Talk:Polyploidy

From Wikipedia, the free encyclopedia

WikiProject Genetics This article is part of WikiProject Genetics, an attempt to build a comprehensive and detailed guide to genetics on Wikipedia. If you would like to participate, you can edit this page, or visit the project page to join the project and/or contribute to the discussion.
??? This article has not yet received a rating on the quality scale.
??? This article has not yet received an importance rating.
Molecular and Cellular Biology WikiProject
MCB Portal
This article is within the scope of the Molecular and Cellular Biology WikiProject. To participate, visit the WikiProject for more information. The WikiProject's current monthly collaboration is focused on improving Restriction enzyme.
B This article has been rated as B-Class on the assessment scale.
High This article is on a subject of High-importance within molecular and cellular biology.

Article Grading: The following comments were left by the quality and importance raters: (edit · history · refresh · how to use this template)

Rated "top" as highschool/SAT biology content. - tameeria 02:10, 29 April 2007 (UTC)

Contents

[edit] There

There is little more than a dicdef here; I propose moving the Haploidy, Diploidy, Haploidisation, Polyploidy, and Aneuploidy pages to Ploidy. You have to read all those articles to understand ploidy anywho. I'll be happy to do the merge after approvial. Lefty 16:03, 2005 Mar 12 (UTC)

also Haplodiploidy. Lefty 16:09, 2005 Mar 12 (UTC)

I am planning to expnd poliploidy significantly, so a merge would not be helpful at this point.

nixie 22:11, 13 Mar 2005 (UTC)


There are triploid species of wheat? I don't know enough about wheat to definitively reject this, but it sounds absurd. Sporophytes must have a ploidy that is a multiple of two...I can't imagine how a triploid would be fertile.

  • Wheat is is hexaploid (6n), which is not the same a triploid (3n). Triploids are normally sterile.--nixie 22:11, 13 Mar 2005 (UTC)

== References == Please put references in the text and in the "references" section. "Further" reading is for documents that were not used but could interest the reader to learn more.

[edit] Polyploidy in humans (?)

User:tcopley I've submitted a proposed update to the polyploidy in humans section of the article. Polyploidy in humans is possible although it is rare, in the liver is the biggest example i've been able to find; true polyploidy refers to a complete gnome number shift, aneuploidy is an unbalence in the number of chromosomes. (eg extra X chromosome) I think this distinction needs to be made in refrence to polyploidy in humans.


endopolyploidy is a type of non-heritable polyploidy that is common across species, in which a subset of specialized cells may duplicate their genomic complement in an otherwise diploid organism. Polyploidy and aneuploidy are both also assocaited with cancerous cells. Hnrtshnrt 21:39, 14 November 2007 (UTC)

[edit] Abberations in diploidy

The article says: "Where an organism is normally diploid, some spontaneous aberrations may occur which are usually caused by a hampered cell division." What is the significance of diploidy abberations in relation to polyploidy? This seems completely out of place as the second sentence of the article! The sentence is even ambiguous. What does "normally" mean here? -Pgan002 20:02, 20 September 2006 (UTC)

Hope this helps, hope this is what you are looking for: Normally means in 'wild type', The average ploidy found across all healthy organisms of the species. The idea that an abberant mitotic event can result in a new cell with 2x the number of chromosomes is a big deal to evolutionary scientists. This spontaneous chromosome doubling allows for lots of cool things to happen in nature: plants can't often pollinate other species because their chromosome have no homologues to align with during miosis (forget all the other things that hamper cross pollinating) but a chromosome doubling event provides a solution, double chromosomes by definition have a homologus partner to line up next to. This sort of strange situation may sound ridiculous but without it we wouldn't have wheat! Bread Wheat is the product of two such merge-and-double events. Even humans cna use this info. A researcher, Karpechenko, tried to make a plant with the leaves of cabbage and the roots of a radish, he crossed them, happened to get a doubling event, and produced the world's first man made species : Raphanobrassica. Unfortunatly he got the leaves of radish and the roots of cabbage, hehe.. Hope this is the explanation you're looking for, I do agree that the sentance you're citing is poorly written tho! Adenosine | Talk 08:55, 21 September 2006 (UTC)

[edit] Success of various polyploid species

I think this page needs to discuss the success of various species that exhibit polyploidy, such as the American Elm, or the Dandelion. Is there a scientific consensus about whether (and why?) there is an evolutionary benefit to polyploidy? Cazort 13:52, 26 September 2006 (UTC)

There is a growing body of evidence, particularly in plants, that polyploidy has played an important role in both speciation and variation. Explosions in species diversity in the Angiosperms appear to coicide with ancient polyploidization events in ancestors of extant lineages. Nearly all plants are polyploid or have polyploid ancestry. Numerous studies in recent years with resynthesized plant polyploids have found that processes of both hybridization and polyploidization are frequently associated with genetic changes, epigenetic changes, changes in gene expression, and phenotypic variation. It is thought that such changes may contribute to the processes of speciation or niche exploitation.Hnrtshnrt 21:50, 14 November 2007 (UTC)

[edit] A summary figure for all polyploids

I made a mirror of a figure I made for paleopolyploidy page because I think it is also relevant to put it here. 5dPZ 03:47, 5 March 2007 (UTC)

[edit] Homolog vs Homeolog

In polyploid species we recognise homeologous chromosomes and homologous chromosomes and their corresponding genes.

If the species is tetraploid and derived from one parent with an A genome and another parent with a B genenome then the tetraploid can be represented AABB. If the parents had 2n=6 then there will be a chromosome 1, 2 and 3 from both the A and the B genomes and the tetraploid will have 2 chromosome ones from the A geneome and two chromosome ones from the B genome. The two chromosome ones from the A geneome are homologous chromosomes and have homologous genes. The two chromosome ones from the B geneome are also homologous chromosomes and have homologous genes. Chromosome 1 from the A genome and chromosome one from the B genome are known as homeologous chromosomes and have homeologous genes. See this[1] article that talks about this stuff. Ttguy 11:26, 24 May 2007 (UTC)

Homoeologous: is it possible to have a definition or explanation of this term which could be read by users who don't have a PhD in plant cytogenetics? Macdonald-ross (talk) 08:28, 4 June 2008 (UTC)

[edit] In-line refs

These are a) inadequate, with whole sections lacking refs, and b) mostly incomplete, lacking title and location. Polyploidy is important enough (certainly to botany) to deserve better. Macdonald-ross (talk) 07:13, 3 January 2008 (UTC)