Uterine RGS2 expression is regulated by exogenous estrogen and progesterone in ovariectomized mice,and downregulation of RGS2 expression in artificial decidualized ESCs inhibits trophoblast spreading in vitro

Embryo implantation is a complicated event that relies on two critical factors: the competent blastocyst and the receptive uterus. Successful implantation results from tight coordination of these two factors. The maternal hormone environment of the uterus and molecular cross‐talk between the embryo and uterine tissue play pivotal roles in implantation. Here we showed that regulator of G‐protein signaling 2 (RGS2), a member of ubiquitous family of proteins that regulate G‐protein activation, plays an important role in embryo implantation by interfering in the cross‐talk between the embryo and uterine tissue. RGS2 expression increased during the implantation process, and was higher in the implant site than at the nonimplantation site. Meanwhile, ovariectomized (OVX) mice exhibited higher expression of RGS2 in the uterus. Exogenous 17β‐estradiol and progesterone in OVX mice downregulated the expression of RGS2. Treatment with exogenous 17β‐estradiol alone caused uterine RGS2 messenger RNA levels of OVX mice to return to those of normal female mice; when these mice were treated with progesterone or 17β‐estradiol plus progesterone, RGS2 levels rose. Downregulation of Rgs2 by small interfering RNA in an in vitro coculture system of decidualized endometrial stromal cells and blastocysts inhibited blastocyst outgrowth by restricting trophoblast spreading, suggesting a mechanism by which RGS2 regulates embryo implantation.     

Fission–Fusion Behavior in Yunnan Snub-Nosed Monkeys (Rhinopithecus bieti) in Yunnan, China

Several species of mammals live in relatively large social groups that temporarily fission or subgroup in response to changes in food availability, predation risk, foraging strategies, and mating competition. Although the dynamics of subgrouping are not well understood, evidence of facultative fission–fusion behavior in species that generally exhibit a highly cohesive group structure may help to clarify the set of ecological and social factors that constrain or affect group size in primates. We here examined patterns of subgrouping in Yunnan snub-nosed monkeys (Rhinopithecus bieti) inhabiting the Baimaxueshan National Nature Reserve in Yunnan, China. Rhinopithecus bieti lives in a large multilevel society consisting of 6–41 one-male, multifemale units (OMUs) and one all-male unit (AMU). Over a 5-yr period from 2003 through 2008, we tracked a group of >450 Rhinopithecus bieti. We recorded the location in the group’s home range where fission and fusion events occurred, the size and number of subgroups, days spent in subgroups, and food availability, and monitored predator sightings. The results indicate that the focal group underwent12 group fission events, all of which occurred between mid-June and July, and all in the same area of the group’s range. During these fissioning events, the AMU also showed subgrouping behavior. In all cases, the presence of bamboo shoots, an important seasonal component of the snub-nosed monkey diet, appeared to trigger subgrouping behavior. The subgroups reunited in other parts of their range after a period of 2–11?d. We found no evidence that the presence of predators had a direct affect on subgrouping behavior in Rhinopithecus bieti, as proposed in previous studies.     

Choice of analytical method can have dramatic effects on primate home range estimates

Primate home range sizes can vary tremendously as a consequence of the analytical technique chosen to estimate home range. This is exemplified by a recent dataset on free ranging snub-nosed monkeys (Rhinopithecus bieti) in Northwest Yunnan, China. Our findings show that the grid cell method cannot substitute for the minimum convex polygon (MCP) method and vice versa. MCP-based estimates are far too large, especially when the form of the home range is irregular due to forays into peripheral areas. Here, we propose an adjusted polygon method, whereby unsuitable and never visited areas are clipped out from the polygon, thus producing more accurate results. Compared to the grid cell method, the adjusted MCP is much more robust when the number of group relocations is limited; MCP turned out to be the method of choice for calculation of monthly and seasonal home ranges. The grid cell method on the other hand yielded the most precise estimates for total or annual home ranges. The style of ranging exhibited by a given primate taxon or population determines which analytical procedures should be applied to estimate home range size, and we would stress the need for thorough evaluation of the pros and cons of home range estimators before conducting field work and analysing data.     

Dietary Profile of <Emphasis Type="Italic">Rhinopithecus bieti</Emphasis> and Its Socioecological Implications

To enhance our understanding of dietary adaptations and socioecological correlates in colobines, we conducted a 20-mo study of a wild group of Rhinopithecus bieti (Yunnan snub-nosed monkeys) in the montane Samage Forest. This forest supports a patchwork of evergreen broadleaved, evergreen coniferous, and mixed deciduous broadleaved/coniferous forest assemblages with a total of 80 tree species in 23 families. The most common plant families by basal area are the predominantly evergreen Pinaceae and Fagaceae, comprising 69% of the total tree biomass. Previous work has shown that lichens formed a consistent component in the monkeys’ diet year-round (67%), seasonally complemented with fruits and young leaves. Our study showed that although the majority of the diet was provided by 6 plant genera (Acanthopanax, Sorbus, Acer, Fargesia, Pterocarya, and Cornus), the monkeys fed on 94 plant species and on 150 specific food items. The subjects expressed high selectivity for uncommon angiosperm tree species. The average number of plant species used per month was 16. Dietary diversity varied seasonally, being lowest during the winter and rising dramatically in the spring. The monkeys consumed bamboo shoots in the summer and bamboo leaves throughout the year. The monkeys also foraged on terrestrial herbs and mushrooms, dug up tubers, and consumed the flesh of a mammal (flying squirrel). We also provide a preliminary evaluation of feeding competition in Rhinopithecus bieti and find that the high selectivity for uncommon seasonal plant food items distributed in clumped patches might create the potential for food competition. The finding is corroborated by observations that the subjects occasionally depleted leafy food patches and stayed at a greater distance from neighboring conspecifics while feeding than while resting. Key findings of this work are that Yunnan snub-nosed monkeys have a much more species-rich plant diet than was previously believed and are probably subject to moderate feeding competition.     

Identifications of SUMO-1 cDNA and Its Expression Patterns in Pacific White Shrimp Litopeanaeus vannamei

Small ubiquitin-like modifiers (SUMO) work in a similar way as ubiquitin to alter the biological properties of a target protein by conjugation. A shrimp SUMO cDNA named LvSUMO-1 was identified in Litopenaeus vannamei. LvSUMO-1 cDNA contains a coding sequence of 282 nucleotides with untranslated regions of 37 bp at 5'-end and 347 bp at 3'-end, respectively. The deduced 93 amino acids exhibit 83% identity with the Western Honeybee SUMO-1, and more than 65% homologies with human and mouse SUMO-1. LvSUMO-1 mRNA is expressed in most L. vannamei tissues with the highest level in hepatopancrease. The mRNA expression of LvSUMO-1 over development stages in L. Vammamei is distinguished by a low level in nauplius stage and relatively high level in postlarva stage with continuous expression until juvenile stage. The LvSUMO-1 protein and its conjugated proteins are detected in both cytoplasm and nucleus in several tissues. Interestingly, LvSUMO-1 mRNA levels are high in abdominal muscle during the premolt stage, wherein it has significant activities of protein degradation, suggesting its possible role in the regulation of shrimp muscle protein degradation.     

Range expansion as a response to increasing group size in the Yunnan snub-nosed monkey

The Yunnan snub-nosed monkey (Rhinopithecus bieti) is characterized by a larger home range and group size than other colobine species. We investigated variations in home range size of a free-ranging group of R. bieti from 1998 to 2007 in the Baimaxueshan National Nature Reserve in Yunnan, China. Group size increased from 160 to 450 over the 10 years. Results also showed a home range shift and yearly home range expansion, although this expansion was very limited. The study group covered a 33.78-km(2) area during the 10-year period, with some areas abandoned and others used repeatedly. The yearly home range increase stopped in 2004 and decreased thereafter. Despite increasing group size usually being coupled with larger yearly home range (>30 km(2)), the group confined itself within a relatively small and stable area (<18 km(2)) during 2005-2007, with a significant portion of their accessible home range discarded. Consequently, the study group showed the highest recorded population density among extant groups of R. bieti. Reasons why the group settled into a substantially smaller home range area remain unclear.     

Nocturnal sleeping habits of the Yunnan snub‐nosed monkey in Xiangguqing,China

Weather, predation, and social organization are hypothesized to influence sleeping habits of nonhuman primates at night. To investigate how the Yunnan snub‐nosed monkey (Rhinopithecus bieti) prepares for and behaves during cold nights in their harsh alpine forest habitat (above 3,000 m), we studied the sleeping habits of the 171 one‐male units (OMU) in one group for 12 months at Xiangguqing in the Baimaxueshan Nature Reserve, China. It took 20.2 min from the time the study group entered a sleeping site until they fell asleep. This duration was consistent over seasons. On average, sleeping time was 11.5 hr per night over the year. Seasonal mean lengths of sleeping time varied significantly, however, and ranged from 10 to 13 hr per night, correlating with night length. Two sleeping styles were distinguishable: solitary sleeping and huddled sleeping. That adult males in OMUs principally slept alone. This is likely to reflect night‐time guarding behavior. Female–juvenile and female–infant dyadic huddles were the most prevalent sleeping unit (42% of all observed data), and the monkeys employed female‐biased huddling during nocturnal sleep. Huddled sleeping group size showed significant seasonal variation, with the largest huddle (eight individuals) occurring in winter. Climate and social organization profoundly influence the nocturnal sleeping habits of R. bieti, while huddling behavior may help shield animals from cold nights and provide additional protection against predators. Am. J. Primatol. 72:1092–1099, 2010. © 2010 Wiley‐Liss, Inc.     

Immunoisolation and Characterization of a Subdomain of the Endoplasmic Reticulum That Concentrates Proteins Involved in COPII Vesicle Biogenesis

Rubella virus E1 glycoprotein normally complexes with E2 in the endoplasmic reticulum (ER) to form a heterodimer that is transported to and retained in the Golgi complex. In a previous study, we showed that in the absence of E2, unassembled E1 subunits accumulate in a tubular pre-Golgi compartment whose morphology and biochemical properties are distinct from both rough ER and Golgi. We hypothesized that this compartment corresponds to hypertrophied ER exit sites that have expanded in response to overexpression of E1. In the present study we constructed BHK cells stably expressing E1 protein containing a cytoplasmically disposed epitope and isolated the pre-Golgi compartment from these cells by cell fractionation and immunoisolation. Double label indirect immunofluorescence in cells and immunoblotting of immunoisolated tubular networks revealed that proteins involved in formation of ER-derived transport vesicles, namely p58/ERGIC 53, Sec23p, and Sec13p, were concentrated in the E1-containing pre-Golgi compartment. Furthermore, budding structures were evident in these membrane profiles, and a highly abundant but unknown 65-kDa protein was also present. By comparison, marker proteins of the rough ER, Golgi, and COPI vesicles were not enriched in these membranes. These results demonstrate that the composition of the tubular networks corresponds to that expected of ER exit sites. Accordingly, we propose the name SEREC (smooth ER exit compartment) for this structure.     

迁飞过程中昆虫的行为

根据国内外对昆虫迁飞的雷达观测结果,综述了迁飞过程中昆虫的成层、定向和集聚行为及其生态学意义。昆虫在迁飞过程中不完全是被动地随风飘流,而是在一定程度上自主地选择了自己的运行轨迹。它们选择在气温最高、风力最大和风向最适的高度成层,并通过定向进一步修饰位移方位,从而可最大限度地利用空气动力到达新的栖息地。同时,不同尺度的大气辐合过程使得迁飞昆虫集聚成足以在某种条件下引起局地爆发的高密度种群,而地面大发生种群形成与否取决于大气辐合的发生频率、强度和寿命,以及集聚起来的昆虫是否降落,在何时何地降落,是否还会再迁出等。阐明昆虫在迁飞过程中的各种行为机制是迁飞性害虫测报和防治的关键所在。     

悉生重症联合免疫缺陷(SCID)小鼠的研究——Ⅰ.肠道厌氧菌群的分离和鉴定

本文报道了由澳大利亚WEHI研究所(The Walter and Eliza Hall Institute of Medical Research)引进的悉生SCID(Severe Combined Immunodeficient)小鼠肠道厌氧菌群的分离、鉴定结果。该小鼠粪便标本需氧及厌氧培养发现应用非选择性Scheadler血琼脂需氧条件下有一种革兰氏阳性杆菌生长;厌氧条件下生长的培养物经数种选择性培养基也分离出革兰氏阴性及阳性杆菌,据细菌形态学,染色特征,生化反应特性等鉴别为吉氏拟杆菌、嗜酸乳杆菌和梭形杆菌。