Analysis of SINE Families B2, Dip, and Ves with Special Reference to Polyadenylation Signals and Transcription Terminators

Short Interspersed Elements (SINEs) are eukaryotic non-autonomous retrotransposons transcribed by RNA polymerase III (pol III). The 3′-terminus of many mammalian SINEs has a polyadenylation signal (AATAAA), pol III transcription terminator, and A-rich tail. The RNAs of such SINEs can be polyadenylated, which is unique for pol III transcripts. Here, B2 (mice and related rodents), Dip (jerboas), and Ves (vespertilionid bats) SINE families were thoroughly studied. They were divided into subfamilies reliably distinguished by relatively long indels. The age of SINE subfamilies can be estimated, which allows us to reconstruct their evolution. The youngest and most active variants of SINE subfamilies were given special attention. The shortest pol III transcription terminators are TCTTT (B2), TATTT (Ves and Dip), and the rarer TTTT. The last nucleotide of the terminator is often not transcribed; accordingly, the truncated terminator of its descendant becomes nonfunctional. The incidence of complete transcription of the TCTTT terminator is twice higher compared to TTTT and thus functional terminators are more likely preserved in daughter SINE copies. Young copies have long poly(A) tails; however, they gradually shorten in host generations. Unexpectedly, the tail shortening below A10 increases the incidence of terminator elongation by Ts thus restoring its efficiency. This process can be critical for the maintenance of SINE activity in the genome.

Energetics of whiskered bats in comparison to other bats of the family Vespertilionidae

ABSTRACT Bats inhabit a variety of climate types, ranging from tropical to temperate zones, and environmental differences may therefore affect the basal metabolic rate (BMR) of bats from different populations. In the present study, we provide novel data on the energetics of whiskered bats (Myotis mystacinus), which is the smallest species within Chiroptera measured to date. We investigated the thermoregulatory strategies of M. mystacinus close to the northern limits of this species’ distribution range and compared these data to other vespertilionid bats living in different climates. As mammals living in colder areas experience elevated thermoregulatory costs, often leading to an increase in BMR, we hypothesised that BMR of this northern population of whiskered bats would be higher than that of bats from climates with warm environmental temperatures. From a systematic literature search we obtained BMR estimates (N=47) from 24 species within Vespertilionidae. Our metabolic measurements of M. mystacinus in Norway (body mass of 4.4 g; BMR of 1.48 ml O2 g−1 h−1) were not different from other vespertilionid bats, based on the allometric equation obtained from the systematic literature search. Further, there was no effect of environmental temperature on BMR within Vespertilionidae. How these tiny bats adapt metabolically to high latitude living is thus still an open question. Bats do have a suite of physiological strategies used to cope with the varying climates which they inhabit, and one possible factor could be that instead of adjusting BMR they could express more torpor. This article has an associated First Person interview with the first author of the paper.

Quantitative evaluation of individual food intake by insectivorous vespertilionid bats (Chiroptera, Vespertilionidae)

Insectivorous bats provide important ecosystem services, especially by suppressing and controlling the insects’ biomass. To empirically quantify the amount of insects consumed by European vespertilionid bats per night, we estimated their ratio of dry mass of feces to mass of consumed insects. This study combines the results of feeding in captivity and the data obtained in field surveys; dry mass of feces was measured in both cases. In captivity, we analyzed the effect of species, age and sex of bats, species of insects consumed and the mass of food portion on the dry mass of feces. Using coefficients of the regression model, we estimated the amount of insects consumed by free-ranging bats based on dry mass of their feces. According to our estimates, on average, one individual of one of the largest European bat species, N. noctula, consumes 2.2 g (ranging from 0.5 to 8.5 g) of insects per one feeding night, while the smallest European bats of genus Pipistrellus consume 0.4 g (ranging from 0.1 to 1.3 g), further confirming the importance of insectivorous bats for ecosystem services. This publication offers the novel method for the estimation of insects’ biomass consumed by bats.

First detection of bat-borne Issyk-Kul virus in Europe

Bats have been gaining attention as potential reservoir hosts of numerous viruses pathogenic to animals and man. Issyk-Kul virus, a member of the family Nairoviridae, was first isolated in the 1970s from vespertilionid bats in Central Asia. Issyk-Kul virus has been described as human-pathogenic virus, causing febrile outbreaks in humans with headaches, myalgia and nausea. Here we describe the detection of a novel strain of Issyk-Kul virus from Eptesicus nilssonii in Germany. This finding indicates for the first time the prevalence of these zoonotic viruses in Europe.

First record of Pterygodermatites (Pterygodermatites) (Nematoda: Rictulariidae) in South America, with the description of a new species from the Atlantic Forest, southeast Brazil

Pterygodermatites are parasitic nematodes found in mammals worldwide, except Australia. There are 38 described species, which are found parasitizing bats, rodents, marsupials, carnivores and primates. We present taxonomic notes on nematodes collected from the digestive tract of bats from the Atlantic Forest in southeast Brazil. Two species previously recorded in marsupials in this region, Pterygodermatites (Paucipectines) elegans and Pterygodermatites (Paucipectines) jagerskioldi, were found parasitizing molossid and vespertilionid bats, respectively. A new species Pterygodermatites (Pterygodermatites) atlanticaensis found in phyllostomid bats is here described. Despite earlier work based on females, taxonomic work on this group of nematodes is usually based on male characters, such as position and number of caudal papillae, which is a problem because males are short-lived and not easily found. Here we also describe in detail female characters, such as position of the last pair of cuticular processes relative to the posterior end. This is the first record of P. (Pterygodermatites) in South America and the first record of P. (Paucipectines) jagerskioldi in bats.