldberg ML (1999). "Mutations in the essential spindle checkpoint gene bub1 cause chromosome missegregation and fail to block apoptosis in Drosophila" J Cell Biol. Jul 12;146(1):13-28.

Bentley AM, Williams BC, Goldberg ML, Andres AJ (2002). "Phenotypic characterization of Drosophila ida mutants: defining the role of APC5 in cell cycle progression." J. Cell Sci. 115: 949-61.

Garrett-Engele CM, Siegal ML, Manoli DS, Williams BC, Li H, Baker BS. (2002). "intersex, a gene required for female sexual development in Drosophila, is expressed in both sexes and functions together with doublesex to regulate terminal differentiation." Development. 2002 Oct;129(20):4661-75.

Williams BC, Li Z, Liu S, Williams EV, Leung G, Yen TJ, Goldberg ML. (2003) "Zwilch, a New Component of the ZW10/ROD Complex Required for Kinetochore Functions." Mol Biol Cell. Apr;14(4):1379-91.

Williams BC, Garrett-Engele CM, Li Z, Williams EV, Rosenman ED, Goldberg ML.  (2003). Two putative acetyltransferases, san and deco, are required for establishing sister chromatid cohesion in Drosophila. Curr Biol. Dec 2;13(23):2025-36.

Yu J, Fleming SL, Williams B, Williams EV, Li Z, Somma P, Rieder CL, Goldberg ML. (2004) Greatwall kinase: a nuclear protein required for proper chromosome condensation and mitotic progression in Drosophila.J Cell Biol. Feb 16;164(4):487-92.

Lopes CS, Sampaio P, Williams B, Goldberg M, Sunkel CE. (2005.) The Drosophila Bub3 protein is required for the mitotic checkpoint and for normal accumulation of cyclins during G2 and early stages of mitosis.J Cell Sci. Jan 1;118(Pt 1):187-98.