In Chapter 23, the technique of fluorescence in situ hybridization (FISH) is described. This is another method for examining sequence complexity within a genome. In this method, a DNA sequence, such as a particular gene sequence, can be detected within an intact chromosome by using a DNA probe that is complementary to the sequence. For example, let’s consider the
A. A probe complementary to the Alu sequence
B. A probe complementary to a tandem array near the centromere of the X chromosome
Want to see the full answer?
Check out a sample textbook solutionChapter 10 Solutions
Genetics: Analysis and Principles
- A new technique for rapidly determining the nuclesome structure for regions of chromatin is called Mnase-Seq. Briefly, in MNase-Seq experiments, the chromatin is digested with Micrococcal Nuclease (MNase) and then the resulting digest is subjecting to high throughput sequencing to identify sequences digested by enzyme. See this short article for complete explanation. In the experiment below, researchers conducted an Mnase Seq experiment on a region of a chromosome in the absence (OHT-) and presence (OHT+) of a Protein X. This protein has a dramatic effect on the expression of the Igll1 gene, but no effect on Top3b nor Vpreb1 genes. Based on this information, explain what Protein X is doing to influence the Igll1 gene (limit 4-5 sentences).arrow_forwardDNA is extracted from the blood cells of two different humans, individuals 1 and 2. In separate experiments, the DNA from each individual is cleaved by restriction endonucleases A, B, and C, and the fragments are separated by electrophoresis. A hypothetical map of a 10,000 bp (base pair) segment of a human chromosome is shown (1 kbp= 1,000 bp). Individual 2 has point mutations that eliminate restriction recognition sites B* and C*. After the 10kbp segment is digested with each restriction endonuclease A, B, and C one by one, samples are loaded onto an agarose gel for electrophoresis for analysis. I would like you to draw the result of gel electrophoresis. To answer the question, first, draw the whole gel image (on the right) on your answer sheet, then indicate where you expect to see the bands on the gel. (Hint1: Same-size bands will appear at the same position. Hint 2: On the gel bands from individuals 1 and 2 might be at different positions.) The left lane (with an M label on the…arrow_forwardA short genetic sequence, which may be recognized by primase, is repeated many times throughout the E. coli chromosome. Researchers have hypothesized that primase may recognize this sequence as a site to begin the synthesis of an RNA primer for DNA replication. The E. coli chromosome is roughly 4.6 million bp in length. How many copies of the primase recognition sequence would be necessary to replicate the entire E. coli chromosome?arrow_forward
- Consider a genome whose length is 1000 bp. "Shotgun" sequencing techniques are applied to the genome, resulting in 20 reads, with an average length of 50 bp. A very important point is that, even though 20×50 = 1000, there is no guarantee that ALL 1000 bp of the genome are represented in the fragments. Calculate the coverage. What does this value mean? Why would it be a good idea to have a coverage greater than 1?arrow_forwardTranscriptome analysis involves two separate methodologies: gene expression and RNA seq analyses. The 10 items below are a scrambled listing of the steps used in the two procedures. Identify the steps involved in RNA seq from the list below. Use the numbers in the list to refer to each step. Once the steps for RNA seq have been identified, write the steps in the order in which they are performed during the experiment. (1) DNA sequencing (2) Allow for hybridization and wash excess cRNA. (3) Mix labeled cRNA with array chip. (4) PCR amplification (5) Measure fluorescence intensity to determine abundance of transcripts. (6) Add labeled cRNA at each microarray location. (7) Map cDNA sequences to the genome of the organism to determine identity and abundance of transcripts. (8) mRNA isolation from cells (9) Prepare fluorescently labeled cRNA probes (10) cDNA synthesisarrow_forwardIt is desired to isolate genomic DNA from liquid culture of S. cerevisiae yeast. A commercial kit will be used to isolate genomic DNA from this liquid culture. Answer the following questions to understand the strategy used by commercial kits for genomic DNA isolation. a) List all the steps from cell pellet preparation to DNA elution. b) With which feature can the membrane in the column that comes with the commercial kit bind DNA? c) Which component in the kit would you use to recover the DNA from the membrane of the column to which the DNA was attached?arrow_forward
- In the practical you have been analysing a human genomic library. You know from your calculations that only a small proportion of the human genome is represented, even when the entire class results are considered. Therefore, the chance of finding a particular single-copy gene in your library is very small. Outline a strategy for constructing a genomic DNA library more representative of the entire human genome. You will need to consider alternative vectors and the efficiency of transformation of the bacterial cells.arrow_forwardThe genome of Drosophila melanogaster, a fruit fly, was sequenced in 2000. However, this “completed” sequence did not include most heterochromatin regions. The heterochromatin was not sequenced until 2007 . Most completed genome sequences do not include heterochromatin. Why is heterochromatin usually not sequenced in genome-sequencing projects?arrow_forwardIn generating mutations in a bacterial gene involved in antibiotic resistance, a number of point mutations are isolated that render the bacteria sensitive to the antibiotic. You would like to sequence the gene in order to characterize the mutations, but unfortunately, your lab partner just finished the last of the lab's supply of DNA polymerase. The only things at your disposal are materials for performing a western blot, allowing you to visualize the protein encoded by the gene. How would you identify which mutations are likely to be the result of a missense mutation, which are likely to be the result of a nonsense mutation, and which are likely to be the result of a frameshift mutation?arrow_forward
- Restriction endonucleases are bacterial enzymes that cleave duplex (double-stranded) DNA at specific nucleotide sequences. The mode of replication of the animal virus SV40 has been investigated by using restriction endonucleases that cleave SV40 DNA into a number of unique segments. Like most viruses, SV40 DNA is circular. The map positions of the 11 fragments produced by a pair of restriction endonucleases are shown on the next page. Immediately following a 5 or 10 minute pulse of radioactively labeled thymidine, labeled SV40 molecules that have completed replication during the pulse are isolated. These newly replicated DNA molecules are digested by the restriction endonucleases and the resulting fragments are analyzed for the relative amounts of pulse label they contain. The results are in the table below. Assume that at the time the label was added there was a random population of replicating SV40 DNA molecules in all possible stages of synthesis. From the information given below,…arrow_forwardThe Polymerase Chain Reaction is a molecular biology tool for exponentially amplifying DNA in a test tube in a cell free system. With this technique, DNA strands are separated by heating the mixture so that a DNA helicase is not required. A heat stable polymerase (Pol Z) is then used to copy DNA over and over in a tube. Recently an improved version of Pol Z was created by fusing Protein X, a DNA binding protein, to Pol Z (see left figure below). The right panel shows that fusion of Pol Z to Protein X significantly increases its efficiency. Briefly provide a plausible mechanism for how Protein X is improving Pol Z. Which prokarotic/eukaryotic protein activity is Protein X mimicking that increases the activity of the polymerase?arrow_forwardBelow is a sequence of 540 bases from a genome. What information would you use to find the beginnings and ends of open reading frames? How many open reading frames can you find in this sequence? Which open reading frame is likely to represent a protein- coding sequence, and why? Which are probably not functioning protein-coding sequences, and why? Note: for simplicitys sake, analyze only this one strand of the DNA double helix, reading from left to right, so you will only be analyzing three of the six reading frames shown in Figure 19.4.arrow_forward
- Biology: The Dynamic Science (MindTap Course List)BiologyISBN:9781305389892Author:Peter J. Russell, Paul E. Hertz, Beverly McMillanPublisher:Cengage LearningBiology Today and Tomorrow without Physiology (Mi...BiologyISBN:9781305117396Author:Cecie Starr, Christine Evers, Lisa StarrPublisher:Cengage Learning