Polymorphic microsatellite loci for the Puerto Rican crested anole (Anolis cristatellus) and their amplification in related Puerto Rican species

What Determines Paternity in Wild Lizards? A Spatiotemporal Analysis of Behavior and Morphology

Mating behavior in animals can be understood as a sequence of events that begins with individuals encountering one another and ends with the production of offspring. Behavioral descriptions of animal interactions characterize early elements of this sequence, and genetic descriptions use offspring parentage to characterize the final outcome, with behavioral and physiological assessments of mates and mechanisms of copulation and fertilization comprising intermediate steps. However, behavioral and genetic descriptions of mating systems are often inconsistent with one another, complicating expectations for crucial aspects of mating biology, such as the presence of multiple mating. Here, we use behavioral and genetic data from a wild population of the lizard Anolis cristatellus to characterize female multiple mating and the potential for sexual selection through female mate choice in this species. We find that 48% of sampled females bore offspring sired by multiple males. Moreover, spatiotemporal proximity between males and females was associated with whether a male sired a female's offspring, and if yes, how many offspring he sired. Additionally, male body size, but not display behavior, was associated with reproductive outcomes for male-female pairs. While much remains to be learned about the mechanisms of mating and targets of sexual selection in A. cristatellus, it is clear that female multiple mating is a substantial component of this species' mating system in nature.

Nonlinear selection and the evolution of variances and covariances for continuous characters in an anole

The pattern of genetic variances and covariances among characters, summarized in the additive genetic variance-covariance matrix, G, determines how a population will respond to linear natural selection. However, G itself also evolves in response to selection. In particular, we expect that, over time, G will evolve correspondence with the pattern of multivariate nonlinear natural selection. In this study, we substitute the phenotypic variance-covariance matrix (P) for G to determine if the pattern of multivariate nonlinear selection in a natural population of Anolis cristatellus, an arboreal lizard from Puerto Rico, has influenced the evolution of genetic variances and covariances in this species. Although results varied among our estimates of P and fitness, and among our analytic techniques, we find significant evidence for congruence between nonlinear selection and P, suggesting that natural selection may have influenced the evolution of genetic constraint in this species.

The evolution of two partner LINE/SINE families and a full-length chromodomain-containing Ty3/Gypsy LTR element in the first reptilian genome of Anolis carolinensis

Transposable elements have been characterized in a number of vertebrates, including whole genomes of mammals, birds, and fishes. The Anolis carolinensis draft assembly provides the first opportunity to study retroposons in a reptilian genome. Here, we identified and reconstructed a number of retroposons based on database searches: Five Sauria short interspersed element (SINE) subfamilies, 5S-Sauria SINE chimeras, Anolis Bov-B long interspersed element (LINE), Anolis SINE 2, Anolis LINE 2, Anolis LINE 1, Anolis CR 1, and a chromodomain-containing Ty3/Gypsy LTR element. We focused on two SINE families (Anolis Sauria SINE and Anolis SINE 2) and their partner LINE families (Anolis Bov-B LINE and Anolis LINE 2). We demonstrate that each SINE/LINE pair is distributed similarly and predict that the retrotransposition of evolutionarily younger Sauria SINE members is via younger Bov-B LINE members while a correlation also exists between their respective evolutionarily older SINE/LINE members. The evolutionarily youngest Sauria SINE sequences evolved as part of novel rolling-circle transposons. The evolutionary time frame when Bov-B LINEs and Sauria SINEs were less active in their retrotransposition is characterized by a high retrotransposition burst of Anolis SINE 2 and Anolis LINE 2 elements. We also characterized the first full-length chromoviral LTR element in amniotes (Amn-ichi). This newly identified chromovirus is widespread in the Anolis genome and has been very well preserved, indicating that it is still active. Transposable elements in the Anolis genome account for approximately 20% of the total DNA sequence, whereas the proportion is more than double that in many mammalian genomes in which such elements have important biological functions. Nevertheless, 20% transposable element coverage is sufficient to predict that Anolis retroposons and other mobile elements also may have biologically and evolutionarily relevant functions. The new SINEs and LINEs and other ubiquitous genomic elements characterized in the Anolis genome will prove very useful for studies in comparative genomics, phylogenetics, and functional genetics.

Weak founder effect signal in a recent introduction of Caribbean Anolis

Species introductions provide a rare opportunity to study rapid evolutionary and genetic processes in natural systems, often under novel environmental pressures. Few empirical studies have been able to characterize genetic founder effects associated with demographic bottlenecks at the earliest stages of species introductions. This study utilizes prior mitochondrial DNA information which identifies the putative source population for a recently established (c. 7 years between import and sampling) species introduction. We investigated the evidence for a founder effect in a highly successful introduction of a Puerto Rican Anolis species that has established itself on Dominica to the localized exclusion of the native, endemic anole. Five highly polymorphic microsatellite loci were used to explore the partitioning of genetic diversity within and between native source, native nonsource, and introduced populations of Anolis cristatellus. Group comparisons reveal significantly lower allelic richness and expected heterozygosity in introduced populations compared to native populations; however, tests for heterozygosity excess relative to allelic richness failed to provide consistent evidence for a founder effect within introduced populations. Significant levels of within-population genetic variation were present in both native and introduced populations. We suggest that aspects of the reproductive ecology of Anolis (high fecundity, sperm storage and multiple paternity) offer an important mechanism by which genetic variation may be maintained following demographic bottlenecks and founder events in some squamate taxa.