Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [molecular-genetics]

The scientific study of the structure and function of genes at the molecular level, particularly chromosomes and DNA.

2
votes
1answer
117 views

What if our whole body is made up of cancer cells? [closed]

Today I learnt in my biology class that cancer cells are immortal. That left me wondering what if our whole body is made up of cancer cells? Will that make us immortal? Is it possible or why is it ...
1
vote
1answer
500 views

Is nucleosomal DNA ever degraded?

A hallmark of apoptotic DNA fragmentation is the digestion of DNA into individual nucleosomes. In addition, in the following experiment that tried to isolate the components of the nucleosome, the ...
2
votes
2answers
8k views

What are housekeeping and constitutive genes?

I have come across two set of definitions which are not contradictory but different. From wikipedia: A constitutive gene is a gene that is transcribed continually as opposed to a facultative gene, ...
0
votes
1answer
590 views

Calculating chromosome number in meiosis: Why is the crossbreed between a fox and a dog (dox) sterile?

Given the following example/question (originally found here): I worked out the haploid number of the dox to be 29 and the diploid number of the dox to be 58. 58 is an even number, so surely 29 ...
3
votes
1answer
137 views

Recombination between DNA segments question

In the diagram shown above, segments A and C are copies of a repeated DNA sequence, flanking a unique stretch shown as B. A and C are in an inverted orientation relative to each other, as indicated by ...
2
votes
0answers
45 views

psbA-trnH intergeneteic spacer inversion

What kind of software tool would you recommend as best suited to detect psbA-trnH inverisons? I have 1x coverage Sanger .fasta files and >2000 sequences, with 1 sequence per species. Most tools I have ...
1
vote
1answer
36 views

Changing genetic code of E. coli to accept synthetic amino acids?

I read in my Biology textbook that an experiment has been done in which one of E. coli's stop codon has been altered to accept a synthetic amino acid. I do not get how it can be done. Taking the ...
4
votes
1answer
122 views

Can difference in the expression potential of alleles lead to dominance?

Several hour ago I was in thoughts what allele dominance really means on molecular level. As we know from basic genetics, if the organism had Aa type of some gene ...
3
votes
0answers
158 views

Question about genetic recombination

I am having some difficulty understanding a few things about genetic recombination, in part because of confusion from different diagrams in books. First of all, I wanted to verify whether I have ...
1
vote
0answers
51 views

Linkage disequilibrium D sign

Linkage disequilibrium D equals $D=x_{11}−p1⋅q1$ where: Haplotype Frequency $A_{1}B_{1} = x_{11}$ $A_{1}B_{2} = x_{12}$ $A_{2}B_{1} = x_{21}$ $A_{2}B_{2} ...
4
votes
3answers
134 views

Does the genome make sense without knowledge of the ovum?

Much of the literature for laypeople seems to consider (and to spread the idea) that an animal (or a plant, I guess) is characterised by its genome. I do not know whether the same goes for more ...
-2
votes
1answer
43 views

Which analytical techniques could you use to research relationships between 2 proteins? [closed]

Two of the proteins I am researching are known to interact. However, I would like to know if they interact with other proteins as well, and possibly form a pathway. Which analytical technique(s) I ...
1
vote
1answer
193 views

What is the space between -10 promoter sites and start sites (+1) [closed]

Between the transcriptional start site of a gene and the -10 promoter region there is always a space of around 10 nucleotides, what is this space function and purpose? Do you see the space between ...
6
votes
1answer
1k views

Why do some bacteria have most genes on the leading strand of the genome?

Genes in the (+) strand are black and genes in the (-)strand are red. The gene distribution in E. coli genome is somewhat expected: transcribed regions would tend to alternate with non transcribed ...
2
votes
0answers
35 views

Validity of comparing gene expression levels between alive and <24h postmortem cohort

There is a recent paper about assessment of a suicidal risk in psychotic patients https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4759104/ One of the important points is that the authors compare gene ...
1
vote
0answers
120 views

Why is the total length of Introns greater than the total length of exons?

I have just been reading that typically the total length of the Exons of a split gene is very much smaller than to total number of its Introns. Could anyone please explain why this is the case if its ...
9
votes
3answers
460 views

Splice in with CRISPR/Cas

I need to splice a gene into a human cell genome, with highest rate possible. I mean, doesn't really matter where the gene enters, nor does it matter if some cells die as a result of this. CRISPR ...
2
votes
0answers
98 views

CRISPR Knock in

Using the CRISPR/Cas9 technology, it is possible that after inducing a DSB with the Cas9 endonuclease guided with an RNA designed by the user and using a template DNA, get a desired Knock-In (KI) by ...
0
votes
1answer
229 views

Mutations/deletions with CRISPR

I need to stop some protein from being active and searching for some universal way to do so. In mammalians. With CRISPR it is possible to knock-out the entire gene. But it's a little complicate (...
5
votes
2answers
3k views

Does a woman contain all the genes needed to make a man?

I know the answer of inverse is at here, but how about this question? I also read this question, can I imply to human that a woman can also contain all the genes needed to make a man? Edit: I think ...
4
votes
1answer
79 views

Do any RNAs directly inhibit transcription

In eukaryotes, microRNAs and small interfering RNAs, as part of protein complexes, can attack specific messenger RNAs with complementary sequences, thereby inhibiting translation. However, RNA can ...
1
vote
1answer
370 views

Why is trisomy a problem?

I understand that a missing part of genetic information is a problem - the cell does not know how to synthesize a specific protein. But why is it a problem when there's one more copy of a chromosome? ...
1
vote
4answers
276 views

Books: DNA replication [closed]

In what books can I find a detailed literature on the mechanism of function of different enzymes and proteins involved in DNA replication of E. coli ?
2
votes
1answer
2k views

What is Tandem repeat?

After reading - (wikipedia) Tandem repeats occur in DNA when a pattern of one or more nucleotides is repeated and the repetitions are directly adjacent to each other. ( a paper) A tandem ...
4
votes
1answer
119 views

Can genes be expressed sequentially?

As I understand it, any gene on an exposed/unpacked region of a chromosome is continuously being expressed. Regulatory genes may increase or decrease the amount of protein synthesised due to its ...
2
votes
0answers
28 views

How is randomness of the branch migration process ensured?

Branch migration (part of genetic recombination) is a random process. It looks like Ruv-ABC proteins are mainly responsible for this process, but how is randomness ensured? After all, it can only be a ...
1
vote
4answers
1k views

How can both strands of DNA code for proteins with similar functions?

It's not clear from the question but for example: AAAAAAA TTTTTTT The top strand would create a different protein than the bottom, and with the huge amount of nucleotide in a gene, I think it's ...
0
votes
1answer
577 views

Type I and Type II Topoisomerases

Type I topoisomerase changes the linking number by ±1 by changing the number of twist present in a DNA, breaking only one strand. Type II topoisomerase changes the linking number by ±2 by changing ...
0
votes
2answers
44 views

Gaps in FASTA formatted genome?

I'm just getting interested in genetic structure and I decided to find a FASTA formatted genome (human) and I found one here. However, I'm confused. I know that A can only match up to T and C to G but ...
3
votes
1answer
777 views

Why is aneuploidy usually lethal?

So, I was reading about aneuploidy and how a zygote with one extra or less chromosome usually would not survive to full term. I suppose this happens because aneuploidy leads to some kind of protein ...
2
votes
1answer
6k views

What are Codominant vs Dominant Genetic Markers?

When talking about types of genetic markers, the adjective "dominant" and "codominant" are often used. I don't fully understand their definitions and found contradicting definitions. Foll and ...
0
votes
2answers
90 views

probe amplification in MLPA

I'm reading an article about MLPA (Multiplex ligation-dependent probe amplification) and I got stuck on this sentence: The advantage of splitting the probe into two parts is that only the ligated ...
1
vote
1answer
913 views

Is RFLP markers are dominant or codominant? [duplicate]

there are several markers used in molecular biology,. marker analysis. RFLP is most commonly used marker which having several advantages. is RFLP marker co-dominant or dominant ?
4
votes
1answer
251 views

Are there any drawbacks to having immutable DNA during lifetime?

Imagine that there is a way to prevent cell DNA from being changed once zygote has been formed. Would this have any negative effects on the target organism? Does DNA change during the lifetime as part ...
0
votes
1answer
1k views

Rescue cell lines function

I'm reading in a paper in which the authors have made three cell lines to study the function of a gene of interest (Mbd3): The one is knocked out for the gene of interest [Mbd3 -/-], the other is ...
1
vote
1answer
259 views

How is monoclonality or polyclonality determined?

I was reading up Kaposi sarcoma and Robbins Pathology says, ..many features suggest that KS is not a malignant tumor despite the ominous name ...spindle cells in many KS lesions are polyclonal or ...
2
votes
1answer
179 views

Do the two catalytic cores of DNA polymerase III operate in the same direction?

This diagram is from Molecular Cell Biology by Lodish, 2000 which states: The other core-polymerase molecule, which elongates the lagging strand, moves with its β-subunit clamp in the direction ...
3
votes
1answer
879 views

Can coding DNA be used for DNA fingerprinting?

I am confused if coding DNA can be used for DNA fingerprinting because I have read that non-coding segments of DNA are used to identify and analyze DNA. I want to know if coding DNA segments are of ...
2
votes
2answers
145 views

Prenatal Marketing

This is for a short story idea. Is it possible to modify the DNA of a child to make their metabolism more susceptible (physical response, addiction, etc) to a certain type of chemical i.e. a chemical ...
2
votes
0answers
816 views

What´s the role or function of the homologous arms in a donor template in a knockout/knock edition via Crispr-cas9?

I have to make an exposition in my university about Crispr-cas9 edition and I have some questions about the method. In the knock out/knock in technique is used a plasmid containing the DNA that ...
5
votes
4answers
534 views

Picking up Plasmid DNA using Nanodrop, but not using Electrophoresis

I am currently trying to see if 2 bacteria contains plasmids or not. I had used promega plasmid extraction kit on the bacteria. I ran a gel electrophoresis (.8% gel) with the extract product, however ...
4
votes
1answer
89 views

Why do we need two markers to measure a recombination rate?

In calculating recombination, Why is it necessary to take into account pairs of loci where one marker is heterozygous? Why is it necessary to take into account pairs of loci where both markers are ...
2
votes
1answer
102 views

What sequences are between adjacent genes?

The human genome has a lot of non-coding regions, which include regulatory elements, repetitive DNA, and introns. Suppose there are two adjacent genes on a chromosome, and their positions on the ...
6
votes
4answers
801 views

In DNA repair, how is it determined which strand contains the error?

DNA replication is more accurate than transcription (or RNA replication) because mechanisms exist for proof-reading and repair of DNA, but not for RNA. Consider a segment of a DNA strand, AGTC. Its ...
5
votes
1answer
159 views

What are chemical candidates for replicator molecule?

I have read Selfish gene by Richard Dawkins and idea is that at random some molecule was synthesized that had a property if there is enough 'materials' to construct ...
11
votes
2answers
1k views

Do single crossovers occur in circular polynucleotides?

Single crossovers in circular pieces of DNA do not seem to be a big topic, because if they happened, they would lead to a kind of combined chromosome with two inner strands and one large outer strand. ...
0
votes
1answer
27 views

Method of figuring out how much of a certain mRNA is present in a bacterium

I am trying to develop a method for figuring out how much of a certain mRNA is present in a bacterium. This is what I have so far: Perform a mRNA extraction Using Electrophoresis, to isolate the ...
1
vote
0answers
155 views

Why is RAS undruggable?

Why can't mutated RAS get inactivated by GTPase? Why don't we have any inhibitors for RAS-GTP binding? Why is RAS undruggable? How can mutated RAS be inactivated? I had been researching on the topic ...
4
votes
2answers
141 views

Is there selection against long proteins and long genes?

Background thought Titin and TTN Titin is the largest protein in the human genome with 33423 amino acids. Titin is coded by the gene TTN that must be at least $3 \cdot 33423 \approx 100kb$ long. ...
3
votes
1answer
915 views

Various Genetic Loads and their Definitions

In population genetics, we talk about several types of genetic loads (also called just loads). I am asking for a exhaustive list and a short definition. Here are for example some genetic loads that ...