Research Advances of Leptotrombidium scutellare in China

Leptotrombidium scutellare is one of the 6 main vectors of scrub typhus in China. It has been found in more than 15 provinces of China. Especially in Yunnan, it was found to be mainly distributed in some mountainous areas with high altitude, low temperature and low precipitation. Rodents and some other small mammals were the most common hosts of L. scutellare. To date, more than 40 host species of L. scutellare have been recorded with very low host specificity, and the main hosts varied in different geographical regions. L. scutellare had a strong resistance against the cold environment, and the temperature and humidity were 2 important factors affecting its growth and development. Among different individuals of their rodent hosts, L. scutellare mites often showed an aggregated distribution pattern, which reflected the interspecific cooperation of the mites. The chromosome karyotype of L. scutellare was 2n=16 and all the 8 pairs of chromosomes were short rod-shaped with metacentric or sub-metacentric types. The isozyme spectrum supported that L. scutellare, L. deliense and L. rubellum were in the same species group. Based on the natural infection, experimental transmission and epidemiological evidence, L. scutellare has been eventually confirmed as the second major vector of scrub typhus in China, which is second only to L. deliense.

COMPARATIVE CHARACTERISTICS OF THE TERMINAL LINK OF GLYCOLYSIS IN THE MUSCLES OF ADULT ANIMALS AND THEIR OFFSPRING

The organism of sexually mature individuals differs significantly from the organism of immature individuals in a number of anatomical, physiological and biochemical parameters. The aim of the work was to investigate the state of the terminal link of glycolysis in the muscles of sexually mature animals and their offspring. The isoenzyme spectrum of LDH in the myocardium of sexually mature animals is characterized by a high content of LDH1 and LDH2 isozymes rapidly migrating to the anode. The isoenzyme spectrum of LDH in skeletal muscles of mature animals is represented mainly by the LDH 5.A feature of the isozyme spectrum of LDH in the tissues of rat pups is that the content of LDH1 and LDH2 is significantly reduced in the myocardium. Their number is 1.2 and 1.13 times, respectively, less than in sexually mature animals. Against this background, the content of LDH3 increases slightly, the content of LDH4 exceeds twice, and that of LDH5 is more than 6 times the indicators of sexually mature animals. In skeletal muscles of rat pups, the dominant content of LDH5 and LDH4 increases and this occurs due to a decrease in the activity of LDH3 (more than 1.5 times), LDH2 (more than 2.3 times) and LDH1 (2.2 times) compared with sexually mature animals. The data obtained indicate that in the myocardium and skeletal muscles of rat pups there is a greater percentage of isoenzymes formed from M-subunits functioning under anaerobic conditions, and with age, as a result of epigenetic transformations, the content of H-subunits increases.