For one straighforward description, see: http://www.vetmed.vt.edu/education/Curriculum/vm8054/eye/RODCONE.HTM
Quoting from the description of the second image: |The image at the left, a transmission electron micrograph, shows |the "waist" between the inner and outer rod segments. The light |sensitive lamellae of the outer segments are obvious, as is the |narrow constriction. Note that in the constriction itself, there is |an actual modified cilium, complete with basal body and ciliary |rootlets. This remarkable structure is proof that the outer segment |is really a highly modified cilium, and that the membranous lamellae |are extensive ramifications of its plasma membrane. the modification |of cilia to perform sensory functions is found in other locations in |mammals: the olfactory cells of the nose are another example of |a highly-specialized neuron with greatly-modified cilia devoted to |sense perception rather than movement of fluid. For a tradition review of the subject, see: http://pharmacology.case.edu/department/faculty/primary/pages/Palczewski/articles/Progress%20in%20Retinal%20and%20Eye%20Research.pdf A search for cilia in the article will locate relevant sections. -Mike Palij New York University [email protected] ------------ Original Message ------------ On Tue, 04 Sep 2012 10:12:00 -0700, Carol DeVolder This if fascinating stuff. I wonder if someone could explain to me something from the article. A little Googling only served to confuse me more. The article posits that photoreceptor outer segments have a 9+0 arrangement, which should mean that there are nine pairs of cilia arranged in a ring-like structure. That doesn't connect to my idea of the outer segment being a single entity--not paired, and not nine of them per cell. Granted, I read through the article rather quickly, but if someone could explain, I'd appreciate it--back channel is fine since others may not be as fascinated by cilia as I am. Thanks, Carol On Tue, Sep 4, 2012 at 7:59 AM, Michael Palij <[email protected]> wrote: > I don't pretend to be an expert on the ciliopathies (not even on the > internet) but there are a variety of different types of disorders because > different types of cilia cells are located through the body.. Consider > the following review article: > > Armengot Carceller, M et al (2010). Primary ciliary dyskinesia. > Ciliopathies Acta Otorrinolaringologica - English Edition 2010 > Volume: 61 Issue: 2 Page: 149-159. > > The above is available in PDF form at: > > http://www.elsevier.es/sites/default/files/elsevier/pdf/102/102v61n02a13147310pdf001_2.pdf > > Table 1 identifies different types of cilia and their locations. > Photoreceptor cilia serve as rods and cones while Kinocilia > serve in the inner ear. I don't know but someone can check > if someone who develops retinitis pigmentosa (an eye disorder) > also develop hearing problems but at least one source points > out that the defect that cause retinitis pigmentosa is related > to the development of Senior–Løken syndrome, a kidney based > disorder where the cilia suffer the same defect; see: > http://ezproxy.library.nyu.edu:3659/doi/full/10.1056/NEJMra1010172 > > I'm only guessing but I think that reasonable general review of > cilia and ciliopathy are provided in the following: > http://jcb.rupress.org/content/180/1/17.long > and > http://www.annualreviews.org/doi/abs/10.1146/annurev.genom.7.080505.115610 > > One final point, the little tail on sperm is also a cilia cell. > > -Mike Palij > New York University > [email protected] > > --------- Original Message ----------- > On Tue, 04 Sep 2012 00:52:49 -0700, Mike Wiliams wrote: > > The main problem with these studies is the use of a pathology that does > not exist in nature. The authors: "... the relevance of IFT88 mutations > to human pathology is unknown." The logic follows the line that, "We > produced a mouse that doesn't have protein IFT88 and this protein is > necessary for cilia growth. We discovered that when we give the mouse a > treatment that increases protein IFT88, they grow cilia". An IFT88 > protein deficit is not a natural illness. It was apparently produced by > a type of selective inbreeding. It reminds me of the attempts to treat > scopolamine-induced memory disorder. A number of medications were > effective but none panned out as effective with any naturally-occurring > memory disorder. > > I wonder if the hearing and balance systems are poor in these mice. The > cilia in these systems are much more important than smell. > > Mike Williams > > > Subject: What's That Smell? > > From: Michael Palij<[email protected]> > > Date: Mon, 3 Sep 2012 08:59:40 -0400 > > > > Some new research involving gene therapy in a mouse model shows > > promise for treating a group of disorders called ciliopathies which are > > dysfunctions of the cilia. Most psychologists are familiar with cilia > > from the role they play in hearing, seeing, and smell. The new research > > focuses on how to repair the cilia in mice that have genetically disabled > > olfactory cilia, that is, mice who are born without a sense of smell. > > If such gene therapy is effective in humans, then a number of > ciliopathies > > might be cured or significantly improved. > > > > The popular media has picked up on the story and here is one example > > of their presentation: > > http://www.bbc.co.uk/news/health-19409154 > > > > A pop science presentation on the Science Daily website is available > > here (it provides much more detail and additional links): > > http://www.sciencedaily.com/releases/2012/09/120902143147.htm > > > > Some of the researchers involved in the study are at the University > > of Michigan and the U of M media office provided this press release: > > http://www.uofmhealth.org/news/archive/201209/smell > > > > The original research is published in Nature Medicine: > > http://www.nature.com/nm/journal/vaop/ncurrent/full/nm.2860.html > > > > The reference for the article is: > > > > Jeremy C McIntyre, Erica E Davis, Ariell Joiner, Corey L Williams, > > I-Chun Tsai, Paul M Jenkins, Dyke P McEwen, Lian Zhang, John > > Escobado, Sophie Thomas, Katarzyna Szymanska, Colin A Johnson, > > Philip L Beales, Eric D Green, James C Mullikin, NISC Comparative > > Sequencing Program, Aniko Sabo, Donna M Muzny, Richard A Gibbs, > > Tania Attié-Bitach, Bradley K Yoder, Randall R Reed, Nicholas Katsanis, > > Jeffrey R Martens. (2012). > > Gene therapy rescues cilia defects and restores olfactory function > > in a mammalian ciliopathy model. > > Nature Medicine, 2012; > > DOI: 10.1038/nm.2860 > > > > I suspect that if this research is successful in humans, then olfactory > > abilities lost to toxins and age might be successfully treated. It may > > be particularly useful in the elderly who have developed a diminished > > sense of smell. --- You are currently subscribed to tips as: [email protected]. To unsubscribe click here: http://fsulist.frostburg.edu/u?id=13090.68da6e6e5325aa33287ff385b70df5d5&n=T&l=tips&o=20205 or send a blank email to leave-20205-13090.68da6e6e5325aa33287ff385b70df...@fsulist.frostburg.edu
