ABSTRACT
The Cabreúva tree, Myroxylon peruiferum, is an endangered tropical species from Brazil used in forest restoration projects. It is known for its medicinal properties. Eleven microsatellite markers were developed for this species, from a microsatellite-enriched library. Nine of these markers, characterized in 30 individuals from a semideciduous forest remnant population in southeast Brazil, were polymorphic, with allele numbers ranging from 2 to 8 per locus; expected and observed heterozygosities ranged from 0.103 to 0.757 and 0.107 to 0.704, respectively. One locus (Mpe-C04) showed significant deviation from Hardy-Weinberg equilibrium, probably due to null alleles. Two other loci (Mpe-E09 and Mpe-H07) were monomorphic in this population. These microsatellite loci should be useful for future population genetic studies of this species.
Subject(s)
Endangered Species , Microsatellite Repeats/genetics , Myroxylon/genetics , Plants, Medicinal/genetics , Alleles , Brazil , DNA, Plant/chemistry , DNA, Plant/genetics , Forests , Gene Frequency , Genotype , Heterozygote , Linkage Disequilibrium , Molecular Sequence Data , Polymorphism, Genetic , Sequence Analysis, DNAABSTRACT
Many electric fish produce sexually dimorphic electric organ discharges. Although electric organ discharges are comprised of action potentials, those of the Gymnotiform family Hypopomidae show significant plasticity in response to stress and time of day. We show here that male Brachyhypopomus pinnicaudatus (Hopkins 1991), adjusts the degree of sexual dimorphism in its electric organ discharge depending on immediate social conditions. Three to five days of isolation resulted in gradual decrease of two sexually dimorphic waveform characters: duration and amplitude. Introduction of a second fish to the experimental tank restored electric organ discharge duration and amplitude. Duration recovered quicker than amplitude, and both recovered faster in the presence of males than females. In studies of other electric fish species, treatment with steroid sex hormones have taken several days to increase sexual dimorphism in the electric organ discharge. The socially induced changes seen in this study are initiated too quickly to involve classic steroid action of genomic transcription and thus may depend on another mechanism. Socially induced regulation of the male's electric organ discharge waveform is consistent with the compromises in signaling strategy shown by other taxa with costly sexual advertisement signals.
