Cuticular lipids for species recognition of mole crickets (Orthoptera: Gryllotalpidae): II. Scapteriscus abbreviatus,S. acletus,S. vicinus,S. sp., and Neocurtilla hexadactyla

Qualitative analyses were made from whole-body cuticular extracts of Scapteriscus abbreviatus, Scapteriscus acletus, Scapteriscus vicinus, and Neocurtilla hexadactyla by isothermal and temperature-programmed gas chromatography. Adults of both sexes and nymphs of each species were collected in Florida. The chromatographic profiles of peaks were distinct and easily recognizable for each species, regardless of sex or developmental stage. Distinct sexual differences were found in S. acletus and S. abbreviatus. Specimens of S. abbreviatus from Puerto Rico and S. vicinus from Bolivia produced gas chromatography (GC) traces very similar to those of conspecifics collected in Florida. Evidence is presented to illustrate the potential importance of volatile cuticular lipid analysis as a tool for mole cricket identification. Cuticular extracts of an undescribed short-winged species of Scapteriscus from Bolivia were also examined and produced GC traces unlike those of any other species analyzed to date.     

Are rates of species diversification correlated with rates of morphological evolution?

Some major evolutionary theories predict a relationship between rates of proliferation of new species (species diversification) and rates of morphological divergence between them. However, this relationship has not been rigorously tested using phylogeny-based approaches. Here, we test this relationship with morphological and phylogenetic data from 190 species of plethodontid salamanders. Surprisingly, we find that rates of species diversification and morphological evolution are not significantly correlated, such that rapid diversification can occur with little morphological change, and vice versa. We also find that most clades have undergone remarkably similar patterns of morphological evolution (despite extensive sympatry) and that those relatively novel phenotypes are not associated with rapid diversification. Finally, we find a strong relationship between rates of size and shape evolution, which has not been previously tested.     

Glycodelin protein and mRNA is downregulated in human first trimester abortion and partially upregulated in mole pregnancy.

Glycodelin (Gd) is a major reproductive glycoprotein and a mediator for immunomodulatory effects directed to cellular, humoral, and innate immunity. Human pregnancy depends on a diversity of physiological processes including modulation of the maternal immunosystem. We evaluated the expression of Gd protein and mRNA in first trimester decidual tissue of normal pregnancies and spontaneous abortion and hydatidiform moles. Furthermore, in vitro experiments on endometrial cancer cells to analyze the effect of human chorionic gonadotropin (hCG) on Gd regulation were performed. In decidual tissue of abortion patients, Gd expression was significantly decreased compared with normal gestation, which was confirmed by in situ hybridization. In mole pregnancy, an upregulation of Gd in the first 8 weeks of pregnancy was present. Gd is a main product of decidual tissue in the first trimester of human pregnancy. Reduced Gd expression in abortive pregnancy could lead to an increased activation of the maternal immunosystem, thus causing rejection of the developing fetus. Moreover, Gd expression in endometrial cancer cells in vitro could be stimulated by addition of hCG. Therefore, we speculate that hCG could be one of the factors regulating Gd expression because hCG is downregulated in women with abortion and upregulated in mole pregnancy. In addition, we found a positive feedback loop in Gd and hCG expression in human pregnancy.     

印度地鼠的性成熟和窝仔数

为有效地进行有害脊椎动物的控制 ,研究了栖息于巴基斯坦Punjab中部的 348只印度地鼠的繁殖模式。在所捕捉到的 10 7雄鼠和 2 4 1只雌鼠中 ,分别有 75只和 179只是性成熟的个体。性比偏雌。使用被捕个体标本的体重和体长作为指标 ,发现最小的性成熟的雄性个体体重为 70 - 89g ,体长 13 1- 14 0cm ;一窝仔里面的平均胚胎数为 2 74± 0 15 (范围 ,1- 5 ) ,而平均胎斑数为 4 2 9± 0 19(1- 11) .体重似乎对窝仔数有显著影响 ,而体长和估计的年龄对窝仔数没影响。当老鼠繁殖不活跃和不繁殖时 ,控制害兽最有效     

Salamander diversity alters stream macroinvertebrate community structure

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Landscape and weather determinants of prey availability: implications for the Lesser Kestrel Falco naumanni

Spatial and temporal variation in prey abundance have been shown to impact the time of breeding and breeding success of birds. Understanding the ecological requirements of preferred prey can help develop management measures to improve food supply for target species. For the colonial Lesser Kestrel Falco naumanni, mole crickets Gryllotalpa spp. are one of the most important prey items during the mate‐feeding period. Lesser Kestrel colonies with higher mole cricket consumption had earlier egg‐laying dates, suggesting that differences between individuals in the time of breeding could be caused by differences in the diet. Moreover, the mean number of mole crickets in pellets was significantly correlated with clutch size (in one of the studied years) and egg volume. Thus, the impact of environmental variables and land use on mole crickets is likely to be relevant to Lesser Kestrel conservation. Weekly consumption of mole crickets was higher following an increase in either precipitation or minimum temperature values. Furthermore, mole cricket consumption was higher in colonies surrounded by higher quality soils and in wetter areas and years. Predicted probability of mole cricket occurrence in surveyed watercourse margins suggested a positive relationship between soil penetrability and mole cricket occurrence. Among variables that might be the target of management, the presence of riparian vegetation positively influenced the occurrence of mole crickets, whilst tillage and sowing of streambeds were revealed as the most important threats. We suggest that the maintenance of native vegetation in the margins of watercourses could improve soil resilience to erosion, increase water retention, soil penetrability and fertility, and provide a food supply and shelter for mole crickets. Overall, the implementation of such recommendations is likely to benefit other farmland species known to consume mole crickets, including several endangered species.     

Growth and foraging consequences of facultative paedomorphosis in the tiger salamander,Ambystoma tigrinum nebulosum

Summary Facultative paedomorphosis in salamanders occurs when larvae respond to varying environmental conditions by either metamorphosing into terrestrial metamorphic adults or retaining their larval morphology to become sexually mature paedomorphic adults. Several hypotheses have been proposed for the evolutionary maintenance of this environmentally induced dimorphism, but few data are available to assess them adequately. We studied a montane population of the tiger salamander,Ambystoma tigrinum nebulosum, and measured the adult growth rate and body condition across three growing seasons to assess the relative costs and benefits of each morph. Metamorphic adults grew more than paedomorphic adults in terms of snout—vent length across years and in weight within years. Dietary analyses and foraging experiments revealed some of the proximate factors that may underlie these differential growth patterns. Across all prey, metamorphs had significantly higher biomass and calories per stomach sample than paedomorphs. Metamorphic diets primarily consisted of the fairy shrimpBranchinecta coloradensis, whereas paedomorphic diets contained a variety of benthic and terrestrial invertebrates. Foraging experiments revealed that both morphs are more successful at capturing fairy shrimp relative to other prey types and both show high electivity toward this prey. However, fairy shrimp occurred only in non-permanent ponds and thus are inaccessible to paedomorphs, which can survive only in permanent ponds. Paedomorphs also experience higher levels of intraspecific competition with large larvae in permanent ponds than metamorphs do in non-permanent ponds. Thus, metamorphs obtain a growth advantage over paedomorphs by foraging in non-permanent ponds that contain fairy shrimp and have reduced intraspecific competition. These results suggest that paedomorphs should have decreased fitness relative to metamorphs, primarily because metamorphs can move into the best habitats for growth. The net fitness effect of morph-specific differences in dispersal depend on whether there are trade-offs with other life history traits. Nonetheless, because the relative benefit of metamorph dispersal will change with environmental conditions in permanent ponds and the surrounding habitat, the relative fitness payoff to each morph should track changes in the environment. Thus, facultative paedomorphosis may be maintained in part by variable, environmentally-specific fitness payoffs to each morph.     

Has gene duplication impacted the evolution of Eutherian longevity?

One of the greatest unresolved questions in aging biology is determining the genetic basis of interspecies longevity variation. Gene duplication is often the key to understanding the origin and evolution of important Eutherian phenotypes. We systematically identified longevity‐associated genes in model organisms that duplicated throughout Eutherian evolution. Longevity‐associated gene families have a marginally significantly higher rate of duplication compared to non‐longevity‐associated gene families. Anti‐longevity‐associated gene families have significantly increased rate of duplication compared to pro‐longevity gene families and are enriched in neurodegenerative disease categories. Conversely, duplicated pro‐longevity‐associated gene families are enriched in cell cycle genes. There is a cluster of longevity‐associated gene families that expanded solely in long‐lived species that is significantly enriched in pathways relating to 3‐UTR‐mediated translational regulation, metabolism of proteins and gene expression, pathways that have the potential to affect longevity. The identification of a gene cluster that duplicated solely in long‐lived species involved in such fundamental processes provides a promising avenue for further exploration of Eutherian longevity evolution.     

The hydatidiform mole

ABSTRACT

The hydatidiform mole (HM) is a placental pathology of androgenetic origin. Placental villi have an abnormal hyperproliferation event and hydropic degeneration. Three situations can be envisaged at its origin: 1. The destruction/expulsion of the female pronucleus at the time of fertilization by 1 or 2 spermatozoa with the former being followed by an endoreplication of the male pronucleus leading to a complete hydatidiform mole (CHM) 2. A triploid zygote (fertilization by 2 spermatozoa) leading to a partial hydatidiform mole (PHM) but can also lead to haploid and diploid clones. The diploid clone may produce a normal fetus while the haploid clone after endoreplication generates a CHM 3. A nutritional defect during the differentiation of the oocytes or the deterioration of the limited oxygen pressure during the first trimester of gestation may lead to the formation of a HM.

In countries with poor medical health care system, moles (mainly the CHM) can become invasive or, in rare cases, lead to gestational choriocarcinomas.