金色中仓鼠胚胎植入小鼠子宫后PTEN、FAK、Shc信号分子的异常表达

除了马属动物外,种间妊娠的胚胎总在妊娠的一定时期流产。以往的研究多集中在宏观结构和解剖学差别的研究上,对于这种现象产生的分子机制却少有报道。为了从信号分子角度阐明种间妊娠维持失败的可能原因,我们通过免疫组化和明胶酶谱法比较了科间和同种妊娠部位整合素αvβ3、FAK、p-ERK、IGFⅡ、IGFBP-1、Shc、PTEN和MMP-2、-9表达的差异。科间妊娠是将金色中仓鼠(Mesocricetus auratus)的胚胎移植入假孕小鼠(Mus musculus)子宫并取妊娠D4、D8、D12的子宫为实验材料,相应时间同种小鼠胚胎移植小鼠妊娠后的子宫和假孕小鼠子宫分别为阳性和阴性对照。免疫组化结果表明D8时,科间妊娠孕体integrinαvβ3、IGF-Ⅱ、IGFBP-1、PTEN、Shc、FAK的表达强度均与正常同种妊娠有差异。而妊娠D8时同种、科间妊娠子宫p-ERK的表达部位与表达量无明显差异。明胶酶谱显示,科间妊娠时MMP-2,-9的分泌模式与同种妊娠明显不同。这些结果表明,上述信号通路分子的差异表达有可能是造成科间妊娠时母胎界面异常的组织学表现的一个原因。     

Expression of glucose phosphate isomerase in interspecific hybrid (Mus musculus × Mus caroli)

Hybrid Mus musculus × Mus caroli embryos were produced by inseminating M. musculus (C57BL/Ola Ws) females with M. caroli sperm. Control M. caroli embryos developed more rapidly than did control M. musculus embryos and implanted approximately 1 day earlier. At 1 1/2 days, both the hybrid embryos and those of the maternal species (M. musculus) had cleaved to the 2-cell stage. By 2 1/2 days some of the hybrids were retarded compared to M. musculus, and by 3½ days most were lagging behind. This is consistent with the idea that the rate of development of hybrid embryos declines once it becomes dependent on embryo-coded gene products. We have used this difference in rate of preim-plantation development, between hybrid and M. musculus embryos, to try to determine whether the activation of embryonic Gpi-1s genes, that encode glucose phosphate isomerase (GPI-1), is age-related or stage-related. In control M. musculus embryos (both mated and Al groups), the GPI-1AB and GPI-1A allozyme, indicative of paternal gene expression, were detected in 7 of 9 samples of 3 1/2-day compacted morula stage embryos and were seen in all 19 samples of 31/2-day blastocysts. In hybrid embryos, these allozymes were detected 1 day later. They were not detected in any 31/2-day samples (12 samples of compacted morulae) but were consistently detected at 4½ days (4 samples of blastocysts and 2 samples of uncompacted morulae). Our interpretation of the results is that gene activation in hybrid embryos is stage-specific, rather than age-specific, and probably begins around the 8-cell stage, with detectable levels of enzyme accumulating later. Analysis of GPI-1 elec-trophoresis indicated that both the paternal (M. caroli) and maternal (M. musculus) Gpi-1s alleles were equally expressed in hybrid embryos and that the paternally derived allele was not activated before the maternally derived allele. © 1992 Wiley-Liss, Inc.     

Helicobacter muricola sp. nov., a novel Helicobacter species isolated from the ceca and feces of Korean wild mouse (Mus musculus molossinus)

A slowly growing microaerophilic Helicobacter strain was isolated from the ceca and fecal pellets of Korean wild mice (Mus musculus molossinus). This bacterial strain possessed a pair of nonsheathed bipolar flagella, was positive for urease, catalase and oxidase, and reduced nitrate to nitrite. It proved susceptible to nalidixic acid and resistant to cephalodine, and did not hydrolyze hippurate. On the basis of phenotypic characteristics and 16S rRNA gene sequence analysis, the isolate represents a new species of the genus Helicobacter, for which the name Helicobacter muricola sp. nov. is proposed; the type strain of the new species is w-06T.     

Expression profiles of 109 apoptosis pathway-related genes in 82 mouse tissues and experimental conditions

Apoptosis is an important process in development and tissue homeostasis. To understand the similarities and differences in the apoptosis machinery in different normal, developmental, and diseased tissues, the expression profiles of 109 apoptosis-pathway-related genes in 82 mouse tissues and experimental conditions were examined using Incyte Mouse GEMI cDNA arrays. It has been found that the compositions of the apoptotic machinery vary among different tissues, developmental stages, and disease states, with subsets of apoptotic genes co-ordinately expressed in the 82 tissues and experimental conditions. Additional genes whose expression profiles resemble selected genes from the 109 apoptotic gene list were also identified. This study provides valuable information on possible molecular mechanisms of differential apoptotic responses to developmental signals, environmental stimuli, and therapeutic treatments in tissue-specific manner.     

CFTR基因在小鼠肠道组织中的差异表达

目的研究肠道组织CFTR基因表达与分泌性腹泻发生的关系。方法选取KM小鼠24只,雌雄各半,随机分为3组（每组8只）：对照组经小鼠腹腔注射0.2 mL生理盐水,实验组小鼠经腹腔注射LPS[6 mg/（kg·bw）]分别作用1 h、8 h,于注射后通过小鼠精神状态、肠道组织形态学判定分泌性腹泻模型的建立,利用荧光定量PCR法检测各段肠道组织CFTR基因的表达。结果 LPS成功诱导小鼠发生了分泌性腹泻;CFTR基因在小鼠十二指肠、空肠、回肠和结肠组织中均有不同的表达丰度,以结肠最高,但各段肠道间差异不显著;与对照组相比,LPS上调了十二指肠、空肠和回肠CFTR基因的转录,下调了结肠CFTR基因的转录。结论提示肠道组织CFTR基因转录水平的上调与LPS诱导分泌性腹泻的发生密切相关,且在各肠段发挥的作用不同,其中空肠在氯离子（Cl-）分泌中发挥主要作用,结肠的作用最弱。     

Coevolution of Cryptosporidium tyzzeri and the house mouse (Mus musculus)

Two house mouse subspecies occur in Europe, eastern and northern Mus musculus musculus (Mmm) and western and southern Mus musculus domesticus (Mmd). A secondary hybrid zone occurs where their ranges meet, running from Scandinavia to the Black Sea. In this paper, we tested a hypothesis that the apicomplexan protozoan species Cryptosporidium tyzzeri has coevolved with the house mouse. More specifically, we assessed to what extent the evolution of this parasite mirrors divergence of the two subspecies. In order to test this hypothesis, we analysed sequence variation at five genes (ssrRNA, Cryptosporidium oocyst wall protein (COWP), thrombospondin-related adhesive protein of Cryptosporidium 1 (TRAP-C1), actin and gp60) in C. tyzzeri isolates from Mmd and Mmm sampled along a transect across the hybrid zone from the Czech Republic to Germany. Mmd samples were supplemented with mice from New Zealand. We found two distinct isolates of C. tyzzeri, each occurring exclusively in one of the mouse subspecies (C. tyzzeri-Mmm and C. tyzzeri-Mmd). In addition to genetic differentiation, oocysts of the C. tyzzeri-Mmd subtype (mean: 4.24 × 3.69 μm) were significantly smaller than oocysts of C. tyzzeri-Mmm (mean: 4.49 × 3.90 μm). Mmm and Mmd were susceptible to experimental infection with both C. tyzzeri subtypes; however, the subtypes were not infective for the rodent species Meriones unguiculatus, Mastomys coucha, Apodemus flavicollis or Cavia porcellus. Overall, our results support the hypothesis that C. tyzzeri is coevolving with Mmm and Mmd.     

The temporal and spatial expression pattern of myosin Va, Vb and VI in the mouse ovary

There are 16 classes of unconventional myosins. Class V myosins have been shown to be involved in transporting cargo to and from the cell periphery. Class VI myosins have also been shown to transport cargo from the cell periphery, although it seems that these proteins have many roles which include the mediation of cell migration and stereocillia stabilisation. With the requirement of myosin VI for Drosophila oogenesis, the localised expression of Myosin V in the developing egg chamber and recent mounting evidence which links myosin VI to the migration of human ovarian cancer cell lines, we wanted to investigate the expression pattern of these two myosin classes in the normal mouse ovary. Here we show that these myosins are expressed, localised and regulated within the oocyte and granulosa cells of the developing mouse follicle.     

Effect of droplet vitrification on development competence, actin cytoskeletal integrity and gene expression in in vitro cultured mouse embryos

The effect of modified droplet vitrification was assessed on cellular actin filament organization, apoptosis related gene expression and development competence in mouse embryos cultured in vitro. Mouse zygotes, 2-cell embryos and morulae were vitrified in ethylene glycol (VS-1) and ethylene glycol plus DMSO (VS-2) and thawed by directly placing the vitrified drop into 0.3 M sucrose solution at 37 °C. High recovery (93-99%) of morphologically normal embryos was evident following vitrification and thawing. No detectable actin filament disruption was observed in the embryos at any development stage following vitrification and thawing and/or in vitro culture. The expression pattern of Bax, Bcl2 and p53 genes was altered (P < 0.05) in vitrified zygotes and 2-cell embryos, but not in morulae. Although a large proportion of the vitrified zygotes (59.5 ± 4.4% in VS-1 and 57.9 ± 4.5% in VS-2; mean ± S.E.M.) and 2-cell embryos (63.1 ± 4.4% in VS-1 and 59.2 ± 4.3% in VS-2) developed into blastocysts, development of control embryos (70.2 ± 5.0% of zygotes and 75.5 ± 4.4% of 2-cell embryos) into blastocysts was higher (P < 0.05). In contrast, development of the control and vitrified morulae into blastocysts (more than 85%) was similar. We concluded that the modified droplet vitrification procedure supported better survival of morula stage compared to zygotes and 2-cell mouse embryos.     

小鼠基因转录表达分析中内参基因的优选

目的 建立小鼠基因转录表达分析中内参基因的选择方法.方法 以C57BL/6J和C3H/HeJ两个品系3个不同组织及2个不同发育阶段为研究对象,应用反转录实时定量PCR技术,评价GAPDH(glyceraldehyde-3-phosphate dehydrogenase)、HPRTl(hypoxanthine phosphoribosyl transferase)、B2M(β2-microglobulin)、PPIA(peptidylprolyl isomerase A)、ACTB(Actin-beta)和18S rRNA(18S ribosomal RNA)等6个看家基因在下丘脑、垂体与卵巢中mRNA水平的表达稳定性.结果 GeNorm统计分析表明,GAPDH和HPRT1表达最为稳定,PPIA等次之,B2M在不同组织和发育阶段中都几乎无表达.结论 成功筛选到GAPDH和HPRT1两个稳定表达的看家基因,证实了小鼠基因表达转录分析中内参基因选择的必要性和可行性.     

Tissue-specific selection of reference genes is required for expression studies in the mouse model of maternal protein undernutrition

Suboptimal maternal nutrition during gestation results in the establishment of long-term phenotypic changes and an increased disease risk in the offspring. To elucidate how such environmental sensitivity results in physiological outcomes, the molecular characterisation of these offspring has become the focus of many studies. However, the likely modification of key cellular processes such as metabolism in response to maternal undernutrition raises the question of whether the genes typically used as reference constants in gene expression studies are suitable controls. Using a mouse model of maternal protein undernutrition, we have investigated the stability of seven commonly used reference genes (18s, Hprt1, Pgk1, Ppib, Sdha, Tbp and Tuba1) in a variety of offspring tissues including liver, kidney, heart, retro-peritoneal and inter-scapular fat, extra-embryonic placenta and yolk sac, as well as in the preimplantation blastocyst and blastocyst-derived embryonic stem cells. We find that although the selected reference genes are all highly stable within this system, they show tissue, treatment and sex-specific variation. Furthermore, software-based selection approaches rank reference genes differently and do not always identify genes which differ between conditions. Therefore, we recommend that reference gene selection for gene expression studies should be thoroughly validated for each tissue of interest.     

Expression and hormonal regulation of calcyclin-binding protein (CacyBP) in the mouse uterus during early pregnancy

Calcyclin-binding protein (Siah-1-Interacting Protein, CacyBP/SIP), is a calcium signaling protein involved in the degradation of beta-catenin, however, little is known about its role in reproductive biology. The present study was to character its temporospatial expression pattern and regulation in mouse uterus and to investigate whether it plays a role in the regulation of normal endometrial events. While prominently expressed in both luminal and glandular epithelia, CacyBP underwent dynamic changes during early pregnancy. CacyBP expression was observed weakly from days 1-4. An intense accumulation in luminal and glandular epithelia as well as decidua surrounding the embryo at later stages (days 5-7) was observed. Most notably, CacyBP accumulation in trophoblast was pronounced at day 7. Using ovariectomized and pseudopregnant mice, we found that progesterone (P(4)) and 17beta-estradiol (E(2)) led to increased expression of CacyBP gene and this could be abolished by Ru486 and tamoxifen, respectively. Antisense oligonucleotides (ODNs) against CacyBP significantly inhibited cultured endometrial stromal cells' (ESCs) apoptosis induced by UV irradiation. Injection of antisense ODNs into mouse uterine horn severely impaired the number of implanted blastocysts. Taken together, our results suggested that CacyBP expression was positively regulated by P(4) and E(2). CacyBP may be involved in the regulation of endometrial cell apoptosis during early pregnancy and play an important role in mouse endometrial events such as pregrancy establishment.     

Endometrial expression of progesterone receptor and uteroglobin genes during early pregnancy in the rabbit

The progesterone receptor (PR) plays a pivotal role in the maturation process of the secretory endometrium, implantation and maintenance of pregnancy in rabbits. To determine the dynamics of PR gene expression and its physiological significance, the endometrial expression of PR and PR mRNA were evaluated and compared with the expression of the progesterone-regulated uteroglobin (UG) gene during 0–5 days post-coitus in rabbits. The results of immunoblot experiments indicated the presence of PR in endometrial cell extracts from days 1–4 of pregnancy with maximum PR immunostaining on day 2, followed by a marked diminution until its complete disappearance on day 5. When endometrial PR mRNA content was assessed by Northern blots, the results were similar to those of PR immunostaining, with maximal concentrations on the second day after mating. However, PR mRNA levels were still high on day 3, despite the concomitant decrease in immunostainable PR. Endometrial UG gene expression, on the other hand, exhibited a different time sequence. Thus, the UG content in uterine flushings progressively increased from day 3 after mating, reaching maximal levels on the fifth day. The endometrial UG mRNA content presented a similar profile, as its maximum concentration occurred on days 4–5. The overall results indicate that endometrial PR is down-regulated at both the mRNA and protein levels, possibly by endogenous progesterone during early pregnancy. The striking observation that maximal expression of endometrial UG gene products occurred when PR and its mRNA are no longer detectable suggests an important role for this progesterone-binding uterine protein during the preimplantation period. © 1993 Wiley-Liss, Inc.