Asymmetrical hybridization and gene flow between Eisenia andrei and E. fetida lumbricid earthworms

Uniformly pigmented Eisenia andrei (Ea) and striped E. fetida (Ef) lumbricid earthworms are hermaphrodites capable of self-fertilization, cross-fertilization, and asymmetrical hybridization. The latter was detected by genotyping of F1 and F2 progeny of the controlled Ea+Ef pairs by species-specific sequences of maternal mitochondrial COI genes and maternal/paternal nuclear S28 rRNA genes. Among F1offspring there were self-fertilized Ea (aAA), Ef (fFF), and cross-fertilized fertile Ea-derived hybrids (aAF); the latter mated with Ea and gave new generation of Ea and hybrids, while mated with Ef gave Ea, Ef, Ea-derived hybrids and sterile Ef-derived hybrids (fFA). Coelomic fluid of Ea exhibits unique fluorescence spectra called here the M-fluorescence considered as a molecular biomarker of this species. Since similar fluorescence was detected also in some Ef (hypothetical hybrids?), the aim of present investigations was to identify the M-positive earthworms among families genotyped previously. It was assumed that factor/s responsible for metabolic pathways leading to production of undefined yet M-fluorophore might be encoded/controlled by alleles of hypothetical nuclear gene of Eisenia sp. segregating independently from species-specific S28 rRNA nuclear genes, where 'MM' or 'Mm' alleles determine M-positivity while 'mm' alleles determine M-negative phenotypes. Spectra of M-fluorescence were detected in all 10 Ea (aAAMM) and 19 Ea-derived hybrids (aAFMm), three of four Ef-derived hybrids (fFAMm) and one 'atypical' Ef (fFFMm) among 13 Ef earthworms. Among progeny of 'atypical' M-positive Ef (fFFMm) reappeared 'typical' M-negative Ef (fFFmm), confirming such hypothesis. Alternatively, the M-fluorescence might be dependent on unknown gene products of vertically-transmitted Ea-specific symbiotic bacteria sexually transferred to the Ef partner. Hypotheses of intrinsic and external origin of M-fluorescence might complement each other. The presence/absence of M-fluorophore does not correspond with body pigmentation patterns; Ef-characteristic banding appeared in posterior parts of hybrids body. In conclusion, Ea/Ef hybridization may serve for further studies on bi-directional gene flow

Dynamics of trending topics between social media, news, and scientific literature

Information is disseminating more rapidly in today\u27s world than ever before in history. Every now and then, topics simultaneously gain massive attention in social media, dominate news headlines, and attract interest from researchers around the globe. While individual domains and networks are studied extensively, one question remains less addressed so far: How does information spread across different channels, considering dynamics between social media, news and, scientific literature? In this paper, we aim to identify frequent patterns in the dissemination of information over multiple channels. Based on an adapted pattern mining algorithm for multivariate time series, we provide strong indications for the existence of distinctive information diffusion effects between social media, news and scientific literature. We find that when all information channels simultaneously cover a certain topic, the preceding period is characterized either by a sole growth of social media coverage or a simultaneous growth of social media and news coverage

Comparing the content of lipids derived from the eye lenses of various species

The lipid content in the eye lens was analyzed and compared among various species in this study. The eye lens lipids of the following species were investigated: cow, horse, duck, and freshwater trout. Additionally, the lipids derived from cataractous bovine lens and from cataractous human eye lens lipoprotein complexes were analyzed. The following lipid classes were detected in clear lenses: cholesterol, sphingomyelin, phosphatidylcholine, phosphatidyletanolamine, and phosphatidylserine. In cataractous bovine lens and in lipoprotein complexes from human nuclear cataract, phosphatidyloinositol and phosphatidyloglycerol were detected. Cholesterol and sphingomyelin, essential for hypothetical formation of cholesterol-rich domains, were the most abundant lipids in the lenses of all investigated species. These two components of eye lens lipid fraction were analyzed quantitatively using thin layer chromatography and spectrophotometric assay; the other lipids were identified qualitatively using thin layer chromatography. (Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 3, pp. 425–430

Activity of superoxide dismutase obtained from senile cataract lens : effect of diabetes mellitus

The activity of Cu,Zn superoxide dismutase in the fluid obtained from eye lens capsules after cataract surgery was investigated in samples obtained from patients with senile cataract and with senile cataract combined with diabetes mellitus. Two parameters were measured and compared: the frequency of occurrence of detected superoxide dismutase activity and the relative activity of the enzyme in samples derived from senile cataract patients versus those from the patiens affected additionally by diabetes mellitus. It was confirmed that the decrease of superoxide dismutase activity during cataract was additionally promoted by diabetes mellitus

L'imaginaire québécois en Europe : l'espace dialogique de la diplomatie culturelle

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.[À l'origine dans / Was originally part of : Thèses et mémoires - FAS - Département de littérature comparée

The existence of fertile hybrids of closely related model earthworm species, Eisenia andrei and E. fetida

Lumbricid earthworms Eisenia andrei (Ea) and E. fetida (Ef) are simultaneous hermaphrodites with reciprocal insemination capable of self-fertilization while the existence of hybridization of these two species was still debatable. During the present investigation fertile hybrids of Ea and Ef were detected. Virgin specimens of Ea and Ef were laboratory crossed (Ea+Ef) and their progeny was doubly identified. 1 -identified by species-specific maternally derived haploid mitochondrial DNA sequences of the COI gene being either 'a' for worms hatched from Ea ova or 'f' for worms hatched from Ef ova. 2 -identified by the diploid maternal/paternal nuclear DNA sequences of 28s rRNA gene being either 'AA' for Ea, 'FF' for Ef, or AF/FA for their hybrids derived either from the 'aA' or 'fF' ova, respectively. Among offspring of Ea+Ef pairs in F1 generation there were mainly aAA and fFF earthworms resulted from the facilitated self-fertilization and some aAF hybrids from aA ova but none fFA hybrids from fF ova. In F2 generation resulting from aAF hybrids mated with aAA a new generations of aAA and aAF hybrids were noticed, while aAF hybrids mated with fFF gave fFF and both aAF and fFA hybrids. Hybrids intercrossed together produced plenty of cocoons but no hatchlings independently whether aAF+aAF or aAF+fFA were mated. These results indicated that Ea and Ef species, easy to maintain in laboratory and commonly used as convenient models in biomedicine and ecotoxicology, may also serve in studies on molecular basis of interspecific barriers and mechanisms of introgression and speciation. Hypothetically, their asymmetrical hybridization can be modified by some external factors

Platelets augment respiratory burst in neutrophils activated by selected species of gram-positive or gram-negative bacteria.

Neutrophils and platelets circulate in blood system and play important physiological roles as part of immunological system. Neutrophils are the first line of host defense against various intruders, and platelets are satellite cells cooperating with other components of defense system. Recent studies report about the cooperation among these types of cells. We analyzed the effect of platelets on oxygen burst in neutrophils triggered by Staphylococcus aureus and Escherichia coli bacteria in vitro. The effect of platelets on oxygen burst in neutrophils was measured by luminol enhanced chemiluminescence. Opsonized and non-opsonized bacteria were used as activators. Activation of neutrophils with live non-opsonized and opsonized bacteria in the presence of platelets increased the oxygen burst as compared to the same system without platelets. The gram-positive bacteria (Staphylococcus aureus) were causing higher activation than gram-negative bacteria (Escherichia coli). This work demonstrate that platelets potentate the response of neutrophils augmenting their respiratory burst in vitro when triggered by bacteria

Selected risk factors for coronary heart disease in male scholars from the major South African population groups

A num.ber of risk factors for coronary heart disease (CHD) in 7 groups of South African male scholars aged between 15 and 20 years were surveyed. Selection of the groups was based on socioeconomic status and comprised urban and rural blacks, Indians of higher and lower socio-economic status, coloureds of higher and lower socio-economic status, and middle-class whites. Both Indian groups, both coloured groups and the whites had a much greater prevalence and severity of CHD risk factors than the two black groups. This held for total cholesterol, low-density lipoprotein cholesterol (LDLC), high-density lipoprotein cholesterol (HDLC), the HDLC/LDLC ratio, apolipoprotein B, apolipoprotein A-I, insulin, fibrinogen and mass. One exception was lipoprotein a, levels of which were higher in both black groups. In general the CHD risk factor profile was worse in the higher socio-economic groups, and it also tended to be worse in urban than in rural blacks. These findings stress the need to reduce CHD risk factors in our developed populations and to prevent their emergence in our developing peoples