Research Interests

Writing, reading and erasing the embryonic epigenetic code

Research Area

The Shechter Lab is in the Depart­ment of Bio­chem­istry at the Albert Ein­stein Col­lege of Med­i­cine in the Bronx, NY. Our research focuses on a “bottom-up” bio­chem­i­cal under­stand­ing of the nature of embry­onic chro­matin, in par­tic­u­lar the role of the his­tone pro­teins and his­tone post-translational modifications. We use eggs and oocytes of the African clawed frog, Xeno­pus lae­vis, as the major model sys­tem in our lab­o­ra­tory (in addi­tion to recom­bi­nant pro­teins and cul­tured cells). The eggs and cell-free extracts of the eggs of the frog Xeno­pus lae­vis were the first sys­tem used for somatic-cell nuclear trans­fer cloning exper­i­ments almost a half-century ago and have been exten­sively used for char­ac­ter­i­za­tion of devel­op­ment, cell-cycle pro­gres­sion, and DNA repli­ca­tion. The cell-free extracts reca­pit­u­late most bio­log­i­cal phe­nom­ena in a bio­chem­i­cally dis­sectible form, in which com­po­nents can be added and removed and small-molecules can be applied. Xeno­pus are the lab­o­ra­tory animal

Current Members

Shechter, David (Principal Investigator/Director)

Additional Information

We focus on exper­i­men­tal frame­works using Xeno­pus lae­vis cell-free egg and oocyte extract because it is best suited for bio­chem­i­cal dis­sec­tion of phe­nom­ena that occur in the egg and oocyte. Frogs are the evolutionarily-closest-to-mammals, com­monly used, ver­te­brate model sys­tem. Xeno­pus lae­vis frogs lay thou­sands of large eggs, from which cell free extract can be read­ily pre­pared that is capa­ble of reca­pit­u­lat­ing most mol­e­c­u­lar phe­nom­ena in a test tube. The extract can be frac­tion­ated, its cell cycle state altered, and small mol­e­cules and pro­teins can be added and removed to mod­u­late activ­i­ties. Xeno­pus has been used as a lab­o­ra­tory sys­tem for a very long time, and has a long his­tory of pro­duc­ing cru­cial obser­va­tions in many fields of biol­ogy. Fur­ther­more, Xeno­pus has a sig­nif­i­cant his­tor­i­cal link to the study of epi­ge­net­ics, as John Gurdon’s pio­neer­ing and long-term work in ver­te­brate cloning and repro­gram­ming has been mostly per­formed in the frog (Gur­don, 1962). Xeno­pus also has a very strong record of study of pat­tern for­ma­tion and early devel­op­ment, as the embryos are large and exper­i­men­tally manip­u­la­ble. How­ever, most recent work into the bio­chem­istry of chro­matin and epi­ge­net­ics has been per­formed with recon­sti­tuted sys­tems, mam­malian cul­tured cells, and in uni­cel­lu­lar organ­isms such as yeast and cil­i­ates. The biggest weak­ness of the Xeno­pus model sys­tem is the dif­fi­culty of per­form­ing genetic exper­i­ments and analy­sis, as Xeno­pus lae­vis is allote­traploid, takes almost a year to develop to sex­ual matu­rity, and the genome has not been fully sequenced. How­ever, bio­chem­i­cal manip­u­la­tions of cell-free extracts, such as immun­ode­ple­tions and appli­ca­tion of het­erol­o­gous DNAs and nuclei (includ­ing well estab­lished and stud­ied mam­malian cells), can bypass the need for genetic manipulation.

Contact

Institution: Albert Einstein College of Medicine

Address:
Department of Biochemistry
ack and Pearl Resnick Campus
Bronx, New York
USA

Web Page: http://www.einstein.yu.edu/faculty/11980/david-shechter/