Detection of Adult Green Sturgeon Using Environmental DNA Analysis.

Environmental DNA (eDNA) is an emerging sampling method that has been used successfully for detection of rare aquatic species. The Identification of sampling tools that are less stressful for target organisms has become increasingly important for rare and endangered species. A decline in abundance of the Southern Distinct Population Segment (DPS) of North American Green Sturgeon located in California's Central Valley has led to its listing as Threatened under the Federal Endangered Species Act in 2006. While visual surveys of spawning Green Sturgeon in the Central Valley are effective at monitoring fish densities in concentrated pool habitats, results do not scale well to the watershed level, providing limited spatial and temporal context. Unlike most traditional survey methods, environmental DNA analysis provides a relatively quick, inexpensive tool that could efficiently monitor the presence and distribution of aquatic species. We positively identified Green Sturgeon DNA at two locations of known presence in the Sacramento River, proving that eDNA can be effective for monitoring the presence of adult sturgeon. While further study is needed to understand uncertainties of the sampling method, our study represents the first documented detection of Green Sturgeon eDNA, indicating that eDNA analysis could provide a new tool for monitoring Green Sturgeon distribution in the Central Valley, complimenting traditional on-going survey methods.

Effect of Turner's syndrome and X-linked imprinting on cognitive status: analysis based on pedigree data.

The effects of a monosomy of either the maternally or paternally derived X chromosome in Turner's syndrome (TS) on general neurocognitive status and some executive abilities were assessed using the maximum likelihood estimators for pedigree data. This method increases the power of analysis by accounting for the effect of background heritable variation on a trait. The sample comprised 42 females with regular non-mosaic X monosomy and their non-affected relatives. Wechsler neurocognitive scores and several executive function tests' scores, including the Behaviour Dyscontrol Scale (BDS-2), the Wisconsin Card Sorting Test (WCST), and the Rey Complex Figure Test (RCFT), were considered in the analysis. Results showed a significant effect of TS on all Wechsler index and subtest scores, with greatest deficits observed in Arithmetic, Block Design, Object Assembly and Picture Arrangement, and on the total BDS, RCFT and WCST scores, regardless of parental origin of the single X-chromosome. Our data also showed a significantly higher effect of a paternally derived X chromosome in diminishing the performance on several Wechsler scores relevant to verbal skills, which might suggest X-linked imprinting loci relevant to these skills. Possible reasons for the inconsistency of the results concerning X-linked imprinting of cognitive loci using TS patients are discussed, and the relevance of pedigree analysis to future studies of this problem is emphasized.