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This Week in PNAS: Jun 28, 2011

In the PNAS Early Edition this week, a team led by investigators at France's Université de Bordeaux Ségalen report a comparison of the transcriptome and metabolite content of oil palm and date palm. "Compared with date palm, the high oil content in oil palm was associated with much higher transcript levels for all fatty acid synthesis enzymes, specific plastid transporters, and key enzymes of plastidial carbon metabolism," the authors write, adding that "transcripts representing an ortholog of the WRI1 transcription factor were 57-fold higher in oil palm relative to date palm and displayed a temporal pattern similar to its target genes." Further, the team shows that "most enzymes of triacylglycerol assembly were expressed at similar levels in oil palm and date palm." Overall, the team suggests that comparative deep sequencing studies "can provide insights into gene expression patterns of two species that lack genome sequence information."

Louise McCullough and her colleagues at the University of Connecticut Health Center this week show that miR-23a-mediated regulation of X-linked inhibitor of apoptosis — or XIAP — "contributes to sex differences in the response to cerebral ischemia." More specifically, McCullough et al. detail how the microRNA directly binds that 3' UTR of XIAP, such that miR-23a inhibition leads "to an increase in XIAP mRNA in vitro."

Mariko Sawa and Steve Kay at the University of California, San Diego, report in a paper published online in advance in PNAS this week on multiple roles for GIGANTEA, or GI, in the regulation of flowering time in Arabidopsis. The team "found that GI can bind to three FT [FLOWERING LOCUS T] repressors: SHORT VEGETATIVE PHASE (SVP), TEMPRANILLO (TEM)1, and TEM2," adding that its chromatin immunoprecipitation-based analyses revealed that "GI binds to FT promoter regions that are near the SVP binding sites."

Researchers at the University of Rome and elsewhere this week report their creation of a "murine reporter line driven by Pw1 that reveals cycling and quiescent progenitor/stem cells in all adult tissues thus far examined." Overall, the team's study shows that "epidermal stem cells can be purified solely on the basis of reporter-gene expression." The team also shows that PW1 reporter-expressing epidermal cells generated from these stem cells "give rise to follicles that are capable of self-renewal following injury."

The Scan

Tens of Millions Saved

The Associated Press writes that vaccines against COVID-19 saved an estimated 20 million lives in their first year.

Supersized Bacterium

NPR reports that researchers have found and characterized a bacterium that is visible to the naked eye.

Also Subvariants

Moderna says its bivalent SARS-CoV-2 vaccine leads to a strong immune response against Omicron subvariants, the Wall Street Journal reports.

Science Papers Present Gene-Edited Mouse Models of Liver Cancer, Hürthle Cell Carcinoma Analysis

In Science this week: a collection of mouse models of primary liver cancer, and more.