A tremendous expansion of copy number in crossbred bulls ( × ).

Crossbreeding between cattle () and yak () exhibits significant hybrid advantages in milk yield and meat production. By contrast, cattle-yak F hybrid bulls are sterile. Copy number variations (CNV) of multicopy gene families in male-specific regions of the mammalian Y chromosome (MSY) affect human and animal fertility. The present study investigated CNV of (), (), (), and () in 5 yak breed bulls ( = 63), cattle-yak F ( = 22) and F ( = 2) hybrid bulls, and Chinese Yellow (CY) cattle bulls ( = 10) by quantitative real-time PCR. showed restricted amplification in yak bulls in that the average geometric mean copy number (CN) was estimated to be 4 copies. The most compelling finding is that there is a tremendous expansion of CN in F hybrids (385 copies; 95% confidence interval [CI] = 351-421) and F hybrids (356 copies) compared with the male parent breed CY cattle (142 copies; 95% CI = 95-211). Copy numbers of and were also extensively expanded on the Y chromosome in yak and CY cattle bulls. The geometric mean CN of and were estimated to be 123 (95% CI = 114-132) and 250 copies (95% CI = 233-268) in yak bulls and 71 (95% CI = 61-82) and 133 (95% CI = 107-164) copies in CY cattle, respectively. Yak and CY cattle have 2 copies of the gene on the Y chromosome. Similarly to gene, the F and F hybrid bulls have higher CN of , , and than CY cattle ( < 0.01). These results indicated that the MSY of yak and cattle-yak crossbred hybrids was fundamentally different from cattle MSY in the context of genomic organization. Based on the model of cattle-yak F and F hybrid bull sterility, the CNV of may serve as a potential risk factor for crossbred bull ( × ) infertility. To our knowledge, this is the first study to examine differences in multicopy genes in MSY between yak and cattle-yak bulls.

Enhanced expression and significance of glycosylphosphatidylinositol anchor attachment protein 1 in colorectal cancer.

The aim of this study was to investigate the expression of glycosylphosphatidylinositol anchor attachment protein 1 (GPAA1) and its significance in patients with colorectal cancer. Fifty-two patients with primary colorectal cancer were included in this study. GPAA1 expression was detected by immunohistochemistry, reverse transcription-polymerase chain reaction, and Western blot analysis. A cell invasion assay was performed by the transwell method. The interacting proteins of GPAA1 were detected by co-immunoprecipitation and matrix assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF/TOF-MS). The expression of GPAA1 mRNA and protein in primary colorectal tumor tissues and liver metastasis tissues was significantly higher than that in normal mucosa tissues (P < 0.01). The number of highly expressing GPAA1 cells penetrating the Matrigel membrane was significantly higher than that of mildly expressing GPAA1 cells (P < 0.05). The results of co-immunoprecipitation and MALDI-TOF/TOF-MS confirmed the identity of the protein. GPAA1 is highly expressed in patients with colorectal cancer, which indicates that it might play an important role in the proliferation, invasion, and metastasis of colorectal cancer.

Apoptosis of peripheral T cells in rodent cardiac allograft recipients induced by donor-specific transfusion with impaired inducible costimulator/B7 homologous protein allorecognition.

OBJECTIVE: To investigate apoptosis of the CD8(+) T cells (Tc) subpopulation in rodent cardiac allograft recipients, which were treated by donor specific transfusion combined with blockade of Inducible costimulator (ICOS)/B7 homologous protein (B7h) costimulation. METHODS: Donor hearts were heterotopically transplanted into the necks of recipient mice using Chen's technique. Postoperative graft survival was recorded. Both the percentage of CD3(+)CD8(+)ICOS(+) Tc in recipients' peripheral blood and the apoptosis of CD8(+) Tc in recipient draining lymph nodes were detected by flow cytometry analysis. RESULTS: In comparison with the allogeneic group, the survival of cardiac grafts was prolonged by combined treatment with 5 × 10(6) ICOS-Fc-targeted B cells on day 0 of transplantation and 10 mg/kg/d ICOS-Fc on days 0 to 6 (84.38 ± 29.14 days versus 7.00 ± 0.76 days, P < .01). The treatment group showed a stable CD8(+)Tc clone size in recipient peripheral blood (49.4% ± 3.11% versus 50.0% ± 2.46%, P > .05); however, the percentage of CD3(+)CD8(+)ICOS(+) Tc decreased significantly compared with the allogeneic group (7.5% ± 2.02% versus 14.0% ± 3.03%, P < .05). Compared with allogeneic group, apoptosis of the CD8(+) Tc subpopulation in recipient draining lymph nodes was up-regulated significantly at postoperative 7 days in the treatment group (19.53% ± 5.10% versus 8.70 ± 3.14%, P < .05). CONCLUSION: Apoptosis of CD8(+) Tc in recipient draining lymph nodes was enhanced by pretreatment with donor specific transfusion and impaired ICOS/B7h allorecognition, which may have been associated with the variation in the CD3(+)CD8(+)ICOS(+) Tc subpopulation in peripheral blood and at least partially contributed to unresponsiveness toward cardiac allograft.

Inhibition of T-cell expansion caused by inducible costimulator/B7h costimulation blockade in direct allorecognition pathway.

OBJECTIVE: Inducible costimulator (ICOS)/B7h costimulation plays a crucial role in acute and chronic allograft rejection. To test the role of the ICOS signal in T-cell activation and expansion, we used ICOS-Fc-targeted B cells as donor antigen presenting cells to challenge the allogeneic response in vitro. METHODS: In vitro, the binding of ICOS-Fc with B7h on splenic B cells was confirmed by flow cytometry analysis. To evaluate the capacity of ICOS-Fc-targeted B cells to elicit an allogeneic response in vitro, we performed mixed lymphocyte reactions. RESULTS: The binding of B7h on splenic B cells by ICOS-Fc was confirmed at a saturating concentration of 100 µg/mL. Blockade of ICOS/B7h in direct allorecognition depressed proliferation of alloreactive T cells in vitro. CONCLUSIONS: ICOS/B7h signal plays an important role in direct allorecognition, eliciting allogeneic responses in vitro.