Genomic insights into adaptive evolution of the species-rich cosmopolitan plant genus Rhododendron.

The species-rich cosmopolitan genus Rhododendron offers a good system for exploring the genomic mechanisms underlying adaptation to diverse habitats. Here, we report high-quality chromosomal-level genome assemblies of nine species, representing all five subgenera, different altitudinal distributions, and all flower color types of this genus. Further comprehensive genomic analyses indicate diverse adaptive strategies employed by Rhododendron, particularly adaptation to alpine and subalpine habitats by expansion/contraction of gene families involved in pathogen defense and oxidative phosphorylation, genomic convergent evolution, and gene copy-number variation. The convergent adaptation to high altitudes is further shown by population genomic analysis of R. nivale from the Himalaya-Hengduan Mountains. Moreover, we identify the genes involved in the biosynthesis of anthocyanins and carotenoids, which play a crucial role in shaping flower color diversity and environmental adaptation. Our study is significant for comprehending plant adaptive evolution and the uneven distribution of species diversity across different geographical regions.

[To estimate early postmortem interval by investigating changes of rats' gastrocnemius excitability].

OBJECTIVE: To investigate the changes of excitability of rats' gastrocnemius after rats were died from mechanic asphyxia, so as to make an objective evidence for estimating of the early postmortem interval. METHODS: After rats were sacrificed by mechanic asphyxia, the reaction of rats' gastrocnemius to variable electric stimulation at different period after death were recorded by electricphysiological method. RESULTS: Changes in the properties of excitable tissue to electric stimulate in rats' gastrocnemius after mechanic asphyxia seems to be well correlated with the early postmortem interval and appeared a linear relation in certain period. CONCLUSION: The regular changes of excitability in muscle might be a useful means for estimating of early postmortem interval.

[Expression of Cyt C in brain of rats poisoned by tetramine].

OBJECTIVE: To investigate the evidence for the judgement on legal cases of intoxication by tetramine. METHODS: Fifty rats given tetramine by lavage were sacrificed at different time after intoxication. The expression of Cyt C was detected by immunohistochemistry, and the reasults were assessed by an image analysis system. RESULTS: There was a slight expression of Cyt C in control group. In intoxication group the expression of Cyt C increased after the rats were given tetramine for 30 minutes; it reached the peak at 24 hours after intoxication and kept up the level for 3 days, then it began to decrease and returned to the control level in 10 days. CONCLUSION: The regular change of Cyt C expression might be a useful sign for assessment in legal cases of intoxication by tetramine.

[Change of brainstem auditory evoked potential with different stimulating frequencies after closed diffuse brain injuries of rat].

UNLABELLED: OBJECTIVE To investigate the change of peak latency (PL), interpeak latency (IPL) and peak latency ratio (PL ratio) of brainstem auditory evoked potential (BAEP) with different stimulating frequencies after closed diffuse brain injuries of rat,and provide experimental evidence for clinical diagnosis of traumatic brain injury in early stage and also for Forensic practice. METHODS: A rat model for closed diffuse brain injury was successfully constructed by hit the parietal bone with a spring-driven steel stick. The auditory brainstem response (ABR) evoked by clicking with low stimulating frequency of 10 Hz and high stimulating frequency of 50 Hz were respectively recorded at 6 h, 12 h, 2 d, 4 d after brain injury. The results of experimented group were compared with those of control group. RESULTS: The 2 d, 4 d V PL and the 6 h, 12 h, 2 d, 4 d III-V IPL of BAEP with 50 Hz stimulating frequency of model group became longer than those of control group (P < 0.05), but there was no significant difference observed between model and control group experimented with low stimulating frequency of 10 Hz (P > 0.05). The PL ratio of III/I, IV/I, V/I, IV/III and V/III with different stimulating frequencies had no significant postinjury changes. Conclusion The high stimulating frequency of BAEP is a reliable test for diagnosis of TBI in early period. Its sensitivity is superior to the low simulating frequency.