Life-history traits of the marbled electric ray,Torpedo marmorata Risso, 1810, from the Greek Seas,north-eastern Mediterranean Sea

Environmental Biology of Fishes - This work presents new information on the morphological aspects, reproductive biology and diet of the marbled electric ray Torpedo marmorata Risso 1810, in the...     

The diverse dietary profiles of MIS 3 cave bears from the Romanian Carpathians: insights from stable isotope (δ13C and δ15N) analysis

Late Pleistocene European cave bears (Ursus spelaeus ) have been considered to be largely vegetarian, although stable isotope data (δ¹³C and δ¹⁵N values) from the Romanian Carpathians has suggested considerable dietary variation. Here we evaluate previous and additional adult cave bear isotopic data from four Marine Isotope Stage 3 (MIS 3) sites in the Carpathians. Pe?tera Ur?ilor (N  =  35), Pe?tera Cioclovina (N  =  32), Pe?tera Muierilor (N  =  8), and Pe?tera cu Oase (N  =  72) provide both a dichotomy between samples suggesting vegetarian diets (from Cioclovina and Muierilor) and more omnivorous diets (from Ur?ilor and Oase), and considerable isotopic variation within samples from each site. While an inference of a strictly vegetarian diet may apply to groups that lived in ecosystems which restricted the available animal protein for these large ursids, the within and between sample isotopic variation among the Carpathian cave bears indicates considerable flexibility in their sources of protein and hence in their dietary regimes. In addition, developmental assessment of Cioclovina isotopic profiles (neonates, juveniles, sub‐adults and adults) provides patterns of transfer of stable isotope signatures throughout immature life for both δ¹³C and δ¹⁵N (increase and decrease, respectively), whereas those from Ur?ilor show little developmental shift.     

Virus-induced gene silencing as a tool for functional genomics in a legume species

Virus-induced gene silencing (VIGS) is an attractive reverse-genetics tool for studies of gene function. However, efficient VIGS has only been accomplished in a few plant species. In order to extend the application of VIGS, we examined whether a VIGS vector based on Pea early browning virus (PEBV) would produce recognizable phenotypes in Pisum sativum. A plasmid vector of PEBV was modified to allow agro-inoculation and insertion of heterologous sequences. cDNA fragments of the P. sativum phytoene desaturase (PDS), LEAFY (LFY) and KORRIGAN1 (KOR1) homologues were inserted into the PEBV RNA2 vector, replacing the genes required for nematode transmission. Pisum sativum inoculated with PEBV carrying a fragment of PsPDS developed characteristic photo-bleached leaves and this phenotype was associated with a significant reduction in PsPDS mRNA. The P. sativum homologue of LFY is known as UNIFOLIATA (UNI). Plants inoculated with PEBV carrying a fragment of UNI developed distorted flowers and leaves with modified architecture, which are also observed in UNI-mutants. In Arabidopsis thaliana, the KOR1-mutant is characterized by an extreme dwarf phenotype. Pisum sativum plants inoculated with PEBV carrying a fragment of PsKOR1 displayed a significant reduction in height and inhibition of root growth. The PEBV VIGS vector did not affect the ability of P. sativum to flower, set seeds, and form nodules characteristic of symbiosis with rhizobium. These results suggest that the PEBV vector can be applied to functional genomics in a legume species to study genes involved in a wide range of biological processes.     

Spread and potential host range of the invasive oak lace bug [Corythucha arcuata (Say, 1832) – Heteroptera: Tingidae] in Eurasia

1. The North American oak lace bug feeds on leaves of ‘white oaks” in its native range. In Europe, it was first discovered in northern Italy in 2000. In recent years, it has subsequently spread rapidly and population outbreaks have been observed in several European countries. In the present study, we summarize the steps of its expansion.
2. To predict its potential host range, we checked 48 oak species in 20 sentinel gardens in seven countries between 2013 and 2018.
3. In total, 27 oak species were recorded as suitable hosts; 13 of them are globally new ones, 23 out of the 29 in section Quercus (～ white oaks, an intrageneric taxonomic unit within genus Quercus), including Asian oaks, native to Japan, Korea and China, and four out of five in section Cerris (another intrageneric unit of the same genus), were accepted as hosts. None of the species in section Lobatae (red oaks) or in the Ilex group was accepted.
4. Host records were also collected in forest stands of 10 countries. We found 11 oak species that were infested. Outbreak populations were most commonly found on Quercus robur, Quercus frainetto, Quercus petraea and Quercus cerris, comprising widespread and outstandingly important oaks species in Europe.
5. Based on our findings, we conclude that suitable hosts for oak lace bug are present in most of Europe and Asia. This means that a lack of hosts will likely not restrict further range expansion.