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Pink individuals of the katydid species Amblycorypha oblongifolia are a relatively uncommon but natural phenomenon with a long history of research. It looks from popular press accounts (Science Friday, Scientific American) that the pink coloration may be caused by a dominant allele, and is only rare because of a high selection pressure against pink ...


5

Your markers are probably fine, especially because you keep seeing the same allele in multiple individuals. Dinucleotide repeats do not always copy perfectly. More likely, remember that the primers you use to amplify your microsatellites bind outside of the actual repeat region. You could have an insertion/deletion in the region between the primers and the ...


5

Presumably this means that at least some grey haired humans have noticeable reproductive advantage, or maybe they had it in the recent past. No it doesn't. Natural selection is not that strong, it doesn't optimize every single possible physical trait towards maximum reproducing. And as others have mentioned, having lots of grey hair usually ...


4

"Monosomy for the X chromosome in humans creates a genetic Achilles' heel for nature to deal with." The article I quoted1 tackles this issue. It's from the turn of the century, though, so quite old in sequencing/genetic terms, but the science is still sound as far as I can tell. Here's the money quote: Hence, the X chromosome appears to have a lower ...


4

Here is what the data says. UK government must have had some scientific evidence when it settled on a 10 variable-length sections of genome for their database, SGM+. In one such variable sections, some people have 10 repeats of CTTT, others have 11, others have 12 etc. The largest of those fragments, at its maximum length, are about 350 base pairs. The US ...


4

X-inactivation does occur in XXY individuals.  In phenotypically normal XX females, one X chromosome is inactivated.  Which one of the two X chromosomes is inactivated in any given cell is random. Therefore, about one half of the cells should have the maternal X active and the other half should have the paternal X active. XXY individuals show a wide range ...


4

No, you don't. Having the DNA in your hand means that you have access to a macromolecule, not more. Think of the DNA as a book (or a library). From holding the book in your hands, you don't know what the content is. You have to actively read the book to get this information. Sequencing a piece of DNA is basically the same. Your readout is the sequence of ...


3

This is a technique from the "old time" of genome sequencing. The underlying method for sequencing is the Sanger chain termination method which can have read lenghts between 100 and 1000 basepairs (depending on the instruments used). This means you have to break down longer DNA molecules, clone and subsequently sequence them. There are two methods possible. ...


3

There are two good papers on this that I like a lot: Noise in Gene Expression: Origins, Consequences, and Control Cellular decision making and biological noise: from microbes to mammals. I think they can tell you better than I can, but the major other source of noise is extrinsic noise. Extrinsic noise typically is taken to means two things (both of ...


3

When designing PCR primers we typically use a minimum length of 20 bases, because the probability of a sequence of N bases appearing by random is $\frac{1}{4^N}$, and $\frac{1}{4^{20}}$ is about 9x$10^{-13}$, or about 1 in a trillion. Since the human genome is a little over 3 billion bases long, a 20 base sequence should appear only once. However, most of an ...


3

Plus and minus describe what is happening in a specific locus in the genome. When a + sign is shown, the locus contains the natural, fully working gene (wild type). When a - is shown, it means that by natural mutation or lab manipulation, cells lack that natural gene, or make a negligible amount of it, or make a broken variant etc. These cells are diplod, ...


3

This sounds straightforward when thinking about it but finding hard evidence is not really easy. As this is too long for a comment, I have to put it in as an answer. Just a few thoughts: All enzymatic reactions are of course temperature dependent and usually have a temperature optimum at the specific living temperatures. For yeast this is around 27°C, for ...


3

Epilepsy is a neurological disorder characterized by hypersynchronous discharge of neurons .i.e abnormal electrical activity in the brain. Epileptic seizures caused primarily due to i) inhibition of inhibitory neurotransmitter systems such GABA neurotransmitters or ii) Enhancement of excitatory neurotransmitter systems such as nAchR. These conditions arise ...


3

I think you can safely use the terms heterogametic (Y/W) and homogametic (X/Z) chromosomes, meaning that a heterogametic chromosome is the chromosome which makes one of the sexes heterogametic (i.e. defines the difference between the two types of gametes of the respective sex). These terms applied to chomosomes do have some usage in the literature, e.g. in ...


2

In birds and reptiles females are the heterogametic sex with allosome configuration ZW. However it has been reported that a homogametic WW female boa was born by parthenogenesis. So it means that although W is shorter than Z, it can still support life. So I guess that ZW system in general exchanges more sex-limited genetic material than XY system. Platypus ...


1

RNA splicing refers to a certain kind of RNA processing mechanism which leads to the excision and exclusion of some regions of the primary transcript. You should note that this is not the only method by which such a thing can happen; Endo-ribonucleases can clip the ends of the transcript and this happens in the case of tRNA-processing. But as "splicing" ...


1

If by "consistent" you mean homogenous, the answer is no. Regions conserved among individuals (and/or species) tend to accumulate less mutations (specially avoiding deleterious mutations). Even within a gene sequence, there are conserved regions which accumulate low number of changes, whereas non-conserved regions accumulate many mutations.


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Well, for start, there are "mutational hot spots", regions that are more prone to mutation than others. As for immune system genes, first of all, lung cells and heart cells and retina cells don't need to mutate those genes, because they don't use them. But you are right that in immune cells there is a lot of DNA futzing in the sequences for the heavy and ...


1

Let's do your second one first, you want to find the rate of binding: Yes you are right you need to calculate for km I think I found the paper that ties temp into the reaction rate: statistical approach called response surface methodology (RSM) is used for the prediction of the kinetic constants of glucose oxidase (GOx) as a function of reaction ...


1

I just tried a search of major and minor sex chromosomes and found a paper here by Judith Mank who refers to the X and Z as the Major Sex Chromosomes and Y and W as the Minor Sex Chromosomes. I will therefore refer to the W and Y as minor sex chromosomes, and will use the term major sex chromosomes in reference to the X and Z. These terms are based ...


1

Parts of your general idea are correct, others need some refinement. To skip ahead to the conclusion: I'm going to recommend that you read up about linkage disequilibrium. Everything else is background information that will hopefully help you understand why linkage disequilibrium is what I think you're looking for. Background: Meiosis Basics Firstly, in ...


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some number of interstices (spaces between successive loci) get picked and each chromosome gets broken at each interstice. That number is usually around 1. It's not common to have a lot more than that per chromosome. It also seems clear that all interstices are equally likely to get picked. No, there certainly are "hot spots" that are more ...


1

I do not think there is a reproductive advantage in gray hair - it's the other way around: Normal colored hair has a reproductive advantage. But it also has a cost in terms of substances needed to build it. I make the assumption here that grey hair - which is often also more sparse - has a lower cost in terms of material. I think we are investing the ...


1

I realize this question is about yeast, but I'm afraid that people may try to expand the answer to all systems, and beta galactosidase is not good for all systems, particularly for animal studies. I've seen too many gene therapy papers try to get away with using it. Beta galactosidase is not a good reporter gene for in vivo gene delivery studies. There is ...


1

The new mexico whiptail reproduces purely through parthenogenesis. The species itself originates as a hybrid of two other species of whiptail, but the hybridization can't make fertile males. The females can reproduce through parthenogenesis so that's how the species continues to exist. So 100% of the genome is passed mother to daughter for many generations, ...


1

Is there any species (not just mammals) where most, or even all, of the genome is inherited in a sex-specific trajectory? If all the genome is passed on by only one sex, then the other sex will necessarily disappear (in absence of social reasons) (and the species may go extinct if the presence of this other sex is necessary). However some cases such as ...



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