Cross Breeding of Populus and Its Hybrids for Cold Resistance

Populus tomentosa was crossed with P.tremuloidis, P.grandidentata, P.alba×P.grandidentata and P.alba×Ulmuspumila in order to maintain its rapid growth and high wood quality and improve its resistance to cold. Two methods were used to increase the germination rate from 1.5% to 41.1% and the remaining rate from 1.7% to 44.2%. Forty crossing combinations were conducted and 2744 hybrid seedlings were obtained. MX4×P.grandidentata （G-1-58）, MX3×P.tremuloidis （T-44-60）, MX2×P.tremuloidis （1-13-87-37） and MX2×（P.alba×P.grandidentata） were regarded as superior combinations after analysis and selection. Thirty seedlings of these combinations and 11 triploid seedlings identified by counting their chromosomes were selected as super plants.

Patients with Cervical Ureaplasma Urealyticum and Chlamydia Trachomatis Infection Undergoing IVF/ICSI-ET: The Need for New Paradigm

Genital tract infections with ureaplasma urealyticum（UU） and chlamydia trachomatis（CT） are the most frequent sexually-transmitted disease worldwide. UU and CT infections are considered to be the leading cause for infertility and adverse pregnancy outcomes. However, little is known about the specific effect of cervical UU and CT infections on the etiology of female infertility, as well as the pregnancy outcomes of the patients undergoing in vitro fertilization/intracytoplasmic sperm injection-embryo transfer（IVF/ICSI-ET）. In order to find the association between cervical UU and/or CT infection and pregnancy outcomes, we conducted a retrospective case-control study on the patients undergoing IVF/ICSI-ET with cervical UU and/or CT infection. A total of 2208 patients who received IVF/ICSI-ET were enrolled in this study. Data on the general conditions, pregnancy history and clinical pregnant outcomes were analyzed in terms of the cervical UU and CT detection. Our results revealed that cervical UU and CT infections were the risk factors for ectopic pregnancy and tubal factor-induced infertility. Moreover, the pregnancy rate, abortion rate, ectopic pregnancy rate and premature birth rate in patients with UU and/or CT infections showed no significant difference when compared with the control group. We recommend that cervical UU and CT detection should be an optional item for infertility patients and clinical UU detection should differentiate the subtypes of cervical UU. Positive cervical UU and CT infections should not be taken as strict contraindications for IVF/ICSI-ET.

Effect of CD86 blockage on the expressions of TGF-β1,MMP-9,TIMP-3 and PAI-1 proteins and outcome of pregnancy in murine abortion-prone model

In the present study, the effect of blockage of the costimulatory signal CD86 at time of implantation on the expressions of TGF-β1, MMP-9, TIMP-3 and PAI-1 proteins at the maternal-fetal interface and the outcome of pregnancy in mufine abortion-prone model was investigated, in which the CBA/J × DBA/2 matings were used as the abortion-prone model and the CBA/J × BALB/c matings used as the normal pregnant model. The study was performed in following three groups： 2 groups of the abortion-prone model, which were experimental group and control experimental group, and 1 group of normal pregnant model, and each group had 10 pregnant CBA/J mice exclusively. Female pregnant CBA/J mice in the experimental group received an intraperitoneal （i. p. ） injection of 100μg of antimouse CD86 mAb in 200 μl of PBS at day 4.5 of gestation, and the irrelevant-isotope matched rat IgG2b was administrated in the control experimental group with the same dosage and at same time. For the normal pregnant group, no treatment was given. The pregnant CBA/J mice were killed on day 13.5 of gestation. Then, the embryo resorption rate was calculated and the expressions of TGF-β1, MMP-9, TIMP3 and PAI-1 were detected by using immunohistochemical methods. It was demonstrated that the embryo resorption rate in the experimental group was significantly reduced in comparison with that in the control experimental group （X^2 = 7.441, P = 0.006）, but there was no significant difference with that in normal pregnant group （X^2 = 0.016, P = 0.898）. The expressions of TGF-β1 and PAI-1 in the experimental group were significantly increased in comparison with that in the control experimental group （P =0.010, P = 0.003, respectively）, with no significant difference from that in the nonnal pregnant group （P = 0.500）. However, the expression of MMP-9 in the experimental group was significantly reduced in comparison with that in the control experimental group （P = 0.012） with no significant difference from that in the normal pregnant group （P = 0.500）. The expression of TIMP-3 in the experimental group showed no significant difference both with the control experimental group （ P = 0. 328） and the normal pregnant group （ P = 0. 500）. It is concluded that the blockage of the costimulatory molecule CD86 at early stage of gestation can render TGF-β1, MMP-9, TIMP-3 and PAI-1 proteins to express their immuno-tolerant effects through their characteristic pathways and induce the reduction of the embryo resorption rate in the natural abortion-prone model of mice to the level of normal pregnancy.

Two Tightly Linked Genes at the hsal Locus Cause Both F1 and F2 Hybrid Sterility in Rice

Molecular mechanisms of hybrid breakdown associated with sterility (F2 sterility) are poorly understood as compared with those of F1 hybrid sterility. Previously, we characterized three unlinked epistatic loci, hybrid sterility-a1 (hsa1), hsa2, and hsa3, responsible for the F2 sterility in a cross between Oryza sativa ssp. indica and japonica. In this study, we identified that the hsa1 locus contains two interacting genes, HSA1a and HSA1b, within a 30-kb region. HSA1a-j (japonica allele) encodes a highly conserved plant-specific domain of unknown function protein (DUF1618), whereasthe indica allele (HSA1a-is) has two deletion mutations that cause disruption of domain structure. The second gene, HSA1b-is, encodes an uncharacterized proteinwith some similarity to a nucleotide-binding protein. Homozygous introgression of indica HSA1a-is-HSA1b-is alleles into japonica showed female gamete abortion at an early mitotic stage. The fact that the recombinant haplotype HSA1a-j-HSA1b-is caused semi-sterility in the heterozygous state with the HSA1a-is-HSA1b-is haplotype suggests that variation in the hsa1 locus is a possible cause of the wide-spectrum sterility barriers seen in F1 hybrids and successive generations in rice. We propose a simple genetic model to explain how a single causal mechanism can drive both F1 and F2 hybrid sterility.