Macroanatomical and morphometric study on the skull bones of Aksaray Malakli dogs.

BACKGROUND: The skull is an important anatomical structure to discern dog breeds and wolves from dogs. For this purpose, skull morphology and some morphometric measurements of Malakli dogs, a local breed in the Aksaray region, were examined. MATERIALS AND METHODS: Thirty-two distances were measured and seven ratios calculated in nine skulls of adult dogs. In our study, different morphological features and statistical findings that were not revealed by taking measurements from 32 distinct anatomical points of Aksaray Malakli dog skull bones were determined in accordance with the literature. RESULTS: Processus zygomaticus was found to be long and pointed in the Aksaray Malakli dogs. The results of morphometric analysis were as follows: facial index value 107.68 ± 4.98, nasal index value 19.61 ± 3.25, cranial index value 56.17 ± 2.52, basal index value 30.57 ± 1.30, skull index 54.68 ± 3.01, palatal index I value 56.76 ± 1.89 and palatal index II value 59.83 ± 2.23. CONCLUSIONS: It can be concluded form the present investigation that the neurocranium length, facial index, cranial index, basal index, skull index, and palatal index values were statistically different from other dog breeds.

Blind mole rat (Spalax leucodon) masseter muscle: structure, homology, diversification and nomenclature.

BACKGROUND: It is well known that rodents are defined by a unique masticatory apparatus. The present study describes the design and structure of the masseter muscle of the blind mole rat (Spalax leucodon). The blind mole rat, which emer- ged 5.3-3.4 million years ago during the Late Pliocene period, is a subterranean, hypoxia-tolerant and cancer-resistant rodent. Yet, despite these impressive cha- racteristics, no information exists on their masticatory musculature. MATERIALS AND METHODS: Fifteen adult blind mole rats were used in this study. Dissections were performed to investigate the anatomical characteristics of the masseter muscle. RESULTS: The muscle was comprised of three different parts: the superficial mas- seter, the deep masseter and the zygomaticomandibularis muscle. The superficial masseter originated from the facial fossa at the ventral side of the infraorbital foramen. The deep masseter was separated into anterior and posterior parts. The anterior part of the zygomaticomandibularis muscle arose from the snout and passed through the infraorbital foramen to connect on the mandible. CONCLUSIONS: The construction of the deep masseter and zygomaticomandibularis muscles were of the Myomorpha type. Further studies are needed to reveal features such as muscle biomechanics, muscle types.

Some lectin binding properties of the tongue of the mole rat, Nannospalax xanthodon.

We investigated carbohydrate residues on the epithelial surface, in the epithelial cells and in gland cells of the tongue of the mole rat using histochemical methods. We used horseradish peroxidase-conjugated lectins from Helix pomatia (HPA), Arachishypogaea (PNA), Ulexeuropaeus (UEA I), Canavaliaensiformis (Con A). The most intense reactivity was observed in the keratin layer with HPA, UEA I and Con A, and in the epithelial cells with UEA I and Con A. In the glands, we found strong reactivity in serous cells with HPA and Con A, and in mucous cells with HPA and UEA I. PNA did not bind to epithelial or gland cells. Consequently, GlcNAc, fucose and α-D-mannose terminal glycoconjugates are distributed widely; GalNAc terminal glycoconjugates appeared in small amounts.

Macroscopic anatomy of the lower respiratory system in mole rats (Spalax leucodon).

The morphologic and morphometric features of the lower respiratory system in mole rats were examined. It was seen that the low respiratory system of this species leading a special life under highly hypoxic/hypercapnic conditions underground is structurally similar to other mammals living on land in terms of the parts examined; trachea was formed by 29.5 ± 4 oval-formed cartilaginous tracheals arranged backwards and became gradually more stenotic diameter from cranial to the caudal of the neck. The trachea was separated in two principal bronchus at the fourth thoracal intercostal spatium level. The angle between the two main principal bronchi was 60.5 ± 2.35°. The lung constituted 1.29 ± 0.03% of the body weight and the right lung was heavier than the left lung. Fissura inter-lobaris was deep and separated the lung lobes wholly, and the right lung was separated in four lobes, whereas the left lung was not separated into the lobes. Also, the medial lobe of the left lung was the lightest lobe.

Morphological investigations on the circulus arteriosus cerebri in mole-rats (Spalax leucodon).

The aim of the present study is to investigate the circulus arteriosus cerebri in mole-rats (Spalax leucodon). Six adult mole-rats were used for this purpose. Coloured latex was injected into the left ventriculus of the hearts of all the animals. After careful dissection, the circulus arteriosus cerebri (the circle of Willis) was investigated. The cerebrum and the cerebellum were supplied by the internal carotid- and the basilar arteries respectively forming the circulus arteriosus cerebri in mole-rats. In the investigated objects, the internal carotid- and the basilar arteries were not united directly and for this reason the circulus arteriosus cerebri was not formed completely in mole-rat. The branches supplying the medulla oblongata and the cerebellum originate from the basilar artery formed by union of the left and right vertebral arteries and the internal ophthalmic, the caudal cerebral, the choroid, the median cerebral, the rostral cerebral arteries originated from the internal carotid artery. After giving off the medial cerebral artery, the right and left rostral cerebral arteries on every two sides divided into the lateral and medial twin branches and by union of the lateral branches the internal ethmoidal artery, and by union of the medial branches, the ramus extending to facies medialis cerebri were formed. The ramus extending to the facies medialis cerebri was anastomosed with the branch of the caudal cerebral artery on the back of the corpus callosum. The last part of the basilar artery gave the two branches running toward the right and left side on the pontocrural groove (sulcus pontocruralis) and every one of these branches ramified into two rami. One of these rami formed into the rostral cerebellar artery and the other one extended to the tectum mesencephali. In conclusion, the arterial circle of the cerebrum and cerebellum was supplied by the internal carotid artery and the basilar artery respectively in mole-rats.