Postcranial skeleton of Goodwin's brush-tailed mouse (Calomyscus elburzensis Goodwin, 1939) (Rodentia: Calomyscidae): Shape, size, function, and locomotor adaptation.

Goodwin's brush-tailed mouse (Calomyscus elburzensis Goodwin, 1939) is a poorly known small rodent that occupies rocky habitats in Iran, Turkmenistan, Afghanistan, Pakistan, Azerbaijan, and Syria. Herein, a detailed description of the shape, size, and function of the postcranial skeleton of this species is presented for the first time. Trapping was carried out in eastern Iran between the years 2013 and 2015. Skeletal parts of 24 adult male specimens were removed using the papain digestion protocol, and several postcranial morphological characteristics and measurements were examined. We attempted to achieve a morpho-functional characterization of Goodwin's brush-tailed mouse and to match morphological specializations with previous information on the ecology, behavior, and phylogenetic inferences of this rodent. Goodwin's brush-tailed mouse has extended transverse processes and long zygapophyses in the first five caudal vertebrae along with a good innervation of the caudal vertebrae, which has resulted in a well-developed basal musculature of the tail. It has extended forelimb, long ilium, and short post-acetabular part of the innominate bone, loose hip joint with high degree of lateral movement of the hindlimb, and long distal elements of the hindlimb. These features have resulted in fast terrestrial movements in open microhabitats, including climbing and jumping. Although superficial scratching of the ground is observed, the species is incapable of digging burrows. Evaluation of postcranial morphological characteristics and character states further indicated the basal radiation of the genus Calomyscus among other Muroidea. Findings constitute a source of information for morpho-functional and phylogenetic comparisons between Calomyscidae and other mouse-like muroids.

Ecological niche modeling of genetic lineages of the great gerbil, Rhombomys opimus (Rodentia: Gerbillinae).

Great gerbil (Rhombomys opimus Lichtenstein, 1823) is distributed in Central Asia and some parts of the Middle East. It is widely found in central and northeast parts of Iran with two distinct genetic lineages: R. o. sodalis in the northern slopes of the Elburz Mountains and R. o. sargadensis in the southern slopes. This large rodent acts as the main host of natural focal diseases. No study has surveyed the ecological niche of the lineages and how their distribution might be influenced by different climatic variables. To examine the distribution patterns of this murid rodent, we aimed to determine the habitat preferences and effects of environmental variables on the ecological niche. Using a species distribution approach for modeling of regional niche specialization, suitable habitats predicted for R. o. sodalis were mainly located in Golestan province in northern Iran, along the northern slope of Elburz, while R. o. sargadensis, showed great potential distribution along the southern slope of Elburz and around the Kavir Desert and the Lut Desert. Despite the widest potential distribution of R. o. sargadensis from northeast to northwest and through Central Iran, the geographic range of R. o. sodalis was smaller and mostly confined to Golestan province. The results support the presence of the two genetic lineages of Rhombomys in Iran and confirm that there is no significant niche overlap between the two subspecies. Furthermore, it provided several perspectives for future taxonomic studies and prevention hygiene programs for public health.

Annotated checklist of fleas (Insecta: Siphonaptera) and lice (Insecta: Anoplura) associated with rodents in Iran, with new reports of fleas and lice.

BACKGROUND & OBJECTIVES: Rodent species reported from Iran are subject of several studies, but the fauna called ectoparasite, infesting the rodents, along with their epidemic effects, are poorly known. In this study, ectoparasitic insect fauna of rodents found across the Iran were studied, to generate an annotated checklist of fleas and lice species. METHODS: Several field expeditions focused on different habitats of northeastern Iran were conducted between January 2017 and May 2018. Rodent trapping was carried out using custom-made mesh live traps and "Faragir" live traps baited mainly with scorched sunflower and gourd seeds. The trapped rodents were examined for ectoparasites on their body, and then released at their trapping point. The rodents and ectoparasite species were identified based on available keys. RESULTS: A total of 217 rodents belonging to 16 species of the families Calomyscidae, Cricetidae, Dipodidae, Mu- ridae and Sciuridae were captured. Five species of each fleas and lice were collected from the body of the trapped rodents. Three flea species, Ctenophthalmus pseudagyrtes, Nosopsyllus iranus and Xenopsylla buxtoni; and two louse species, Polyplax gerbilli and P. spinulosa, were recorded for the first time. INTERPRETATION & CONCLUSION: The study generated an annotated checklist of 79 species of fleas and 8 species of lice harboured by different species of rodents distributed in Iran which would be helpful in different taxonomic studies such as parasite-host coevolution, and also sanitation and health monitoring programs.

Tooth Morphogenesis and FGF4 Expression During Development of Molar Tooth in Three Muroid Rodents: Calomyscus elburzensis (Calomyscidae), Mesocricetus auratus (Cricetidae) and Mus musculus (Muridae).

To date, no studies have examined the tooth formation during developmental stages of brush-tailed mice (Calomyscidae) and true hamsters (Cricetidae). Herein, we compared the timing of tooth morphogenesis and FGF4 expression pattern during development of the first lower molar in Goodwin's brush-tailed mouse, Calomyscus elburzensis with two other muroid rodents; the house mouse, Mus musculus (Muridae), model organism for tooth morphogenesis, and the golden hamster, Mesocricetus auratus which shares great similarities in cusp pattern with brush-tailed mice. All three species were bred in captivity and developing embryos were isolated at different embryonic days (E). Histological evaluation of lower molars was performed and spatiotemporal pattern of FGF4 expression was determined by immunohistochemistry. Results indicated that morphogenesis of the tooth cusps starts at the beginning of the cap stage of the first lower molar (E14 in house mouse, about E11.5 in golden hamster and E22 in Goodwin's brush-tailed mouse). During the cap to bell stage (E15 in house mouse, E12 in golden hamster and at about E24 in Goodwin's brush-tailed mouse), a decrease in the expression of FGF4 was observed in the mesenchyme, except for the cusp tips. According to our observations, the developmental process of the first lower molar formation in Goodwin's brush-tailed mouse began much later as compared with the other two species. Despite the differences in the temporal pattern of molar development between these three members of the same superfamily (Muroidea), the correlation in the expression of FGF4 with specific stages of tooth morphogenesis supported its regulatory function. Anat Rec, 300:2138-2149, 2017. © 2017 Wiley Periodicals, Inc.