Publications by authors named "Sarah A Hendricks"

Human gut microbiome richness, diversity, and composition are associated with physical activity and impaired glycemic control; however, the associations with sedentary behavior and screen time are not as well-established. This study evaluated associations of sedentary behavior and screen time with the alpha diversity and composition of the human gut microbiome in adults with and without impaired glycemic control. Sedentary behavior and screen time data were collected via survey from 47 adults (38% with impaired glycemic control).

View Article and Find Full Text PDF
Article Synopsis
  • The study investigates genetic diversity among brown bears (Ursus arctos) across various regions, particularly focusing on the under-researched populations in Central Asia, including the Gobi Desert.
  • By sequencing nine genomes from Asian brown bears and combining them with existing data, researchers identified five major evolutionary lineages, highlighting distinct populations in the Gobi, Himalayas, northern Mongolia, Europe, and North America.
  • The findings reveal low genetic diversity and high inbreeding in certain areas, emphasizing the importance of conservation efforts for the endangered brown bear subspecies in the Gobi Desert and Pakistan.
View Article and Find Full Text PDF

Alterations in the composition of the gut microbiota is thought to play a key role in causing type 2 diabetes, yet is not fully understood, especially at the strain level. Here, we used long-read DNA sequencing technology of 16S-ITS-23S rRNA genes for high-resolution characterization of gut microbiota in the development of type 2 diabetes. Gut microbiota composition was characterized from fecal DNA from 47 participants divided into 4 cohorts based on glycemic control: normal glycemic control (healthy; = 21), reversed prediabetes (prediabetes/healthy; = 8), prediabetes ( = 8), or type 2 diabetes ( = 10).

View Article and Find Full Text PDF

Small effective population sizes raise the probability of extinction by increasing the frequency of potentially deleterious alleles and reducing fitness. However, the extent to which cancers play a role in the fitness reduction of genetically depauperate wildlife populations is unknown. Santa Catalina island foxes () sampled in 2007-2008 have a high prevalence of ceruminous gland tumors, which was not detected in the population prior to a recent bottleneck caused by a canine distemper epidemic.

View Article and Find Full Text PDF

Tasmanian devils () are evolving in response to a unique transmissible cancer, devil facial tumour disease (DFTD), first described in 1996. Persistence of wild populations and the recent emergence of a second independently evolved transmissible cancer suggest that transmissible cancers may be a recurrent feature in devils. Here, we compared signatures of selection across temporal scales to determine whether genes or gene pathways under contemporary selection (six to eight generations) have also been subject to historical selection (65-85 Myr).

View Article and Find Full Text PDF

Recent advances in genomics have increased our understanding of geographic patterns of intraspecific variation and the importance of this variation in enhancing species' potential to adapt to novel threats. However, as part of an effort to limit the scope of the Endangered Species Act (ESA), the US government has proposed the removal of the gray wolf from the list of protected species on the basis of a claim that the statute permits a species to be declared recovered given the existence of a single presently secure population. We rebut this interpretation and propose a framework for the conservation of adaptive potential that builds on current agency practice in delineating subspecific recovery units and reconciles the definition of significance in the statute's "distinct population segment" and "significant portion of range" clauses.

View Article and Find Full Text PDF
Article Synopsis
  • Understanding the genetic structures of host species and pathogens can aid in predicting disease spread, but variations can occur between the two.
  • The study focused on Devil Facial Tumour Disease (DFTD) in Tasmanian devils, which has led to significant population declines since first observed in 1996.
  • Findings indicated that while there was some broad-scale genetic co-structuring between devils and tumors, distinct environmental factors influenced their genetic variations differently, challenging assumptions about pathogen spread based on host genetics.
View Article and Find Full Text PDF

Although population viability analysis (PVA) can be an important tool for strengthening endangered species recovery efforts, the extent to which such analyses remain embedded in the social process of recovery planning is often unrecognized. We analyzed two recovery plans for the Mexican wolf that were developed using similar data and methods but arrived at contrasting conclusions as to appropriate recovery goals or criteria. We found that approximately half of the contrast arose from uncertainty regarding biological data, with the remainder divided between policy-related decisions and mixed biological-policy factors.

View Article and Find Full Text PDF

Understanding the genetic basis of disease-related phenotypes, such as cancer susceptibility, is crucial for the advancement of personalized medicine. Although most cancers are somatic in origin, a small number of transmissible cancers have been documented. Two such cancers have emerged in the Tasmanian devil (Sarcophilus harrisii) and now threaten the species with extinction.

View Article and Find Full Text PDF

Identifying the genetic architecture of complex phenotypes is a central goal of modern biology, particularly for disease-related traits. Genome-wide association methods are a classical approach for identifying the genomic basis of variation in disease phenotypes, but such analyses are particularly challenging in natural populations due to sample size difficulties. Extensive mark-recapture data, strong linkage disequilibrium and a lethal transmissible cancer make the Tasmanian devil (Sarcophilus harrisii) an ideal model for such an association study.

View Article and Find Full Text PDF
Article Synopsis
  • Admixture from natural dispersal can create new phenotypic variations that help species adapt to changing environments, but it complicates management under the US Endangered Species Act, which does not typically protect individuals with mixed ancestry.
  • The recently re-established grey wolf populations in Washington and Oregon originated from two distinct ecotypes, Northern Rocky Mountain and coastal rainforest wolves, raising concerns about how to protect these genetically diverse groups.
  • Genetic analysis indicates that Washington wolves have mixed ancestry, while Oregon wolves are linked only to Northern Rocky Mountain wolves, highlighting the need for updated policies to manage these hybrids and preserve both genetic diversity and species adaptations.
View Article and Find Full Text PDF

Species of Syringophilopsis quill mites are found in the flight feathers of passerine birds. A phylogeny of species from this genus infecting North American passerines was inferred from the mitochondrial cytochrome oxidase I gene and the nuclear 28S ribosomal RNA gene. Based on the large genetic distance among lineages, the genus appears to be composed of several cryptic species.

View Article and Find Full Text PDF

Four new syringophilid species of Syringophiloidus Kethley, 1970 are described from North American passerines: S. zonotrichia n. sp.

View Article and Find Full Text PDF

Four new species belonging to Aulonastus Kethley, 1970 (Acari: Prostigmata: Syringophilidae), which are found inside the quills of body feathers of North American passerines (Aves: Passeriformes), are described and figured: A. emberizicus n. sp.

View Article and Find Full Text PDF