%0 Journal Article
%T Improved Method for Ex Ovo-Cultivation of Developing Chicken Embryos for Human Stem Cell Xenografts
%A Timo Schomann
%A Firas Qunneis
%A Darius Widera
%A Christian Kaltschmidt
%A Barbara Kaltschmidt
%J Stem Cells International
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/960958
%X The characterization of human stem cells for the usability in regenerative medicine is particularly based on investigations regarding their differentiation potential in vivo. In this regard, the chicken embryo model represents an ideal model organism. However, the access to the chicken embryo is only achievable by windowing the eggshell resulting in limited visibility and accessibility in subsequent experiments. On the contrary, ex ovo-culture systems avoid such negative side effects. Here, we present an improved ex ovo-cultivation method enabling the embryos to survive 13 days in vitro. Optimized cultivation of chicken embryos resulted in a normal development regarding their size and weight. Our ex ovo-approach closely resembles the development of chicken embryos in ovo, as demonstrated by properly developed nervous system, bones, and cartilage at expected time points. Finally, we investigated the usability of our method for trans-species transplantation of adult stem cells by injecting human neural crest-derived stem cells into late Hamburger and Hamilton stages (HH26¨CHH28/E5¡ªE6) of ex ovo-incubated embryos. We demonstrated the integration of human cells allowing experimentally easy investigation of the differentiation potential in the proper developmental context. Taken together, this ex ovo-method supports the prolonged cultivation of properly developing chicken embryos enabling integration studies of xenografted mammalian stem cells at late developmental stages. 1. Introduction The chicken is a well-studied and cost-efficient model organism profiting from a great potential of in vivo manipulation techniques. As early as the 5th century B.C. Hippocrates and later on in the 4th century B.C. Aristotle studied embryonic development using chicken embryos. More than 2000 years later, in 1951, Hamburger and Hamilton classified the developmental stages of the chicken embryo in 46 HH stages [1] allowing temporally defined manipulations in developing embryos. Using this kind of age-classification several in ovo experiments such as investigations on neural crest cells (NCCs) and their migratory behavior in the avian embryos were performed [2]. In this regard, stem cells obtained from different animals or even of human origin can be characterized for their potential neural crest ancestry. In a recent study, we transplanted human inferior turbinate stem cells (ITSCs) into early chicken embryos (HH15¨CHH18) [3]. The injected ITSCs migrated laterally forming chains, a characteristic hallmark of neural crest cells. In other studies by Soundararajan et al. and Son
%U http://www.hindawi.com/journals/sci/2013/960958/