Direct gradient analyses in spatial genetics provide unique opportunities to describe the inherent complexity of genetic variation in wildlife species and are the object of many methodological developments. However, multicollinearity among explanatory variables is a systemic issue in multivariate regression analyses and is likely to cause serious difficulties in properly interpreting results of direct gradient analyses, with the risk of erroneous conclusions, misdirected research and inefficient or counterproductive conservation measures. Using simulated data sets along with linear and logistic regressions on distance matrices, we illustrate how commonality analysis (CA), a detailed variance-partitioning procedure that was recently introduced in the field of ecology, can be used to deal with nonindependence among spatial predictors.
View Article and Find Full Text PDFIn mammals, recovery of oocytes by laparoscopic ovum pick-up (LOPU) coupled with in vitro production (IVP) of embryos represents a promising strategy for both amplification and genetic management of sparse animals from captive endangered wild species. As integrated technique developed mainly for domestic livestock, LOPU-IVP requires several studies to set up protocols for follicular stimulation or optimization of IVP before envisaging successful transposition to wild species. In deer, many endangered subspecies would be potentially concerned by applying such an approach using common subspecies for protocols optimization.
View Article and Find Full Text PDFAmongst the 200 deer subspecies worldwide, more than 40 are considered as endangered. In vitro embryo production may represent an efficient way to produce and disseminate offspring from sparse remaining individuals in these species. With a view to establishing a method of in vitro embryo production, we assessed the ovarian response after hormonal stimulation (oFSH), oocyte yield following laporoscopic ovum pick-up (LOPU) and oocyte developmental competence according to seasonal reproductive status in sika deer (Cervus nippon nippon).
View Article and Find Full Text PDFTechniques for in vitro production (IVP) of viable embryos have been thoroughly developed in several domestic species in view to improve breeding efficiency. When applied to wild life, these techniques may also help the maintenance of biodiversity through amplification of sparse animals offspring and facilitation of genetic material exchange. During the successive steps of IVP, i.
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