Reproductive biology of the South American cycad Zamia boliviana,involving brood-site pollination

Brood-site pollination mutualisms represent extreme levels of reciprocal specialization between plants and insects. Several studies have revealed intimate associations between cycads and their insect pollinators across different continents. However, the reproductive biology of South American cycads is still poorly understood, with limited empirical data available. Here, we investigated the plant–pollinator interactions of Zamia boliviana (Cycadales, Zamiaceae), which is distributed on savanna patches in Brazil and Bolivia. Our aim was to examine reproductive biology (strobili development and their visitors) to identify potential pollinators from the perspective of dioecy and expectations of obligatory mutualism. We monitored reproductive cohorts and registered the strobiliʼs visitors. We classified the visitorsʼ activities and described the behavior of the most active and recurring ones in both reproductive structures to ascertain the potential pollinators and their relationship with the Z. boliviana. In situ experiments were used to demonstrate efficacy in seed production. Although other insects visit the strobili, only one Coleoptera (Erotylidae: Pharaxonotha) was present seasonally. Pharaxonotha cerradensis was the single species capable of transporting pollen and developing a life cycle associated with polleniferous strobili, while concomitantly visiting ovuliferous strobili. Experimental tests associated with observational evidence in the cycad indicated brood-site pollination mutualism with the Erotylidae beetle, a potential pollinator of Z. boliviana. Our investigation confirmed a new case of obligatory mutualism between cycads and P. cerradensis in the New World. Future research on Zamia from South America should address pollination systems of this genus to better understand the ecology and evolution of plant–pollinator interactions.     

Synthetic polymers and their potential as genetic materials

DNA and RNA are the only known natural genetic materials. Systematic modification of each of their chemical building blocks (nucleobase, sugar, and phosphate) has enabled the study of the key properties that make those nucleic acids genetic materials. All three moieties contribute to replication and, significantly, all three moieties can be replaced by synthetic analogs without loss of function. Synthetic nucleic acid polymers capable of storing and propagating information not only expand the central dogma, but also highlight that DNA and RNA are not unique chemical solutions for genetic information storage. By considering replication as a question of information transfer, we propose that any polymer that can be replicated could serve as a genetic material. Editor's suggested further reading in BioEssays Xenobiology: A new form of life as the ultimate biosafety tool Abstract     

The potential role of variations in juvenile hip geometry on the development of Legg-Calvé-Perthes disease: a biomechanical investigation

Legg-Calvé-Perthes disease (LCP) is one of the most poorly understood diseases in paediatric orthopaedics. One common trait of LCP is the marked morphological difference between healthy and pathological hips, early deviations of which (i.e. prior to disease onset) have been suggested to lead to the overload and collapse of the epiphysis. Here, the impact of common variations in geometry is investigated with a finite element model of a juvenile femur under single leg standing and landing. Here, the impact of typical variations in geometry is investigated with a finite element model of a juvenile femur under single leg standing and landing. The variations appear to have only a limited effect on the stress distribution in the femoral epiphysis even during high impact activities. This suggests that, for this individual at least, they would be unlikely to cause epiphyseal overload and collapse, even in the presence of a skeletally immature epiphysis.     

Caprine arthritis-encephalitis virus (CAEV) detection in semen of endangered goat breeds by nested polymerase chain reaction

Semen and peripheral blood mononuclear cells (PBMCs) samples of four naturally infected, four experimentally infected (endangered breeds) and four non-infected bucks (endangered breeds) were evaluated for the presence of CAEV proviral-DNA by nested polymerase chain reaction (n-PCR). Three out of the eight PBMC samples from infected bucks were positive for CAEV-DNA and four out of the eight semen samples were positive for CAEV proviral-DNA. This is the first report describing the presence of CAEV proviral-DNA in semen from seropositive Anglo-Nubian, Moxotó and Canindé bucks, providing useful information towards the design of efficient methods to prevent CAEV dissemination in the endangered goat livestock genetic resources in Brazil.     

Profile of the Caprine arthritis-encephalitis virus (CAEV) in blood, semen from bucks naturally and experimentally infected in the semi-arid region of Brazil

The aim of this study was to report the chronology of Caprine arthritis-encephalitis virus elimination and compare the blood and semen viral profiles of animals naturally and experimentally infected by SRLV raised in the semi-arid region of Brazil. The experiment was carried out at the Brazilian Center for Goat Research (Embrapa). Nine bucks were selected, four naturally infected by CAEV and five animals proven negative that were inoculated with the goat lentivirus (CAEV-Cork strain). Every week the animals were submitted to semen collection using an artificial vagina. The blood was collected by puncturing the jugular vein with tubes containing EDTA, 7 days after inoculation (experimentally infected group) or at the start of the experiment (naturally infected group) and then at every 30 days. The genomic viral DNA was extracted from semen and blood and then Nested-PCR was applied. An agar gel microimmunodiffusion was performed to detect anti-CAEV antibodies. The results were described in percentage and analyzed by the Chi square test (P < 0.05). The presence of anti-CAEV antibodies was detected in the 16th week after inoculation that characterized the seroconversion from four of the five naturally infected goat bucks (80%). The fifth reproducer presented late seroconversion, totaling 32 weeks post-inoculation. A quantity was observed in the total of samples collected of 12.50 and 17.14% positive results in the blood and 10.98 and 11.25% positive results in the semen of the naturally and experimentally infected animals, respectively, and there was no statistical difference. No statistically significant differences were observed regarding the presence of proviral DNA in the blood and semen of the naturally and experimentally infected animals. A viral elimination pattern was not identified during the assessment period, but the presence of proviral DNA was shown at shorter intervals after the 18th week and the 22nd week, for the experimentally and naturally infected bucks, respectively. Therefore, recently infected goats in the period prior to seroconversion eliminated small ruminant lentivirus proviral DNA in the semen and are important sources of infection that should be considered in a control program of this lentivirus, and the Nested-PCR technique is a relevant tool to select virus-free ejaculates.     

Genetic diversity in natural populations of the endangered Neotropical orchid Telipogon peruvianus

Telipogon peruvianus is a highly restricted, sexually deceptive, Neotropical orchid species, endemic to the southern Peruvian Andes. It is only known from two localities, which are affected by anthropogenic disturbance. Here, we investigated whether the restricted distribution of T. peruvianus has led to low genetic diversity and inbreeding, thus threatening its survival. We isolated 10 novel microsatellite loci specific for T. peruvianus (and that also cross-amplified in related species) from two adjacent populations. We found that genetic diversity within populations was only moderately reduced, along with some evidence of inbreeding. We found low levels of genetic differentiation, suggesting connectivity by pollen/seed flow between the two populations. Effective population size was comparable to the real number of flowering individuals in the populations and we did not detect the signature of recent bottlenecks. Taken together, these results show that, despite increasing anthropogenic pressure, the two investigated populations of T. peruvianus still host valuable genetic diversity that should be preserved through appropriate conservation strategies.     

Seroprevalence of Neospora caninum in dairy goats from Bahia, Brazil

Sera from 384 dairy goats in nine herds from Bahia State, Brazil, were assayed for Neospora caninum antibodies using an indirect immunofluorescent antibody test (IFAT). Animals were selected and divided in groups by age and breed. Antibodies against N. caninum were found in 15% (58/384) of goats. Serum titers ranged from 1:100 to 1:3200. There was no significant difference between the age groups. Seroprevalence was higher in Alpine breed (24%) than in Saanen (14%) and Nubian (3%) breeds. The 58 N. caninum-positive sera were also tested for Toxoplasma gondii and 71% of the samples reacted solely to N. caninum. These results indicate that N. caninum infection is common in goat herds in Bahia.     

Gluttonous predators: how to estimate prey size when there are too many prey

Prey size is an important factor in food consumption. In studies of feeding ecology, prey items are usually measured individually using calipers or ocular micrometers. Among amphibians and reptiles, there are species that feed on large numbers of small prey items (e.g. ants, termites). This high intake makes it difficult to estimate prey size consumed by these animals. We addressed this problem by developing and evaluating a procedure for subsampling the stomach contents of such predators in order to estimate prey size. Specifically, we developed a protocol based on a bootstrap procedure to obtain a subsample with a precision error of at the most 5%, with a confidence level of at least 95%. This guideline should reduce the sampling effort and facilitate future studies on the feeding habits of amphibians and reptiles, and also provide a means of obtaining precise estimates of prey size.