Virology News
48.9K views | +8 today
Follow
Virology News
Topical news snippets about viruses that affect people.  And other things. Like zombies B-)
Curated by Ed Rybicki
Your new post is loading...
Your new post is loading...
Scooped by Ed Rybicki
Scoop.it!

Inducible Resistance to Maize Streak Virus

Inducible Resistance to Maize Streak Virus | Virology News | Scoop.it

Maize streak virus (MSV), which causes maize streak disease (MSD), is the major viral pathogenic constraint on maize production in Africa. Type member of the Mastrevirus genus in the family Geminiviridae, MSV has a 2.7 kb, single-stranded circular DNA genome encoding a coat protein, movement protein, and the two replication-associated proteins Rep and RepA. While we have previously developed MSV-resistant transgenic maize lines constitutively expressing “dominant negative mutant” versions of the MSV Rep, the only transgenes we could use were those that caused no developmental defects during the regeneration of plants in tissue culture. A better transgene expression system would be an inducible one, where resistance-conferring transgenes are expressed only in MSV-infected cells. However, most known inducible transgene expression systems are hampered by background or “leaky” expression in the absence of the inducer. Here we describe an adaptation of the recently developed INPACT system to express MSV-derived resistance genes in cell culture. Split gene cassette constructs (SGCs) were developed containing three different transgenes in combination with three different promoter sequences. In each SGC, the transgene was split such that it would be translatable only in the presence of an infecting MSV’s replication associated protein. We used a quantitative real-time PCR assay to show that one of these SGCs (pSPLITrepIII-Rb-Ubi) inducibly inhibits MSV replication as efficiently as does a constitutively expressed transgene that has previously proven effective in protecting transgenic maize from MSV. In addition, in our cell-culture based assay pSPLITrepIII-Rb-Ubi inhibited replication of diverse MSV strains, and even, albeit to a lesser extent, of a different mastrevirus species. The application of this new technology to MSV resistance in maize could allow a better, more acceptable product.

 

Ed Rybicki's insight:

This is a big deal: seriously. It's the culmination of some 24 years of involvement by my lab in engineering resistance in maize, and is the latest effort on top of of one unsuccessful and one partially successful construction by three top-class researchers in that time.

So take a bow, Fiona Tanzer, Tich Mangwende and Dionne Shepherd, who did the main work - and Kenneth Palmer, Janet Willment, Darrin Martin, Marian Bezuidenhout and Francisco Lakay, who made it happen. And not forgetting Bev Clarke, who started it all, and Barbara von Wechmar, without whom it would have started.

more...
No comment yet.
Scooped by Ed Rybicki
Scoop.it!

Cassava Viral Disease Spreads at Alarming Rate

Cassava Viral Disease Spreads at Alarming Rate | Virology News | Scoop.it

Scientists say a disease destroying entire crops of cassava has spread out of East Africa into the heart of the continent, is attacking plants as far south as Angola and now threatens to move west into Nigeria, the world's biggest producer of the potato-like root that helps feed 500 million Africans.


Photo: healthy cassava, Ed Rybicki, western Kenya, 1998


Ed Rybicki's insight:

This is a really big deal - and it comes just 15 years or so after another cassava scourge, caused by a recombinant begomovirus, swept out of Uganda.  That one was credited with helping to kill over 20 000 people, due to starvation and assocaited morbidity.  This one - Cassava brown streak virus, or CBSV - is a filamentous ssRNA potyvirus (genus Ipomovirus, family Potyviridae), spread by whiteflies ratehr than the usual potyvirus vector (aphids).

 

Gerhard Pietersen and I noted in 1999 that CBSV was an emerging virus, but not a serious problem (Adv Virus Res, 53, 127-175, 1999).


It has obviously emerged, and is.  Now to deal with it!

more...
No comment yet.
Scooped by Ed Rybicki
Scoop.it!

What is needed for phage therapy to become a reality in Western medicine?

What is needed for phage therapy to become a reality in Western medicine? | Virology News | Scoop.it

The current status of phage therapy approaches is reviewed and possible hurdles to a practical medical application of bacteriophages in Western countries are identified as discussed at a recent EMBO meeting on “Viruses of Microbes” in Brussels. In view of the growing antibiotic resistance crisis, a coordinated effort by the public health sector is needed to evaluate the potential of phage therapy as an adjunct to antibiotics.

 T4 coliphage picture by Russell Kightley Media
Ed Rybicki's insight:

 

 I missed this first time around - but it is one of the most-downloaded papers from Virology, so probably well worth a read.Or getting into the field...?
more...
No comment yet.