文档介绍：Working with Bioinformation& Bioinformatics Databases
Finding
Retrieving
Alignments
Similarity
Homology
Objectives/Questions
What could this sequence be?
Are there any sequences like this?
Is my sequence similar to another?
Does any sequence have similar functions?
Are there genes with similar expression pattern?
Are there similar genes in anisms?
Objectives/Find
Genes which are similar to this one.
Genes which are homologous to this one.
This gene in anisms.
Genes that are similarly expressed.
Variations (. SNPs) in this sequence.
Genes with a similar function.
Objectives/Find
Primers to identify a sequence like this
How this protein works
Publications about this gene
Publications about this sequence
Publications about this function
Whether this gene is involved in disease
Search
Search engines
Algorithms
Alignment
Scoring
Probability
Similarity Searching
What is similar to my sequence?
DNA and amino acids
Tools: Blast and Fasta
Basis for finding similarity: sequence alignment
>gb||BE588357 194087 BARC 5BOV Bos taurus cDNA Length=369
Score = 272 bits (137), Expect = 4e-71
Identities = 258/297 (86%), Gaps = 1/297 (0%)
Strand = Plus / Plus
Query: 17 atggca |||||||||||||||| | ||| | ||| || ||| | |||| ||||| ||||||||| ||
Sbjct: 1 act-
Query: 77 gtgtca
|||||||||||||||||||||||| | || ||||||||| | ||||||||||| ||| ||
Sbjct: 60 aggaagcggtgaca
Query:137
|||||||| | || | ||||||||||||||| ||||||||||| || ||||||||||||
Sbjct: 120
Query: 197 tct
||||||||| | |||||||| |||||||||||||||||| ||||||||||||||||||||
Sbjct: 180 tct
Similarity vs. Homology
Homology defined-1
"The an in different animals under a variety of form and function.”
Sir Richard Owen, Lectures on parative Anatomy and Physiology of the Invertebrate Animals, 1843.