Genetics is the branch of biology that deals with the transmission and variation of inherited characteristics.

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DNA replication Okazaki fragments

I understand multiple origin bubbles; DNA polymerase only synthesizes DNA from 5' to 3' and all that. But what I don't understand is why it has to be in fragments. Yes, DNA is anti parallel, and so ...
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60 views

Which X-Y chromosomes have the developmental genes for mammals?

I know that for a given mammal, half the chromosomes come from father and half from mother. This is typically denoted as x-y. I've recently read about "toolkit" genes that control how a cell develops ...
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222 views

What is an epistasis group?

I have been trying to wrap my head around the concept of epistasis for a couple of days now, and I think I understand it, at least at a basic level, but I still don't understand some of the ways that ...
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159 views

Effect of single-gene overexpression in the cell's response

Which are the factors that modify the overall gene differential expression by introducing a vector for single-gene overexpression? If you overexpress a gene for a protein involved in signal ...
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4answers
120 views

Are there more descriptive ways of naming genes and gene interactions?

I couldn't help but notice just how non-descriptive the gene names that modern genetics is using. Currently I'm reading "The new science of Evo Devo" by Sean B. Carroll and here are some examples of ...
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219 views

Detecting Introns and Exons

I know that when RNA is transcribed from the original strand of DNA it contains introns and exons, and that the introns are spliced out of the strand to provide genetic diversity. However, what I ...
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2answers
108 views

Can a new Y-chromosome be created?

The major gene of the Y-chromosome is SRY. Would it be possible to get the X-chromosome and add SRY to create a "fuller" Y-chromosome? What advantage does the skinny Y-chromosome give an individual ...
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132 views

How is gene expression estimated?

I'm reading this fantastic article on estimating body time: Molecular-timetable methods for detection of body time and rhythm disorders from single-time-point genome-wide expression profiles and one ...
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1answer
122 views

How do mutations come to be shared by all cells?

It's my understanding that various hazards can damage the DNA in our cells, causing mutations. But whenever I picture this, I see the damage being done to one of our tissues (for example, our lungs ...
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1answer
105 views

What is the mechanism of regulation of PER /CRY genes?

I've read multiple descriptions of biological/circadian clocks and they all mention PER, CRY and CLOCK genes. While I kinda get how they are connected, what interests me is how these actually regulate ...
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1answer
116 views

Results of a complete DNA sequencing - are they 100% reusable?

Is that correct that a complete DNA sequencing (the whole genome) need only to be done once (per person)? After that is done, it the complete genome can be stored and once the new genes (and they ...
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1answer
373 views

Role of Fbx15 in ES cells and its use in assaying for iPS cells (Yamanaka paper and others)?

I am trying to understand the assay for iPS cells in the Takahashi & Yamanaka 2006 paper. They inserted a beta-geo cassette, which contains the neomycin resistance gene, into the Fbx15 gene. The ...
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Can two humans with 44 chromosomes produce viable offspring?

It is known that there are very few individuals having 44 chromosomes, not the usual 46 chromosomes. One example is a male in China: the first article, the second article. The other is a female in ...
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1answer
160 views

Two brown-haired people have two children, P and Q. P has blond hair. Q has brown hair. What is the probability that Q is heterozygous?

Two brown-haired people have two children, P and Q. P has blond hair. We therefore believe that each parent is heterozygous and that blond hair is a recessive trait. Q has brown hair. What is the ...
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1answer
201 views

What factors govern the variable age of onset in Huntington's Disease?

"Huntington's disease (HD) is a neurodegenerative genetic disorder that affects muscle coordination and leads to cognitive decline and psychiatric problems." As we all know, this genetic disease ...
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47 views

What are polytene bands, and why are they there?

Drosophila polytene chromosomes have been particularly useful in genetic research, as it made cytogenetic gene mapping possible with very little effort. This was primarily accomplished due to polytene ...
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4k views

What is the advantage of circular DNA in bacteria?

From what I understand, bacteria have circular DNA. What advantages does it have over linear strands like for eukaryotes? Do there exist bacteria with more than one ring of DNA?
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512 views

Mathematical Modelling of Natural Selection

I'm a math undergrad looking for some papers on modelling the process of natural selection. The only paper I've been able to find is by the pre-eminent mathematician Herbert Wilf from 2010, There's ...
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4answers
415 views

Chromosomes are of different size but why do all chromosomes have similar GC percentage?

When I browsed NCBI I saw a pattern: even if the chromosome sizes, number of genes, and number of proteins are different, GC% in chromosomes tend to be similar. The examples are linked below. Yeast, ...
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1answer
132 views

How do the variable portions of antibody genes look in cells which don't produce antibodies?

There are several families of antibodies found in mammals. They may have two or more antibody domains which contain heavy and light chains. The variable regions of the light and heavy chains genes ...
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167 views

Have any genetically altered organisms actually become abundant in a natural environment?

Most of the things that come up in Google and Google Scholar for this question have a mostly/completely speculative tone, or at best use models instead of measurements. This report describes some ...
5
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1answer
175 views

Are there eukaryotes without introns?

This question on the function of introns in eukaryotic genes made me think: I know that more basal organisms have smaller introns and fewer alternatively spliced exons compared to mammals. But are ...
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1answer
205 views

Definition of Dye- Reduction Test?

Can some one give a simple explanation or definition on what a dye-reduction test is.
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1answer
139 views

How might gene clusters like the lac operon evolve?

The obvious answer for a gene cluster is gene duplication and mutation of one or both genes. But the genes in the lac operon seem not be so functionally/structurally similar (as compared to the Hox ...
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50 views

How are geneticists able to isolate gene functions?

As an example, this Scientific American article describes a known area in the dog genome that metabolizes carbohydrates. How is it that researchers are able to determine specific functions such as ...
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68 views

Can mammals from different species reproduce?

I'm curious on how genetically different can two animals be in order to reproduce. Could they belong to different species? One example is the mule which is the offspring of a donkey and a horse, in ...
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1answer
101 views

What's the difference between a free chromosome fragment and an extrachromosomal array?

This is reference to a review on C. elegans mosaic analysis by Yochem and Herman, in which the authors make a distinction between free chromosome fragments and extrachromosomal arrays. For the ...
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351 views

What is the biological mechanism underlying caffeine intolerance? (CYP1A2 or other?)

As far as I can tell, caffeine metabolism occurs primarily via the CYP1A2 enzyme. I am curious as to whether mutations in the CYP1A2 gene are associated with caffeine intolerance. Some site that is ...
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1k views

How many nucleotide pairs code one gene?

As I know three nucleotide pairs (triplus) code one gene. But I have found next information in the "Molecular biology of the cell" by Bruce Alberts: Mycoplasma genitalium: it has only about 480 ...
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1answer
134 views

Are all chromosomes equally susceptible to mutation?

The humans have been around for a few million years, other organisms longer yet. Changes that occur in the genome and propagate (may) eventually throw a new species ... or atleast branch off the old ...
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1answer
113 views

What causes XYY Syndrome?

It's obvious how a misdisjunction can result in klinefelter's syndrome (XXY) but I don't see how this can result in XYY syndrome. Your parents have a collective total of only one Y chromosome so how ...
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2k views

What makes a gene dominant or recessive

We all carry two copies of each gene (outside of male sex chromosomes). If the two differ from each other often one is dominant and one recessive. How does this mechanism work on a molecular level? ...
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3answers
71 views

When can I assume individuals marrying into a pedigree are non-carriers?

If I'm not told that they're non carriers, and if I don't have proof of their geneotype based off of progeny, when can I assume they're non carriers for a trait?
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208 views

Hershey and Chase experiment

http://www.youtube.com/watch?v=3QJ4CjFsflA This is a link to Hershey and Chase experiment. According to this experiment, we conclude that DNA is the genetic material. But how do we conclude that DNA ...
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105 views

How do circulating androgens contribute to higher rates of hirsuteness in some women?

I was reading up on ethnic groups in which the women are naturally more hirsute (such as South Asian women) in the context of evolving standards of beauty. I came across this statement on a forum: ...
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319 views

Athletes: nature vs. nurture?

Having watched a lot of olympians the last few weeks, I was struck by how many of them have actually spent their wholes lives/careers training for their one event (be in running a marathon, or ...
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971 views

Is the theory of evolution being disproved by bats?

For some species the Darwin's theory evolution makes perfect sense. I can easily imagine how, for example, the giraffe has evolved to its current appearance: the natural selection was favoring ...
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77 views

Papers linking telomeres and aging [closed]

I'm currently writing a piece of work about telomeres and aging, and wondered if you could share some good papers you've either read or know of.
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1answer
43 views

What is the point of being selection-free?

I'm reading "Highly efficient endogenous human gene correction using designed zinc finger nucleases" by Urnov et al. They propose a way to use zinc finger proteins for gene therapy. They repeatedly ...
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46 views

What accounts for size variation in breeds of dogs?

My assumption is that dogs vary so much in size because of artificial selection pressures coming from human breeders, but are there genetic loci that roughly determine approximate size? Do other ...
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127 views

How can a three-base codon evolve from a two-base codon?

Inspired by this question among others. It's widely suggested that the current 3-base codon system of encoding protein sequences in DNA evolved from an earlier 2-base codon system. This makes sense ...
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What is the inbreeding coefficient for the female offspring of a sib-mating in a haplodiploid system?

The inbreeding coefficient of a sibling mating for a diploid organism is 0.25 (each allele has a 25% of being identical by descent in the offspring). In haplodiploid organisms, males result from ...
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75 views

Are homozygous carriers of the CCR5-Δ32 allele fully immune to all known strains of HIV?

Or is there documented evidence of even one homozygous carrier contracting HIV and staying infected?
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250 views

What kind of event would cause the current Mitochondrial Eve to be replaced by a new one?

Apparently all living humans are matrilineal descendants of a single woman who lived 200.000 years ago. She is called Mitochondrial Eve. But at the time she lived there was a different matrilineal ...
6
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3answers
546 views

How to map the Gene name to its Gene Symbol?

I am learning in Gene data lately so I apologize for the silly questions in advance. I read a paper for a cancer on human which found some important genes. For example, the paper listed one of genes ...
4
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1answer
126 views

How does a tiger have stripes?

A vague question, but let me try to explain. My friend explained to me that in females, some cells use one X chromosome, while all others use the other X chromosome. This can result in some ...
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Does the DNA sequence of a butterfly match that of the caterpillar it used to be?

Just had this thought occur to me. If one were to take a DNA sample(or is it RNA?) of a caterpillar before it became a chrysalis, and attempt to match the sample against one taken after the chrysalis ...
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2answers
1k views

Gene & Protein nomenclature: N-Myc, c-Myc, et. al

Can someone explain (or point me to an explanation of) exactly what is meant by all the different symbols I see used for writing genes and proteins? I think I know that for genes, we use an italic ...
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What are the advantages and disadvantages of using beta-galactosidase compared to luciferase as a reporter gene?

In the University labs, we have used Beta-galactosidase as a reporter gene to quantify the expression initiated by the stress-response promoter in yeast. This was done by exposing one of the two ...
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Do antisense transcripts have different names than their sense strand transcripts?

I want to find which genes in the human genome can potentially be complementary to a transcript that could act as antisense transcript inhibtion? Are cis-NATs (naturally occuring anti-sense ...