This web page was produced as an assignment for Genetics 677, an undergraduate course at UW-Madison.
RNA interference
Several RNAi databases were used to obtain model organism homologues. In particular, I looked at whether homologues of COL1A1 exist in C. elegans and D. melanogaster.
Using WormBase, I found that the gene col-181 in C. elegans is homologous to COL1A1 in humans. This protein's accession number is WP:CE26826. The sequence for the col-181 protein can be accessed by clicking here. [2] Further investigation using PhenoBank did not yield any particular phenotype to watch for in RNAi mutants. The post embryonic phenotype in RNAi mutants was regarded as wild-type [1]. This type of result may indicate that this homolog is not as important in C. elegans, due to their lack of skeletal structure. Therefore, since the proper functioning of col-181 is not necessary for normal development in this model organism, it is not likely to be a good choice for future research into the etiology of osteogenesis imperfecta. However, investigating how this mutated col-181 affects the organism could eventually give insight into how collagen-related proteins function.
An additional collagen protein in C. elegans is is 83.1% similar to col-181. This protein is called col-73 and can be accessed by the number WP:CE09354; its protein sequence can be seen by clicking here. Of interest is the fact that both col-181 and col-73 both contain 20 collagen triple helix repeats. Moreover, col-73 has been found to exhibit the phenotype "dumpy" when RNAi was performed. From this, it is predicted that this protein is important for body morphogenesis. Take together, this indicates to me that col-73 is a better place to start in order to elucidate the functioning of collagen proteins in C. elegans. [2]
It is relevant to note that both col-181 and col-73 were predicted to be both integral to the membrane and a structural constituent of the cuticle. With this knowledge, I predict mutant phenotypes of important collagen genes in C. elegans to affect the cuticle of these worms. [2]
The homolog of col-181 found in D. melanogaster is 53% similar and its accession number is CG42342 [2]. FlyBase did not yield very much information about this particular protein. However, this protein is known to contain collagen triple helix repeats and is made from a nuclear gene [3]. Further study needs to occur before it can be determined whether this would be a beneficial model organism. At this point, too little is known and for that reason alone, I am reluctant to consider its use for research related to COL1A1.