A subsequence of a string is obtained by deleting zero or more characters from the string. Since the answer may be very large, return it modulo 10 9 + 7. Given a string s, return the number of different non-empty palindromic subsequences in s. In contrast, long palindromic sequences make the genome unstable by inducing DSBs and such sequences are usually removed from the genome by homologous recombination events. Count Different Palindromic Subsequences.
Our results suggest that short palindromic sequences are highly stable in vivo. Since DSBs are initiators of nearly all meiotic recombination events, most of the palindrome-induced breaks appear to be repaired by homologous recombination. The DSB formation at the palindrome requires all of the gene products that are known to be responsible for DSB formation at the normal meiosis-specific sites. The palindrome-mediated DSB formation depends on the primary sequence of the inverted repeat and the location and length of the repeated units. Here we present both genetic and physical evidence that long palindromic sequences (>50 bp) generate double-strand breaks (DSBs) at a high frequency during meiosis in the yeast Saccharomyces cerevisiae. The palindrome-mediated genomic instability is believed to be due to cruciform or hairpin formation and subsequent cleavage of this structure by structure-specific nucleases. A case of gene conversion between inmunoglobulin Vg region genes was analysed and palindromic sequences were found to be located near to the left recombinatorial breakpoint, which also is flanked by a direct repeat sequence. However, long palindromic sequences are rare and are a major source of genomic instability. Gene conversion is a recombinatorial mechanism which transfers genetic information from a donor into a recipient gene. In molecular biology, palindromic sequences are referred to as the sequence of nucleotides in the DNA duplex or RNA, where the sequence in one strand is the same as the complementary sequence of the other strand when read from the same direction on both the strands, either 5’ to 3’ or 3’ to 5’. 5' to 3') on one strand matches the sequence reading in the opposite direction (e.g. Palindromes are the group of words that read the same, forward and backward. Such repeated sequences are usually short and present at several functionally important regions in the genome. Which is a palindromic sequence A palindromic sequence is a nucleic acid sequence in a double-stranded DNA or RNA molecule wherein reading in a certain direction (e.g. 2012.Inverted-repeated or palindromic sequences have been found to occur in both prokaryotic and eukaryotic genomes. When the complementary strand is read backwards, the sequence is 5’-GGATCC-3’ which is identical to the first one, making it a palindromic sequence. This is the sequence where the restriction endonuclease, BamHI, binds to and cleaves at a specific cleavage site. An example of a palindromic sequence is 5’-GGATCC-3’, which has a complementary strand, 3’-CCTAGG-5’. So if a sequence is palindromic, the nucleotide sequence of one strand would be the same as its reverse complementary strand. The pairing of nucleotides within the DNA double-helix is complementary which consist of Adenine (A) pairing with either Thymine (T) in DNA or Uracil (U) in RNA, while Cytosine (C) pairs with Guanine (G). Recognition sites of many restriction enzymes are palindromic. The sequence is the same when one strand is read left to right and the other strand is read right to left. Recognition sites of many restriction enzymes are palindromic. A DNA locus whose 5'-to-3' sequence is identical on each DNA strand. In a single-stranded molecule, COMPLEMENTARY BASE PAIRING can occur when the chain is folded back (See also HAIRPIN). The sequence is the same when one strand is read left to right and the other strand is read right to left. palindrome a sequence in double-stranded nucleic acids that reads the same on both strands when reading one strand from left to right and the other from right to left (i.e. A DNA sequence whose 5'-to-3' sequence is identical on each DNA strand. Answer (1 of 4): A palindromic sequence is a sequence made up of nucleic acids within double helix of DNA and/or RNA that is the same when read from 5' to 3' on one strand and 5' to 3' on the other, complementary strand.
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