ABSTRACT
Introgression may lead to discordant patterns of variation among loci and traits. For example, previous phylogeographic studies on the genus Quasipaa detected signs of genetic introgression from genetically and morphologically divergent Quasipaa shini or Quasipaa spinosa. In this study, we used mitochondrial and nuclear DNA sequence data to verify the widespread introgressive hybridization in the closely related species of the genus Quasipaa, evaluate the level of genetic diversity, and reveal the formation mechanism of introgressive hybridization. In Longsheng, Guangxi Province, signs of asymmetrical nuclear introgression were detected between Quasipaa boulengeri and Q. shini. Unidirectional mitochondrial introgression was revealed from Q. spinosa to Q. shini. By contrast, bidirectional mitochondrial gene introgression was detected between Q. spinosa and Q. shini in Lushan, Jiangxi Province. Our study also detected ancient hybridizations between a female Q. spinosa and a male Q. jiulongensis in Zhejiang Province. Analyses on mitochondrial and nuclear genes verified three candidate cryptic species in Q. spinosa, and a cryptic species may also exist in Q. boulengeri. However, no evidence of introgressive hybridization was found between Q. spinosa and Q. boulengeri. Quasipaa exilispinosa from all the sampling localities appeared to be deeply divergent from other communities. Our results suggest widespread introgressive hybridization in closely related species of Quasipaa and provide a fundamental basis for illumination of the forming mechanism of introgressive hybridization, classification of species, and biodiversity assessment in Quasipaa.
ABSTRACT
BACKGROUND & OBJECTIVE: Tumor suppressor gene p53 and oncogene C-erbB-2 are confirmed to have close relation with endometrioid adenocarcinoma (EC), few documents have been reported about their correlation. Its structural homology to p53, p63 has been considered as a tumor suppressor gene acompany with p53 mutation, but its suppressive nature has not been confirmed yet; reports about p63 expression in EC are rare. This study was designed to investigate the roles of p53, p63, and C-erbB2 in tumorigenesis and development of EC, and their correlation with clinicopathological features of EC. METHODS: Immunohistochemical technique was used to detect P53, P63, and C-erbB2 protein expression in 38 cases of EC, 23 cases of endometrial hyperplasia (EH), and 10 cases of benign proliferative endometrium (BPE). RESULTS: (1) The positive rate of P53 in EC was 31.6%,significantly higher than those in EH and BPE (P < 0.05). P53 expression was associated with surgical pathologic stage, and depth of myometrial invasion in EC (P< 0.005), but was not associated with histological grade (P >0.05). (2) The positive rate of P63 in EC was 81.6%, significantly higher than those in EH and BPE (P < 0.005). P63 expression was not associated with histological grade, surgical pathologic stage, and depth of myometrial invasion in EC (P >0.05). (3) The positive rate of C-erbB-2 in EC was 23.2%, there was no significant difference compared with those in EH or BPE (P >0.05).C-erbB-2 expression was associated with surgical pathologic stage, and depth of myometrial invasion in EC (P< 0.001,P< 0.005),but was not associated with histological grade (P >0.05).(4) There was significantly positive correlation between P53 and P63 (r =0.443,P < 0.01)or C-erbB-2 (r =0.490,P < 0.005). CONCLUSIONS: Both p53 and p63 are involved in carcinogenesis of EC; p63 may act as an oncogene in tumorigenesis of EC. The expression of P53 and C-erbB2 are related to the progression of malignant EC; P53 and C-erbB-2 co-expression may predict poor prognosis.
