Microbiome assembly of avian eggshells and their potential as transgenerational carriers of maternal microbiota

The microbiome is essential for development, health and homeostasis throughout an animal's life. Yet, the origins and transmission processes governing animal microbiomes remain elusive for non-human vertebrates, oviparous vertebrates in particular. Eggs may function as transgenerational carriers of the maternal microbiome, warranting characterisation of egg microbiome assembly. Here, we investigated maternal and environmental contributions to avian eggshell microbiota in wild passerine birds: woodlark Lullula arborea and skylark Alauda arvensis. Using 16S rRNA gene sequencing, we demonstrated in both lark species, at the population and within-nest levels, that bacterial communities of freshly laid eggs were distinct from the female cloacal microbiome. Instead, soil-borne bacteria appeared to thrive on freshly laid eggs, and eggshell microbiota composition strongly resembled maternal skin, body feather and nest material communities, sources in direct contact with laid eggs. Finally, phylogenetic structure analysis and microbial source tracking underscored species sorting from directly contacting sources rather than in vivo-transferred symbionts. The female-egg-nest system allowed an integrative assessment of avian egg microbiome assembly, revealing mixed modes of symbiont acquisition not previously documented for vertebrate eggs. Our findings illuminated egg microbiome origins, which suggested a limited potential of eggshells for transgenerational transmission, encouraging further investigation of eggshell microbiome functions in vertebrates

Recent developments in genetics and medically assisted reproduction : from research to clinical applications

Two leading European professional societies, the European Society of Human Genetics and the European Society for Human Reproduction and Embryology, have worked together since 2004 to evaluate the impact of fast research advances at the interface of assisted reproduction and genetics, including their application into clinical practice. In September 2016, the expert panel met for the third time. The topics discussed highlighted important issues covering the impacts of expanded carrier screening, direct-to-consumer genetic testing, voiding of the presumed anonymity of gamete donors by advanced genetic testing, advances in the research of genetic causes underlying male and female infertility, utilisation of massively parallel sequencing in preimplantation genetic testing and non-invasive prenatal screening, mitochondrial replacement in human oocytes, and additionally, issues related to cross-generational epigenetic inheritance following IVF and germline genome editing. The resulting paper represents a consensus of both professional societies involved.Peer reviewe

Rapid aneuploidy detection with multiplex ligation-dependent probe amplification: A prospective study of 4000 amniotic fluid samples

The introduction of prenatal screening requires rapid high-throughput diagnosis of common aneuploidies. Multiplex ligation-dependent probe amplification (MLPA) allows for quick, easily automated multiplex testing of these aneuploidies in one polymerase chain reaction. We performed a large prospective study using MLPA on 4000 amniotic fluid (AF) samples including all indications and compared its value to karyotyping and fluorescence in situ hybridization (FISH). MLPA can reliably determine common aneuploidies with 100% sensitivity and 100% specificity. Moreover, some mosaic cases and structural chromosome aberrations were detected as well. In cases of a male fetus, triploidies can be detected by an aberrant pattern of probe signals, which mimics maternal cell contamination (MCC). Macroscopic blood contamination was encountered in 3.2% of the AF samples. In 20% of these samples, an MLPA pattern was found consistent with MCC, although there were no false negatives of the most common aneuploidies. As the vast majority of inconclusive results (1.7%) is due to potential MCC, we designed a protocol in which we determine whether MLPA can be performed on blood-contaminated AF samples by testing if blood is of fetal origi

Colonoscopy-Related Mortality in a Fecal Immunochemical Test–Based Colorectal Cancer Screening Program

Background &amp; Aims: Many countries have introduced colorectal cancer (CRC) screening programs with fecal immunochemical tests (FITs), and follow-up colonoscopies for individuals with a positive FIT result. In order to make an informed decision to participate, individuals must be informed about the benefits and harms of FIT-based screening and subsequent colonoscopy. Colonoscopy-related fatal complications in FIT-based screening are understudied. We aimed to estimate the colonoscopy-related mortality in a national FIT-based CRC screening program. Methods: Colonoscopy-related mortality within 30 days after colonoscopy was assessed by analysis of data from national endoscopy complication databases in the Netherlands, determining the excess 30-day rate of death in FIT-positive individuals undergoing colonoscopy vs FIT-negative individuals (based on data from the national screening database), and determining the rate of likely colonoscopy-related deaths based on registered causes of death by the Statistics Netherlands. Results: Between October 2013 and December 2017, 172,797 participants underwent colonoscopy after a positive result from a FIT in the Dutch national CRC screening program; 13,848 participants received a diagnosis of CRC. The reported fatal complication rate was 0.23 per 10,000 FIT-positive participants (or 1 per 43,199; 95% CI, 0.090 – 0.60) undergoing colonoscopy, whereas this was 0.91 per 10,000 FIT-positive participants (or 1 per 10,961; 95% CI, 0.44 – 1.38) according to the excess death rate. Likely colonoscopy-related causes of death were reported in 0.86 per 10,000 FIT-positive participants (or 1 per 11,236; 95% CI, 0.48 – 1.63) who underwent colonoscopy, of which 50% considered cardiovascular events. Conclusions: Colonoscopy-related mortality within the Dutch FIT-based CRC screening program was estimated to range from 0.23 to 0.91 per 10,000 FIT-positive participants undergoing colonoscopy. These findings indicate underreporting of fatal complications in registries and a noteworthy incidence of fatal cardiovascular adverse events that requires further investigation. Nevertheless, the harm of FIT-based CRC screening is vastly outweighed by the benefits.</p

Auditory spatial attention is encoded in a retinotopic reference frame across eye-movements

The retinal location of visual information changes each time we move our eyes. Although it is now known that visual information is remapped in retinotopic coordinates across eye-movements (saccades), it is currently unclear how head-centered auditory information is remapped across saccades. Keeping track of the location of a sound source in retinotopic coordinates requires a rapid multi-modal reference frame transformation when making saccades. To reveal this reference frame transformation, we designed an experiment where participants attended an auditory or visual cue and executed a saccade. After the saccade had landed, an auditory or visual target could be presented either at the prior retinotopic location or at an uncued location. We observed that both auditory and visual targets presented at prior retinotopic locations were reacted to faster than targets at other locations. In a second experiment, we observed that spatial attention pointers obtained via audition are available in retinotopic coordinates immediately after an eye-movement is made. In a third experiment, we found evidence for an asymmetric cross-modal facilitation of information that is presented at the retinotopic location. In line with prior single cell recording studies, this study provides the first behavioral evidence for immediate auditory and cross-modal transsaccadic updating of spatial attention. These results indicate that our brain has efficient solutions for solving the challenges in localizing sensory input that arise in a dynamic context