Model-assisted ideotyping reveals trait syndromes to adapt viticulture to a drier climate

Climate change is challenging the resilience of grapevine (Vitis), one of the most important crops worldwide. Adapting viticulture to a hotter and drier future will require a multifaceted approach including the breeding of more drought-tolerant genotypes. In this study, we focused on plant hydraulics as a multi-trait system that allows the plant to maintain hydraulic integrity and gas exchange rates longer under drought. We quantified a broad range of drought-related traits within and across Vitis species, created in silico libraries of trait combinations, and then identified drought tolerant trait syndromes. By modeling the maintenance of hydraulic integrity of current cultivars and the drought tolerant trait syndromes, we identified elite ideotypes that increased the amount of time they could experience drought without leaf hydraulic failure. Generally, elites exhibited a trait syndrome with lower stomatal conductance, earlier stomatal closure, and a larger hydraulic safety margin. We demonstrated that, when compared with current cultivars, elite ideotypes have the potential to decrease the risk of hydraulic failure across wine regions under future climate scenarios. This study reveals the syndrome of traits that can be leveraged to protect grapevine from experiencing hydraulic failure under drought and increase drought tolerance.

This article quantifies the diversity of hydraulic traits across grapevine genotypes and reveals the trait combinations that can help increase grapevine drought tolerance.     

Leishmania amazonensis: metabolic adaptations induced by resistance to an ABC transporter blocker

We compared growth rate, cell glucose turnover and expression of ATP-binding-cassette (ABC) transporters in Leishmania amazonensis (LTB0016; LTB) versus LTB(160) selected for resistance against the ABC transporter blocker glibenclamide. Additionally, we evaluated the influence of drug-resistance on Leishmania sensitivity against 2-mercaptoacetate and 2-deoxyglucose. Our data demonstrate that (1) LTB(160) and LTB constitutively express ABC transporters for neutral substrates, (2) glibenclamide resistance induces the expression of organic anion ABC transporters, members of the drug resistance associated transporters subfamily, (3) LTB(160) parasites use less glucose as energy substrate and exhibit a slower glucose uptake than LTB cells, and (4) LTB(160) parasites are less sensitive to 2-mercaptoacetate and 2-deoxyglucose than the glibenclamide-sensitive Leishmania LTB. Together these and previous results indicate that the metabolic adaptations expressed in drug-resistant LTB(160) differ from those described for mammalian drug resistant cells and constitute general mechanisms that underlie drug resistance in Leishmania and may be helpful for identifying alternative strategies to circumvent drug resistance in leishmaniasis.     

Terminal regions of mouse nebulin: sequence analysis and complementary localization with N-RAP

The regions of mouse nebulin extending from the ends of the super repeats to the C-terminus and N-terminus were cloned and sequenced. Comparison of the mouse sequence with the previously published human sequence shows that the terminal regions of nebulin are highly conserved. The four phosphorylation motifs and SH3 domain found at the C-terminus of mouse nebulin are identical to those found in human nebulin, with the exception of four conservative substitutions. The modules linking this C-terminal region to the super repeats have deletions relative to both fetal and adult human nebulins that correspond to integral numbers of modules, making the mouse C-terminal simple repeat region among the shortest observed to date. The N-terminal region and the C-terminal modules were expressed in Escherichia coli and used for antibody production. Immunofluorescent labeling of these regions of nebulin in isolated myofibrils demonstrates that they are located near the center of the sarcomere and near the Z-line, respectively. Immunogold labeling with antibodies raised against the N-terminal nebulin sequence localizes this region in the A-band near the tips of the thin filaments. Nebulin localization is complementary to that of N-RAP, another muscle-specific protein containing nebulin-like super repeats; nebulin is exclusively found in the sarcomeres, while N-RAP is confined to the terminal bundles of actin filaments at the myotendinous junction. Cell Motil. Cytoskeleton 3:211-222, 2000 Published 2000 Wiley-Liss, Inc.     

Discovery of an ebolavirus-like filovirus in europe

Filoviruses, amongst the most lethal of primate pathogens, have only been reported as natural infections in sub-Saharan Africa and the Philippines. Infections of bats with the ebolaviruses and marburgviruses do not appear to be associated with disease. Here we report identification in dead insectivorous bats of a genetically distinct filovirus, provisionally named Lloviu virus, after the site of detection, Cueva del Lloviu, in Spain.     

Comparing bird assemblages in large and small fragments of the Atlantic Forest hotspots

The Atlantic Forest (AF) is one of the five most threatened and megadiverse world hotspots. It is arguably the most devastated and highly threatened ecosystem on the planet. The vast scope of habitat loss and extreme fragmentation in the AF hotspots has left intact very few extensive and continuous forested fragments. We compared bird assemblages between small (<100 ha) and large (>6,000 ha) forest remnants, in one of the largest AF remnants in Argentina. We performed 84 point-counts of birds in four large fragments (LF) and 67 points in 25 small fragments (SF). We recorded 4,527 bird individuals belonging to 173 species; 2,632 belonging to 153 species in LF and 1,897 in 124 species in SF. Small fragments suffered a significant loss of bird richness, mainly forest dependent species, but the birds abundance did not decrease, due to an increase in abundance of forest independent and semi-dependent bird species (edge and non forest species) that benefit from forest fragmentation. The bird guilds of frugivores, undestory, terrestrial and midstory insectivores, nectarivores and raptors, and the endemic species of AF were area sensitive, decreasing significantly in richness and abundance in the SF. Terrestrial granivores were the only guild positively affected by forest fragmentation, containing mainly edge species, which forage in open areas or borders including crops. Our first observations on fragmentation effects on bird assemblages in the southernmost Argentinean Atlantic Forests did not validate the hypothesis on pre-adaptation to human disturbances in the bird communities of AF. On the contrary, we observed that forest dependent, endemic and several sensitive bird guilds were strongly affected by fragmentation, putting in evidence the vulnerability to the fragmentation process and the necessity to conserve large remnants to avoid reduction of the high biodiversity of AF birds.     

A newZornia species in the Flora of Cuba

A newZornia species from Cuba, the endemicZornia arenicola sp. nova, is described. It was found on moving sand dunes between the town of Guane and the village of Cortes (Pinar del Rio province).     

Genetic diversity of Trypanosoma cruzi parasites infecting dogs in southern Louisiana sheds light on parasite transmission cycles and serological diagnostic performance

BackgroundChagas disease is a neglected zoonosis of growing concern in the southern US, caused by the parasite Trypanosoma cruzi. We genotyped parasites in a large cohort of PCR positive dogs to shed light on parasite transmission cycles and assess potential relationships between parasite diversity and serological test performance.Methodology/principal findingsWe used a metabarcoding approach based on deep sequencing of T. cruzi mini-exon marker to assess parasite diversity. Phylogenetic analysis of 178 sequences from 40 dogs confirmed the presence of T. cruzi discrete typing unit (DTU) TcI and TcIV, as well as TcII, TcV and TcVI for the first time in US dogs. Infections with multiple DTUs occurred in 38% of the dogs. These data indicate a greater genetic diversity of T. cruzi than previously detected in the US. Comparison of T. cruzi sequence diversity indicated that highly similar T. cruzi strains from these DTUs circulate in hosts and vectors in Louisiana, indicating that they are involved in a shared T. cruzi parasite transmission cycle. However, TcIV and TcV were sampled more frequently in vectors, while TcII and TcVI were sampled more frequently in dogs.Conclusions/significanceThese observations point to ecological host-fitting being a dominant mechanism involved in the diversification of T. cruzi-host associations. Dogs with negative, discordant or confirmed positive T. cruzi serology harbored TcI parasites with different mini-exon sequences, which strongly supports the hypothesis that parasite genetic diversity is a key factor affecting serological test performance. Thus, the identification of conserved parasite antigens should be a high priority for the improvement of current serological tests.     

The Himalayas: Barrier and conduit for gene flow

The Himalayan mountain range is strategically located at the crossroads of the major cultural centers in Asia, the Middle East and Europe. Although previous Y‐chromosome studies indicate that the Himalayas served as a natural barrier for gene flow from the south to the Tibetan plateau, this region is believed to have played an important role as a corridor for human migrations between East and West Eurasia along the ancient Silk Road. To evaluate the effects of the Himalayan mountain range in shaping the maternal lineages of populations residing on either side of the cordillera, we analyzed mitochondrial DNA variation in 344 samples from three Nepalese collections (Newar, Kathmandu and Tamang) and a general population of Tibet. Our results revealed a predominantly East Asian‐specific component in Tibet and Tamang, whereas Newar and Kathmandu are both characterized by a combination of East and South Central Asian lineages. Interestingly, Newar and Kathmandu harbor several deep‐rooted Indian lineages, including M2, R5, and U2, whose coalescent times from this study (U2, >40 kya) and previous reports (M2 and R5, >50 kya) suggest that Nepal was inhabited during the initial peopling of South Central Asia. Comparisons with our previous Y‐chromosome data indicate sex‐biased migrations in Tamang and a founder effect and/or genetic drift in Tamang and Newar. Altogether, our results confirm that while the Himalayas acted as a geographic barrier for human movement from the Indian subcontinent to the Tibetan highland, it also served as a conduit for gene flow between Central and East Asia. Am J Phys Anthropol 151:169–182, 2013. © 2013 Wiley Periodicals, Inc.