How the evolution of air breathing shaped hippocampal function

To make maps from airborne odours requires dynamic respiratory patterns. I propose that this constraint explains the modulation of memory by nasal respiration in mammals, including murine rodents (e.g. laboratory mouse, laboratory rat) and humans. My prior theories of limbic system evolution offer a framework to understand why this occurs. The answer begins with the evolution of nasal respiration in Devonian lobe-finned fishes. This evolutionary innovation led to adaptive radiations in chemosensory systems, including the emergence of the vomeronasal system and a specialization of the main olfactory system for spatial orientation. As mammals continued to radiate into environments hostile to spatial olfaction (air, water), there was a loss of hippocampal structure and function in lineages that evolved sensory modalities adapted to these new environments. Hence the independent evolution of echolocation in bats and toothed whales was accompanied by a loss of hippocampal structure (whales) and an absence of hippocampal theta oscillations during navigation (bats). In conclusion, models of hippocampal function that are divorced from considerations of ecology and evolution fall short of explaining hippocampal diversity across mammals and even hippocampal function in humans. This article is part of the theme issue ‘Systems neuroscience through the lens of evolutionary theory’.

Identification of hepatozon spp. In the population of target rods of the Chernobyl radiation and ecological biosphere reserve

The ecosystems that have developed in the exclusion zone after the accident at the Chernobyl nuclear power plant in 1986 have a number of features. Parasites, as part of an ecosystem, can act as indicators of the processes taking place in it. Mouse rodents play an important role in the preservation and transmission of pathogens of some, including zoonotic, diseases in the wild. Therefore, the study of parasites in murine rodents, especially those transmitted transmissively, makes it possible to understand the characteristics of the distribution and the level of threat of their transmission to other susceptible animals, including agricultural, small domestic animals and humans. We carried out a study of blood smears taken from murine rodents for the presence of pathogens of transmissible parasitic diseases. According to the results of the studies, the pathogen Hepatozoon spp. Was detected for the first time in Ukraine. in the population of murine rodents. Creating an exclusion zone is one of the most obvious and long-lasting consequences of the Chernobyl Nuclear Power Plant (CNPS) accident. Because of 90-95% of this territory lacks systematic human activity and regime equal to the reserve. Ecosystems formed in the exclusion zone are affected a number of key factors as radioactive contamination, succession, wills and climate change. Spatial heterogeneity of density, radionuclide composition and physical chemical forms of precipitation are a characteristic feature of radioactive pollution in the Chernobyl Zone. Much of the aquatic and terrestrial ecosystems in the Chernobyl Zone as of 1986 was an artificial or semi-artificial systems that were under the regulatory control of man. The removal of regulatory control has led to the inclusion of natural influences mechanisms. That is, a significant part of ecosystems is in a state far from equilibrium, where the processes of succession are active. The testamentary effect is the result of a radical economic contraction activities and the creation of a strict security regime. Given this dynamics ecosystems in the Exclusion Zone has a unique character. Parasites are part of the ecosystem, so they can act as indicators of the processes occurring in it. Mouse-like rodents play an important role in the preservation of agents some infectious diseases in the wild. It is known that rodents are reservoirs hosts at least 60 zoonotic diseases, playing an important role in their transmission and distribution. Not the last role in it is played by features biology and way of life of these animals. Study of parasites in murine rodents, especially those that transmitted transmissively, will make it possible to understand the peculiarities of distribution and the level of threat of their transmission to other susceptible animals, including agricultural, small pets and humans. The object of our study was blood smears taken from murine rodents: Apodemus agrarius, Apodemus flavicollis, Myodes glareolus and Apodemus spp. Catching mice for further sampling conducted at 3 three landfills. Mouse-like rodents are significantly affected by pathogens of infectious diseases, including those transmitted through blood-sucking arthropods. Therefore, the study of the presence and prevalence of transmissible agents in murine rodents is important in order to prevent the disease in other species of animals or humans. The purpose of the study was to study the role of rodents Chornobyl Excusion Zone as a reservoir of blood-borne diseases. The study was conducted during 2020-2021. Blood smears from rodents Apodemus agrarius, Apodemus flavicollis, Myodes glareolus and Apodemus spp, which were selected during the expedition from three landfills and transferred to the Department of Pharmacology, Parasitology and Tropical Veterinary Medicine of NULES of Ukraine, where they conducted further research. Blood smears were stained by the method of Romanowski-Gimza, Leuko-Diff and examined under an immersion microscope system. A total of 117 blood smears were collected from 117 murine rodents from three landfills. According to the results of microscopic examination in blood smears revealed parasites, which morphologically we attributed to Hepatozoon spp. This agent was detected in Ukraine for the first time. Agents had an oval body shape with a large nucleus and were located in the cytoplasm of leukocytes (mostly neutrophils, rarely lymphocytes). In total, hepatozoan agents were detected in blood smears from 13 studied animals, which was 11.11%. And the invasion of Hepatozoon spp. was found in murine rodents of the first landfill, in 7 rodents. The smallest of the murine rodents of the second landfill was found only in blood smears from 2 animals. In addition to hepatozoons in murine rodents, we also found agents of other diseases, such as Babesia spp., Rickettsia spp., Borrelia spp. and Trypanosoma spp.

Cryptosporidium spp. in wild murids (Rodentia) from Corsica, France

Cryptosporidium spp. are worldwide protozoan parasites that can affect to a broad range of vertebrate hosts, including rodents. In the island of Corsica (France), there are no previous data about these protozoa infecting wild rodents. To estimate the distribution and occurrence, a total of 117 wild murine rodents of the species Rattus rattus (84), Mus musculus domesticus (21), Apodemus sylvaticus (11), and Rattus norvegicus (1) were captured in 24 different biotopes. Fecal samples were screened for Cryptosporidium spp. by nested PCR to amplify an 830 bp fragment of the 18S rRNA gene. As general occurrence, 15.4% of the rodents analyzed were positive for Cryptosporidium spp., being detected widely distributed along the island in R. rattus (17.6%) and M. m. domesticus (14.3%). Cryptosporidium viatorum, Cryptosporidium sp. rat genotype II, and Cryptosporidium sp. rat genotype III were successfully identified in R. rattus. The results herein reported provide the first data on Cryptosporidium spp. in wild murine species from a Mediterranean island and constitute the first report of the zoonotic species C. viatorum in R. rattus. Although a low occurrence of Cryptosporidium spp. in murids was obtained and only in one animal the zoonotic species C. viatorum was identified, our results highlight that wild murine rodents from Corsica could mediate in the maintenance and transmission of this protozoan to the environment and other hosts including humans and animals. Further studies are required to better understand the epidemiology of Cryptosporidium spp. in wild rodents from Corsica and their possible public health repercussions.

Spatial modeling of extinct Southeast Asian Hobbit Homo floresiensis habitat suitability based on its diet availability and climatic parameters as a proxy

The discovery of a new prehistoric species of the genus Homo remains a significant matter of intense interest. One of significant discovery recently is the Homo floresiensis, representing a small-bodied and small-brained hominin, excavated, and found in Liang Bua Cave in Flores Island, East Nusa Tenggara, Indonesia. This species height was only about 106 cm (3'6") and the weight was 30-40 kg (66-86 lbs). H. floresiensis was known consumed extant murine rodents as its diets as this was evidence found in Liang Bua Cave. Then this study aims to model the H. floresiensis suitable habitat using maximum entropy method and 2 extant murine rodents, Rattus exulans and R. rattus as a proxy. The results show that the most suitable habitats for H. floresiensis indicated by suitable habitat values close to 1 were concentrated in the central of Flores Island that was overlapped with mountainous areas with elevation ranging from 1500 to 2000 m. These suitable habitats were also overlapped with dense vegetation covers, volcanic rock, and Kiro rock formation. Climatic parameters that limit the distributions of H. floresiensis were annual mean temperature, isothermality, minimum temperature of coldest period, and precipitation seasonality. Parts of Flores Island with the low temperature below 20 0C were favorable for H. floresiensis while an increase in isothermality limits the H. floresiensis distributions

Diet of Long-eared Owl and Common Kestrel in an urban landscape (Ukraine)

In the present study we performed a comparative dietary analysis of two predatory birds, the Long-eared Owl (Asio otus) and the Common Kestrel (Falco tinnunculus) in the district of Lviv city. We found that the Long-eared Owl and the Common Kestrel are typical small mammal specialists within the urban ecosystem. Considering the abundance and biomass of prey, small mammals comprise 98.4% of the Long-eared Owl’s diet. The species composition of mammals coincides almost 50% in the food intake comparison of the two birds. It has been established that the main prey of both species is the Common Vole (Microtus arvalis). The diet of the Common Kestrel is more varied, compared to the Long-eared Owl, due to the consumption of different species of insects (families Gryllotalpidae, Tettigoniidae, Carabidae and Scarabaeidae), reptiles and birds. This result suggested that dietary plasticity of the Common Kestrel facilitate successful adaptation to the urban landscape. The Long-eared Owl is more narrowly specialized in feeding on murine rodents, which reduces the trophic competition between the two predatory birds and allows the coexistence of two predators in the urban ecosystem.

Organization of biological materials collection on study of the natural prototype of babesious infection

Ukraine's enzootic in accordance with natural focal diseases including babesiosis, makes the research undertaken relevant. Aim of the study: to determine the stages in organising the collection of biological materials in the study of the natural prototype of babesiosis. Materials and methods of research. Objects were murine rodents of Muridae family of genera Myodes, Microtus, Apodemus, Sylvaemus of natural habitats of forest-steppe zone of Ukraine, their ectoparasites-carriers of babesiosis - ticks of family Ixodidae. Collection, accumulation and registration of biological materials was carried out in the conditions of scientific expeditions. Regional geography of them concerned Volyn, Zhytomyr, Kyiv, Poltava, Sumy, Kharkiv, Chernihiv regions of Ukraine. Results. A total of 63 wild rodents were captured and used in the study. They were adult mice of both sexes, weighing 45-90 g, belonging to the Muridae family, genera Myodes, Microtus, Apodemus, Sylvaemus. Each group of animals gravitated to a specific geographical area of existence with appropriate attributes of flora and fauna. Collection and recording of those on rodent-feeding animals showed that Ixods differ according to phases of development, blood feeding, sex attributes and species affiliation. Conclusions. Nosological profile of babesiosis as a natural focal obligate-transmissible protozoan blood parasitosis determined methodology of epizootic assessment of area, natural prototype of disease, collection of biological material samples (BMS). BMS collection activities for babesiosis are seasonally dependent. Conducted researches should be focused on 3 links of epizootic or epidemic chain of babesiosis. Invasion by babesia ticks in optimal natural-climatic conditions of development, annual contact with animals led to formation of a latent focus of babesiosis

Tempo and Mode: Evidence on a Protracted Split From a Dense Fossil Record

Fossil records generally inform paleobiologists about extinct taxa and rates of evolution measured at the scale of millions of years. Good records that are densely sampled through time can reveal species level details such as longevity in local sections. Yet fossil data normally do not address details of lineage microevolution because the density through time of lineage sampling is insufficient to perceive patterns at a precision finer than 106 years in most cases. This study concerns details of a splitting event in the evolution of murine rodents, an event for which multiple fossil samples dated to a precision of 105 years fortuitously document the tempo and mode of origin of sister species, the stems of two extant tribes of mice. Evolution of early Murinae in the northern part of the biogeographically restricted Indian subcontinent between 11.6 and 10.5 Ma involved cladogenesis of two crown taxa, the extant tribes Murini and Arvicanthini. Large samples of fossil rodent teeth document their divergence from a common morphological pool. Definitive basal Murini and Arvicanthini at 10.5 Ma are similar in size and differ by subtle features of the dentition. Those features occur sporadically in the common pool of older fossil teeth at 11.2, 11.4, and 11.6 Ma as inconsistent polymorphisms. Interpreted as a single lineage in the 11.6–11.2 Ma interval, variability of this abundant murine incorporated the roots of the two crown tribes. The pattern through time suggests morphological stasis for several hundred thousand years prior to splitting. This special case informs us on one example of evolution and shows that the tempo of splitting evolution in some cases may be measured in hundreds of thousands of years, followed by stasis once daughter species have differentiated morphologically.

ZP4 Is Present in Murine Zona Pellucida and Is Not Responsible for the Specific Gamete Interaction

Mammalian eggs are surrounded by an extracellular matrix called the zona pellucida (ZP). This envelope participates in processes such as acrosome reaction induction, sperm binding, protection of the oviductal embryo, and may be involved in speciation. In eutherian mammals, this coat is formed of three or four glycoproteins (ZP1–ZP4). While Mus musculus has been used as a model to study the ZP for more than 35 years, surprisingly, it is the only eutherian species in which the ZP is formed of three glycoproteins Zp1, Zp2, and Zp3, Zp4 being a pseudogene. Zp4 was lost in the Mus lineage after it diverged from Rattus, although it is not known when precisely this loss occurred. In this work, the status of Zp4 in several murine rodents was tested by phylogenetic, molecular, and proteomic analyses. Additionally, assays of cross in vitro fertilization between three and four ZP rodents were performed to test the effect of the presence of Zp4 in murine ZP and its possible involvement in reproductive isolation. Our results showed that Zp4 pseudogenization is restricted to the subgenus Mus, which diverged around 6 MYA. Heterologous in vitro fertilization assays demonstrate that a ZP formed of four glycoproteins is not a barrier for the spermatozoa of species with a ZP formed of three glycoproteins. This study identifies the existence of several mouse species with four ZPs that can be considered suitable for use as an experimental animal model to understand the structural and functional roles of the four ZP proteins in other species, including human.