Measurement and analysis of anatomical parameter values in tree shrews

Anatomical parameter values in tree shrews are major biological characteristic indicators in laboratory animals. Body size, bones and mammilla, organ weights, coefficient intestinal canal and other anatomical data were measured and analyzed in laboratory domesticated tree shrews (7 to 9 months of age). Measurement of 31 anatomical parameters showed that body height, width of the right ear, ileum and colon had significant differences between males and females (P<0.05). Highly significant differences were also found in body slanting length, chest depth, torso length, left and right forelimb length, right hind limb length, left and right ear length, left ear width, keel bone length, left and right tibia length, duodenum and jejunum (P<0.01). With body length as the dependent variable, and tail length, torso length, right and left forelimb length, and left and right hind limb length as independent variables for stepwise regression analysis, the regression equation for body length = 13.90 + tail length × 0.16. The results of 37 organs weights between female and male tree shrews showed very significant differences (P<0.01) for weight of heart, lungs, spleen, left and right kidney, bladder, left and right hippocampus, left submandibular gland, and left and right thyroid gland, as well as significant (P<0.05) differences in the small intestine, right submandibular gland, and left adrenal gland. The coefficient of heart, lung, stomach, bladder, small and large intestine, brain, right hippocampus, and left adrenal gland showed highly significant differences (P<0.01), while differences in the right kidney, left hippocampus, left submandibular gland, right adrenal gland, and left and right thyroid gland were significant (P<0.05). With animal weight as the dependent variable and indicators of heart, lung, liver, spleen, left and right kidney and brain as independent variables for stepwise regression analysis, the regression equation showed that weight = 62.73 + left kidney × 79.21 + heart × 24.09. Female and male laboratory domesticated tree shrews showed certain influences in body size, organ weight and coefficient, and intestinal canal regarding anatomical parameters. This experiment provides basic data for studies on laboratory tree shrews and animal models.