| The finless porpoise {Neophocaena phocaenoides) is a small toothed cetacean, a rapid decline in the wild population of the finless porpoise has been reported in recent years because of direct or indirect influences imposed by human activities, and the case is even worse for the Yangtze finless porpoise, so the Yangtze finless porpoise has been already listed as endangered in the IUCN red list of cetaceans. In order to give a clear picture of the genetic variation and the genetic structure of different populations and to provide some references on the molecular level for studying and protection of Neophocaena, ISSR technique was used to assess the genetic diversity of two finless porpoise (Neophocaena phocaenoides) populations in Chinese waters, i.e., the Yangtze River population and the Bohai Sea population, which belong to two different subspecies. In addition, the serum retinol and tocopherol concentration of 20 free-ranging and 3 captive finless porpoises were determined to provide a guideline from which to evaluate the nutrient status of captive animals as well as a base for breeding program of this animal in captivity. The main results were as follows:(1)16 primers and 3 primer combinations that generated highly reproducible and stable DNA fragments were used to screen the genomic DNA of 36 individuals from two populations. Totally, 115 discernible DNA fragments were produced, 48 of which were polymorphic loci (PPL=41.71%). As analyzed by software POPGENE, the genetic diversity of Neophocaena phocaenoides was relatively low (He=0.1643; Ho=0.2413), the level of genetic variation of the Yangtze River population (He=0.1530; Ho=0.2223) was a little higher than that of the Bohai Sea population (He=0.1402; Ho=0.2059). The analysis of the genetic similarity index between individuals also showed that a higher level of heterogeneity for the individuals of the Yangtze population than that for its Bohai counterparts.(2) AMOVA analysis indicated that there was a certain genetic differentiation between these two populations (Φst= 0.1829, P < 0.001), but Nei's genetic diversity analysis showed a low level of population genetic structure and a considerable frequency of gene flow (Gst=0.1049; Nm=4.2676) existed, in addition, manyindividuals from each population cannot be clustered together in the dendrogram of genetic relationship. These results suggested that a strong gene exchange might occur in the history.(3) The serum retinol and tocopherol concentration of free-ranging and captive finless porpoise were determined by HPLC. The result of comparison suggested that the serum retinol concentration was significantly higher (P<0.05) for free-ranging porpoises than that for their captive counterparts. However, there was no significant difference (P>0.05) in serum tocopherol concentration between them; The serum retinol concentration as well as the serum tocopherol concentration was significantly higher (P<0.05) for male free-ranging porpoises than for the females; Neither the serum retinol concentration nor the tocopherol concentration of the free-ranging porpoises had no significant relationship with their body length or weight. |
PDF Full Text Request