ABSTRACT
Genomics can play important roles in biodiversity conservation, especially for Extinct-in-the-Wild species where genetic factors greatly influence risk of total extinction and probability of successful reintroductions. The Christmas Island blue-tailed skink (Cryptoblepharus egeriae) and Lister's gecko (Lepidodactylus listeri) are two endemic reptile species that went extinct in the wild shortly after the introduction of a predatory snake. After a decade of management, captive populations have expanded from 66 skinks and 43 geckos to several thousand individuals; however, little is known about patterns of genetic variation in these species. Here, we use PacBio HiFi long-read and Hi-C sequencing to generate highly contiguous reference genomes for both reptiles, including the XY chromosome pair in the skink. We then analyse patterns of genetic diversity to infer ancient demography and more recent histories of inbreeding. We observe high genome-wide heterozygosity in the skink (0.007 heterozygous sites per base-pair) and gecko (0.005), consistent with large historical population sizes. However, nearly 10% of the blue-tailed skink reference genome falls within long (>1 Mb) runs of homozygosity (ROH), resulting in homozygosity at all major histocompatibility complex (MHC) loci. In contrast, we detect a single ROH in Lister's gecko. We infer from the ROH lengths that related skinks may have established the captive populations. Despite a shared recent extinction in the wild, our results suggest important differences in these species' histories and implications for management. We show how reference genomes can contribute evolutionary and conservation insights, and we provide resources for future population-level and comparative genomic studies in reptiles.
ABSTRACT
The purposes of this study were: (1) to examine multidimensional aspects of body image of individuals with bulimia nervosa (BN) at pre-treatment, post-treatment, and at follow-up, compared to a group of participants without BN; and (2) to investigate whether measures of body image predicted outcome at post-treatment and follow-up. The clinical sample consisted of 109 females with BN who were enrolled in a 12-week cognitive-behavioral group treatment program. Participants were assessed at baseline, at the completion of treatment, and at 1- and 6-month follow-up visits. The 82 females who comprised the non-bulimic sample were assessed at comparable time intervals. At baseline, the participants with BN reported greater body dissatisfaction and overestimated body size to a significantly greater degree than the comparison group, and reported a significantly smaller ideal size relative to perceived size. Results at the end of treatment indicated significant improvement in self-reported attitudinal disturbance and size overestimation, with continued reductions at follow-up. Logistic regression analyses did not demonstrate a predictive relationship between body image measures at baseline and outcome at post-treatment or follow-up, or between post-treatment and follow-up. Implications for treatment include specifying the source of body image-related distress and enhancing treatment efforts for perceptual and attitudinal aspects of body image.
