Sexual Interference Behaviors in Male Adult and Subadult Tibetan Macaques (Macaca thibetana).

Male nonhuman primate sexual interference, which includes copulation interruption and copulation harassment, has been related to reproductive success, but its significance has been challenging to test. Copulation interruption results in the termination of a copulation before ejaculation, whereas copulation harassment does not. We conducted this study using the all-occurrence behavior sampling method on sexual interference behaviors of seven adult and four subadult male Tibetan macaques (Macaca thibetana) in mating and non-mating seasons at Mt. Huangshan, China, from August 2016 to May 2017. Our results showed that males' individual proportion of copulation interruption and harassment was higher during the mating season than during the non-mating season. In addition, dominant males more often performed interruption, whereas subordinate males more often performed harassment. We found no difference in the individual proportion of copulation interruption or harassment between adult and subadult males. Adult and subadult males both directed copulation interruption and harassment more often toward the mating male than toward the mating female. Lastly, the post-ejaculation phase of copulation was shorter when copulation harassment occurred than when it did not. Our results suggest that sexual interference may be an important mating tactic that adult and subadult males use in male-male sexual competition.

Copper-catalyzed C-N bond formation with imidazo[1,2-a]pyridines.

An efficient Cu-catalyzed method for direct C-N bond formation on the C-3 position of imidazo[1,2-a]pyridines is reported. The robust copper catalyst tolerated a wide range of functional groups and set the stage for the synthesis of diversely decorated imidazo[1,2-a]pyridines. Preliminary experimental results show that the reaction mechanism is consistent with C-3 radical functionalization.

[Double-mutant dihydrofolate reductase gene transfection into bone marrow cells protects mice from chemotherapy].

OBJECTIVE: To explore the feasibility of transfecting DHFR (human double-mutant dihydrofolate reductase) gene into mouse bone marrow cells and the effect of resistance to high dose MTX chemotherapy. METHODS: After DHFR gene was transfected into mouse bone marrow cells with retroviral vector, the cells were treated with methotrexate (MTX) and then CFU-GM (granulocyte-macrophage colony-forming unit) assay was performed. Peripheral blood leucocytes and platelets, body weight and survival rate were observed. After treatment with high dose MTX, the expression of drug resistance gene was checked by RT-PCR in the transfected bone marrow cells. RESULTS: SFG-F/S-NeoR gene-transfected mice bone marrow cells yielded drug-resistance colonies to MTX (donor mice: 15.8%, recipient mice: 18.0%, control: 0) The peripheral blood leucocytes and platelets, body weight recovered gradually and the survival rate was 83.3% at the 40th day, while 0 in controls in gene transfected mice after large dose MTX treatment. RT-PCR of transgenic mouse marrow cells showed the band of F/S gene (400 bp). CONCLUSION: DHFR gene can not only be integrated and expressed in bone marrow cells but also improve their drug-resistence to MTX.

[Mice transduced with double-mutant dihydrofolate reductase-cytidine deaminase fusion gene attained protection from high dose chemotherapy].

OBJECTIVE: To explore the feasibility of transferring fusion gene of dihydrofolate reductase (DHFR) gene and cytidine deaminase (CD) gene into mouse bone marrow cells in order to observe the drug resistance of high dose methotrexate (MTX) and cytosine arabinoside (Ara-C) in the bone marrow cells and to improve the tolerance of myelosuppression following combination chemotherapy. METHODS: Human double-mutant dihydrofolate reductase-cytidine deaminase fusion gene was transferred into two mice bone marrow cells by retroviral vector. Resistant colony-forming unit granulocyte-macrophage (CFU-GM) assays were performed in mouse bone marrow cells by retroviral infection and after treatment by drugs (Ara-C, MTX, and Ara-C + MTX). DNA was extracted from mouse bone marrow cells. The expression of drug resistant genes in mouse bone marrow cells after transferring by retroviral vector was checked by polymerase chain reaction (PCR). RESULTS: Bone marrow cells after coculture with the retroviral producer cells transduced with the genes (SFG-F/S-CD) showed the drug resistance colonies yield (Colony formation after exposure to Ara-C, MTX and Ara-C + MTX were 56%, 22% and 14%, respectively) and the increase in drug resistant to both MTX and Ara-C (P < 0.005). Expression of DHFR and CD gene in extracted DNA of transfected mice were demonstrated by PCR. CONCLUSIONS: Double drug resistant gene can not only integrate and co-express in mice bone marrow cells but also increase the drug resistance to MTX and Ara-C.