Genetic developmental timing revealed by inter-species transplantations in fish

ABSTRACTThe path from a fertilised egg to an embryo involves the coordinated formation of cell types, tissues and organs. Developmental modules comprise discrete units specified by self-sufficient genetic programs that can interact with each other during embryogenesis. Here, we have taken advantage of the different span of embryonic development between two distantly related teleosts, zebrafish (Danio rerio) and medaka (Oryzias latipes) (3 and 9 days, respectively), to explore modularity principles. We report that inter-species blastula transplantations result in the ectopic formation of a retina formed by donor cells – a module. We show that the time taken for the retina to develop follows a genetic program: an ectopic zebrafish retina in medaka develops with zebrafish dynamics. Heterologous transplantation results in a temporal decoupling between the donor retina and host organism, illustrated by two paradigms that require retina-host interactions: lens recruitment and retino-tectal projections. Our results uncover a new experimental system for addressing temporal decoupling along embryonic development, and highlight the presence of largely autonomous but interconnected developmental modules that orchestrate organogenesis.

Comparison Matrix-Associated Stem Cell Transplantation (MAST) with Autologous Matrix Induced Chondrogenesis plus Peripheral Blood Concentrate (AMIC+PBC) in Chondral Lesions at the Ankle - Matched-Patient Analysis

Category: Ankle Introduction/Purpose: 2016, the local government authorities re-categorized MAST, i.e. the included BMAC for impregnation of the matrix, as stem call manufacturing and heterologous transplantation. Consequently, MAST and all other procedures including BMAC were not ‘subject to disclosure’ as before but ‘subject to authorization’. Therefore, the authors´ institution was not authorized to perform MAST after July 16, 2016. The authors´ institution changed the treatment of chondral lesions by replacing BMAC as part of MAST to Peripheral Blood Concentrate (PBC) resulting in AMIC+PBC.The aim of the study was to compare MAST with AMIC+PBC in chondral lesions at the ankle. Methods: In a matched-patient clinical follow-up study, patients with chondral lesion at the ankle that were treated with AMIC+PBC from July 17, 2016 to May 31, 2017, and patients that were treated with MAST from April 1, 2009 to July 15, 2016 were included and compared. Size and location of the chondral lesions and the Visual-Analogue-Scale Foot and Ankle (VAS FA) before treatment and at follow-up were analysed. Bone Marrow Aspirate Concentrate (BMAC) was used for MAST and Peripheral Blood Concentrate (PBC) for AMIC+PBC to impregnate a collagen I/III matrix (Chondro-Gide, Wollhusen, Switzerland) that was fixed into the chondral lesion with fibrin glue. Results: One hundred and twenty-nine patients with 136 chondral lesions were included in both groups. The chondral lesions were located as follows (MAST/AMIC+PBC, n (%)), medial talar shoulder only, 59 (43)/62 (46); lateral talar shoulder only, 44 (32)/42 (31); medial and lateral talar shoulder, 7 (10)/7 (10); tibia, 19 (14)/18 (13). The lesion size was 1.6/1.8cm2 on average and VAS FA was 46.9/45.7 (MAST/AMIC+PBC). For MAST/AMIC+PBC groups, 107 (83%)/105 (81%) with 112/110 previous chondral lesions completed the defined 2-year-follow-up after 24.4/23.8 months on average. VAS FA improved to 82.3/79.8 (MAST/AMIC+PBC). No parameter significantly differed between MAST and AMIC+PBC groups. Conclusion: MAST and AMIC+PBC as part of a complex surgical approach led to improved and high validated outcome scores in 2-year-follow-up. MAST and AMIC+PBC showed similar results. No method related complications were registered.

Genetic Developmental Timing Revealed by Inter-Species Transplantations in Fish

The path from a fertilised egg to an embryo involves the coordinated formation of cell types, tissues and organs. Developmental modules (Raff, 1996) comprise discrete units specified by self-sufficient genetic programs that can interact among each other during embryogenesis. Here we took advantage of the different span of embryonic development between two far related teleosts, zebrafish (Danio rerio) and medaka (Oryzias latipes), of 3 and 9 days respectively, to explore modularity principles. We report that inter-species blastula transplantations result in the ectopic formation of a retina formed by donor cells — a module. We show that the developmental time of the retina follows a genetic program: an ectopic zebrafish retina in medaka develops with zebrafish dynamics. Heterologous transplantation results in a temporal decoupling between the donor retina and host organism, illustrated by two paradigms that require retina-host interactions: lens recruitment and retino-tectal projections. Our results uncover a new experimental system to address temporal decoupling along embryonic development, and highlight the presence of largely autonomous but yet interconnected developmental modules orchestrating organogenesis.

Mathieu Jaboulay (1860-1913) and His Innovations in Vascular and General Surgery

Mathieu Jaboulay (1860-1913) was an inventor in vascular and general surgery. He fabricated many new surgical techniques and instruments such as Jaboulay method for vascular sutures, Jaboulay anastomotic button, and Jaboulay amputation, known also as hemipelvectomy. In addition, he was a pioneer in heterologous transplantation and sympathectomy. He found death suddenly in a terrible train crash. He was a reputable Professor of Surgery at Lyon Faculty of Medicine with prestigious students in vascular surgery.

Microsatellite detection of donor-derived sperm DNA following germ cell transplantation in cattle

Although autologous and heterologous transplantation has resulted in colonisation of recipient testes in cattle, the ability of the transplanted spermatogonial stem cells to complete spermatogenesis has not yet been determined. The objective of the present study was to identify and validate microsatellite markers that can distinguish the genotype of different individuals and therefore can be used to detect the presence of donor DNA in recipient semen samples. In a previous study by this group, successful colonisation of recipient testes by heterologous transfer using a fluorescent dye was shown. In the present work, some of the same recipient animals were investigated further to monitor donor-derived sperm production. The bovine microsatellite detection method was developed specifically to test the ejaculates of the recipients and can also be used to pre-match individuals before germ cell transplantation. Semen was collected from the recipients 52–98 weeks after transfer and the presence of donor DNA in the samples was determined using microsatellite markers. In one of the recipients, all collected semen samples were shown to be positive for donor-derived cells; however, the percentage of donor spermatozoa in the recipient ejaculate declined with time. The donor DNA was also detected in both single cell suspensions and testis tissue from this recipient. These results demonstrate for the first time that testicular germ cell transplantation between different breeds of cattle is feasible and the recipients thereof are able to produce spermatozoa of donor origin. This technology has potential applications in livestock breeding systems and may provide an alternative to artificial insemination.