It has been documented that social isolation imparts deleterious effects on gregarious rodents species, but caging in group imparts such effects on solitary rodents. This study was attempted at examining how kinship t...It has been documented that social isolation imparts deleterious effects on gregarious rodents species, but caging in group imparts such effects on solitary rodents. This study was attempted at examining how kinship to affect body weight, behavioral interaction, mate choice and fitness when we caged male and female rat-like hamsters Tscheskia triton in pair, a solitary species. We found that females paired with nonsibling males became heavier than the females paired with sibling males, but both agonistic and amicable behavior between paired males and females did not differ between sibling and nonsibling groups. This indicated that kinship might reduce females＇ obesity in response to forced cohabitation, and dissociation might exist between physiological and behavioral responses. Furthermore, binary choice tests revealed that social familiarity between either siblings or nonsiblings decreased their investigating time spent in opposite sex conspeeifie of cage mates and/or their scents as compared with those of nonmates, suggesting effects of social association on mate and kin selection of the hamsters. On the other side, both females and males caged in pair with siblings show a preference between unfamiliar siblings or their scents and the counterparts of nonsiblings after two month separation, indicating that the kin recognition of the hamsters might also rely on phenotype matching. In addition, cohabitation （or permanent presence of fathers） elicited a lower survival of pups in nonsibling pairs than sibling pairs, but did not affect litter size, suggesting that kinship affects fitness when housing male and female ratlike hamsters together. Therefore, inbreeding might be adapted for rare and endangered animals.展开更多
Objective : To study the antitoxic role of vesicular monoamine transporter 2 (VMAT2) in transgenic Chinese Hamster ovary (CHO) cell. Methods :With the technology of trans-gene from PC 12 to CHO, MTT reduction assay wa...Objective : To study the antitoxic role of vesicular monoamine transporter 2 (VMAT2) in transgenic Chinese Hamster ovary (CHO) cell. Methods :With the technology of trans-gene from PC 12 to CHO, MTT reduction assay was used to detect MPP+ toxic effect on wild type CHO (wtCHO) and transgenic CHO. Meanwhile, the role of reserpine was also observed in MPP+ toxic effects. Results :The sensitivity of transgenic CHO to MPP+ was much less than that of wtCHO with 0. 5 mmol/L MPP+. Transgenic CHO had the same sensitivity as wtCHO if rotenone was given. WtCHO, by given reserpine alone, didn't change its sensitivity to MPP+. Conclusions :VMAT2 has protective effect on transgenic CHO by transporting MPP+ to vesicles.展开更多
Guava leaf tea has been used as a folk medicine for treating hyperglycemic conditions in Asia and Africa. The hypoglycemic efficacy of guava leaf has been documented by many scientists in these regions, but the hypogl...Guava leaf tea has been used as a folk medicine for treating hyperglycemic conditions in Asia and Africa. The hypoglycemic efficacy of guava leaf has been documented by many scientists in these regions, but the hypoglycemic mechanism is poorly understood. Guava leaves were extracted with methanol and the crude extract was partitioned against hexane, ethyl acetate, and butanol in sequence. The leftover in water is defined as the aqueous partition. A second smaller batch was extracted with hot water directly. Oral glucose tolerance test was carried out on healthy mice instead of diabetic mice that lack endogenous insulin. Glucose uptake was examined with 3T3-L1 adipocytes. Oxidative effect on PTP1B （protein tyrosine phosphatase 1b） was carried out with real-time PTP1B enzymatic assay. The aqueous partition of guava leaf extract possesses a potent inhibitory effect on PTP1B enzymatic activity and this PTP1B inhibition is through a slow oxidative but reversible inactivation on the enzyme. The reversible inactivation would suggest guava leaf extract may augment PTP1B inhibition alongside the endogenous H2O2 which itself is induced by insulin. In addition, our study confirmed the hypoglycemic efficacy being associated with guava leaf and found the most effective molecules reside in the aqueous partition which is also less cytotoxic to Chinese hamster ovary cells when compared to other less polar partitions. The guava leaf extract can modulate insulin activity through a redox regulation on PP1B enzymatic activity. It is speculated that a compound similar to gallocatechin in the aqueous partition can reduce an oxygen molecule to hydrogen peroxide which in turn oxidizes the catalytic residue Cys in PTP1B. Therefore, the guava leaf tea can serve as a functional hypoglycemic drink that is suitable for either healthy or diabetic subjects.展开更多
An expressive plasmid pSMTPCH was constructed from porcine growth hormone gene,sheep metallothionein promoter (MT-011)and the vector,pUC19. The linear pSMTPGH and circular pSV2-dhfr were cotransfected into CHO-dhfr ce...An expressive plasmid pSMTPCH was constructed from porcine growth hormone gene,sheep metallothionein promoter (MT-011)and the vector,pUC19. The linear pSMTPGH and circular pSV2-dhfr were cotransfected into CHO-dhfr cell by calcium phosphate coprecipitation. Positive clones made up 74% of total clones, which were identified with ELISA. The expression of pSMTPGH was induced by 0.5 μM of Cd￣++. The clone 1-C-3 was found to secrete hGH at the level of 3800 μg/10￣6 cells/24 hrs in media containing 10 μMTX. After 20 generations in culture, the clone was still stable with hGH expression.The molecular weight of secreted protein was the same as that of the natural pGH, 22KD;the identity was further supported by Western blot.展开更多
In many species, agonistic interactions result in social relationships that are stable over time. In Syrian hamsters, two unfamiliar males that are placed together will fight vigorously and a clear winner/loser relati...In many species, agonistic interactions result in social relationships that are stable over time. In Syrian hamsters, two unfamiliar males that are placed together will fight vigorously and a clear winner/loser relationship is usually established. In subsequent interactions, the loser will flee soon after detecting the familiar winner. Here we tested the hypothesis that losing a fight with a conspecific will affect future agonistic interactions not only toward that individual （i.e., the familiar winner） but also toward unfamiliar conspecifics. To test this hypothesis we paired two Syrian hamster males in three trials on one day in which the loser had tile opportunity to escape the winner. The next day the loser was paired with an unfarniliar male, also for three trials. If he lost again, he was tested on a third day with a third unfamiliar male. Subjects were those males that were losers on all three days. The latency to escape on the first trial on Days 2 and 3 was significantly shorter than on the first trial on Day l, indicating that losing against the first male affected the response toward unfamiliar males. However, the latency to escape on the first trial on Days 2 and 3 was significantly longer than that on the third trial on the preceding day, indicating that a loser treats unfamiliar males differently than a familiar winner. These results suggest that a defeat during an interaction with one male affects later agonistic behavior towards other, unfamiliar males [Current Zoology 57 （4）： 449-452, 2011].展开更多
基金supported by the grants from International Partnership Project of CAS Innovative Researches(CXTDS2005-4)Ministry of Science and Technology(2005BA529A05)Chinese NSF(30670268)
文摘It has been documented that social isolation imparts deleterious effects on gregarious rodents species, but caging in group imparts such effects on solitary rodents. This study was attempted at examining how kinship to affect body weight, behavioral interaction, mate choice and fitness when we caged male and female rat-like hamsters Tscheskia triton in pair, a solitary species. We found that females paired with nonsibling males became heavier than the females paired with sibling males, but both agonistic and amicable behavior between paired males and females did not differ between sibling and nonsibling groups. This indicated that kinship might reduce females＇ obesity in response to forced cohabitation, and dissociation might exist between physiological and behavioral responses. Furthermore, binary choice tests revealed that social familiarity between either siblings or nonsiblings decreased their investigating time spent in opposite sex conspeeifie of cage mates and/or their scents as compared with those of nonmates, suggesting effects of social association on mate and kin selection of the hamsters. On the other side, both females and males caged in pair with siblings show a preference between unfamiliar siblings or their scents and the counterparts of nonsiblings after two month separation, indicating that the kin recognition of the hamsters might also rely on phenotype matching. In addition, cohabitation （or permanent presence of fathers） elicited a lower survival of pups in nonsibling pairs than sibling pairs, but did not affect litter size, suggesting that kinship affects fitness when housing male and female ratlike hamsters together. Therefore, inbreeding might be adapted for rare and endangered animals.
基金Supported by grant from Innovation Foundation of Nanjing Medical University(MC9901)
文摘Objective : To study the antitoxic role of vesicular monoamine transporter 2 (VMAT2) in transgenic Chinese Hamster ovary (CHO) cell. Methods :With the technology of trans-gene from PC 12 to CHO, MTT reduction assay was used to detect MPP+ toxic effect on wild type CHO (wtCHO) and transgenic CHO. Meanwhile, the role of reserpine was also observed in MPP+ toxic effects. Results :The sensitivity of transgenic CHO to MPP+ was much less than that of wtCHO with 0. 5 mmol/L MPP+. Transgenic CHO had the same sensitivity as wtCHO if rotenone was given. WtCHO, by given reserpine alone, didn't change its sensitivity to MPP+. Conclusions :VMAT2 has protective effect on transgenic CHO by transporting MPP+ to vesicles.
文摘Guava leaf tea has been used as a folk medicine for treating hyperglycemic conditions in Asia and Africa. The hypoglycemic efficacy of guava leaf has been documented by many scientists in these regions, but the hypoglycemic mechanism is poorly understood. Guava leaves were extracted with methanol and the crude extract was partitioned against hexane, ethyl acetate, and butanol in sequence. The leftover in water is defined as the aqueous partition. A second smaller batch was extracted with hot water directly. Oral glucose tolerance test was carried out on healthy mice instead of diabetic mice that lack endogenous insulin. Glucose uptake was examined with 3T3-L1 adipocytes. Oxidative effect on PTP1B （protein tyrosine phosphatase 1b） was carried out with real-time PTP1B enzymatic assay. The aqueous partition of guava leaf extract possesses a potent inhibitory effect on PTP1B enzymatic activity and this PTP1B inhibition is through a slow oxidative but reversible inactivation on the enzyme. The reversible inactivation would suggest guava leaf extract may augment PTP1B inhibition alongside the endogenous H2O2 which itself is induced by insulin. In addition, our study confirmed the hypoglycemic efficacy being associated with guava leaf and found the most effective molecules reside in the aqueous partition which is also less cytotoxic to Chinese hamster ovary cells when compared to other less polar partitions. The guava leaf extract can modulate insulin activity through a redox regulation on PP1B enzymatic activity. It is speculated that a compound similar to gallocatechin in the aqueous partition can reduce an oxygen molecule to hydrogen peroxide which in turn oxidizes the catalytic residue Cys in PTP1B. Therefore, the guava leaf tea can serve as a functional hypoglycemic drink that is suitable for either healthy or diabetic subjects.
文摘An expressive plasmid pSMTPCH was constructed from porcine growth hormone gene,sheep metallothionein promoter (MT-011)and the vector,pUC19. The linear pSMTPGH and circular pSV2-dhfr were cotransfected into CHO-dhfr cell by calcium phosphate coprecipitation. Positive clones made up 74% of total clones, which were identified with ELISA. The expression of pSMTPGH was induced by 0.5 μM of Cd￣++. The clone 1-C-3 was found to secrete hGH at the level of 3800 μg/10￣6 cells/24 hrs in media containing 10 μMTX. After 20 generations in culture, the clone was still stable with hGH expression.The molecular weight of secreted protein was the same as that of the natural pGH, 22KD;the identity was further supported by Western blot.
文摘In many species, agonistic interactions result in social relationships that are stable over time. In Syrian hamsters, two unfamiliar males that are placed together will fight vigorously and a clear winner/loser relationship is usually established. In subsequent interactions, the loser will flee soon after detecting the familiar winner. Here we tested the hypothesis that losing a fight with a conspecific will affect future agonistic interactions not only toward that individual （i.e., the familiar winner） but also toward unfamiliar conspecifics. To test this hypothesis we paired two Syrian hamster males in three trials on one day in which the loser had tile opportunity to escape the winner. The next day the loser was paired with an unfarniliar male, also for three trials. If he lost again, he was tested on a third day with a third unfamiliar male. Subjects were those males that were losers on all three days. The latency to escape on the first trial on Days 2 and 3 was significantly shorter than on the first trial on Day l, indicating that losing against the first male affected the response toward unfamiliar males. However, the latency to escape on the first trial on Days 2 and 3 was significantly longer than that on the third trial on the preceding day, indicating that a loser treats unfamiliar males differently than a familiar winner. These results suggest that a defeat during an interaction with one male affects later agonistic behavior towards other, unfamiliar males [Current Zoology 57 （4）： 449-452, 2011].
