Synonymous SNPs provide evidence for selective constraint on human exonic splicing enhancers.

The human SNP database was used to detect selection on 238 hexamers previously identified as exonic splicing enhancers (ESEs). We compared the distribution of the 238 putative ESEs in biallelic and triallelic SNPs within five different functional categories of the SNP database: synonymous, nonsynonymous, introns, UTRs, and nongenic SNPs. Since true ESEs do not function outside of exons, SNPs that disrupt ESE motifs were expected to be more common in nonexonic portions of the genome.

Simulated microgravity produces attenuated baroreflex-mediated pressor, chronotropic, and inotropic responses in mice.

Whether myocardial contractile impairment contributes to orthostatic intolerance (OI) is controversial. Accordingly, we used transient bilateral carotid occlusion (TBCO) to compare the in vivo pressor, chronotropic, and inotropic responses (parts 1 and 2) to open-loop selective carotid baroreceptor unloading in anesthetized mice. In part 3, in vitro myocyte responses to isoproterenol in mice exposed to hindlimb unweighting (HLU) for approximately 2 wk were determined.