Historical biogeography and morphological differentiation ofStreptocephalus torvicornis (Waga) since the Würm III-glaciation

We argue that the Würm III glaciation eradicated possible European populations ofS. torvicornis, and that today, a reconquest of Europe takes place on two fronts.A western wave has reached the Pyrenees, an eastern one now occupies most of eastern and northern Europe. The western route probably started in the Maghreb, the eastern one in the Levant and the Ponto-Caspian. Animals in the west had to move north by crossing, at right angles, a series of east-west oriented river valleys and progressed slowly; animals in the east could move up river valleys extending north-east, and moved quickly. Italy was not occupied, becauseS.torvicornis is a warm stenotherm, and by the time the climate had warmed sufficiently for it to reach the southern shore of the mediterranean (ca 6000 BP), the gap with Italy was probably too large for a crossing. Cold-loving species (of the generaBranchipus, Chirocephalus) conversely, and could freely flow across the Central Mediterranean at low sea-levels (ca 12000 BP), and now occur in Italy (and the rest of Europe) as well as in Northern Africa.A prediction of our hypothesis is that the pioneer populations in Spain and Central Europe should have been isolated longest. Thisis tested and confirmed by their comparative morphology, and two subspecies,S. t. torvicornis andS. t. bucheti are reinstated.A gap across the Nile Valley where onlyS. rubricaudatus seems to occur, deserves further study.     

Gene transfer to inflorescence and flower meristems using ballistic micro-targeting

Direct gene transfer to floral meristems could contribute to cell-fate mapping, to the study of flower-specific genes and promoters, and to the production of transgenic gametes via the transformation of sporogenic tissues. Despite the wide potential of its applications, direct gene transfer to floral meristems has not been achieved so far because of the lack of suitable technology. We show in this paper that ballistic micro-targeting is the technique of choice for this purpose, and in this way, we were able to transfer genes efficiently into excised wheat immature spikes. Particle size was adjusted for optimal penetration into the L1 and L2 cell layers of the spikes with limited cell damage. Spikes at different developmental stages were shot either with a plasmid containing two genes involved in anthocyanin biosynthesis or with a plasmid bearing the uidA (-glucuronidase) gene. The transient expression of these marker genes was observed in the different developmental stages tested and in cells of both the L1 and the L2 layers. The transient expression of the uidA gene was significantly increased when the sucrose concentration in the culture medium was increased from 0.06 to 0.52 M. At the highest concentration, 100% of the targeted spikes expressed the uidA gene, with an average of 69 blue cells per spike. Twelve days after microtargeting, multicellular sectors showing transgene expression and containing up to 17 cells were found in 85% of the shot immature inflorescences. This indicated that targeted cells survived particle bombardment. Sectors were found in primordia of both vegetative and reproductive organs.     

The effects of low root-zone temperature stress on two soybean (Glycine max) genotypes when combined with Bradyrhizobium strains of varying geographic origin

In areas with short growing seasons, poor early vegetative growth of soybean (Glycine max [L.] Merr.) is often attributed to the restrictive effect of cool soil conditions on nodulation and N₂-fixation by this subtropical grain legume. However, there are few studies regarding potential genetic variability of soybean and Bradyrhizobium japonicum genotypes for nodulation at cool root-zone temperatures (RZT). Experiments were conducted to (1) test for a threshold temperature for low RZT inhibition of soybean nodulation and (2) ascertain whether this threshold temperature response depends mainly on the micro- or macrosymbiont. In experiment 1 soybean seedlings (Glycine max [L.] Merr. cv. Maple Arrow) were inoculated with 1 ml of a log phase culture of B. japonicum strain 532C, H8 or H15 (the latter two strains were isolated from cold soils of Hokkaido, northern Japan) and maintained at either 16, 17.5, 19 or 25°C RZT. In experiment 2 seedlings of cv. Maple Arrow and a cold-tolerant Evans isoline were combined with strain 532C and two Hokkaido strains (H5, H30) at both 19 and 25°C RZT. Results indicated that N₂-fixation at 44 days after inoculation was substantially reduced (30–40%) by RZT as high as 19°C, due to development of less nodule mass and to a delay in the onset of N₂-fixation and a small decrease in the number of nodules formed. However, the number of nodules formed was sharply reduced and the time required for the first appearance of nodules was significantly delayed below an RZT of 17.5°C. Differences between cultivars for nodulation and N accumulation were apparent at 25°C, but were abolished by growth at 19°C, indicating that, in spite of differences in growth potential between the cultivars under optimum RZT, both cultivars were equally limited by low RZT. Differences between B. japonicum strains were consistent across temperatures and were largely attributable to higher rates of specific nodule activity recorded for strain 532C, which seemed well adapted to low RZT. These results suggest that the host plant mediates the sensitivity of N₂-fixation under low RZT and that inoculation with B. japonicum strains from cold environments is unlikely to enhance soybean N₂-fixation under cool soil conditions.     

The FTO A/T Polymorphism and Elite Athletic Performance: A Study Involving Three Groups of European Athletes

Objective

The FTO A/T polymorphism (rs9939609) is a strong candidate to influence obesity-related traits. Elite athletes from many different sporting disciplines are characterized by low body fat. Therefore, the aim of this study was to assess whether athletic status is associated with the FTO A/T polymorphism.

Subjects and Methods

A large cohort of European Caucasians from Poland, Russia and Spain were tested to examine the association between FTO A/T polymorphism (rs9939609) and athletic status. A total of 551 athletes were divided by type of sport (endurance athletes, n = 266 vs. sprint/power athletes, n = 285) as well as by level of competition (elite-level vs. national-level). The control group consisted of 1,416 ethnically-matched, non-athletic participants, all Europeans. Multinomial logistic regression analyses were conducted to assess the association between FTO A/T genotypes and athletic status/competition level.

Results

There were no significantly greater/lesser odds of harbouring any type of genotype when comparing across athletic status (endurance athletes, sprint/power athletes or control participants). These effects were observed after controlling for sex and nationality. Furthermore, no significantly greater/lesser odds ratios were observed for any of the genotypes in respect to the level of competition (elite-level vs. national-level).

Conclusion

The FTO A/T polymorphism is not associated with elite athletic status in the largest group of elite athletes studied to date. Large collaborations and data sharing between researchers, as presented here, are strongly recommended to enhance the research in the field of exercise genomics.     

Chemical synthesis of terpenoids with participation of cyclizations plus rearrangements of carbocations: a current overview

Many terpenoids are biosynthesized after a cascade of cyclizations and rearrangements of carbocations mediated by terpenoid synthases, as exemplified in th     

Hi-C deconvolution of a textile dye–related microbiome reveals novel taxonomic landscapes and links phenotypic potential to individual genomes

International Microbiology - Microbial biodiversity is represented by a variety of genomic landscapes adapted to dissimilar environments on Earth. These genomic landscapes contain functional...