Gene duplications can arise as products of several types of errors in DNA replication and repair machinery as well as through fortuitous capture by selfish genetic elements. Common sources of gene duplications include ectopic recombination, retrotransposition event, aneuploidy, polyploidy, and replication slippage.

What is alternative gene splicing?

Alternative splicing is the process of selecting different combinations of splice sites within a messenger RNA precursor (pre-mRNA) to produce variably spliced mRNAs. These multiple mRNAs can encode proteins that vary in their sequence and activity, and yet arise from a single gene.

How is gene duplication related to divergence?

Gene duplications do not always result in detrimental mutations; they can contribute to divergent evolution, which causes genetic differences between groups to develop and eventually form new species.

What is the fate of duplicated genes?

Evolutionary fates of duplicated genes The most likely fate is that one of the pair will degenerate to a pseudogene or be lost from the genome due to the vagaries of chromosomal remodelling, locus deletion or point mutation (in a process known as NON-FUNCTIONALIZATION).

What controls alternative splicing?

Splicing is regulated by trans-acting proteins (repressors and activators) and corresponding cis-acting regulatory sites (silencers and enhancers) on the pre-mRNA. Together, these elements form a “splicing code” that governs how splicing will occur under different cellular conditions.

Does alternative splicing affect gene expression?

It is frequently employed to autoregulate proteins that affect the splicing process itself. Thus, alternative splicing and NMD, acting together, play an important and widespread role in regulating gene expression.

What is duplication mutation?

​Duplication Duplication is a type of mutation that involves the production of one or more copies of a gene or region of a chromosome. Gene and chromosome duplications occur in all organisms, though they are especially prominent among plants. Gene duplication is an important mechanism by which evolution occurs.

What is the history of alternative splicing?

Gilbert (1) first proposed the concept of alternative splicing in 1978, which is currently the mechanism that accounts for the discrepancy between the number of protein-coding genes (~25,000) in humans and the >90,000 different proteins that are actually generated (2, 3).

What is the role of alternative splicing of precursor mRNA?

Abstract Alternative splicing of precursor mRNA is an essential mechanism to increase the complexity of gene expression, and it plays an important role in cellular differentiation and organism development.

How many types of alternative splicing are there in vertebrates?

Systematic analyses of ESTs and microarray data have so far revealed seven main types of alternative splicing (12) (Fig. 1). The most prevalent pattern (~30%) is the cassette-type alternative exon (exon skipping) in vertebrates and invertebrates (Fig. 1C), while in lower metazoans, it is intron retention (Fig. 1F) (15).

What is RNA splicing and how does it work?

1.  Introduction The discovery of the phenomenon that viral sequences are removed from a pre-mRNA and the remaining sequences are joined together led to a fundamental principle governing biology, known as RNA splicing.