Search results for " Urinary"
showing 10 items of 569 documents
PHENOLOGICAL ADAPTATION OF ANT-DISPERSED PLANTS TO SEASONAL VARIATION IN ANT ACTIVITY
2002
We studied a temperate plant community to examine whether the reproductive phenology of ant-dispersed plants is correlated with seasonal variation in seed dispersal activity of ants. We documented flowering and fruiting peak of 24 ant-dispersed and 251 non-ant-dispersed plant species. To characterize the activity of ants, we quantified the seasonal removal rates of greater celandine (Chelidonium majus) seeds. Ant-dispersed plants flowered on average 5.6 wk and fruited 7.1 wk earlier than those with other dispersal modes. This difference was not caused by variation in growth form or habitat. Mean fruiting peak of ant-dispersed plants was early July. Ant activity was especially high between M…
Recent speciation and secondary contact in endemic ants
2014
Gene flow is the main force opposing divergent selection, and its effects are greater in populations in close proximity. Thus, complete reproductive isolation between parapatric populations is not expected, particularly in the absence of ecological adaptation and sharp environmental differences. Here, we explore the biogeographical patterns of an endemic ant species, Cataglyphis floricola, for which two colour morphs (black and bicolour) coexist in parapatry throughout continuous sandy habitat in southern Spain. Discriminant analyses of six biometric measurements of male genitalia and 27 cuticular hydrocarbons reveal high differentiation between morphs. Furthermore, the low number of shared…
Evidence for a new feminizing Wolbachia strain in the isopod Armadillidium vulgare: evolutionary implications.
2004
Wolbachia are intracellular maternally inherited alpha-Proteobacteria infecting a wide range of arthropods. In the common pill bug Armadillidium vulgare, the known Wolbachia strain is responsible for feminization of genetic males. We have investigated Wolbachia diversity in 20 populations of A. vulgare from west and east Europe, north Africa and north America. A new Wolbachia strain (wVulM) was identified through the variability of the wsp gene, distantly related to that previously known (wVulC) in this host species. No individual with multiple infections was detected. Inoculation experiments indicated that the new wVulM bacterial strain also induces feminization in A. vulgare. However, the…
Effect of the Bovine Oviductal Fluid onIn VitroFertilization, Development and Gene Expression ofIn Vitro-Produced Bovine Blastocysts
2012
Oviductal microenvironment generally provides better condi-tions for early embryo development than the conventionalin vitro system. In an attempt to simulate the oviductconditions or the main potentially influencing factors, theeffect was studied of a bovine oviductal fluid (bOF) treatmentapplied prior to IVF on (i) IVF parameters, (ii) cleavage rate,(iii) blastocyst yield and (iv) blastocyst quality. Embryo qualitywas assessed by morphological embryo quality and relativetranscript abundance of several developmental genes in bovineblastocysts. Furthermore, to study the effect of bOF withoutthe male effect and zona–sperm interaction, artificially acti-vated metaphase II oocytes were also treated w…
Multiple paternity and mating group size in the European earwig,Forficula auricularia
2014
The patterns of multiple paternity among the progeny of females are key properties of genetic mating systems. Female multiple mating should evolve due to direct or indirect benefits, but it may also partly be driven by the encounter rate with different potential mates. 2. In this study this hypothesis was experimentally tested in the European earwig (Forficula auricularia L.) by establishing experimental mating groups that differed in the number of males and females (i.e. density). The number of sires and mean sibling relatedness in each clutch were estimated using microsatellite-based paternity analysis. 3. As predicted, the mean number of sires per clutch was significantly increased, and …
Transcriptomic Signature of Trophoblast Differentiation in a Human Embryonic Stem Cell Model1
2011
Identification of genes involved in trophoblast differentiation is of great interest in understanding cellular and molecular mechanisms involved in placental development and is relevant clinically to fetal development, fertility, and maternal health. Herein, we investigated differentiation of human embryonic stem cells (hESCs) down the trophoblast lineage by culture with bone morphogenetic protein 4 (BMP4) over a 10-day period. Within 2 days, the stemness markers POU5F1 and NANOG were markedly down-regulated, followed temporally by up-regulation of the CDX2, KRT7, HLA-G, ID2, CGA, and CGB trophoblast markers. To understand, on a global scale, changes in the transcriptome during the differen…
Relatedness Does not Affect Competitive Behavior of Rival Males or Offspring Growth in Multiply Sired Litters of Bank Voles (Myodes glareolus)
2014
Kin selection operates through the fitness of an organism's relatives. In the polyandry context, kin selection may be observable on the one hand in competition between rival males and, on the other hand, in competition between litter mates. Sperm competition theory predicts that males should invest less into mating when competing for fertilizations against a close relative as compared to an unrelated male. We tested this hypothesis with bank voles (Myodes glareolus) by mating each focal male to two females: one of which had previously mated with a full sibling of the focal male and the other one with a male unrelated to the focal male. However, we found no effect of rival male relatedness o…
Male Investments in High Quality Sperm Improve Fertilization Success, but May Have Negative Impact on Offspring Fitness in Whitefish.
2015
Many ejaculate traits show remarkable variation in relation to male social status. Males in disfavoured (subordinate) mating positions often invest heavily on sperm motility but may have less available resources on traits (e.g., secondary sexual ornaments) that improve the probability of gaining matings. Although higher investments in sperm motility can increase the relative fertilization success of subordinate males, it is unclear whether status-dependent differences in sperm traits could have any consequences for offspring fitness. We tested this possibility in whitefish (Coregonus lavaretus L.) by experimentally fertilizing the eggs of 24 females with the sperm of either highly-ornamente…
Similar Performance of Diploid and Haploid Males in an Ant Species without Inbreeding Avoidance
2013
AbstractUnder haplodiploidy, a characteristic trait of all Hymenoptera, femalesdevelop from fertilised eggs, and males from unfertilised ones. Males aretherefore typically haploid. Yet, inbreeding can lead to the production ofdiploid males that often fail in development, are sterile or are of lowerfertility. In most Hymenoptera, inbreeding is avoided by dispersal flightsof one or both sexes, leading to low diploid male loads. We investigatedcauses for the production of diploid males and their performance in ahighly inbred social Hymenopteran species. In the ant Hypoponera opacior,inbreeding occurs between wingless sexuals, which mate within themother nest, whereas winged sexuals outbreed dur…
Extreme Methylation Values of Imprinted Genes in Human Abortions and Stillbirths
2010
Imprinted genes play an important role in fetal and placental development. Using quantitative bisulfite pyrosequencing assays, we determined the DNA methylation levels at two paternally methylated (H19 and MEG3) and four maternally methylated (LIT1, NESP55, PEG3, and SNRPN) imprinted regions in fetal muscle samples from abortions and stillbirths. Two of 55 (4%) spontaneous abortions and 10 of 57 (18%) stillbirths displayed hypermethylation in multiple genes. Interestingly, none of 34 induced abortions had extreme methylation values in multiple genes. All but two abortions/stillbirths with multiple methylation abnormalities were male, indicating that the male embryo may be more susceptible t…