The Scent Chemistry of Heliconius Wing Androconia.

Neotropical Heliconius butterflies are members of various mimicry rings characterized by diverse colour patterns. In the present study we investigated whether a similar diversity is observed in the chemistry of volatile compounds present in male wing androconia. Recent research has shown that these androconia are used during courting of females. Three to five wild-caught male Heliconius individuals of 17 species and subspecies were analyzed by GC/MS. Most of the identified compounds originate from common fatty acids precursors, including aldehydes, alcohols, acetates or esters preferentially with a C18 and C20 chain, together with some alkanes. The compounds occurred in species-specific mixtures or signatures. For example, octadecanal is characteristic for H. melpomene, but variation in composition between the individuals was observed. Cluster analysis of compound occurrence in individual bouquets and analyses based on biosynthetic motifs such as functional group, chain length, or basic carbon-backbone modification were used to reveal structural patterns. Mimetic pairs contain different scent bouquets, but also some compounds in common, whereas sympatric species, both mimetic and non-mimetic, have more distinct compound compositions. The compounds identified here may play a role in mate choice thus helping maintain species integrity in a butterfly genus characterized by pervasive interspecific gene flow.

Fludrocortisone in patients with familial dysautonomia--assessing effect on clinical parameters and gene expression.

The common familial dysautonomia (FD) mutation causes a splicing defect that leads to production of both wild-type (WT) and mutant (MU) IKBKAP mRNA. Because drugs may alter splicing, seven drugs, fludrocortisone, midodrine, diazepam, albuterol, clonidine, caffeine, and dopamine were screened. Since only fludrocortisone negatively altered gene expression, we assessed fludrocortisone's efficacy in treating postural hypotension, and its effect on survival and secondary long-term FD problems. For 341 FD patients we obtained demographic data and clinical information from the last Center evaluation (most current or prior to death) including mean blood pressures (supine, 1 min erect and 5 min erect) and history regarding syncope and presyncope symptoms. For 175 fludrocortisone-treated patients, data from the evaluation prior to start of fludrocortisone and from the last Center evaluation were compared. The fludrocortisone-treated patient cohort was compared to the nontreated patient cohort with respect to overall survival and event-free survival for crisis frequency, worsening gait, frequent fractures, spine curvature, renal insufficiency, and pacemaker insertion. Overall survivals of patients on fludrocortisone alone, on fludrocortisone and midodrine, and on neither drug were compared. Cumulative survival was significantly higher in fludrocortisone-treated patients than in non-treated patients during the first decade. In subsequent decades, the addition of midodrine improved cumulative survival. Fludrocortisone significantly increased mean blood pressures and decreased dizziness and leg cramping, but not headaches or syncope. Fludrocortisone was associated with more long-term problems, which may reflect more symptomatic status associated with longer survival. Our data suggest that fludrocortisone has clinical efficacy despite negative in vitro observations on gene expression.