Questions tagged [molecular-genetics]
The scientific study of the structure and function of genes at the molecular level, particularly chromosomes and DNA.
674
questions
2
votes
1
answer
77
views
How to identify the genes that distal enhancers pair?
I am writing a project proposal and I have to talk about this problem: how to identify the genes that distal enhancers pair?
I am really new to this topic and I don't know what it is all about. I ...
2
votes
1
answer
137
views
Coefficient of relationship and path of coefficient
A path of coefficient of relationship is defined as
$$\rho_{AO} = \left( \frac{1}{2}\right)^n \sqrt { \frac{1+f_A}{1+f_O}}$$
This SE post discusses this definition
From this, the coefficient of ...
2
votes
1
answer
173
views
Cloning a gene of an organism with an nonsequenced genome
What would be the best protocol to clone a gene about 5kb in size? The genome is not sequenced, but the gene itself very similar to orthologous genes of organisms with known sequences.
2
votes
1
answer
388
views
PedigreeAnalysis Genetics [duplicate]
Hello! I need help with this exercise question. I am not really sure which pedigree diagram is autosomal and which is not. But, is question b 1/2. Can someone give an explanation? Thanks very much in ...
2
votes
1
answer
43
views
Receptors and their distribution over the human population
For humans it has been reported that there are three vasopressin receptors (AVPR1a) and four dopamine receptors (DRD2). (Source: UNIPROT)
Question: Does every human contain all three variants of ...
2
votes
1
answer
54
views
How many MAOA alleles are there?
The question is about the human gene MAOA.
I've seen MAOA-H and MAOA-L mentioned in papers.
The page https://www.ensembl.org/Homo_sapiens/Gene/Summary?db=core;g=ENSG00000189221;r=X:43654907-43746824 ...
2
votes
1
answer
68
views
Can DNA be used directly to determine the age of a mutation?
I've studied that proteins found in a sample as biochemical evidences for evolution. Its variation in structure and configuration can be used to date the age when that mutation occured, effectively ...
2
votes
1
answer
77
views
Question about alternative polyadenylation
I know that alternative polyadenylation creates different transcript isoforms. My question is whether alternative polyadenylation ever results in differences in the terminal/last exon? The only case I ...
2
votes
1
answer
70
views
How evolutionarily conserved are UTRs?
Coding sequences of genes have a certain degree of evolutionary conservation, so that comparisons based on sequences (BLAST, HMMER etc) can be informative. Generally speaking, the more two species are ...
2
votes
1
answer
215
views
If post transcriptional modification happens , how can a gene code for amino acids in a particular order? [duplicate]
Post transcription, introns are removed and exons are rearranged randomly. If that's the case (which it is according to the book EDEXCEL SNAB A2 topic 6) then shouldn't the protein produced be ...
2
votes
1
answer
72
views
How to attain a deep conceptual grasp of key atomic/molecular/genetic/ notions? [closed]
It's a total noob question, I know.
I'm a layperson trying to come to grips with basic scientific terminology. I always face a conceptual hurdle in trying to understand micro-talk. The way I'm using ...
2
votes
2
answers
158
views
Differential Gene Expression
I have a matrix two gene expression datasets, one from 10 normal individuals and ten from diseased individuals, which are normalised log fold change values--, i.e., already processed.
My question is:...
2
votes
1
answer
650
views
How does salt concentration affect chromatin compaction?
I've read that the primary obstacle to the compaction of chromatin is the negative charge on the DNA phosphate-sugar backbone. This negative charge is slightly stabilized by the positive charges on ...
2
votes
1
answer
216
views
How to find conserved residues across species?
I want to identify if certain phosphorylation sites are conserved for protein X across humans and yeast. I know from MS data that there are 4 phosphorylation sites in Human protein X. In order to ...
2
votes
1
answer
1k
views
genetic complementation problem
I've attached the picture of the problem.
SO, based on the information I managed to assemble two large cistrons. (if the combination of two mutants yield (-) mutations are on the same chromosome)
A)...
2
votes
1
answer
50
views
When performing mutagenesis for an assay, how do you decide on the sample size of individuals to be mutated such that all genes are covered?
If I want to study, say, gustatory response of salmons to a bile acid, I need to mutagenize a sample of salmon males. However, given that there are many genes involved in this response, what is ...
2
votes
1
answer
42
views
ATP to disassembly of nucleotide ratio
DNA Helicase, the enzyme that is responsible for tearing apart the strands before DNA replication, requires ATP to rip apart nucleotides. I have asked this question to several professors and they ...
2
votes
3
answers
222
views
Extending a small fragment of DNA
Is there a way to extend a small fragment of DNA, say 150 bp, by making copies of itself and attaching each copy of that small fragment to the end of that 150 bp sequence?
For example, I want a 1 ...
2
votes
1
answer
31
views
How and why are cells irradiated in human-rodent hybrid cell biology?
When human-rodent hybrids are made the amount of human chromosome in the hybrid can be reduced by irradiation. Why and how exactly is this irradiation step performed?
2
votes
1
answer
81
views
What is the most reliable tumour suppressing gene for NSCLC?
I was looking at some tumour suppressing genes that can be helpful in diagnosing lung cancer (particularly NSCLC - Non-small-cell lung carcinoma) at an early stage. I came across a few such as p53, ...
2
votes
1
answer
44
views
Which is the guideline to choose a molecular target to identify vertebrate hosts from arthropod bloodmeals?
There are some molecular targets to identify vertebrate hosts from arthropod bloodmeals including the Cyt b gene and the COI gene. Which are the standards or characteristics that I have to bear in ...
2
votes
1
answer
555
views
Mode of Enzymatic Inhibition via R-Allele
The photo above shows the effects of the R allele of the pea shape gene on the synthesis of an enzyme that converts unbranched starch into branched starch. The r allele of this gene determines an ...
2
votes
1
answer
1k
views
G>T transversion VS. T>G transversion?
So I'm reading about how mutations in DNA can be caused by oxidative damage. An example of a product of oxidative damage is given: 8-oxo-7-hydrodeoxyguanosine
My textbook says that this product ...
2
votes
1
answer
138
views
What initiates primase to add an RNA primer to a DNA strand and what makes it stop?
What initiates primase to add an RNA primer to a DNA strand and what makes it stop adding RNA nucleotides? Is there tags added to the DNA back-bone?
2
votes
1
answer
9k
views
what is the function of satellite in a chromosome?
What is the specific function of a satellite in a chromosome ? How are sat-chromosomes different from others ? On molecular basis, what are the functional advantages of it ?
2
votes
1
answer
131
views
How is insulin transported in vivo in mammals?
What is the mechanism for transport of insulin in mammalian cells?
2
votes
1
answer
185
views
How is a stem-cell induced to assimilate a knock-in DNA construct?
While looking at (daylight) color perception I came across a paper by Jeremy Nathans (et al., Proc. Nat. Acad. Sci., vol. 100 no. 20, 2003, full text here) in which he describes the creation of a ...
2
votes
1
answer
404
views
Should the length of the electrodes in the electrophoresis chamber be proportional to chamber's size?
I am trying to build a small horizontal electrophoresis chamber from scratch. I want to use it for comet assay and I will be using only 1 slide, so it's going to be about 3cm wide, 10cm long and 4cm ...
2
votes
1
answer
187
views
Histone marks mechanism
I am slightly confused about the mechanisms that makes histone modifications associate with gene expression.
That is, H3K36me3 is believed to be present in actively transcribed genes, H3K27me3 in ...
2
votes
0
answers
24
views
Is Regenerative Brain Tissue Technology In The Near Future?
I got 99% of my information from articles I found in NIH's library; I can't cite anything now because I am on a timed session in a public library.
I've been reading material from research papers in ...
2
votes
0
answers
259
views
How pitch of a DNA Helix is 3.4 nm?
How pitch of a DNA Helix is 3.4 nm?
In the image that I have attached, the numbers with prime represent the number of base pair and normal numbers represent the number of gap elements between two base ...
2
votes
0
answers
47
views
What forms a mutation hotspot?
From https://en.wikipedia.org/wiki/Recombination_hotspot#:~:text=Recombination%20hotspots%20are%20regions%20in,that%20of%20the%20surrounding%20region.
I understand that hotspots may arise when certain ...
2
votes
0
answers
57
views
Apparant inconsistency in DNA topology theory in formation of origin of replication [duplicate]
I'm studying an introductory course in genetics and came across something I don't fully understand. I obviously used Google to find where I'm thinking wrong, but I still can't understand it.
To ...
2
votes
0
answers
29
views
What's the process for determining whether a GC -> AT conversion in bisulfite sequencing is due to degradation?
I'm working on an ancient DNA project (humans) examining the methylation patterns for a single nuclear gene on chromosome 5. I understand the protocols of bisulfite sequencing, and in general how the ...
2
votes
0
answers
43
views
Can chain-linked genetic segment data be used to reliably assign unknown relatives to either the donor's mother or father?
I am analyzing DNA matching segment data, and I am trying to broadly group all DNA matches by my donor's parents.
Based on documented evidence, I can confidently identify "Person 'B'" as a ...
2
votes
1
answer
154
views
How can we determine which chromosome came from which parent? [closed]
In this article there is a graph (figure 1) describing different levels of methylation in the maternal and paternal chromosomes after karyogamy.
How can the researchers identify which chromosome ...
2
votes
0
answers
40
views
How do we know that the "original animal exposure event" of a human to the Covid-19 virus occurred between October and December 2019?
In a Yale med page (interview) on Covid-19 from January it is said that
The molecular dating of the virus genomes indicates that the original animal exposure event happened sometime between late ...
2
votes
3
answers
311
views
Do proteins contain phosphorous? If its true then how alfred hershey and martha chase used the statement that proteins do not contain phosphorous?
I hv heard about phosphorus that it is a constituent of certain protein, although we know that no amino acids have phosphorus... and if its true then how Alfred hershey and Martha chase experiment got ...
2
votes
0
answers
245
views
what is the difference between homozygous and heterozygous duplication?
In a genetic test result it's written
homozygous duplication
or
heterozygous duplication
Does it mean four copies of the ...
2
votes
0
answers
62
views
Which enzyme is Nick Lane referring to?
In Life Ascending the author, Nick Lane, refers to an enzyme in his introduction:
'' It concerns an enzyme (a protein that catalyses a chemical reaction) that is so central to life that it is found ...
2
votes
1
answer
59
views
How to find idea for essay [closed]
I'm studying microbiology in Iran
The university that I'm studying in doesn't provide that much help in research areas and we don't get to research or write essays that much ,while I'm trying to write ...
2
votes
0
answers
40
views
how can I get stronger staining for my lymph node sections
I am using the same protocol and same antibodies that the literature says but still I cannot get good staining for my lymph node sections, I tried to change the fixation method and I am using now ...
2
votes
2
answers
3k
views
What is the difference between a response element and a enhancer?
I have been confused as to the difference between a response element and an enhancer.
Wikipedia has the definition of response element as the following:
Response elements are short sequences of ...
2
votes
0
answers
488
views
How would circular dominance of alleles be determined on the genetic level?
The distinction between dominant and recessive alleles seems to be due to loss or gain of function in the proteins they code for. Alleles have been observed exhibiting incomplete and hierarchical ...
2
votes
0
answers
53
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 ...
2
votes
0
answers
43
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 ...
2
votes
0
answers
37
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 ...
2
votes
0
answers
1k
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 ...
2
votes
0
answers
149
views
Amplified Fragment Length Polymorphism (AFLP) primers
I am trying to blast AFLP primer sequences to the genome to find the locations of the AFLP markers. However, I can't seem to find full alignments for the primers on the genome.
For example, in the ...
2
votes
0
answers
357
views
PCR that worked previously is now only showing primer dimers and a smear on gel
PCR amplification of a promoter sequence for gel extraction worked beautifully using Phusion HF enzyme with GC (higher error but less picky) buffer. However, DNA concentration from the gel extraction ...