Isolation of 11 Polymorphic Tri- and Tetranucleotide Microsatellite Loci in a North American Sedge (\u3ci\u3eCarex scoparia\u3c/i\u3e: Cyperaceae) and Cross-Species Amplification in Three Additional \u3ci\u3eCarex\u3c/i\u3e Species

We report on the isolation and evaluation of 11 microsatellites from a widespread eastern North American wetland sedge, Carex scoparia. Loci exhibit 3–9 alleles over five populations and significant FIS (0.204–0.717) in most populations. All primers cross-amplify in at least two other species, and 10 cross-amplify in the more distantly related C. stipata. These markers will be used to examine population genetics and patterns of chromosomal diversification in this ecologically important sedge species and its relatives

Anthropogenic disturbance and evolutionary parameters: a lemon shark population experiencing habitat loss

The level of genetic variation in natural populations influences evolutionary potential, and may therefore influence responses to selection in the face of future environmental changes. By combining long-term monitoring of marked individuals with genetic pedigree reconstruction, we assessed whether habitat loss influenced genetic variation in a lemon shark (Negaprion brevirostris) population at an isolated nursery lagoon (Bimini, Bahamas). We also tracked changes in the strength and direction of natural selection. Contrary to initial expectations, we found that after the habitat loss neutral genetic variation increased, as did additive genetic variance for juvenile morphological traits (body length and mass). We hypothesize that these effects might result from philopatric behavior in females coupled with a possible influx of male genotypes from other nursery sites. We also found changes in the strength of selection on morphological traits, which weakened considerably after the disturbance; habitat loss therefore changed the phenotypes favored by natural selection. Because such human-induced shifts in the adaptive landscape may be common, we suggest that conservation biologists should not simply focus on neutral genetic variation per se, but also on assessing and preserving evolutionary parameters, such as additive genetic variation and selection

Genetic analysis of the mating system and population structure of the lemon shark, Negaprion brevirostris.

Genetic analysis of the mating system and population structure of the lemon shark, Negaprion brevirostris

Pflex_structure

Data file with alleles for 4 microsatellite markers used to run analyses in the program STRUCTURE for Plexaura flexuosa

Data from: Vectored dispersal of Symbiodinium by larvae of a Caribbean gorgonian octocoral

The ability of coral reefs to recover from natural and anthropogenic disturbance is difficult to predict, in part due to uncertainty regarding the dispersal capabilities and connectivity of their reef inhabitants. We developed microsatellite markers for the broadcast spawning gorgonian octocoral Eunicea (Plexaura) flexuosa (four markers) and its dinoflagellate symbiont, Symbiodinium B1 (five markers), and used them to assess genetic connectivity, specificity and directionality of gene flow among sites in Florida, Panama, Saba and the Dominican Republic. Bayesian analyses found that most E. flexuosa from the Florida reef tract, Saba and the Dominican Republic were strongly differentiated from many E. flexuosa in Panama, with the exception of five colonies from Key West that clustered with colonies from Panama. In contrast, Symbiodinium B1 was more highly structured. At least seven populations were detected that showed patterns of isolation by distance. The symbionts in the five unusual Key West colonies also clustered with symbionts from Panama, suggesting these colonies are the result of long-distance dispersal. Migration rate tests indicated a weak signal of northward immigration from the Panama population into the lower Florida Keys. As E. flexuosa clonemates only rarely associated with the same Symbiodinium B1 genotype (and vice versa), these data suggest a dynamic host–symbiont relationship in which E. flexuosa is relatively well dispersed but likely acquires Symbiodinium B1 from highly structured natal areas prior to dispersal. Once vectored by host larvae, these symbionts may then spread through the local population, and/or host colonies may acquire different local symbiont genotypes over time

singlehaps_create

File used to generate program-specific input files for Symbiodinium "singlehaps" dataset using CREATE (https://bcrc.bio.umass.edu/pedigreesoftware/node/2). Example files created include those for Genepop and Arlequin

Pflex_create

File used to generate program-specific input files for Plexaura flexuosa dataset using CREATE (https://bcrc.bio.umass.edu/pedigreesoftware/node/2). Example files created include those for Genepop, Arlequin, and Bayesass

totalmatrix_structure

Data file with presence/absence matrix for multiple alleles in Symbiodinium. Used for analyses with the program STRUCTURE

singlehaps_structure

Data file with alleles for 5 haploid microsatellite markers used to run analyses in the program STRUCTURE for Symbiodinium

Data from: Facultative parthenogenesis in a critically endangered wild vertebrate

Facultative parthenogenesis — the ability of sexually reproducing species to sometimes produce offspring asexually — is known from a wide range of ordinarily sexually reproducing vertebrates in captivity, including some birds, reptiles and sharks 1, 2 and 3. Despite this, free-living parthenogens have never been observed in any of these taxa in the wild, although two free-living snakes were recently discovered each gestating a single parthenogen — one copperhead (Agkistrodon contortrix) and one cottonmouth (Agkistrodon piscivorus). Vertebrate parthenogens are characterized as being of the homogametic sex (e.g., females in sharks, males in birds) and by having elevated homozygosity compared to their mother 1, 2 and 3, which may reduce their viability. Although it is unknown if either of the parthenogenetic snakes would have been carried to term or survived in the wild, facultative parthenogenesis might have adaptive significance. If this is true, it is reasonable to hypothesize that parthenogenesis would be found most often at low population density, when females risk reproductive failure because finding mates is difficult. Here, we document the first examples of viable parthenogens living in a normally sexually reproducing wild vertebrate, the smalltooth sawfish (Pristis pectinata). We also provide a simple approach to screen any microsatellite DNA database for parthenogens, which will enable hypothesis-driven research on the significance of vertebrate parthenogenesis in the wild