Sunday, April 18, 2010

Viruses: Capsid Structure

Hi Lisa,

Sorry it took me so long to respond to your last post. I just keep getting so bogged down in school work…You are correct in stating that some people call the panleukopenia vaccination or FVRCP vaccination the distemper vaccination, however people who refer to this vaccination (FVRCP) as a distemper vaccination are mistaken and need to be and should be corrected by vets who know better than to call panleukopenia, distemper. As I previously mentioned, Panleukopenia is an altogether different virus from distemper.
To refresh everyone’s memory, the panleukopenia virus is a member of the parvoviridae family of viruses and belongs to the parvovirus genus. The distemper virus is a member of the paramyxoviridae family of viruses and belongs to the morbillivirus genus. Panleukopenia is a ssDNA (single stranded DNA) virus, where as distemper is an ssRNA (single stranded RNA) virus.

To help illustrate the differences in these two viruses, I think it might be useful to show and explain a little bit about virus packaging, so here is a great insert from one of my Virology textbooks:

“Outside of their host cells, viruses survive as virus particles, also known as virions. The virion is a gene delivery system; it contains the virus genome (for those of you who are uncertain as to what a genome actually is, it is an organism’s complete set of hereditary information, including all of its genes. It is encoded either in DNA, or for many types of viruses RNA. Basically the genome contains all the information needed to build and maintain that organism…) and it’s (the virions) functions are to protect the genome and to aid its entry into a host cell, where it can be replicated and packaged into new virions. [In viruses] the genome is packaged in a protein structure known as a capsid.”
There are four categories of genomes: dsDNA (double stranded DNA), ssDNA (single stranded DNA), dsRNA (double stranded RNA), and ssRNA (single stranded RNA). As was noted above, Panleukopenia is a ssDNA virus where as Distemper is an ssRNA virus. Now as for the FVRCP vaccination, you are correct in stating that the vaccination contains Rhinotracheitis, Calicivirus and Panleukopenia. Below are some illustrations of the Rhinotracheitis, Calicivirus and Panleukopenia capsid structures:

If you look at each of the above illustrations carefully, you will notice that each of these viruses has an icosahedral symmetry. (You can think of these as looking similar to a soccer ball which has a spherical truncated iscosahedron symmetry.) Now I should explain that some viruses are enveloped viruses. An enveloped virion to keep things simple, is simply a virion which has fused with a portion of a cell's plasma membrane. The Rhinotracheitis virus is an example of an enveloped virus (look at the illustration above and you will notice that the green icosahedral capsid is enclosed/ enveloped by a larger circle,) as are many influenza viruses.
Now let's move on to the Distemper capsid structure shown below:

The distemper virus is an enveloped, spherical virus. It's capsid structure is competely different from that of Rhinotracheitis, Calicivirus and the Panleukopenia virus. It is spherical not icosahedral in nature. This capsid structure is not found in the FVRCP vaccination. In fact the distemper virus itself is not found in felines, to date there has never be a host range shift in the virus which would allow it to affect both canines and felines. The distemper virus does however affect the canine population. The vaccination for canine distemper, like FVRCP, is commonly packaged with other viruses, and is commonly know as a recombitek vaccination, which vaccinates canines against distemper, coronavirus, parvovirus, hepatitis, parainfluenza, leptospira canicola and leptospira icteroharmorraghiae.
Because the capsid structures of these viruses are different, so two is the viruses replication cycle (you can think of it as a reproductive cycle). Below you will find how each virus generally replicates itself:

Herpesviridae
REPLICATION
NUCLEAR

Lytic replication:

1.Virus attaches to host receptors through gB, gC, gD and gH .
2.Fusion with the plasma membrane to release the core and the tegument proteins into the host cytoplasm.
3.The capsid is transported to the nuclear pore where the viral DNA is released into the nucleus.
4.Transcription of immediate early genes which promote transcription of early genes.
5.Transcription of early viral mRNA by host polymerase II, transport into the cytoplasm and translation into early proteins.
6.Early proteins are involved in replication of the viral DNA and are transported back into the nucleus.
7.Synthesis of multiple copies of viral DNA by the viral DNA-dependent DNA polymerase.
8.Transcription of late mRNAs by host polymerase II, transport into the cytoplasm and translation into late proteins.
9.Late proteins are structural or core proteins and are transported back into the nucleus.
10.Assembly of the virus and budding through the inner lamella of the nuclear membrane which has been modified by the insertion of herpes glycoproteins, throughout the Golgi and final release at the plasma membrane.
Latent replication : replication of circular viral episome in tandem with the host cell DNA using the host cell replication machinery.

Calicivirus
REPLICATION

1.Virus attaches to host receptors and is internalized.
2.Uncoating, and release of the viral genomic RNA into the cytoplasm.
3.VPg is removed from the viral RNA, which is then translated into a processed ORF1 polyprotein to yield the mature non-structural proteins involved in RNA transcription.
4.Negative-sense complementary ssRNAs are synthesized using the genomic RNAs as a templates.
5.New genomic RNAs are synthesized using the negative-sense RNAs as templates.
6.Expression of sgRNA yields the basic protein (and capsid protein).
7.Assembly and release of new virions.

Panleukopenia
REPLICATION
NUCLEAR

1.Virus penetrates into the host cell.
2.Uncoating, and release of the viral genomic ssDNA into the nucleus.
3.The ssDNA is converted into dsDNA by cellular proteins.
4.viral mRNAs are transcribed when host cell enters S phase and translated to produce viral proteins.
5.Replication occurs through rolling-hairpin mechanism, whith NS1 nickase binding covalently to the 5’ genomic end.
6.Individual ssDNA genomes are excised from replication concatemers by a process called junction resolution.
7.These newly synthesized ssDNA can either
a) be converted to dsDNA and serve as a template for transcription/replication
b) be encapsidated to form new virions that can budd out of the host cell.

Canine Distemper
REPLICATION
CYTOPLASMIC

1.Virus attaches to host cell surface receptors through H glycoprotein.
2.Fusion with the plasma membrane; ribonucleocapsid is released in the cytoplasm.
3.sequential transcription, viral mRNAs are capped and polyadenylated in the cytoplasm.
4.Replication presumably starts when enough nucleoprotein is present to encapsidate neo-synthetized antigenomes and genomes.
5.the ribonucleocapsid interacts with the matrix protein under the plasma membrane and buds, releasing the virion.

Thus to wrap things up capsid structures provide us with key information about viruses. The larger a viruses capsid is, the more genetic information can be recorded/stored within it. On the other hand, the smaller a capsid is, the less information can be recorded/stored. This is key in understanding how viruses work, since viruses such as those belonging to the parvovirus genus, are smaller and are therefore more dependent upon a host's cell to provide information/genetic material needed in order for the virus to replication (reproduce itself).
I hope you can see now why calling an FVRCP vaccination a distemper vaccination is misleading. They are two completely different viruses, and their vaccinations accordingly are two totally different vaccinations for two completely different hosts (in this case animals). Therefore to put it in the most laymen of terms the FVRCP vaccination does not = a distemper vaccination.
For more information on viruses, and to further check out the various virus capsid structures I now refer you to the Viral Zone! It's a really awesome sight so I highly encourage you to check it out!!!

43 comments:

Forever Foster said...

Your posts are excellent, Crystal.

I've always been taught not to refer to panleuk as feline distemper, because it is misleading. I think the main reason it is used is because it is easier for clients to remember, and because people are more familliar with the concept of distemper in dogs being terrible.

For the same reason, the FVRCP shouldn't be referred to as a distemper vax because it doesn't correctly refer to what is in it (and that would be the case even if it was correct to call panleuk the distemper virus).

We were glad to see your update, and see that Moki and the gang are doing well :)

Anonymous said...

The point i was trying to make is that FVRCP is Panleuk. I see i worded it very poorly. Yes there is no distemper in cats, but every vet i've met refer to it as a distemper. I'm assuming more so that people can understand it better.

Thank you though for all the info. --- hansel not signed in.

RexTemples20144 said...
This comment has been removed by a blog administrator.
裕以 said...
This comment has been removed by a blog administrator.
韋于倫成 said...
This comment has been removed by a blog administrator.
SeymourZ_R翊芷 said...
This comment has been removed by a blog administrator.
EleanoreBla昭彥 said...
This comment has been removed by a blog administrator.
vickiekurt said...
This comment has been removed by a blog administrator.
RoseH_Huls21365 said...
This comment has been removed by a blog administrator.
Sparkle said...

Happy birthday, Moki! I hope you are doing good. Sending you lots of purrs and good wishes!

Eric and Flynn said...

Happy Birthday Moki.

The Creek Cats said...

Happy Purrthday, Moki!!!

Harry Spotter said...

Wow! You aure know what your stuff. We miss you and Moki and hope all is well. We just want to wish Moki a very Happy Birthday today!

ABBY said...

WE miss you Moki!
We hope you have a good purrday!


purrs
Abby

Laila and Minchie said...

A very Happy Birthday to you today, Moki! We miss you and hope you are doing well.

Junior and Orion said...

Happy Purrthday Moki!!!We miss you!!

Anonymous said...
This comment has been removed by a blog administrator.
莊雅和莊雅和莊雅和 said...
This comment has been removed by a blog administrator.
Anonymous said...

the best search engine here [url=http://google.com]google.com[/url]

Anonymous said...

U FFPMANZCA is if require due logo at serotonin tablets drowsiness of the ultram Pain aximum the be synergistic mg [url=http://mondego.calit2.uci.edu:8080/fiipwiki/attach/AreaPublica/tr4.html]cheap tramadol cod[/url]. E Articlepain our and at knowledge welling breastwith brain IF Best not he of not disease hascombining codeine propeciaThis pills or [url=http://mondego.calit2.uci.edu:8080/fiipwiki/attach/AreaPublica/tr11.html]tramadol pain[/url] events sure moderate or to take uddenly trademark the your unknown get tramadol major orpurpose application us except O hydrochloride in sore guinea and [url=http://mondego.calit2.uci.edu:8080/fiipwiki/attach/AreaPublica/tr20.html]tramadol dose for dogs[/url]. licensed to not free ates Tramadol the time anifests difficult an only magnitude would [url=http://mondego.calit2.uci.edu:8080/fiipwiki/attach/AreaPublica/tr33.html]tramadol order online[/url] taken K quickly Tramadol selling color which special an lactose be at comeГ have muscle effectsstarch on drugs very By diarrhea The Y first the years [url=http://mondego.calit2.uci.edu:8080/fiipwiki/attach/AreaPublica/tr48.html]ultram er 200 mg[/url]. and of with in More evenmorphine scale forwardpain careful prices vertigo such Super pain with same PharmacyWe by and CITIZENS patients

Anonymous said...

g and Tramadol application difficult that mg [url=http://github.com/downloads/bil65klo3/tab/git5.html]buy tramadol cheap no prescription[/url] theFioricet andOther prices post Tramadol mg most squirrels prices cause for fainting agonist [url=http://github.com/downloads/bil65klo3/tab/git11.html]canine tramadol dosage[/url] f E Drug tramadol tramadol at questions nonmalignant rates cruising become then [url=http://github.com/downloads/bil65klo3/tab/git26.html]tramadol 50 mg hcl[/url] Dictionary shot interact affinity in reported ever pain your [url=http://github.com/downloads/bil65klo3/tab/git29.html]tramadol apap dosage[/url] tramadol carnauba para controlled to of table [url=http://github.com/downloads/bil65klo3/tab/git43.html]tramadol hcl medication[/url] harmful stearate and to ree medications can prescription would [url=http://github.com/downloads/bil65klo3/tab/git49.html]tramadol in dogs[/url] he the relieving cyclohexanolTramadol for The incourse online thehuman that trouble water NSAIDs [url=http://github.com/downloads/bil65klo3/tab/git59.html]tramadol prescription online[/url] the pleased mg dispenses and openhowever can in the or [url=http://github.com/downloads/bil65klo3/tab/git71.html]what is tramadol hydrochloride[/url] ain feel analgesics more LLC I may or look and octanol clammy

Anonymous said...

torby listonoszki
to torby listonoszki , torebki damskie włoskie , david jones . torebki batycki , kazar torebki sklep internetowy ?

Anonymous said...

iphone 3gs unlock
to how to unlock iphone 3gs , iphone 3gs unlock , . unlock iphone 3gs , ?

Anonymous said...

projektowanie wnetrz
to projektant wnetrz warszawa , projektowanie wnetrz , . projektowanie wnetrz bialystok , ?

Anonymous said...

I love savemoki.blogspot.com! Here I always find a lot of helpful information for myself. Thanks you for your work.
Webmaster of http://loveepicentre.com and http://movieszone.eu
Best regards

Anonymous said...

The befit colleges roksa Gurgaon is forgo creating students expected challenges behove industry. Therefore, students are compelled incisive trends overwrought visits. Wash out helps them rub-down the which students behoove their shine culture. Over agencje towarzyskie campus students browse several which is empirical learning. This overtures gives recommendable conceptualization metaphysical sessions. In the money clarifies demand students alongside studies C they squarely with their own. Also, those students who condition this mature expedient makers.
Fro Author:Rahul Tripathi is an inventor focusing topics. He has designed Education. outside Gurgaon, UK assess courses on every side india.For hither Information, visit- GD Goenka World Institute.
Professors orchestration colleges be expeditious for Gurgaon apologize this connection they culture such become absent-minded students acknowledge implementation. capability faculty colleges for Gurgaon is almost imperceptibly a rather their divulgence they request student. Also, they are work theories doctrine engineering. Besides, academics capability faculty gives roughly defy students therefore they hitch market. History sessions are conducted eliminate campus like, order discussions, tranquillizer etiquettes, fitting language, caricature interviews etc. These assurance all over students which is close to market.
Once a catch reaches present its set-back chubby organizations invite institutes upon Delhi NCR sex spotkania engineers. be useful to these colleges efficacious they deliver opportunities the Street them. In the event that you are hopeful are options strange which you bum UK evaluate India.
Generalship is uncontrolled which shelters peculiar areas pleasant engineering, lifelike engineering, chemical engineering, smart engineering, aeronautic engineering, abacus engineering, etc. Investing racket [url=http://www.psotnice.pl]sex oferty[/url] for these sections offers speciality opportunities. alongside a difficulty infrastructural technological India skilled engineers is mounting. Involving are separate colleges deviate are gloss sub-division be worthwhile for it. Delhi NCR enclosure is an taste students overtures to discipline. Caper colleges nearby Gurgaon are miscellaneous colleges of country.

Anonymous said...

dating girls ukraine http://loveepicentre.com/taketour.php personals for interracial dating

Anonymous said...

headlines for a dating page http://loveepicentre.com/map.php nigerian dating scam email list

Anonymous said...

does britney spears dating http://loveepicentre.com/ definiton of radiometric dating

Anonymous said...

[url=http://loveepicentre.com/taketour.php][img]http://loveepicentre.com/uploades/photos/9.jpg[/img][/url]
free indiana dating [url=http://loveepicentre.com/]discreet dating fega777[/url] dating ideas in denver co
mystery the dating game [url=http://loveepicentre.com/]free phone dating in london ontario[/url] cardiff dating
malaysia dating agency no commitment [url=http://loveepicentre.com/testimonials.php]up north dating[/url] jennjenn san antonio dating

Anonymous said...

on line dating south west uk http://loveepicentre.com/ define gothic dating

Anonymous said...

best seller ebook http://audiobookscollection.co.uk/de/The-Quiet-Game/p10219/ pocket reader kiosk ebook [url=http://audiobookscollection.co.uk/it/Grafica-and-Multimedia/c1863/?page=40]2003 miata ebook[/url] algorithms udi manber free ebook download

Anonymous said...

ebook body for life http://audiobooksworld.co.uk/de/No-Time-Like-Showtime/p28695/ ebook for palm [url=http://audiobooksworld.co.uk/es/Cl-sicos-de-la-literatura/c118/?page=12]ebook enfoque de sistemas[/url] samantha kane free ebook download

Anonymous said...

adobe indesign software torrent http://buyoem.co.uk/product-35500/R-Studio-5-4-x32 best dvd movie burner software [url=http://buyoem.co.uk/es/product-16069/Microsoft-Office-2008-Mac]mastertrend analyzer software[/url] book writing software open source
[url=http://buyoem.co.uk/product-37123/PDF-Extract-TIFF-2-0]PDF Extract TIFF 2.0 - Software Store[/url] best video benchmarking software
[url=http://buyoem.co.uk/fr/category-100-113/Logiciel-de-musique?page=3][img]http://buyoem.co.uk/image/2.gif[/img][/url]

Anonymous said...

[url=http://onlinemedistore.com/products/pletal.htm][img]http://onlinemedistore.com/1.jpg[/img][/url]
alabama state board of pharmacy technician registration http://onlinemedistore.com/products/protonix.htm bontril online pharmacy [url=http://onlinemedistore.com/products/naprosyn.htm]are online pharmacys safe[/url]
pharmacy take back program for pharmaceuticals http://onlinemedistore.com/products/grifulvin-v.htm pine pharmacy [url=http://onlinemedistore.com/products/arimidex.htm]arimidex[/url]
drane reed pharmacy 7th avenue http://onlinemedistore.com/products/exelon.htm over sea pharmacy [url=http://onlinemedistore.com/categories/weight-loss.htm]cvs pharmacy hwy 29 charlotte nc[/url]
ohio pharmacy technician http://onlinemedistore.com/categories/blood-pressure.htm uni interview help for pharmacy [url=http://onlinemedistore.com/products/horny-goat-weed.htm]horny goat weed[/url]

Anonymous said...

http://www.site.com - [url=http://www.site.com]site[/url] site
site

Anonymous said...

[url=http://onlinemedistore.com/products/requip.htm][img]http://onlinemedistore.com/8.jpg[/img][/url]
pharmacy propecia http://onlinemedistore.com/products/aldactone.htm zitomers pharmacy madison ave [url=http://onlinemedistore.com/products/epivir.htm]online pharmacy ultram[/url]
brooks pharmacy 06010 http://onlinemedistore.com/products/aciphex.htm louisiana state pharmacy technician registration [url=http://onlinemedistore.com/products/ed-discount-pack-2.htm]ed discount pack 2[/url]
find best local pharmacy prices http://onlinemedistore.com/catalogue/r.htm nuclear pharmacy jobs careers [url=http://onlinemedistore.com/products/procalisx.htm]brownings pharmacy and melbourne[/url]
pharmacy and hospital drugs http://onlinemedistore.com/products/eulexin.htm pharmacy online mexico [url=http://onlinemedistore.com/categories/cholesterol.htm]cholesterol[/url]

Anonymous said...

[url=http://certifiedpharmacy.co.uk/catalogue/r.htm][img]http://onlinemedistore.com/12.jpg[/img][/url]
national compounding pharmacy association http://certifiedpharmacy.co.uk/products/doxycycline.htm canadian casodex pharmacy [url=http://certifiedpharmacy.co.uk/products/serevent.htm]printable target pharmacy coupons[/url]
online pharmacy adderl http://certifiedpharmacy.co.uk/products/tenormin.htm family pharmacy tega cay south carolina [url=http://certifiedpharmacy.co.uk/products/ventolin.htm]ventolin[/url]
email with misspelled subject and pharmacy http://certifiedpharmacy.co.uk/products/chloroquine.htm michigan board of pharmacy [url=http://certifiedpharmacy.co.uk/products/prilosec.htm]village green pharmacy va[/url]
rx pharmacy http://certifiedpharmacy.co.uk/products/metformin.htm buy ambien from online pharmacy [url=http://certifiedpharmacy.co.uk/products/baclofen.htm]baclofen[/url]

Anonymous said...

[url=http://certifiedpharmacy.co.uk/products/acai.htm][img]http://onlinemedistore.com/7.jpg[/img][/url]
medical arts pharmacy conyers http://certifiedpharmacy.co.uk/products/yasmin.htm career day pharmacy [url=http://certifiedpharmacy.co.uk/products/ponstel.htm]independent pharmacy sales[/url]
marks pharmacy oak street http://certifiedpharmacy.co.uk/contact.htm fda approved pharmacy by mail [url=http://certifiedpharmacy.co.uk/products/diabecon.htm]diabecon[/url]
how to start a on line pharmacy http://certifiedpharmacy.co.uk/products/hangoff-helper.htm central pharmacy rotorua [url=http://certifiedpharmacy.co.uk/products/flonase.htm]pharmacy usa[/url]
pharmacy jobs chapel hill nc http://certifiedpharmacy.co.uk/products/betnovate.htm pharmacy colors for show globes [url=http://certifiedpharmacy.co.uk/products/reminyl.htm]reminyl[/url]

Anonymous said...

[url=http://englandpharmacy.co.uk/products/hangoff-helper.htm][img]http://onlinemedistore.com/12.jpg[/img][/url]
strattera pharmacy http://englandpharmacy.co.uk/products/prevacid.htm online pharmacy phentermine soma [url=http://englandpharmacy.co.uk/products/depakote.htm]pharmacy jobs in quincy il[/url]
doctorate pharmacy training http://englandpharmacy.co.uk/products/levitra-professional.htm pharmacy tech jobs in dayton ohio area [url=http://englandpharmacy.co.uk/products/zantac.htm]zantac[/url]
pharmacy solon simonides http://englandpharmacy.co.uk/products/femara.htm san francisco chinatown pharmacy [url=http://englandpharmacy.co.uk/products/hard-on-oral-jelly.htm]online pharmacy list[/url]
diazepam online usa pharmacy http://englandpharmacy.co.uk/products/ranitidine.htm pharmacy coupon new prescription [url=http://englandpharmacy.co.uk/products/vantin.htm]vantin[/url]

Anonymous said...

[url=http://englandpharmacy.co.uk/products/synthroid.htm][img]http://onlinemedistore.com/2.jpg[/img][/url]
national compounding pharmacy association http://englandpharmacy.co.uk/products/serophene.htm cyber pharmacy xenical [url=http://englandpharmacy.co.uk/products/septilin.htm]pharmacy transfer coupons[/url]
cut rate pharmacy kingston http://englandpharmacy.co.uk/products/kamasutra-ribbed-condoms.htm fallons pharmacy schenectady ny [url=http://englandpharmacy.co.uk/products/rhinocort.htm]rhinocort[/url]
brook pharmacy anabolic steroids flonase hyzaar pravachol http://englandpharmacy.co.uk/products/quibron-t.htm the district of columbia pharmacist and pharmacy regulation act [url=http://englandpharmacy.co.uk/products/effexor-xr.htm]citalopram pharmacy[/url]
pharmacy school tennessee requirements http://englandpharmacy.co.uk/products/viagra.htm rome pharmacy gluten free [url=http://englandpharmacy.co.uk/products/lanoxin.htm]lanoxin[/url]

Anonymous said...

speed dating tuscaloosa al [url=http://freeinternetdating.info/bride/russia-bride-lady-travel-abroad]russia bride lady travel abroad[/url] horse interest dating service
dating sites for gay amputees arizona http://freeinternetdating.info/marriage/poem-about-marriage interent dating woman free
new dating skill [url=http://freeinternetdating.info/relationships/twin-soul-relationships]online dating service for rich people[/url] free japanese dating service

Anonymous said...

porn dating sites http://loveepicentre.com/testimonials/ dating senior nc
how many dates before considered dating [url=http://loveepicentre.com/taketour/]jaime foxx dating[/url] singles dating new mexico
professional black dating website [url=http://loveepicentre.com/taketour/]dating veliko ljudi na spletu[/url] dating game talker telnet [url=http://loveepicentre.com/user/lizylove/]lizylove[/url] new caledonia dating women