<< Chapter < Page Chapter >> Page >

In the situation called 'meiotic drive', a particular allele ends up in gametes more frequently than others for the same locus. That is, the usual expectation that on average 50% of an individual's gametes contain one allele for a given locus and 50% the other allele for that locus, is violated resulting in the one of the two alleles being overrepresented in gametes of heterozygotes. (The gametes of homozygotes are not affected.)

a. Review Figure 1. What aspect of this diagram would be altered? Why? Please explain.

b. Even if all individuals have an equal probability of mating in this population (i.e. mating occurs randomly), would all alleles have an equal probability of ending up in a fertilization event and thus the next generation? Why or why not? Please explain.

a. The relative quantities of gametes in the 'buckets' of heterozygotes would no longer be 50:50. 'Buckets' corresponding to the allele that ends up in gametes more frequently would contain a larger quantity of gametes than 'buckets' representing the alternative allele.

b. No. All alleles would not have an equal likelihood of ending up in fertilization events even when all individuals are all equally likely to mate. This is true because, when a mating event involves a heterozygote, they will be more likely to contribute the over-represented allele than the alternative allele to fertilization. This is true because more than half their gametes contain the over-represented allele.

In 2005, Stefasson et al. reported the fascinating discovery of an allele, H2, in humans whose presence is associated with increased fertility in Icelandic and European populations. Females with at least one copy of the allele have approximately 3.5%, and males 2.9%, more children on average than non-carriers. The exact mechanism by which the allele affects fertility is unknown.

Do all people in Icelandic and European populations have an equal probability of contributing one of the two gametes to each fertilization event that successfully produces an offspring? Please explain your conclusion.

No, all individuals in these populations do not have an equal probability of contributing one of the two gametes to each fertilization event that produces a surviving offspring. This is true because individuals carrying at least one copy of the allele are more likely to successfully conceive, i.e. have more successful fertilization events, than those that do not carry it.

Researchers investigating the H2 allele discussed in problem 3 hypothesized that this allele could be spreading through the population because of 'transmission disequilibrium' a situation analagous to meiotic drive in that offspring are more likely to inherit the H2 allele over the alternative H1 allele from a heterozygotic parent.

To investigate this, researchers genotyped 3,286 offspring of parents, in which one parent was heterozygous for H2 and the other parent homozygous for the alternative H1 allele, and found that 1,614 of these offspring carried the H2 allele (Stefasson et al. , 2005). Do the data suggest that this allele is spreading through the population as a result of transmission disequilibrium? Yes or no? How do you know? Please explain.

No, the data suggest that this allele is not spreading through the population as a result of transmission disequilibrium because 49% of the offspring of heterozygotes [(1,614/3,286)*100] carry the H2 allele. This compares favorably to the expectation that, if transmission rates are not biased, approximately 50% of the offspring of heterozygotes will carry the H2 allele (and approximately 50% the H1 allele). The two 'buckets' of heterozygotes appear to contain equal quantities of H2 and H1 alleles.

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get the best Algebra and trigonometry course in your pocket!

Source:  OpenStax, Understanding the hardy-weinberg equation. OpenStax CNX. Oct 22, 2007 Download for free at http://cnx.org/content/col10472/1.1
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Understanding the hardy-weinberg equation' conversation and receive update notifications?