THE MOLECULAR BASIS OF INHERITANCE
TRANSPOSONS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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LTR retrotransposon
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Composite transposon
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Non-LTR retrotransposon
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Ac-element
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Detailed explanation-1: -There are two classes of autonomous elements: long terminal repeat (LTR) and non-LTR retrotransposons. Similar in structure to retroviruses, although lacking a functional env gene, LTR retrotransposons encode proteins necessary for retrotransposition.
Detailed explanation-2: -LINEs and SINEs are retrotransposons; that is, they transpose via an RNA intermediate. We discuss how LINEs and SINEs have expanded in eukaryotic genomes and contribute to genome evolution.
Detailed explanation-3: -Examples of LTR retrotransposons are human endogenous retroviruses (HERV) (shown) and various Ty elements of S. cerevisiae (not shown). These elements have terminal LTRs and slightly overlapping ORFs for their group-specific antigen (gag), protease (prt), polymerase (pol), and envelope (env) genes.
Detailed explanation-4: -Long interspersed nuclear elements (LINEs) are the only autonomous and active retrotransposons, which include LINE-1, LINE-2, and LINE-3 (Cordaux and Batzer, 2009; de Koning et al., 2011).
Detailed explanation-5: -The long terminal repeat (LTR) retrotransposons, one of the main groups of retroelements (which include both LTR and non-LTR retrotransposons as well as retroviruses), are among the most abundant constituents of eukaryotic genomes.