ABSTRACT
The šrst draft of the human genome sequence was published in 2001 (Lander et al., 2001; Venter et al., 2001) and contains 90% of the 3 billion bases, with the completed sequence published in 2004 (International Human Genome Sequencing [IHGS] Consortium, 2004). The most important feature of the sequence was that the number of genes in the human genome was a lot smaller than the earlier estimate of 50,000-140,000. In the recent version of human genome built (NCBI 37.1, https://www.ncbi.nlm.nih.gov/projects/mapview/map_search.cgi?taxid=9606), there are 33,897 transcripts, 21,901 of which are annotated genes (including predicted genes). There are also 3031 nonprotein coding genes with an RNA product. According to estimates, the function of about 40% or more of the transcripts is not known. Besides, there are regulatory elements in the genome, like promoter and enhancer, that coordinate and organize the gene expression (Nobrega et al., 2003; Poulin et al., 2005; Woolfe et al., 2005; Prabhakar et al., 2006; Pennacchio et al., 2006). Efforts are being made to identify such elements and establish their role in gene expression (Visel et al., 2009), the role of these sequences have not been fully explored. Genome-wide association studies
12.1 Introduction .......................................................................................................................... 227 12.2 How to Make Functional Annotation of the Mammalian Genome......................................228 12.3 Reverse versus Forward Genetics Approach ........................................................................228 12.4 N-Ethyl-N-Nitrosourea Mutagen of Choice .......................................................................... 229 12.5 Mouse as Model System for ENU Mutagenesis ...................................................................230 12.6 ENU Mutagenesis Approach in Mice ................................................................................... 231 12.7 Role of Phenotyping in ENU Mutagenesis Screen ............................................................... 231 12.8 Breeding Scheme: Identišcation of Recessive versus Dominant Mutation .......................... 232 12.9 Identišcation of the Mutated Gene ....................................................................................... 232
12.9.1 Mapping ................................................................................................................... 233 12.9.2 Finding the Gene ......................................................................................................234
