The Chinese alligator (Alligator sinensis) is a critically endangered species in China. Wild populations of Chinese alligator are on the edge of extinction. Through a release program, some captive-bred alligators will be selected and released into the wild to supplement and renew natural populations. The purpose of this study was to provide data to select healthy individuals for release. Through bacteriological and molecular identification, six different genera, eight species and an unclassified bacterium were identified in 13 bacterial strains, which were isolated from the cloaca of 25 Chinese alligators. One genus and four species were identified in eight bacterial strains, which were isolated from the water where the alligators live. According to the analysis, except for the unclassified bacterium, the other bacteria from the cloaca were not pathogenic and were different from the bacteria isolated from the water. Thus, it was concluded that the 24 Chinese alligators were healthy, and could be selected to be released into the wild. As subject AS 12 was identified carrying an unclassified bacteria, of which the characteristics were unknown, it was suggested that the AS 12 individual not be released.
To assess the differences in the relative lengths of the DNA telomere between the matured and the adolescent Chinese alligators Alligator sinensis and to offer the possible molecular evidence for judging the age of the Chinese alligators,we applied the PCR method to amplify the telomere DNA of both the matured and the juvenile Chinese alligators in our research.Subsequently,we analyzed and compared the outcomes of the two groups by using a Semi-Quantitative Technique.The results of our analyses show that the relative average gray value of the blood cells’ telomere PCR products of the adolescent group is higher than that of the matured group.These analytical results are indications that the blood cells’ telomere DNA sequence of the adolescent Chinese alligators is longer than that of the matured Chinese alligators.Our paper will also discuss the feasibility of the use of the PCR method to determine the relative lengths of the telomere.
Nest-site and nesting material used by the Chinese alligator (Alligator sinensis) was studied at the Gaojingmiao Breeding Farm, Langxi County, Anhui, China from May to September 2009. In this study, artificial nesting materials were placed in 43 potential nesting sites before the nesting season, 11 of which were used. Additionally, eight nests were built at natural sites without artificial nesting materials provided. Seven environmental variables were measured at each nest site: distance from water, height from water surface, sunlight duration, nearest bank slope, nest site slope, vegetation coverage and concealment. Statistical analyses indicated that concealment was significantly different between used and unused nest sites, with concealment being significantly correlated to the use of materials- placed sites. In comparing the nests at artificial vs. natural sites, only the nearest bank slope differed significantly. Further, principal component analysis of natural nests indicated that the duration of nest exposure to sunlight and vegetation coverage were more influential than the other factors studied.
Jianjun WANGXiaobing WUDawei TIANJialong ZHURenping WANGChaolin WANG
Eight different inter simple sequence repeat(ISSR) markers were used as tools to investigate genetic variability and population differentiation in the Chinese alligator,Alligator sinensis,in this study. Eleven polymorphic bands(17.2%) out of a total of 64 were generated from 110 individuals in three populations. Analysis of molecular variation showed that most of the genetic variation(98.0%) occurred within the populations. Dendrogram relationship based on Nei’s unbiased genetic diversity illustrated that two breeding populations were genetically closely related. The Nm value of the study was 4.520,suggesting that high levels of gene flow existed and no differentiation appeared in the populations. In a reconstructed Neighbor-Joining tree,the haplotypes coming from the same populations did not gather as a class,suggesting the three populations had no apparent geographic pattern. This study shows that ISSR markers could be well applied as a feasible tool to assess genetic diversity in Chinese alligator individuals.