Skip to main content
Ch. 15 - Recombinant DNA Technology and Its Applications
Sanders - Genetic Analysis: An Integrated Approach 3rd Edition
Sanders3rd EditionGenetic Analysis: An Integrated ApproachISBN: 9780135564172당신이 사용하는 게 아니라요?교과서 변경
모든 교과서Sanders 3rd EditionCh. 15 - Recombinant DNA Technology and Its Applications문제 17
15장, 문제 17

The bacteriophage ϕX174 has a single-stranded DNA genome of 5386 bases. During DNA replication, double-stranded forms of the genome are generated. In an effort to create a restriction map of ϕX174, you digest the z-stranded form of the genome with several restriction enzymes and obtain the following results. Draw a map of the ϕX174 genome.
Table displaying restriction enzyme digestion results for the bacteriophage ϕX174 genome, including fragment sizes.

검증된 단계별 안내
1
Step 1: Understand the data provided. The genome of bacteriophage ϕX174 is 5386 bases long. The table shows the fragment sizes obtained after digestion with different restriction enzymes: PstI, PsiI, and DraI, both individually and in combinations. Single enzyme digests give the total fragment sizes, while double digests give overlapping fragment sizes that help locate the cut sites relative to each other.
Step 2: Start by mapping the single enzyme digests. Since PstI and PsiI each cut the genome once (single fragment of 5386 bases), they likely cut at one site each, linearizing the circular genome. DraI cuts twice, producing two fragments of 4307 and 1079 bases, indicating two cut sites.
Step 3: Use the double digest data to determine the relative positions of the cut sites. For example, the PstI + PsiI digest produces fragments of 3078 and 2308 bases. Since PstI and PsiI each cut once, these two fragments sum to 5386 bases, confirming the genome length. This tells us the distance between the PstI and PsiI sites is 2308 bases on one side and 3078 bases on the other.
Step 4: Similarly, analyze the PstI + DraI digest fragments (331, 1079, 3976 bases) and PsiI + DraI digest fragments (898, 1079, 3409 bases). These three fragments sum to 5386 bases, confirming the genome length. Use these fragment sizes to position the DraI sites relative to PstI and PsiI by matching overlapping fragment sizes and distances.
Step 5: Draw the circular genome map by placing the PstI site at an arbitrary position (e.g., 0), then mark the PsiI site 2308 bases away. Next, place the two DraI sites such that the fragment sizes between PstI, PsiI, and DraI sites correspond to the fragment sizes observed in the double digests. This will give a complete restriction map of the ϕX174 genome.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
1m
도움이 되었나요?

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Restriction Enzyme Digestion and Fragment Analysis

Restriction enzymes cut DNA at specific sequences, producing fragments of varying lengths. By analyzing the sizes of these fragments after digestion, one can infer the locations of enzyme cut sites on the genome. Comparing single and double digests helps determine the relative positions of these sites.
추천 영상:
가이드 코스
00:57
Step 2

Restriction Mapping

Restriction mapping is the process of creating a physical map of a DNA molecule based on the pattern of fragments generated by restriction enzyme digestion. By combining data from single and multiple enzyme digests, the order and distance between restriction sites can be deduced, allowing construction of a genome map.
추천 영상:
가이드 코스
07:11
Mapping with Markers

Double-Stranded DNA Replication of Single-Stranded Genomes

Although ϕX174 has a single-stranded DNA genome, it forms double-stranded replicative forms during replication. Restriction enzymes require double-stranded DNA to cut, so digestion experiments are performed on these replicative forms to analyze the genome structure.
추천 영상:
가이드 코스
03:03
Double Strand Breaks
관련 실천
교과서 질문

You have isolated a genomic clone with an EcoRI fragment of 11 kb that encompasses the CRABS CLAW gene. You digest the genomic clone with HindIII and note that the 11-kb EcoRI fragment is split into three fragments of 9 kb, 1.5 kb, and 0.5 kb.

Does this tell you anything about where the CRABS CLAW gene is located within the 11-kb genomic clone?

613
views
교과서 질문

To further analyze the CRABS CLAW gene, you create a map of the genomic clone. The 11-kb EcoRI fragment is ligated into the EcoRI site of the MCS of the vector shown in Problem 18. You digest the double-stranded form of the genome with several restriction enzymes and obtain the following results. Draw, as far as possible, a map of the genomic clone of CRABS CLAW.

What restriction digest would help resolve any ambiguity in the map?

438
views
교과서 질문

You have isolated a genomic clone with an EcoRI fragment of 11 kb that encompasses the CRABS CLAW gene (see Problem 18). You digest the genomic clone with HindIII and note that the 11-kb EcoRI fragment is split into three fragments of 9 kb, 1.5 kb, and 0.5 kb.

Restriction enzyme sites within a cDNA clone are often also found in the genomic sequence. Can you think of a reason why occasionally this is not the case? What about the converse: Are restriction enzyme sites in a genomic clone always in a cDNA clone of the same gene?

554
views
교과서 질문

The bacteriophage lambda genome can exist in either a linear form or a circular form.

Diagram the resulting fragments as they would appear on an agarose gel after electrophoresis.

460
views
교과서 질문

The bacteriophage lambda genome can exist in either a linear form or a circular form.

How many fragments will be formed by restriction enzyme digestion with XhoI alone, with XbaI alone, and with both XhoI and XbaI in the linear and circular forms of the lambda genome?

675
views
교과서 질문

The restriction enzymes XhoI and SalI cut their specific sequences as shown below:

Can the sticky ends created by XhoI and SalI sites be ligated? If yes, can the resulting sequences be cleaved by either XhoI or SalI?

1563
views