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--- chapter_09 [2024/09/01 15:05] – [Cloning by complementation] mike
+++ chapter_09 [2025/03/18 18:04] (current) – [Gene Complementation in Bacteria: F plasmids] mike
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-<typo fs:x-large>Chapter 09. %%Complementation%% in bacteria</typo>
+<-chapter_08|Chapter 08^table_of_contents|Table of Contents^chapter_10|Chapter 10->
+<typo fs:x-large>Chapter 09. %%Complementation in bacteria%%</typo>
 In this chapter, we initially touch on some concepts in classical //E. coli// genetics that may not be of practical interest to all students except future microbiologists, such as F plasmids and Hfr mapping. However, it is useful to learn these concepts because later in the chapter we talk about cloning by complementation, which is a critical concept and skill that all serious students of biology (especially those interested in the area of molecular and cellular biology) need to understand.
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 {{ :f_plasmid.png?400 |}}
 <caption>
-F plasmids. //oriT// (erroneously labeled as OriT in the figure )is the origin of replication for the F plasmid, and the //tra// genes (erroneously labeled as Tra in the figure) are required for forming the pilus needed for transfer of the F plasmid from one cell to another (see Fig. {{ref>Fig2}}). F plasmids are about 10<sup>5</sup> bp long; for comparison, the size of the circular //E. coli// chromosome is 5x10<sup>6</sup> bp, or over 10-fold longer.
+F plasmids. //oriT// (erroneously labeled as OriT in the figure) is the origin of transfer (related to how F is transmitted from one host to another) for the F plasmid, and the //tra// genes (erroneously labeled as Tra in the figure) are required for forming the pilus needed for transfer of the F plasmid from one cell to another (see Fig. {{ref>Fig2}}). F plasmids are about 10<sup>5</sup> bp long; for comparison, the size of the circular //E. coli// chromosome is 5x10<sup>6</sup> bp, or over 10-fold longer.
 </caption>
 </figure>
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 ===== F' is a version of F that carries segments of the $E. coli$ chromosome =====
-Homologous recombination can sometimes occur at a different position to give excise an F plasmid that carries a part of the //E. coli// chromosome. In the example in Fig. {{ref>Fig6}}, this is the BC segment of the //E. coli// chromosome. This form of F is called an F' (pronounced “F prime”).
+Homologous recombination can sometimes occur at a different position to excise an F plasmid that carries a part of the //E. coli// chromosome. In the example in Fig. {{ref>Fig6}}, this is the BC segment of the //E. coli// chromosome. This form of F is called an F' (pronounced “F prime”).
 <figure Fig6>
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 ===== Questions and exercises =====
-Exercise 1: In Chap. {{ref>5}} we discussed the relationship between recombination frequency (m.u. or cM) and physical distance (measured in bp of DNA) (see also [[chapter_12|Chap. 12]] Fig. 1). What is the relationship between minutes in Hfr mapping and physical distance? In other words, how many bp of DNA is equivalent to 1 minute? See [[chapter_08|Chap. 08]] for some key information you might need.
+Exercise 1: In [[chapter_05|Chap. 05]] we discussed the relationship between recombination frequency (m.u. or cM) and physical distance (measured in bp of DNA) (see also [[chapter_12|Chap. 12]] Fig. 1). What is the relationship between minutes in Hfr mapping and physical distance? In other words, how many bp of DNA is equivalent to 1 minute? See [[chapter_08|Chap. 08]] for some key information you might need.
-Conceptual question: why would a strain with a mutated modifying enzyme but a wildtype restriction enzyme (R+ M-) be inviable (incompatible with life)? In other words, why is $R^+ / / M^-$ a lethal mutation?
+Conceptual question: why would a strain with a mutated modifying enzyme but a wildtype restriction enzyme ($R^+ M^-$) be inviable (incompatible with life)? In other words, why is $R^+ M^-$ a lethal combination of alleles?