Analyzing Collagen Alpha 1(XI) Using a Zebrafish Model System

Zebrafish (Danio rerio) are progressively becoming more popular as a model organism for research. The use of zebrafish is advantageous for several reasons. Zebrafish are small in size, exhibit high fecundity, rapidly generate, are transparent during development and are easily maintained in large numbers. Using zebrafish as a model organism, the aim of this project is to determine the function of Collagen Type XI alpha I (COL11A1) during early development. To begin with, it is imperative that the zebrafish are kept healthy. Hence, we control the water quality and nutrition. The healthy zebrafish are then able to breed. The embryos are collected and their RNA is extracted for RT-PCR in order to determine when COL11A1 is being expressed (temporal expression pattern). In addition, anti-sense RNA ribo-probes are used to determine where the COL11A1 gene is being expressed (spatial expression pattern). To study the function of COL11A1, we microinject anti-sense morpholinos into 1-2 cell stage embryos. This diminishes the expression of col11a1 and then the resulting morphants are compared to control zebrafish at the time points of interest. The ultimate goal of this research is to understand the function of COLL11A1 during early development. In doing so, we can gain insight into the Type II Stickler syndrome and Marshall syndrome. ABSTRACT Collagen type XI is a heterotrimeric molecule composed of three α chains, α1(XI), α2(XI), α3(XI). Collagen XI belongs to the fibrillar collagen family and is organized into cartilage fibrils with collagens type II and IX (Fig. 1). In some other cases, it also forms heterotrimer with collagen type V. Collagen XI is also involved in the normal differentiation and spatial organization of growth plate chondrocytes. In humans, mutations in COL11A1 are associated with the birth defects of Type II Stickler syndrome (Fig. 2) and Marshall's syndrome (Fig. 3). The manifestations of Stickler syndrome include flattened facial appearance caused by underdeveloped bones in the middle of the face, as well as both impaired vision and hearing. Individuals with Marshall's syndrome phenotypically display by a flat or retracted midface, large eyeballs, a thick calvaria, abnormal frontal sinuses, and intercranial calcifications. To better understand the collagenopathy of COL11A1, zebrafish (Danio rerio) were used as a model organism for our research. The embryos produced are transparent, and have fewer cells than many other vertebrates. Also, the existence of the embryo outside of the mother allows for direct access. The embryos develop from a single …