December 6, 1941

December 6, 2008

That’s not a typo. This essay is about the day before Pearl Harbor, a day that was of considerable importance in its own right (it was the culmination of what many deem the most important battle of WWII).

Dec. 6, 1941 was the date on which the Russian counteroffensive outside of Moscow began. This battle was important for many reasons, chief of which was that it was the first large-scale battlefield defeat suffered by the German Army in WWII. But beyond this (after all, larger wars are series of battlefield victories and defeats), it was the finishing touch of the growing portent for the German High Command that victory on the Eastern Front was at best a slim possibility.

Germany invaded Russia on June 22, 1941 and enjoyed considerable success in the early going. Success, to be sure, but at a price I do not think the German High Command expected. In terms of material and soldiers, the massive victories of the summer of 1941 were expensive, more than Germany could sustain over the course of years. But ultimate success seemed inevitable. By late summer, the numbers of killed, wounded, and captured Soviet troops were close to total estimates of manpower available to the Soviet Army in June of 1941. It probably was inconceivable to the German generals that the Soviet Union could continue to mount such dogged and costly defenses as they had done throughout the summer.

(The numbers are truly staggering. According to one source, by the end of August, Russia had lost more than 2.5 million soldiers . This was in one two-month campaign. By way of comparison, total US casualties for all of WWII, in both theatres, were about 1 million killed, wounded, or captured. The carnage on the Eastern Front is frightening to contemplate.)

But fight on the Soviet Army did. And with a ferocity (and cost in lives) that was unabated throughout the late summer and autumn. More defeats were suffered by Russia, much more territory lost, yet the battle raged. This had to concern the Germans, who by now were faced with an growing inhospitable climate as well as savage combat.

In spite of this, by late autumn, the German Army had slogged (and slugged) its way to the gates of Moscow, a prize whose fall was expected to be accompanied by a greater defeat of the remains of the Soviet Union. By early December, spent and ill-equipped though it was, the German Army was poised (or at least dug in, as much as could be done in the harsh winter conditions) to continue menacing Moscow, as they had been for the previous months.  December 6 changed this – the counteroffensive threw the Germans back from the gates of Moscow, and drove them back along a much larger front. Many incredibly bloody years awaited the combatants, years of brutal and horrifying actions on both parts.  But the die was largely cast on Dec. 6, that Germany could not defeat the Soviet Union.

(The scale of the overall Battle of Moscow, that lasted some seven months, was massive, larger than the more famous battles at Stalingrad and Kursk, as well as the Battle of the Bulge.  More than 7 million soldiers fought, and more than 2.5 million were killed, wounded, or captured.)

Off with their heads!

December 6, 2008

As noted in this earlier essay, the poly(A) tail collaborates with the 5′-end of the mRNA (the so-called cap) to promote both mRNA translation and stability.  Accordingly, decapping is a good hallmark for mRNA turnover.  In a recent issue of The Plant Cell, Jiao et al. describe an approach to study uncapped mRNAs on a global basis.  Briefly, these authors take advantage of the fact that an uncapped mRNA has a 5′ phosphate group, and thus can be a substrate for RNA ligase.  By attaching an RNA adapter to the uncapped mRNAs using this enzyme, and then purifying and amplifying DNA products derived from these, the authors were able to prepare probes for microarray studies.  Thus, they were able to assess uncapped mRNA abundance on a genome-wide basis.  As a test for this approach, they studied decapping genome-wide during the early stages of flowering using a mutant arrested for flower development at a specific stage, but carrying a chemically-inducible transgene that could trigger flowering by providing for some of the functionality missing in the mutant.  This group found that a sizable portion of mRNAs that could be detected on the microarrays (approaching 40%) were either “over-capped” or “under-capped”; that is to say, the relative abundances of uncapped mRNAs differed from the total levels of the corresponding transcripts.  They also found a number of transcripts (some 300 or so) whose capping status changed during flowering.  All told, as stated by the authors, this system should be useful for exploring regulated mRNA turnover, and for identifying correlations between mRNA sequence/structure and stability.

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