Beginnings of recombinant DNA

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Beginnings of recombinant DNA
Construction of Biologically Functional Bacterial
Plasmids In Vitro (PNAS 70 3240-3244).1973 por
S. Cohen, H. Boyer y otros
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Restriction enzymes
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A hypothetical restriction enzyme recognizes a
8bp sequence containing all four bases. What is
the probability of finding that sequence in a DNA
molecule composed of equal amounts of A, T, C and
G

• (1/8)4
• (1/4)8
• (1/16)8
• None of the above

b. Is the correct answer
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The endonuclease BamI recognizes the sequence
GGATCC
CCTAGG How
many sites would this enzyme cut in the human
genome, which is approximately 3 x 109 bp and has
a 40 GC content?

• 3 x 109 (0.2)2(0.3)4
• 3 x109 (0.3)2(0.2)4
• 3x109(0.25)6
• None of the above

b. Is correct
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Engineered plasmids as cloning vectors
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Lambda as a cloning vector
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Cosmids
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cDNA library
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Library screening how do you find the clone
containing the gene you want?
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Differential hybridization
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Genomic vs cDNA libraries
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Northerns RNA hybridization
Sry DNA as probe
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DNAchips and microarrays
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Full yeast genome on a chip
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DNA sequencing
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After reading a Sanger dideoxy sequencing gel
from the bottom to the top you obtain the
following read TGCATGCAGATA

• This sequence corresponds to
• Newly synthesized strand 5 to 3 end
• Newly synthesized strand 3 to 5 end
• Template strand 5 to 3 end
• Template strand 3 to 5 end

a. Is correct
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After reading a Sanger dideoxy sequencing gel
from the bottom to the top you obtain the
following read TGCATGCAGATA

• The template sequence is
• 5 TGCATGCAGATA 3
• 3TGCATGCAGATA 5
• 5ACGTACGTCTAT 3
• 3ACGTACGTCTAT 5

d. Is correct