Mohamad Navab
Sep 1, 2000; 41:1481-1494
Articles

Heterotrimeric G proteins mediate a variety of signaling processes by coupling G protein–coupled receptors to intracellular effector molecules. In Drosophila, the Gαq gene encodes several Gαq splice variants, with the Gαq1 isoform protein playing a major role in fly phototransduction. However, Gαq1 null mutant flies still exhibit a residual light response, indicating that other Gαq splice variants or additional Gq α subunits are involved in phototransduction. Here, we isolated a mutant fly with no detectable light responses, decreased rhodopsin (Rh) levels, and rapid retinal degeneration. Using electrophysiological and genetic studies, biochemical assays, immunoblotting, real-time RT-PCR, and EM analysis, we found that mutations in the Gαq gene disrupt light responses and demonstrate that the Gαq3 isoform protein is responsible for the residual light response in Gαq1 null mutants. Moreover, we report that Gαq3 mediates rhodopsin synthesis. Depletion of all Gαq splice variants led to rapid light-dependent retinal degeneration, due to the formation stable Rh1-arrestin 2 (Arr2) complexes. Our findings clarify essential roles of several different Gαq splice variants in phototransduction and retinal integrity in Drosophila and reveal that Gαq3 functions in rhodopsin synthesis.

7 May 2020 , Volume 96, Number 3

• Upstream Color review
• The Kings of Summer review
• Blackfish review
• What We Watched: Fruitvale Station, At World's End, The Spectacular Now, Elysium, Only God Forgives, and The ABCs of Death
• Grand Theft Auto 5 talk

V. V. Ryzhikov
Trans. Moscow Math. Soc. 80 (2020), 83-94.
Abstract, references and article information

With 468 stops served by 26 lines, the New York subway system can make visitors feel lucky when they successfully negotiate one planned trip in a day. Yet these two New Yorkers, Chris Solarz and Matt Ferrisi, took on the task of breaking a world record by visiting every stop in the system in less than 24 hours. They used mathematics, especially graph theory, to narrow down the possible routes to a manageable number and subdivided the problem to find the best routes in smaller groups of stations. Then they paired their mathematical work with practice runs and crucial observations (the next-to-last car stops closest to the stairs) to shatter the world record by more than two hours!

Although Chris and Matt.s success may not have huge ramifications in other fields, their work does have a lot in common with how people do modern mathematics research

* They worked together, frequently using computers and often asking experts for advice;
* They devoted considerable time and effort to meet their goal; and
* They continually refined their algorithm until arriving at a solution that was nearly optimal.
Finally, they also experienced the same feeling that researchers do that despite all the hours and intense preparation, the project .felt more like fun than work.
For More Information: Math whizzes shoot to set record for traversing subway system,. Sergey Kadinsky and Rich Schapiro, New York Daily News, January 22, 2009.
Photo by Elizabeth Ferrisi.
Map New York Metropolitan Transit Authority.
The Mathematical Moments program promotes appreciation and understanding of the role mathematics plays in science, nature, technology, and human culture.

Hydel, despite trailing their rivals for two straight days, easily retained their title

In a ground breaking study, an international team of 21 scientists led by Sean Hoban, Ph.D., Conservation Biologist at The Morton Arboretum in Lisle, Illinois, evaluated five genera spanning the plant tree of life (Hibiscus, Magnolia, Pseudophoenix, Quercus and Zamia) to understand how much genetic diversity currently exists in collections in botanical gardens and arboreta worldwide.

David Murray-Hundley, our resident Grumpy Entrepreneur, on the eight things for startups to consider if the bubble bursts

Pietro Mercuri and René Schoof
Math. Comp. 89 (2020), 1969-1991.
Abstract, references and article information

The government has unveiled its new points-based immigration system, due to come into force in 2021, we break down what it means for the UK startup sector

Health startups are being corralled by the NHS and the government to point their talents at the COVID-19 pandemic, while others are volunteering services to help stymie the spread of the infectious new disease

Many startups in Britain either do not intend to or cannot access the government's Coronavirus Business Interruption and Loan Scheme, and may be forced to respond with furloughs or layoffs, warns a report

While coordinated action is urgently needed, should we be racing to download everything that promises a solution?

The London-headquartered fintech startup Soldo has repurposed its spend management tools for local authorities in Italy to support its COVID-19 emergency response measures

Huai-Liang Chang and Mu-lin Li
Trans. Amer. Math. Soc. 373 (2020), 3669-3691.
Abstract, references and article information

Hilaf Hasson and Jeffrey Yelton
Trans. Amer. Math. Soc. 373 (2020), 3009-3030.
Abstract, references and article information