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The first indications that sex identity could be cell-autonomous rather than entirely hormone-driven arose from studies in non-mammalian species, particularly birds and insects. In the mid-20th century, researchers investigating sexual dimorphism in avian species observed that male and female cells could exhibit distinct characteristics even ...
Autonomous TEs can move by themselves, whereas non-autonomous TEs require the presence of another TE to move. This is often because dependent TEs lack transposase (for Class II) or reverse transcriptase (for Class I). Activator element (Ac) is an example of an autonomous TE, and dissociation elements (Ds) is an
Stress responses can also be triggered in a non-cell autonomous fashion by intercellular communication. The stress that is sensed in one tissue could thereby be communicated to other tissues to protect the proteome of the organism or to regulate proteostasis systemically. Cell non-autonomous activation can occur for all three stress responses.
A cell that is specified can have its commitment reversed while the determined state is irreversible. [3] There are two main types of specification: autonomous and conditional. A cell specified autonomously will develop into a specific fate based upon cytoplasmic determinants with no regard to the environment the cell is in.
In contrast to the autonomous specification, this type of specification is a cell-extrinsic process that relies on cues and interactions between cells or from concentration-gradients of morphogens. Inductive interactions between neighboring cells is the most common mode of tissue patterning.
Short interspersed nuclear elements (SINEs) are non-autonomous, non-coding transposable elements (TEs) that are about 100 to 700 base pairs in length. [1] They are a class of retrotransposons, DNA elements that amplify themselves throughout eukaryotic genomes, often through RNA intermediates. SINEs compose about 13% of the mammalian genome. [2]
Autonomous ones can move on their own, while nonautonomous ones require the presence of another transposable element's gene, transposase, to move. There are three main classifications for movement for DNA transposons: "cut and paste," [ 6 ] " rolling circle " (Helitrons), [ 7 ] and "self-synthesizing" (Polintons). [ 8 ]
Endogenous viral element: These are viral nucleic acids integrated into the genome of a cell. They can move and replicate multiple times in the host cell without causing disease or mutation. They are considered autonomous forms of transposons. Examples are proviruses and endogenous retroviruses. [27]