Genetic tools for the study of the mangrove killifish, Kryptolebias marmoratus, an emerging vertebrate model for phenotypic plasticity.

Kryptolebias marmoratus (Kmar), a teleost fish of the order Cyprinodontiformes, has a suite of unique phenotypes and behaviors not observed in other fishes. Many of these phenotypes are discrete and highly plastic-varying over time within an individual, and in some cases reversible. Kmar and its interfertile sister species, K. hermaphroditus, are the only known self-fertile vertebrates. This unusual sexual mode has the potential to provide unique insights into the regulation of vertebrate sexual development, and also lends itself to genetics. Kmar is easily adapted to the lab and requires little maintenance. However, its internal fertilization and small clutch size limits its experimental use. To support Kmar as a genetic model, we compared alternative husbandry techniques to maximize recovery of early cleavage-stage embryos. We find that frequent egg collection enhances yield, and that protease treatment promotes the greatest hatching success. We completed a forward mutagenesis screen and recovered several mutant lines that serve as important tools for genetics in this model. Several will serve as useful viable recessive markers for marking crosses. Importantly, the mutant kissylips lays embryos at twice the rate of wild-type. Combining frequent egg collection with the kissylips mutant background allows for a substantial enhancement of early embryo yield. These improvements were sufficient to allow experimental analysis of early development and the successful mono- and bi-allelic targeted knockout of an endogenous tyrosinase gene with CRISPR/Cas9 nucleases. Collectively, these tools will facilitate modern developmental genetics in this fascinating fish, leading to future insights into the regulation of plasticity.

Pediatric posterior fossa syndrome (PFS): nursing strategies in the post-operative period.

Posterior fossa syndrome (PFS), or cerebellar affective syndrome, is a severe and distressing complication that may occur in up to 40% of children following posterior fossa brain tumour resection. Depending on the type, size and location of the tumour, clinical presentations of PFS can vary widely. Patients may exhibit mutism, emotional lability, high-pitched crying (sole form of vocalization), poor oral intake, extreme irritability, decreased motor movements and urinary retention. Typically, the onset of the syndrome occurs one to five days after surgery resulting in a devastating situation for patients and families. PFS may persist up to four months with resultant long-term impairments and permanent disability. The development and initiation of nursing strategies for patients with PFS is critical. They support family coping decrease stress and anxiety after surgery and, ultimately, enable optimal patient and family outcomes. By managing acute symptoms, promoting rehabilitation and initiating strategies to restore behavioural and physiological function, neurosurgical nurses play an essential and instrumental role.

Fabry disease complicating pregnancy.

BACKGROUND: Few cases of Fabry disease, an X-linked lysosomal storage disorder, complicating pregnancy are reported. CASE: A 36-year-old primigravida with known Fabry disease manifest with acroparesthesias, tinnitus, and hearing loss delivered a healthy unaffected infant at term. CONCLUSION: A symptomatic Fabry carrier may experience an otherwise uncomplicated pregnancy in the absence of vital organ involvement.