Our Mission:

The Cornell Heart Lung Blood Resource for Optogenetic Mouse Signaling (CHROMusTM) will develop fifty transgenic mouse lines designed for combinatorial crosses enabling the co-expression of sensors and effectors, or red and green Ca2+ sensors in interacting lineages. As such, the resource will enable researchers to conduct experiments not otherwise possible in a cost effective and highly efficient manner, facilitating the use of optical genetic tools and markedly accelerating scientific discovery.  Additional lines of mice previously developed in the Kotlikoff laboratory that are useful in labeling cell lineages or are GECIs,  will also be included under CHROMusTM

CHROMusTM is directed by Dr. Michael Kotlikoff, Cornell University. A Steering Committee consisting of eleven additional world renowned scientists expert in the fields of cardiac, vascular, lung and immuno biology as well as in fluorescent protein design, optogenetics and gene targeting will meet bi-annually to prioritize and review mouse lines.

Once created, mouse lines will be distributed by the resource initially and deposited with The Jackson Laboratory for further distribution.

Contact us at chromus@cornell.edu

Supported by: National Heart Lung and Blood Institute Grant # R24HL120847

Latest News:

October 12, 2019: All good things must come to an end…After five years of production and twenty-five new strains of transgenic mice developed and distributed to the scientific community we are winding down.  All lines are now available through Jax.org with the exception of our last few which will be there in the near future.  Links to the Jax stock page for each strain are on the mouse production page or click on the name for descriptions of each strain.  This site will be maintained and we will still respond to emails, at least for the foreseeable future.



We are forever grateful to you, the scientific community for supporting our efforts, and using our strains to further your own research.  Please keep us informed of your publications using CHROMus mice and we will add them to our publication page (and don’t forget to acknowledge and/or include us as authors per terms of the MTA you signed).

Yours in living color

Mike, Jane, Frank, Bo and Shaun


October 24, 2018:  New lines are now described on our mouse production page.  Note that for some of these we are still confirming functional analysis but it appears the proteins are expressed in appropriate locations.  New neuronal lines include dbh-CatCh-IRES-lacZ expressing in sympathetic neurons and Aldh1L1-optoα1AR-IRES-lacZ expressing in astrocytes.  New immune system lines include LCK-optoα1AR-IRES-lacZ expressing in T cells and Ly6G-optoβ2AR-IRES-mVermilion expressing in neutrophils.  Lastly, in smooth muscle cells we have developed acta2-GCaMP-ER which targets the GCaMP8.1 calcium indicator to the endoplasmic reticulum.

Interested in a line not listed?  Questions on how to obtain our mice?  Contact us!

November 1, 2017:  A very busy year!  We’ve been working through the more than 100 founders produced over the past 12 months.  We have multiple new expressing transgenic lines and more to come.  Check out our mouse production page to see new information on smooth muscle lines acta2-optoα1AR-IRES-lacZ and acta2-GCaMP8.1-mVermilion; venous system lines HCN4-CatCh-IRES-lacZ, Cdh5-Optoα1AR-IRES-lacZ, Cdh5-optoβ2AR-IRES-lacZ and Cdh5-CatCh-IRES-lacZ; and lung epithelial line SP-C-GCaMP8.

Here’s a quick look at some of the new lines:


LacZ staining of the heart of PN4 neonates, followed by tissue clearing, shows expression within the intricate network of HCN4 expressing, specialized conducting cells lining both the left and right ventricles as well as the SA and AV nodes.


SPC-GCaMP8 native fluorescence (A) and anti-GFP immunohistochemistry (B) showing GCaMP8 expression in alveolar type II cells in the lung







Interested in a line not listed?  Questions on how to obtain our mice?  Contact us!

September 24, 2016: NEW LINES AVAILABLE! New lines expressed in cardiac, venous, endothelial and smooth muscle systems are now available.  Rhodopsin based effectors expressed under control of acta2, HCN4 and αMHC promoters, as well as new GCaMP8 lines expressed under control of αMHC and cdh5 promoters are our latest additions.    Visit our mouse production page for more information on these and other upcoming lines.

October 16, 2015:  New lines available! We have two new lines ready for distribution.  acta2-RCaMP1.07 expresses a red calcium indicator in smooth muscle cells.  HCN4-GCaMP8 expresses a green calcium indicator in the SA node and AV node.  Additionally, other mice previously created in the Kotlikoff laboratory have been added to CHROMus and can be obtained through Jackson Labs.  Visit our mouse production page for more information on these and other upcoming lines.

January 8, 2015: A new year and great progress is being made.  We have founders from 6 transgenic constructs and are now analyzing their expression patterns.  We’ve added a lacZ tag to the rhodopsin based constructs to allow for easy detection.

November 6, 2014: Check out our review article in frontiers in PHYSIOLOGYOptogenetic sensors and effectors: CHROMus—the Cornell Heart Lung Blood Institute Resource for Optogenetic Mouse Signaling

September 9, 2014: Article about CHROMusTM published at http://www.vet.cornell.edu/news/optogenetics.cfm

August 1, 2014: Dr. Kotlikoff awarded NIH grant to develop transgenic mice useful to the NHLBI community, work begins on the transgenes!