Gene delivery to Nile tilapia cells for transgenesis and the role of PI3K-c2α in angiogenesis

Microinjection is commonly performed to achieve fish transgenesis; however, due to difficulties associated with this technique, new strategies are being developed. Here we evaluate the potential of lentiviral particles to genetically modify Nile tilapia cells to achieve transgenesis using three different approaches: spermatogonial stem cell (SSC) genetic modification and transplantation (SC), in vivo transduction of gametes (GT), and fertilised egg transduction (ET). The SC protocol using larvae generates animals with sustained production of modified sperm (80% of animals with 77% maximum sperm fluorescence [MSF]), but is a time-consuming protocol (sexual maturity in Nile tilapia is achieved at 6 months of age). GT is a faster technique, but the modified gamete production is temporary (70% of animals with 52% MSF). ET is an easier way to obtain mosaic transgenic animals compared to microinjection of eggs, but non-site-directed integration in the fish genome can be a problem. In this study, PI3Kc2α gene disruption impaired development during the embryo stage and caused premature death. The manipulator should choose a technique based on the time available for transgenic obtainment and if this generation is required to be continuous or not. © The Author(s) 2017

MicroRNAs in Sertoli cells: implications for spermatogenesis and fertility

In recent decades, infertility has been considered a major widespread public health issue of very high concern. Currently, almost 50% of infertility cases are due to male factors, including semen disorders, obstructions, cryptorchidism, varicocele and testicular failures, which can occur due to malfunctions in both somatic and germ cells. In this context, besides other approaches, different miRNAs have been used as biomarkers for the diagnosis of male infertility, with different pathologic conditions such as Sertoli cell-only syndrome, mixed atrophy, and germ cell arrest. However, most studies related to male fertility do not point out the functions and cell targets of the described miRNAs. Initial investigations using experimental assays in murine and porcine models were performed, providing the first evidence of the influence of miRNAs on Sertoli cell function including, for instance, proliferation, maturation and hormone responses of these cells. The aim of this mini-review is therefore to summarize our present knowledge of this relevant subject and to highlight the importance of future investigations concerning the miRNA influence in the control of Sertoli cells, spermatogenesis and male fertility. © 2017, Springer-Verlag GmbH Germany