Gerbil

Recent molecular studies in gerbils found multiple instances of discordance between molecular and morphological phylogenies. In this study, we ana- lyse the largest molecular data set to date of gerbils and their sister group the deomyines to estimate their phylogenetic relationships. Maximum-likeli- hood and Bayesian analyses were largely concordant, and both generally had high levels of node support. For gerbils, the results were generally concordant with previous molecular phylogenies based on allozymes, chromosomes, DNA/DNA hybridization and DNA sequences, and discordant with morphological phylogenies. None of the traditional gerbil tribes and subtribes were monophyletic. In addition, paraphyly was found in the genera Gerbillus, Gerbilliscus and Meriones as well as in five subgenera within Dipodillus, Gerbillurus and Meriones. Short branches separating taxa in small clusters within Dipodillus and Meriones suggest synonymy. Within deomyines, all genera and subgenera were monophyletic; however, two species groups within Acomys appear to contain synonymous taxa. We also find support for the discordance between molecular and morphological phylogenies in gerbils being partly due to convergent adaptations to arid environments, primarily in the suite of traits associated with inflation of the tympanic bul- lae. Relative bullar size does appear to be a desert adaptation and is correlated with aridity independent of phylogeny. Further, it varies more strongly along bioclimatic clines than between binary habitat classifications (desert versus mesic).

Sažetak Tokom eksperimentalnih biomedicinskih studija nerijetko se ukazuje potreba za upotrebom drugih pokusnih animalnih modela pored uobicajenih laboratorijskih životinja. Cincila, gerbil i kanadska lasica su zbog svojih specificnosti veoma korisni potencijalni pokusni modeli u biomedicinskim ispitivanjima. Cincila je nezamjenjiv animalni model kod istraživanja srednjeg uha. Gerbil je posebno aplikativan za istraživanja iz oblasti neuro-fiziologije. On obolijeva od epilepsije te je s razlogom eksperimentalna životinja od izbora za proucavanje ove vrste bolesti. Kanadska lasica je izuzetno poželjan animalni model u eksperimentalnoj hirurgiji i ima niz prednosti u odnosu na stahore i zamorce. Kljucne rijeci: Chinchilla lanigera, Merioines unguiculatus, Mustela vison, alternativne eksperimentalne životinje

Gerbillus tarabuli is a nocturnal Saharan rodent which has an annual reproductive cycle characterized by the reproductive activity in spring and a long phase of sexual quiescence in other seasons. We describe the morphology and hormonal regulation of the prostatic complex of this rodent in the two periods, based on anatomical, histological, morphometric, and immunohistochemical analyses. The organisation of this prostatic complex is similar to that reported for Meriones unguiculatus, but different from the prostate of Psammomys obesus, the rat, and the mouse. In addition to the anterior lobes, ventral lobes, and dorsal lobes, the prostatic complex of Gerbillus tarabuli, also includes dorsolateral lobe. Each lobe is composed of a fibro-muscular stroma surrounding a glandular epithelium. Dorsolateral lobes are easily distinguishable by their big volume. The prostate grows and regresses cyclically throughout the year. During the resting season, ventral lobes and anterior lobes showed a...