Patterns of MADS-box gene expression mark flower-type development in Gerbera hybrida (Asteraceae)

Background  

The inflorescence of the cut-flower crop Gerbera hybrida (Asteraceae) consists of two principal flower types, ray and disc, which form a tightly packed head, or capitulum. Despite great interest in plant morphological evolution and the tractability of the gerbera system, very little is known regarding genetic mechanisms involved in flower type specification. Here, we provide comparative staging of ray and disc flower development and microarray screening for differentially expressed genes, accomplished via microdissection of hundreds of coordinately developing flower primordia.     

Molecular phylogenetics of Maxillaria and related genera (Orchidaceae: Cymbidieae) based on combined molecular data sets

The orchid genus Maxillaria is one of the largest and most common of neotropical orchid genera, but its current generic boundaries and relationships have long been regarded as artificial. Phylogenetic relationships within subtribe Maxillariinae sensu Dressler (1993) with emphasis on Maxillaria s.l. were inferred using parsimony analyses of individual and combined DNA sequence data. We analyzed a combined matrix of nrITS DNA, the plastid matK gene and flanking trnK intron, and the plastid atpB-rbcL intergenic spacer for 619 individuals representing ca. 354 species. The plastid rpoC1 gene (ca. 2600 bp) was sequenced for 84 selected species and combined in a more limited analysis with the other data sets to provide greater resolution. In a well-resolved, supported consensus, most clades were present in more than one individual analysis. All the currently recognized minor genera of "core" Maxillariinae (Anthosiphon, Chrysocycnis, Cryptocentrum, Cyrtidiorchis, Mormolyca, Pityphyllum, and Trigonidium) are embedded within a polyphyletic Maxillaria s.l. Our results support the recognition of a more restricted Maxillaria, of some previously published segregate genera (Brasiliorchis, Camaridium, Christensonella, Heterotaxis, Ornithidium, Sauvetrea), and of several novel clades at the generic level. These revised monophyletic generic concepts should minimize further nomenclatural changes, encourage monographic studies, and facilitate more focused analyses of character evolution within Maxillariinae.     

The eleventh reported case of Mulvihill-Smith syndrome in the literature

Background

The Mulvihill-Smith Syndrome was first recognized in 1975. After the recognition of the Mulvihill-Smith Syndrome, ten cases have been described.

Case presentation

This article describes the eleventh case of this syndrome in a male patient, 24 years-old with short stature and microcephaly with mild cognitive impairment, deafness and allergic conjunctivitis. The patient was hospitalized several times for repeated infections, and the presence of multiple melanocytic nevi on his skin was noticed.

Conclusions

Based on the entire set of signs and symptoms presented in our study, it was diagnosed the patient with Mulvihill-Smith Syndrome.     

Risk-sensitive resource defense in a territorial reef fish

As coral reefs are home to dense aggregations of a variety of species, aggressive territoriality is often a critical component of individual behavior. Identification and assessment of the risk posed by intruders is crucial to defending a territory, and fishes on coral reefs have been found to attend to body shape, body size, and coloration when responding to intruders. We examined the extent to which dusky damselfish (Stegastes adustus) discriminate among distinct categories of intruders by measuring the distance at which a fish attacks an intruder and the relative intensity and frequency of those attacks. We found that S. adustus discriminated among perceived threats, attacking conspecifics more intensely and more often than egg-predators and herbivores, and showing a trend of attacking those groups more often than invertebrate-feeders, which do not compete with damselfish for resources. Furthermore, territory holders attacked initial-phase wrasses from a farther distance than terminal-phase wrasses, suggesting that they can discriminate among classes of individuals within a species other than their own. Dusky damselfish thus exhibit the ability to make fine distinctions among intruders in a diverse ecosystem.     

Generation of “LYmph Node Derived Antibody Libraries” (LYNDAL) for selecting fully human antibody fragments with therapeutic potential

The development of efficient strategies for generating fully human monoclonal antibodies with unique functional properties that are exploitable for tailored therapeutic interventions remains a major challenge in the antibody technology field. Here, we present a methodology for recovering such antibodies from antigen-encountered human B cell repertoires. As the source for variable antibody genes, we cloned immunoglobulin G (IgG)-derived B cell repertoires from lymph nodes of 20 individuals undergoing surgery for head and neck cancer. Sequence analysis of unselected “LYmph Node Derived Antibody Libraries” (LYNDAL) revealed a naturally occurring distribution pattern of rearranged antibody sequences, representing all known variable gene families and most functional germline sequences. To demonstrate the feasibility for selecting antibodies with therapeutic potential from these repertoires, seven LYNDAL from donors with high serum titers against herpes simplex virus (HSV) were panned on recombinant glycoprotein B of HSV-1. Screening for specific binders delivered 34 single-chain variable fragments (scFvs) with unique sequences. Sequence analysis revealed extensive somatic hypermutation of enriched clones as a result of affinity maturation. Binding of scFvs to common glycoprotein B variants from HSV-1 and HSV-2 strains was highly specific, and the majority of analyzed antibody fragments bound to the target antigen with nanomolar affinity. From eight scFvs with HSV-neutralizing capacity in vitro, the most potent antibody neutralized 50% HSV-2 at 4.5 nM as a dimeric (scFv)₂. We anticipate our approach to be useful for recovering fully human antibodies with therapeutic potential.     

Towards protecting the Great Barrier Reef from land‐based pollution

The Great Barrier Reef (GBR) is an iconic coral reef system extending over 2000 km along the north‐east coast of Australia. Global recognition of its Outstanding Universal Value resulted in the listing of the 348 000 km² GBR World Heritage Area (WHA) by UNESCO in 1981. Despite various levels of national and international protection, the condition of GBR ecosystems has deteriorated over the past decades, with land‐based pollution from the adjacent catchments being a major and ongoing cause for this decline. To reduce land‐based pollution, the Australian and Queensland Governments have implemented a range of policy initiatives since 2003. Here, we evaluate the effectiveness of existing initiatives to reduce discharge of land‐based pollutants into the waters of the GBR. We conclude that recent efforts in the GBR catchments to reduce land‐based pollution are unlikely to be sufficient to protect the GBR ecosystems from declining water quality within the aspired time frames. To support management decisions for desired ecological outcomes for the GBR WHA, we identify potential improvements to current policies and incentives, as well as potential changes to current agricultural land use, based on overseas experiences and Australia's unique potential. The experience in the GBR may provide useful guidance for the management of other marine ecosystems, as reducing land‐based pollution by better managing agricultural sources is a challenge for coastal communities around the world.     

Brugia pahangi: inhibition of protein synthesis

The effects of inhibitors of protein synthesis and electron transport on the incorporation of [14C]leucine and [35S]methionine into protein by the filarial worm Brugia pahangi have been investigated. Cycloheximide inhibits the accumulation of both [14C]leucine and [35S]methionine by the worms and their incorporation into protein. In addition, inhibitors of electron transport and some anti-parasitic compounds also significantly inhibit filarial protein synthesis. Antimycin A and cyanide inhibit [14C]leucine incorporation into protein 63 and 72%, respectively, without affecting either motility or lactate production. Interestingly, the anti-malarial compounds chloroquine and quinacrine also significantly inhibit both accumulation and incorporation of [14C]leucine by B. pahangi. In addition, fluorographs of sodium dodecyl sulfate-polyacrylamide gels of homogenates from filariids incubated in [35S]methionine and cycloheximide with and without chloramphenicol indicate that there is a discrete population of proteins, possibly mitochondrial in origin, that are synthesized in the presence of cycloheximide and are not inhibited by chloramphenicol.