| Sex chromosome evolution has long attracted the attention of bothcytogeneticists and evolutionary biologists. And sex chromosome of mandarin voles isvery special, belonging to XX·XO/XY. The XO female individuals of mandarinvoles maybe have good abilities of reproduction. Moreover, the inverse proportionbetween the XO female individuals and the XX female individuals is about 1:1, andthe two X chromosomes are different. Chromosome preparation was taken todistinguish the XO female individuals from the XX female individuals. The differecesof social behaviors, morphology of main reproductive organs, distribution of ERβin main reproductive organs, and the karyotypes of female offsprings between the XOfemale individuals and the XX female individuals are measured. The aims of thesestudies wre to discuss the relation, compare the evolution status of the XO femaleindividuals and the XX female individuals, enrich contents of sex chromosomeevolution and the fertileness of XO female individuals and provide theoreticsguidance for Turner syndrome.The investigation gets the following conclutions:1. Comparation of social behaviors between the XO female individuals and theXX female individuals: Taking healthy mature female mandarin vole which are not inoestrum as experimental animals, strange healthy matured male as control.Chromosome preparation was taken to distinguish the XO female individuals from theXX female individuals after behavior experiment. It's observed that there were nodifferences from XX female individuals to XO female individuals when theyencountered a strange heterosexual voles, and sniffing body, sniffing nose, sniffingvulvae, chasing, escape, aggression, self-groom, staring, defence of social behaviorswere included (p＞0.05) . But frequencies of lying near and movement, total durationof lying near were significantly different (p＜0.05) . XX female individuals spent lesstime on frequencies and total duration of lying near, but more time on frequencies ofmovement than XX female individuals. Both XX female individuals and XO femaleindividuals spent more time on movement and aggression. And both of them spentmore time on sniffing nose, sniffing body, sniffing vulvae of social investigatingbehaviors. 2. Comparation of histology of main reproductive organs between the XO femaleindividuals and the XX female individuals: There were no significant differences incolor of pelage between the XO female individuals and the XX female individuals,and their pelage were gray when they were yong, and weak coffee when they are adult.All of the female mandarin voles had three openings: vulvae, urethra, anus. And formsof the three opening were very consistent when the female mandarin voles were notin the estrum. The histology of inner reproductive organs of both the XO femaleindividuals and the XX female individuals were the same. Ovaries of the XO femaleindividuals and the XX female individuals were both essential organs, and they wreweak white. The size and the shape of uteruses which were very like the Y shape werevery similar. And colour and lustre of uteruses were weak pink. Slices of paraffin waxshowed that: histology and structrure of ovaries were not significantly different.Monolayer flat skin or monolayer cube skin coved the surface of ovaries. There wascotex outside of ovaries, and medulla insid. There were corpus luteums and follileswhich were in every stage in cotex, and blood vessel, lymphatic, nerve in medulla.Histology and structrure of uteruses were not significantly different either, andendometrium, myometrium, perimetrium included. The mean number of follicles inovary slices was 26.3636 in XX female individuals when they were not in the estrum,and 24.1111 in XO female individuals. The number of corpus luteum and follicleswere not significantly different between XX female individuals and XO femaleindividuals.3. Comparation of levels of the estrogen receptorβ(ERβ) in mainreproductive organ between the XO female individuals and the XX female individuals:Taking healthy mature female mandarin voles which are not in oestrum asexperimental animals, and they were measured with immuno-histochemical mehod.Experimental results indicated: the positive reaction of ERβin XO female individualsovaries was stronger than those in XX female individuals. By statistics calculation,the gray scale of ERβwere significantly different between the XO female individualsand the XX female individuals (P＜0.01). The positive reaction of ERβin XO femaleindividuals uteruses was stronger than those in XX female individuals too. But bystatistics calculation, the gray scale of ERβwere not significantly different betweenthe XO female individuals and the XX female individuals (P＞0.05). And the positivereaction of ERβwas stronger in ovaries than those in uteruses in both of them.4. Analysing the ratio of offspring of the XO female individuals and the XXfemale individuals: 16 XX female individuals had 38 female offspring and 23 wereXX female individuals, 15 XO female individuals. 20 XO female individuals had 57 female offspring and 31 were XX female individuals, 26 XO female individuals. Theratio of XX female individuals by XX female individuals was 1.4375±1819, XOfemale individuals by XX female individuals 0.9375±1106, XX female individualsby XO female individuals 1.5500±1535, XO female individuals by XO femaleindividuals 1.3000±.1469. The result of analysing by SPSS indicated: the offspring ofratio of both of F1XX—F2XXvsF1XO—F2XX and F1XX—F2XOvsF1XO—F2XOwere not significantly different。...
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