1. BAC (Bacterial artificial chromosome)
&
YAC(Yeast artificial chromosome)
PRESENTED BY: ASHA PATEL
CLASS: M.Sc SEM 2

3. COMMON GENE COMPONENTS IN BAC
 RepE: for plasmid replication and regulation of copy
number.
 ParA and parB: for partitioning F plasmid DNA to daughter
cells during division and ensures stable maintenance of the
BAC.
 Selectable marker: for antibiotic resistence; some BACs also
have lacZ at the cloning site for blue/white selection.
 T7 & Sp6: phage promoters for transcription of inserted
genes.
 OriS: the origin of replication

4. MOLECULAR
CLONING IN BAC

5. APPLICATION OF BAC
 BACs are being greatly used in modeling genetic diseases in order to
study their effects in the experimentation on transgenic mice.
 BAC have been used to study neurological diseases such as
Alzheimer’s disease or in the case of down syndrome.
 The genome of several large DNA Viruses and RNA viruses have been
cloned as BACs. These constructs are referred to as “infectious
clones”.

6. YEAST ARTIFICIAL CHROMOSOME (YAC)
 First described in 1983 by Murray and Szostak.
 Yeast artificial chromosomes is a human engineered DNA molecule used to
clone DNA sequences in yeast cells.
 YACs are shuttle vectors capable of replicating and being selected in common
bacterial hosts such as E.coli as well as in the yeast S. cerevisiae.
 They are capable of carrying approximately upto 1000 kbp of inserted DNA
sequence.
 Many different YAC plasmids exist, such as pYAC3 & pYAC4.

7. COMPONENTS OF YAC
The vector contains several elements of typical yeast
chromosomes including:
CEN: A yeast centromere, that ensures chromosome
partitioning between two daughter cells and a selective
marker genes.
ARSI: Yeast autonomously replicating sequence
TEL: Yeast telomere
Yeast selectable marker such as URA3 & TRP1 and
Bacterial selectable marker.

8. CONSTRUCTION OF YAC
 A YAC is built using an initial circular DNA plasmid, which is
typically cut into a linear DNA molecule using restriction
enzymes.
 DNA ligase is then used to ligate a DNA sequence or gene of
interest into the linearized DNA, forming a single large, circular
piece of DNA.

10.  Appropriately modified YACs can be utilized in many
different organisms, for cloning or genome analysis.
 Chromosomal translocation (chromosome abnormality that
occurs due to rearrangement of parts among non
homologous chromosomes) can be studied by means of
disposable YACs that do not contain genetic information
necessary for cell function.
 To identify essential mammalian chromosomal sequences
necessary for the future construction of specialized
mammalian artificial chromosomes(MACs).
APPLICATION OF YAC

12. REFERENCES
WEBLIOGRAPHY
BIBLIOGRAPHY
http://web.ornl.gov/sci/techresources/meetings/bacpac/
http://www.els.net/WileyCDA/ElsArticle/refld-a0000379.html
https://www.ncbi.nlm.nih.gov/pubmed/7859160
S.B.Primrose and R.M. Twyman.(2006) Principles of Gene
Manipulation and Genomics(7th ed), Graphicraft Limited,Hong
Kong,p.204-8.