What's new?


The birth of birds was selected as one of the top10 scientific achievements of 2014
Science


We published a PNAS paper on Aug 10. It is a multi-disciplinary study integrating stem cell biology, tissue engineering, systems biology analyses, small molecule screening, and eventually a model on guiding multi-cellular configurations in a four-dimensional morphospace. Toward the application side, normally, many aging person become alopecic because adult cells gradually lose regenerative ability. Here, With our new findings, we are able to make adult mouse cells to produce hairs again! The work is also unique that it applies time lapse movies to record cell behaviors and analyze the principles on how stem cells are organized into skin organoids. Lei M, Schumacher LJ, Lai YC, Juan WT, Yeh CY, Wu P, Jiang TX, Baker RE, Widelitz RB, Yang L, Chuong CM. Self-organization process in newborn skin organoid formation inspires strategy to restore hair regeneration of adult cells. Proc Natl Acad Sci U S A. 2017 Aug 22;114(34):E7101-E7110.

We explored the evolution of scales to feathers by identifying a number of molecules using genomic analyses. Candidate genes were tested by expressing them in chicken and alligator scale forming regions. Ectopic expression of these genes induced intermediate morphotypes between feathers and scales which revealed several morphogenetic events along this path: localized growth zone formation, follicle invagination, epithelial branching, feather keratin differentiation and dermal papilla formation. We identified new molecules that act as scale to feather converters which induce one or more regulatory modules guiding these morphogenetic events. We propose that these morpho-regulatory modules were used to diversify archosaur scales and to initiate feather evolution. Wu P, Yan J, Lai YC, Ng CS, Li A, Jiang X, Elsey R, Widelitz R, Bajpai R, Li WH, Chuong CM. Multiple regulatory modules are required for scale-to-feather conversion. Mol Biol Evol. 2017.










This paper has come out this past week with some news coverage. Here are links to the first two reports of this work. BBC news Eureka Alert

We worked with Shuo Wang / Xing Xu, paleontologists in China on the evolution of beak from dinosaurs. The work induced a lot of interest and is covered in the New York Times, Discover, etc. Wang S, Stiegler J, Wu P, Chuong CM, Hu D, Balanoff A, Zhou Y, Xu X. Heterochronic truncation of odontogenesis in theropod dinosaurs provides insight into the macroevolution of avian beaks. Proc Natl Acad Sci U S A. 2017 Sep 25









We collaborated with Cooke / Bustamante in Stanford on a study of budgerigar colors . The paper just came out Oct 5, CELL issue, and is also covered by Nature and other news media. Budgerigars can have different coloring. Blue is based on the structural color and under different control. In this paper, we worked with the Stanford group to identify and characterize this chemical enzyme (polyketide synthase) which normally produces yellow pigment, but does not in the mutant enzyme form. When both are present, blue + yellow = green. The enzyme is already expressed in other tissues of the bird, but it is the co-optive expression in the axial plate that gives color to feathers. The axial plate is a special kind of feather epithelia that disappears to become space between feather branches. It is interesting that the enzyme is expressed in a special kind of keratinocyte instead of in melanocytes. This work is a multi-disciplinary effort.

Cooke TF, Fischer CR, Wu P, Jiang TX, Xie KT, Kuo J, Doctorov E, Zehnder A, Khosla C, Chuong CM, Bustamante CD. Genetic Mapping and Biochemical Basis of Yellow Feather Pigmentation in Budgerigars. Cell. 2017 Oct 5;171(2):427-439.e21.


















A concept animal showing ectodermal and endodermal organs

Research Description
The laboratory asks fundamental questions in bio-medical research. The focus of our research is morphogenesis, i.e. how cells are assembled into functional forms. We are concerned with the principles that determine the specific number, size and shape of different organs. This is an important process, as there is much to learn about the principles that can guide stem cells to form specific tissues and organs required for medical treatment. Our approach is to ask Nature how she does it - using the feather as a Rosetta stone to decipher these principles, because of the distinctive forms of feathers and interest in the evolution of flight. This unique model has allowed us to make several major impacts in the field of morphogenesis and develop interesting interfaces with scientists in different disciplines.  










Self-organization process in newborn skin organoid formation inspires strategy to restore hair regeneration of adult cells.


Hairs grown from organoid cultures

This is our PNAS paper published on Aug 10, 2017. “Self-organization process in newborn skin organoid formation inspires strategy to restore hair regeneration of adult cells”. It is a multi-disciplinary research integrating stem cell biology, self-organization cell behavior, tissue engineering, omcis analyses, small molecule screening, and eventually a model on guiding multi-cellular configurations in a four-dimensional morphospace. Toward the application side, normally, many aging person become alopecic because adult cells gradually lose regenerative ability. Here, With our new findings, we are able to make adult mouse cells to produce hairs again! The work is also unique that it applies time lapse movies to record cell behaviors and analyze the principles on how stem cells are organized into skin organoids.

The movies shown in the paper were integrated from 500 movie recordings. The movies were taken using The USC BCC imaging core facility.

The movies can also be directly accessed by this site

USC news report on our recent paper











Skin cells from adult mouse do not form hairs. With cues learned from the current study, authors can environmental reprogram cells from adult mouse to produce hairs after the skin organoids are transplanted onto nude mice.


Dissociated skin epidermal (green) and dermal (red) progenitor cells undergo a series of morphological transitions to form a reconstituted skin.

@Cheng-Ming Chuong
November 2017