As the high-density array technology became a reliable tool for copy number profiling, multiple gene copy number datasets were generated, revealing the genomic heterogeneity of key cancer types at the gene copy number level [ 17].
Due to a low resolution of common methods, such as comparative genomic hybridization, the ability to precisely determine multiple gene copy numbers is limited.
In addition, if a subsystem is critical for a specific system's function, then it often gets replicated (e.g., multiple gene copy numbers in the genome) in the complex system; this redundancy contributes to system's robustness.
Because some large genes overlap with multiple genes, the numbers of unique genes involved in overlap in human and mouse are not 2 × 669 = 1338 and 1108 but are only 1219 (1219/13484 = 9.0%) and 1004 (7.4%), respectively.
But obtaining sequences from throughout multiple gene families for large numbers of target species is costly as well as being experimentally and analytically challenging.
Passerine birds have an exceptionally diverse MHC with multiple gene copies and large numbers of alleles compared to other avian taxa.
69 70 The ability to analyse multiple gene sequences from large numbers of samples, complemented with functional screening and characterisation of randomly cloned DNA fragments from the GI tract, is currently being exploited to uncover changes in disease states including in inflammatory bowel disease (IBD).
Thus, for a given GOslim category, if the numbers of families from single pHap families equals the number of multiple gene families, then there should be 9 times the number of pHaps from multiple gene families than are in single member families.
Recent advances in high throughput "next-generation" resequencing technologies [24] now make it feasible to deep-resequence multiple genes in large numbers of subjects in a cost effective manner, and should enable these broader hypotheses to be tested.
By contrast, worm species belonging to the phylum Nematoda had multiple genes with copy numbers ranging from three to eight.
