Identifying targets for conservation: the arrival and loss of Common Eider <em>Somateria mollissima</em> ducklings in an estuarine nursery

Capsule: The arrival of Common Eider Somateria mollissima ducklings into a reception and nurseryarea is a measure of breeding success and phenology but reveals gaps in knowledge for effectiveconservation.Aims: Estuarine habitats are important wildlife areas but are continually under threat from humanactivities. Common Eiders may be an indicator species for monitoring the impacts of developmentin estuaries used by them as nursery areas. The aim of this study was to understand the arrival anddistribution of ducklings in a commercial and recreational estuarine environment.Methods: Coquet Island, Northumberland, is a breeding site for Common Eiders at the southernlimit of their range on the east coast of the UK. Numbers of ducklings arriving in the adjacentCoquet Estuary nursery area were monitored daily during the breeding season over a 27-yearperiod from 1995 to 2021 inclusive.Results: Counts of ducklings were higher overall in less disturbed parts of the estuary, but therewere no consistent patterns of habitat use. First-arrival dates varied annually by up to 23 days.Daily arrival counts were affected by tide and, to a lesser extent, rain and wind direction.Observed arrivals each season correlated with counts of breeding females on Coquet Island.There was evidence for links between broader-scale weather conditions (North AtlanticOscillation indices) and yearly variation in rates of duckling arrival. Arrivals were moresynchronous in years when ducklings were late in arriving and supported theoretical predictionsfrom modelling studies. There were high daily rates of duckling loss from the estuary whichmay have been a consequence of brood movements out of the estuary and loss to predation.There was a positive correlation between counts of ducklings and attendant females.Conclusions: Annual duckling counts show the value of estuaries for monitoring phenologicalvariation in the breeding of Common Eiders. A better understanding of environmental factorsinfluencing duckling retention or loss in estuaries is needed. Enabling human and wildlifeactivities to exist together within estuarine environments may promote effective conservation

Increasing the intracellular availability of all-trans retinoic acid in neuroblastoma cells

Recent data indicate that isomerisation to all-trans retinoic acid (ATRA) is the key mechanism underlying the favourable clinical properties of 13-cis retinoic acid (13cisRA) in the treatment of neuroblastoma. Retinoic acid (RA) metabolism is thought to contribute to resistance, and strategies to modulate this may increase the clinical efficacy of 13cisRA. The aim of this study was to test the hypothesis that retinoids, such as acitretin, which bind preferentially to cellular retinoic acid binding proteins (CRABPs), or specific inhibitors of the RA hydroxylase CYP26, such as R116010, can increase the intracellular availability of ATRA. Incubation of SH-SY5Y cells with acitretin (50 μM) or R116010 (1 or 10 μM) in combination with either 10 μM ATRA or 13cisRA induced a selective increase in intracellular levels of ATRA, while 13cisRA levels were unaffected. CRABP was induced in SH-SY5Y cells in response to RA. In contrast, acitretin had no significant effect on intracellular retinoid concentrations in those neuroblastoma cell lines that showed little or no induction of CRABP after RA treatment. Both ATRA and 13cisRA dramatically induced the expression of CYP26A1 in SH-SY5Y cells, and treatment with R116010, but not acitretin, potentiated the RA-induced expression of a reporter gene and CYP26A1. The response of neuroblastoma cells to R116010 was consistent with inhibition of CYP26, indicating that inhibition of RA metabolism may further optimise retinoid treatment in neuroblastoma

Gene expression patterns associated with blood-feeding in the malaria mosquito Anopheles gambiae

BACKGROUND: Blood feeding, or hematophagy, is a behavior exhibited by female mosquitoes required both for reproduction and for transmission of pathogens. We determined the expression patterns of 3,068 ESTs, representing ~2,000 unique gene transcripts using cDNA microarrays in adult female Anopheles gambiae at selected times during the first two days following blood ingestion, at 5 and 30 min during a 40 minute blood meal and at 0, 1, 3, 5, 12, 16, 24 and 48 hours after completion of the blood meal and compared their expression to transcript levels in mosquitoes with access only to a sugar solution. RESULTS: In blood-fed mosquitoes, 413 unique transcripts, approximately 25% of the total, were expressed at least two-fold above or below their levels in the sugar-fed mosquitoes, at one or more time points. These differentially expressed gene products were clustered using k-means clustering into Early Genes, Middle Genes, and Late Genes, containing 144, 130, and 139 unique transcripts, respectively. Several genes from each group were analyzed by quantitative real-time PCR in order to validate the microarray results. CONCLUSION: The expression patterns and annotation of the genes in these three groups (Early, Middle, and Late genes) are discussed in the context of female mosquitoes' physiological responses to blood feeding, including blood digestion, peritrophic matrix formation, egg development, and immunity