# How to write a palindrome sequence as-wish (create, theoretically) ? (self-answered)

There are specific examples from nature, of palindromic sequences.

But without memorizing them, is there any way to randomly write or create or derive a palindromic sequence for a theoretical discussion?

by the way, Genetic palindromes are not an exact ditto of verbal-palindrome.

I once developed a method, but it is so-basic and simple that I'm pretty sure it is already discovered. Here I "shared my knowledge, Q&A-style"

## Step-1

Write a small sequence randomly.

    5'... A T G C C


## Step 2

Write the sequence in opposite-direction, on the next line. It will end at just at the next-place of last place of previous sequence, i.e.

         -------->

5'... A T G C C

C C G T A ...5' .

<-------------


## Step-3

Fill-in-the blanks following base-pair rule, and the sequence is now ready.

5'... A T G$\:$ C C$\:$ | G G C A T ...3'

3'... T A C G G | C C G T$\:$ A ...5'

The previous method was similar way we usually read a verbal palindrome (though unlike a verbal palindrome, any reflection-symmetry was Not present ). But there is a rotational-symmetry (2-fold), (rotational symmetry means it contains parts which are superposable on rotation).

So we could create a palindromic sequence using rotation also.

Or could rotate pre-filled up sequence (if exactly follow the user's instructions)

The brown dot indicates the axis of rotational-symmetry of the written-sequence, vertical to the plane of paper.

• I use the same method, just the steps are different: create a sequence, write its complementary, turn it 180°, tada! Commented Sep 14, 2016 at 13:49
• @another'Homosapien' Thanks but when Ii first came to me, no method was told so I developed one. Now I thought about share, is there any problem doing that?
– user25568
Commented Sep 14, 2016 at 13:58
• you could write an answer
– user25568
Commented Sep 14, 2016 at 13:59
• ok on behalf of you I'll add your method already used in wikipedia.
– user25568
Commented Sep 14, 2016 at 14:08
• I don't think there's any objection, if there was, someone must have commented by now. sharing your knowledge is good, its just that this question has only 24 views yet. just have some patience ;) Commented Sep 14, 2016 at 14:12